Measuring T2DM Risk with Randox Automated Adiponectin
During the first week of our adiponectin educational month, we focused on different aspects of our free white paper “Early Risk Assessment of Type 2 Diabetes Mellitus Through the use of the Biomarker Adiponectin”, which details the features and benefits of Randox automated Adiponectin, clinical significance and a comparison to traditional methods for diabetes risk assessment.
Randox Adiponectin is an automated biochemistry reagent, used as a biomarker which can powerfully predict the development of pathologies such as Type 2 Diabetes Mellitus (T2DM) and cardiovascular disease (CVD). With the global prevalence of diabetes continually rising in adults over 18 years of age, from 4.7% in 1980 to 8.5% in 2014, adiponectin should be an integral part of every laboratory’s testing panel. Offering an improved method for assessing risk, with a convenient format for routine clinical use, Randox Adiponectin will enable physicians to accurately evaluate more individuals.
Read on to find out more!
Monday 11th September
Traditional Methods for Diabetes Risk Assessment
Randox adiponectin offers a more improved, automated method for assessing Type 2 Diabetes Mellitus (T2DM) risk compared to traditional methods of diabetes risk assessment. Such methods include:
- Fasting Plasma Glucose (FPG) – This is the most commonly used biochemical method of assessing T2DM, however, the specificity of this test is poor. Although many individuals are identified as having impaired fasting glucose (IFG), their absolute risk of conversion to diabetes is only 5-10% per year.
- Oral Glucose Tolerance Test (OGTT) – This method is more accurate for risk assessment than other traditional methods, however, it is rarely used in practice as it is takes two hours to perform and is uncomfortable for patients.
Non-biochemical methods for assessing a patient’s risk of developing T2DM take into consideration gender, age, family history of T2DM, BMI, waist size and high blood pressure to give a risk score. Two of the most popular, traditional indicators include:
- Waist circumference – measures abdominal fat reliably, but its association with visceral fat varies by gender and ethnicity.
- Body Mass Index (BMI) – is another common method, however it has limitations in measuring athletes and varies depending on age, sex and race.
Given the limitations of OGTT and FPG, an improved method for assessing T2DM risk, with a convenient format for routine clinical use, would enable physicians to accurately evaluate more individuals. Randox adiponectin is an automated biochemistry test utilising a latex enhanced immunoturbidimetric method which removes the inconvenience and time consumption associated with traditional methods of testing, making it a superior method of testing T2DM.
Tuesday 12th September
Recent studies have advocated the testing of adiponectin in clinical settings. It has applications in assessing risk in several diabetes-related conditions including prediabetes, T2DM and GDM. These studies include:
BMJ (2016): Adiponectin levels predict prediabetes risk: the Pathobiology of Prediabetes in A Biracial Cohort
This study found that among health white and black adults with parental history of T2DM, adiponectin level is a powerful risk marker of incident prediabetes. Thus, the association of adiponectin with diabetes risk is evident at a much earlier stage in pathogenesis, during transition from normoglycemia to prediabetes.
Diabetes Care (2013): Low Pre-pregnancy Adiponectin Concentrations Are Associated With a Marked Increase in Risk for Development of Gestational Diabetes mellitus
This was a study carried out on 4098 women who had children within 6 years of initial blood sample and none of whom were pre-diabetic or diabetic. It was found that lower adiponectin concentration measured on average 6 years before pregnancy were associated with a 5-fold increased risk of developing GDM.
Implications for Clinicians
Adiponectin measurement is not yet a routinely run test in many laboratories worldwide and it is therefore not available for many clinicians to request. Yet the implications of this becoming widely available could be extremely valuable as it can help to assess:
- Type 2 Diabetes Mellitus and Incident prediabetes
- Cardiovascular events
- Gestational Diabetes
When risk is identified via adiponectin measurement, it is essential for individuals to carry out lifestyle modification to reduce visceral fat levels and lowering T2DM risk. This will also help to prevent the development of cardiovascular diseases and metabolic syndrome through the improvement of adiponectin production. This indicates that Randox automated adiponectin should be a routinely run test across the world.
13th September 2017
Methods of Measuring Adiponectin
Randox adiponectin automated method has many benefits for the laboratory, as the only method of adiponectin measurement available beforehand was through the ELISA assay. The benefits of switching from ELISA to an automated method include efficiencies and expansion.
The main drawback of using ELISAs for clinical testing within a laboratory is that it is time consuming and personnel consuming as it uses heavy resources with manual interaction. Switching from ELISA to an automated method for the detection of adiponectin increases time and personnel efficiency considerably which leads to cost effectiveness. This benefits laboratories through:
- Ensuring quality in testing practices and confidence in clinical results
- Lowering the risk of error and contamination avoiding compromising clinical results
Laboratories can expand their test offerings to patients and clinicians by transitioning analytes which were historically only available on ELISA methods. Adiponectin being available in an automated biochemistry format allows laboratories to expand their test menu with ease and enables the inclusion of adiponectin into routine testing panels. It also allows for detailed patient testing profiles through increased testing range and without the manual restrictions placed by running ELISA techniques.
Randox is presently the only diagnostic manufacturer who has a globally available automated biochemistry test for adiponectin measurement.
14th September 2017
Randox Automated Adiponectin Assay
The Randox adiponectin assay principle:
- The sample is reacted with a buffer and anti-adiponectin coated latex
- The formation of the antibody-antigen complex during the reaction results in an increase in turbidity – this is measured as the amount of light absorbed at 570nm.
- A sample with higher adiponectin levels will contain more adiponectin and so more antibody-antigen complexes will be formed and the increase in turbidimetry
- By constructing a standard curve from the absorbance of the standards, the adiponectin concentration of the sample can be determined.
Benefits of Randox adiponectin:
- A niche product meaning we are one of the only manufacturers to provide the adiponectin test in an automated biochemistry format
- Automated assay removing inconvenience and time consumption associated with traditional ELISA testing
- Applications available for a wide range of automated biochemistry analysers ensuring ease of programming and confidence in results
- Latex Enhanced Immunoturbidimetric method delivering high performance
- Extensive measuring range for measurement of clinically important results
- Complementary controls and calibrators available offering a complete testing package
The Randox automated immunoturbidimetric adiponectin test offers an improved method for assessing T2DM risk, with a convenient format for routine clinical use, to enable physicians to accurately evaluate at-risk individuals.
Please contact us at firstname.lastname@example.org for more information!
Download our white paper from the resource hub.
The Lipoprotein(a) Foundation have commended health and fitness expert Bob Harper for speaking out after recently suffering a heart attack. The celebrity personal trainer and host of the US television series ‘The Biggest Loser’, has revealed that high levels of Lp(a) were responsible for the heart attack he suffered at the age of 51 at the beginning of this year.1
Harper had been completing a normal workout at his gym when he suffered full cardiac arrest. Luckily, two doctors were in the vicinity who saved his life by performing CPR and using an Automated External Defibrillator (AED). In an interview following his heart attack, Harper has said,
“I’ve learned a lot about the fact genetics does play a part in this, it is so important to know your health… I’m a guy that lives a very healthy lifestyle, very regimented, I work out all the time, but there were things going on inside of my body that I needed to be more aware of and I strongly encourage anyone that’s listening right now to go to their doctor, get their cholesterol checked, see what’s going on on the inside”.
Scroll down to watch the interview in full.
What is Lp(a)?
Lp(a) is a particle which is produced in the liver and found in the blood which carries cholesterol, fats and proteins. Levels of Lp(a) in individuals are genetically determined, and are not affected by diet, exercise or lifestyle changes.2
So how does a seemingly fit and healthy person have a heart attack at the age of 51?
Lp(a) is currently the strongest inherited risk factor for heart attack and stroke, with one in five people globally inheriting high Lp(a).1 Levels of Lp(a) are not routinely tested in standard cardiovascular assessments, and despite the particle itself being an altered form of LDL cholesterol, standard cholesterol tests do not reveal inherited Lp(a) levels as it is independent from total cholesterol and LDL levels.3
High Lp(a) can also be unrelated to other common risks factors of cardiovascular diseases for example, smoking, diet, diabetes, high blood pressure and lack of exercise. This is why seemingly healthy individuals can have high Lp(a) in their genes and still be at high risk of cardiovascular diseases.
Why is Lp(a) not routinely measured if high levels pose such a risk?
The widespread use of Lp(a) as an independent risk factor for cardiovascular disease risk has, until recently, been hindered by the lack of internationally accepted standardisation and the fact that many commercial Lp(a) methods suffer from apo(a) size related bias, potentially leading to patient misclassification.
The size of the apo(a) protein is genetically determined and varies widely hence, levels of Lp(a) can vary up to 1000-fold between individuals.4 To find out more about the clinical significance of Lp(a), please refer to the section below entitled ‘For Health Professionals’.
What can you do if you have high Lp(a)?
Research has shown that lowering Lp(a) could significantly reduce the impact of cardiovascular diseases. A recent study published in the American Heart Association journal, Arteriosclerosis, Thrombosis and Vascular Biology, found that reducing high Lp(a) could potentially prevent up to 1 in 14 cases of myocardial infarction (heart attack) and 1 in 7 cases of aortic valve stenosis.5 Of those studied, nearly one third of heart attacks and half of all cases of aortic stenosis were attributed to high Lp(a).6 This study demonstrates the clinical significance of measuring Lp(a), making it a major independent genetic risk factor for cardiovascular diseases.
Why test Lp(a)?
Lp(a) will be tested as part of a lipid profile if: there is a strong family history of CVD, a patient has existing heart or vascular diseases, a patient has an inherited predisposition for high cholesterol or if a person has had a stroke or heart attack but has normal lipid levels.7
Dr Christie Ballantyne, Chief of Cardiology at Baylor College of Medicine, has said “the most important part of knowing your Lp(a) level is understanding your overall risk and finding the right lifestyle modifications or medications to target all the other traditional risk factors. Those risk factors become even more important to monitor when your Lp(a) levels are high”.8
If you are concerned that you may be at risk of having elevated levels of Lp(a) due to your family history, ask your doctor or medical provider to test lipoprotein (a), along with other lipid tests, to clinically evaluate your risk of developing cardiovascular diseases.
For health professionals
Click below for information regarding the challenges associated with the measurement of Lp(a) and the clinical significance it holds.
The widespread use of Lp(a) as an independent risk factor for cardiovascular disease risk has, until recently, been impeded by the lack of internationally accepted standardisation and the fact that many commercial Lp(a) methods suffer from apo(a) size related bias, potentially leading to patient misclassification. The size of the apo(a) protein is genetically determined and varies widely hence, levels of Lp(a) can vary up to 1000-fold between individuals.4
As a result, international criteria has been set to overcome these challenges. The International Federation of Clinical Chemistry (IFCC) Working Group on Lp(a) recommends that laboratories use assays which do not suffer from apo(a) size-related bias, in order to minimise the potential risk of misclassification of patients for coronary heart disease. The Lipoprotein(a) Foundation has referenced Marcovina and Albers (2016) as their recommendation for the best Lp(a) test.9 This recommendation is a result of the following conclusions:
- Robust assays based on the Denka method are available, which are reported in nanomoles per litre (nmol/L) and are traceable to WHO/IFCC reference material
- Five point calibrators with accuracy assigned target values will minimise the sensitivity to apo(a) size
A number of guidelines are in place for the testing of Lp(a) in patients.
-The European Guidelines for Management of Dyslipidaemia state that Lp(a) should be measured in individuals considered at high risk of CVD or with a strong family history of premature CVD.
-The European Atherosclerotic Society suggest that Lp(a) should be measured once in all subjects at intermediate or high risk of CVD/CHD who present with10 :
1. Premature CVD
2. Family hypercholesterolaemia
3. A family history of premature CVD and/or elevated Lp(a)
4. Recurrent CVD despite statin treatment
5. ≥3% 10-year risk of fatal CVD according to the European guidelines
6. ≥10% 10-year risk of fatal and/or non-fatal CHD according to the US guidelines
-EAS Consensus Panel states the evidence clearly supports Lp(a) as a priority for reducing cardiovascular risk, beyond that associated with LDL cholesterol. Clinicians should consider screening statin-treated patients with recurrent heart disease, in addition to those considered at moderate to high risk of heart disease.
- The Randox Lp(a) assay is one of the only methodologies on the market that detects the non-variable part of the Lp(a) molecule and therefore suffers minimal size related bias – providing more accurate and consistent results. The Randox Lp(a) kit is standardised to the WHO/ IFCC reference material SRM 2B and is closest in terms of agreement to the ELISA reference method.
- Five calibrators with accuracy-based assigned target values are provided – which accurately reflect the heterogeneity of isoforms present in the general population
- Measuring units available in nmol/L upon request
- Highly sensitive and specific – method for Lp(a) detection in serum and plasma
- Applications are available for a wide range of biochemistry analysers – which detail instrument-specific settings for the convenient use of Randox Lp(a) on a variety of systems
- Liquid ready-to-use reagents – for convenience and ease-of-use
Watch the interview with Bob Harper here:
1. Lipoprotein(a) Foundation, Lipoprotein(a) Foundation Thanks Bob Harper for Revealing High Lp(a) Levels Led to His Recent Heart Attack on The Dr Oz Show, 2017 Available from: http://www.businesswire.com/news/home/20170425006724/en/ [Accessed: 16 March 2017]
2. Lipoprotein Foundation, Understand Inherited Lipoprotein (a), Available from: https://goo.gl/bH5A8R [Accessed: 16 March 2017]
3. Kumar, V., Abbas, A. K. and Aster, J. C., Robbins and Cotran Pathologic Basic of Disease, (Philadelphia: Elsevier Saunders, 2015), p. 494 in Google books, https://goo.gl/VEnVX9 [Accessed 27th April 2017]
4. Kamstrup P.R., Tybjaerg-Hansen A., Steffensen R., Nordestgaard B.G. Genetically elevated lipoprotein (a) and increased risk of myocardial infarction. JAMA. Vol. 301, p. 2331-2339 (2009).
5. Afshar, M. Kamstrup, P.R., Williams, K., Snidermann, A. D., Nordestgaard, B.G., Thanassoulis, G., Estimating the Population Impact of Lp(a) Lowering on the Incidence of Myocardial Infarction and Aortic Stenosis – Brief Report., Ateriosclerosis, Thrombosis, and Vascular Biology, 2016;36:2421-2423, Available from: http://doi.org/10.1161/ATVBAHA.116.308271
6. The Lipoprotein(a) Foundation, Lipoprotein(a) Foundation Supports National Heart Valve Disease Month, Highlights Genetic Link between Lp(a) and Aortic Valve Disease, Business Wire. (2017), Available from: https://goo.gl/LhQFGj [Accessed: 16 March 2017]
7. Lab Tests Online, Lp(a), 2014, Available from: https://goo.gl/W2PWSN [Accessed: 16 March 2017]
8.Gutierrez, G., The heart attack risk factor you haven’t heard of, Baylor College of Medicine, 2017, Available from: https://goo.gl/9X4Xko [Accessed: 16 March 2017]
9. Marcovina, S.M. and Albers, J.J. Lipoprotein (a) measurements for clinical application. Lipid Res. Vol. 57, p. 526-37 (2016).
10. Nordestgaard, B. G., Chapman, M. J., Ray, K., Bore´n, J., Andreotti, F., Watts, G. F., Ginsberg, H., Amarenco, P., Catapano, A., Descamps, O. S., Fisher, E., Kovanen, P. T., Kuivenhoven, J. A., Lesnik, P., Masana, L., Reiner, Z., Taskinen, M. R., Tokgozoglu, L., and Tybjærg-Hansen, A., for the European Atherosclerosis Society Consensus Panel. Lipoprotein(a) as a cardiovascular risk factor: current status. European Heart Journal. Vol. 23, p. 2844-2853 (2010).
Medical Laboratory Professionals Week (MLPW) is a week dedicated to increasing public understanding and appreciation for the clinical laboratory profession. During this week, we are taking the opportunity to celebrate the hard work of our Research and Development team. Allow us to provide you an insight into the life changing work of our scientists in the laboratories.
At Randox, our scientists work tirelessly to develop revolutionary diagnostic tests that are used in hospital and research laboratories across the globe.
We spoke to one of our biochemistry R&D Scientists to gain an insight into what working in a clinical chemistry laboratory entails. Emmett Donnelly, Clinical Chemistry R&D Scientist, is involved in the development of new reagents and the improvement of existing reagents. Emmett commented, “[My] role also involves the transfer and testing of existing chemistries onto new analyser platforms. Troubleshooting and resolving customer queries also forms part of a clinical analyst’s role”. Emmett’s work is vital to ensure that patient tests are performing correctly, and to develop ground-breaking new technologies leading to better patient outcomes. To find out more about the work Emmett does, watch this video below.
Our scientists are committed to research and development and thrive knowing that their novel research is putting them at the forefront of clinical diagnostics.
In fact, prior to beginning work at Randox, Scott Paulin, Clinical Chemistry R&D team, took part in a three month expedition to Antarctica to intensely study human response-based research in athletes. A number of papers have been published in peer reviewed journals as a result of Scott’s research, as the findings have provided a useful insight into the physiological stress and responses associated with an Antarctic ultra-endurance race and nutritional counterstrategies to help maintain immune responses, function body weight and reduce stress markers. Read the full article here.
At Randox, our scientists are of the highest calibre, with vast experience and expertise which ensures we are producing the highest quality range of clinical diagnostic tests.
Excitingly as a result, American astronauts have enlisted our help to test their antioxidant levels before they go to space! This is essential as it ensures astronauts can survive long periods of time away from earth. To find out more about how important our Total Antioxidant Status (TAS) test is for astronauts, read our blog post here.
The invaluable work our scientists undertake in the laboratory is vital to ensure healthcare is advanced globally. Thanks to those in our Research and Development team, we are proud to be able to offer the widest range of clinical chemistry reagents and unique tests for medical diagnosis. Due to our scientist’s dedication to research, a continual focus is placed on developing tests that assess the risk of diseases, rather than diagnosing the illness after it has occurred. As a result, Randox are helping to change healthcare, as patients are provided the ability to take preventative action early. In the words of our R&D scientist Emmett Donnelly, “for me, my work supports the old saying prevention is better than cure”.
We hope you have enjoyed reading about our fantastic team of R&D Scientists! If you would like to find out more about the work of Randox Reagents, please get in contact by emailing: email@example.com or click here to view our homepage.
The theme this year for British Science Week is change. At Randox, our R&D Scientists are helping to change healthcare. By investing heavily into research and development to develop unique diagnostics tests, Randox provide doctors with the ability to identify disease risk sooner- offering the opportunity to prevent illness, rather than the need to find a cure.
One unique test by Randox, adiponectin, is becoming an increasingly significant biomarker for health professionals. Low levels have been linked with several illnesses including metabolic syndrome, cancer and cardiovascular disease.
What is adiponectin?
Adiponectin is a protein hormone produced and secreted by fat cells called adipose tissue. Adiponectin is normally found in relatively high concentrations in healthy individuals. Its role in the body is to regulate the metabolism of lipids and glucose, which influences the body’s response to insulin and inflammation.
Adiponectin and abdominal visceral fat
Adiponectin levels are inversely correlated with abdominal visceral fat, meaning that lower levels of adiponectin are related to higher amounts of visceral fat in the body.¹ Visceral fat is stored around vital organs and higher levels of this type of fat can be associated with a range of conditions including insulin resistance, high blood pressure and high levels of cholesterol. These factors can subsequently increase a patient’s chance of developing metabolic syndrome, diabetes, cardiovascular disease and in some cases cancer. In fact, it has been found that patients with high abdominal visceral fat or low adiponectin levels have a three-fold increased risk of insulin resistance, with a combination of both doubling this probability.2
Adiponectin as a biomarker
Due to the protective properties of adiponectin, for example in increasing insulin sensitivity or preventing atherosclerosis, adiponectin has been classified as novel and important for a number of reasons.3 A range of studies have demonstrated why adiponectin levels should be considered as a routine test.
Adiponectin and Type 2 Diabetes
Increasing evidence suggests adiponectin is a valid biomarker related to type 2 diabetes. In fact, one study suggests that adiponectin is a powerful marker of diabetes risk in subjects at high risk.4 Decreased adiponectin has been found to be an independent risk factor for the progression of type 2 diabetes.5
Other evidence shows that adiponectin is also a beneficial measure of diabetes treatment response. A recent study has emerged which has found that dipeptidyl peptidase-4 inhibitors, which are used for the treatment of type 2 diabetes, increase adiponectin levels and have a stronger effect in comparison to traditional oral antidiabetic drugs.6
Adiponectin and Gestational Diabetes
Adiponectin levels are also of interest during pregnancy. If a woman has lower adiponectin concentration during the first trimester of pregnancy, they are 3.5 times more likely to develop gestational diabetes.7,8
Adiponectin and Cardiovascular Disease
A range of evidence exists linking serum adiponectin concentration and cardiovascular diseases. Studies have found low levels of adiponectin can have an adverse effect, for example one study suggests adiponectin levels are an independent predictor of CHD in Caucasian men with no previous history of CHD.9 Low adiponectin concentrations have also been associated with myocardial infarction (a heart attack) in individuals below the age of 60, and also been linked with increased risk of new-onset hypertension in men and postmenopausal women.10,11
Adiponectin and Benign Prostatic Hyperplasia (BPH)
Studies have also been conducted to examine the relationship between adiponectin and BPH. BPH is a common condition which is usually associated with men over 50 years of age and causes enlargement of the prostate. Higher adiponectin levels have been associated with reduced risk of BPH, as adiponectin has a protective effect in the progression of BPH.12,13,14
Adiponectin and Cancer
Lower levels of adiponectin have been found to increase the risk of endometrial cancer in women, and also prostate and pancreatic cancer in men.14,15 Researchers have been able to identify that serum adiponectin is inversely linked to the risk of obesity-associated cancers including endometrial cancer, renal cancer, postmenopausal breast cancer, colon cancer and leukaemia.16,17, 18
Why measure adiponectin?
As demonstrated above, the clinical significance of adiponectin is widely studied and has been linked to a range of diseases in which overweight or obese patients are proven to be at higher risk of developing. Measuring serum concentration of adiponectin to determine visceral fat levels is proven to be a more reliable indicator of at-risk patients in comparison to conventional methods of determining whether a patient is overweight or obese, such as body mass index (BMI) or measuring waist circumference.19
Our commitment to research and development ensures that unique tests, such as adiponectin, are available for use by health professionals. Scientists at Randox are continuing to change healthcare every day with their research to develop revolutionary diagnostic solutions. By placing a continual focus on assessing the risk of diseases rather than diagnosing the illness after it has occurred and providing patients with the tools to take preventative action, Randox are helping to change healthcare globally.
For more information, email: firstname.lastname@example.org
- Kishida, K., Kim, K. K., Funshashi, T., Matsuzawa, Y., Kang, H. C., Shimomura, I. Relationships between circulating adiponectin levels and fat distribution in obese subjects. Journal of Atherosclerosis and Thrombosis. 18(7):592-595 (2011)
- Medina-Urrutia, A., Posadas-Romero, C., Posadas-Sánchez, R., Jorge-Galarza, E., Villarreal-Molina, T., González-Salazar, M. C., Cardoso-Saldaña, G., Vargas-Alarcón, G., Torres-Tamayo, M. and Juárez-Rojas, J. G. Role of adiponectin and free fatty acids on the association between abdominal visceral fat and insulin resistance. Cardiovascular Diabetology, vol. 14, no. 20 (2015).
- Chandran, M., Phillips, S. A., Ciaraldi, T., Henry, R. R. Adiponectin: More than just another fat cell hormone? Diabetes Care. 26(8): 2442-2450 (2003)
- Daimon, M., Oizumi, T., Saitoh, T., Kameda, W., Hirata, A., Yamaguchi, H., Ohnuma, H., Igarashi, M., Tominaga, M., Kato, T. and Funagata Study. Decreased serum levels of adiponectin are a risk factor for the progression to type 2 diabetes in the Japanese population. Diabetes Care, vol. 26, no. 7, p. 2015-2020 (2003).
- Mather, K. J., Funahashi, T., Matsuzawa, Y., Edelstein, S., Bray, G. A., Kahn, S. E., Crandall, J., Marcovina, S., Goldstein, B., Goldberg, R. and Diabetes Prevention Program. Adiponectin, change in adiponectin, and progression to diabetes in the Diabetes Prevention Program. Diabetes, vol. 57, no. 4, p. 980-986 (2008).
- Liu, X., Men, P., Wang, Y., Zhai, S., Liu, G. Impact of dipeptidyl peptidase-4 inhibitors on serum adiponectin: a meta-analysis. Lipids in Health and Disease. 15:204 (2016)
- Lacroix, M., Battista, M.C., Doyon, M., Ménard, J., Ardilouze, J.L., Perron, P. and Hivert M. F. Lower adiponectin levels at first trimester of pregnancy are associated with increased insulin resistance and higher risk of developing gestational diabetes mellitus. Diabetes Care, vol. 36, no. 6, p. 1577-83 (2013).
- Hedderson, M. M., Darbinian, J., Havel, P. J., Quesenberry, C. P., Sridhar, S., Ehrlich, S. and Ferrara, A. Low prepregnancy adiponectin concentrations are associated with a marked increase in risk for development of gestational diabetes mellitus. Diabetes Care, vol. 36, no. 12, p. 3930-7 (2013).
- Tsimikas, S., Mallat, Z., MD, Talmud, P. J., Kastelein, J. J. P., Wareham, N. J., Sandhu, M. S., Miller, E. R., Benessiano, J., Tedgui, A., Witztum, J. L., Khaw, K. T. and Boekholdt, S. M. (2010). Oxidation-Specific Biomarkers, Lipoprotein(a), and Risk of Fatal and Nonfatal Coronary Events. JACC. 56:12, p. 946-955.
- Ai, M., Otokozawaw, S., Asztalos, B. F., White, C., Cupples, L. A., Nakajima, K., Lamon-Fava, S., Wilson, P. W., Matsuzawa, Y. and Schaefer, E. J. Adiponectin: an independent risk factor for coronary heart disease in men in the Framingham Offspring Study. Atherosclerosis. Vol. 217, p. 543-548 (2011)
- Persson, J., Lindberg, K., Gustafsson, T. P., Eriksson, P., Paulsson-Berne, G. and Lundman, P. Low plasma adiponectin concentration is associated with myocardial infarction in young individuals. Journal of Internal Medicine. Vol. 268, no. 2, p. 194-205 (2010).
- Fu, S., Xu, H., Gu,M., Liu, C., Wang, Q., Wan, X., Chen, Y., Chen, Q., Peng, Y., Cai, Z., Zhou, J. and Wang, Z. Adiponectin deficiency contributes to the development and progression of benign prostatic hyperplasia in obesity. Available from: 10.1038/srep43771
- Schenk, J. M., Kristal, A.R., Neuhouser, M.L., Tangen, C.M., White, E., Lin, D.W., Thompson, I.M. Serum adiponectin, C-peptide and Leptin and Risk of Symptomatic Benign Prostatic Hyperplasia: Results from the Prostate Cancer Prevention Trial. The Prostate, Vol 69 Issue 12 pp.1-15 (2009) Available from: 10.1002/pros.2097
- Izadi, V., Farabad, E., Azadbakht, L. Serum adiponectin level and different kinds of cancer: a review of recent evidence. ISRN Oncology Vol. 2012, (2012) Available from: 10.5402/2012/982769
- Messier V, Karelis AD, Prud’homme D, Primeau V, Brochu M, Rabasa-Lhoret R. Identifying metabolically healthy but obese individuals in sedentary postmenopausal women. Obesity, vol. 18, pp. 911-7 (2010).
- Dalamaga, M., Diakopoulos, K.N. and Mantzoros, C.S. The Role of Adiponectin in Cancer: A Review of Current Evidence. Endocrine Reviews. 2012 Aug; 33 (4): 547-594 (2012) Available from: 10.1210/er.2011-1015
- Kelesidis, I., Kelesidis, T. and Mantzoros, CS. Adiponectin and cancer: a systematic review. British Journal of Cancer (2006) 94, 1221-1225 Available from: 10.1038/sj.bjc.6603051
- Katira, A. and Tan, P.H. Evolving role of adiponectin in cancer-controversies and update. Cancer Biol Med 2016. Pp.101-119 (2016) Available from: 10.28092/j.issn.2095-3941.2015.0092
- Messier V, Karelis AD, Prud’homme D, Primeau V, Brochu M, Rabasa-Lhoret R. Identifying metabolically healthy but obese individuals in sedentary postmenopausal women. Obesity, vol. 18, pp. 911-7 (2010).
In celebration of British Science Week 2017, we will be giving you an introduction to diagnostics, and exploring how Randox Scientists are helping to change healthcare.
You may or may not already know that Randox are one of the leading diagnostics companies globally. But what exactly does clinical diagnostics involve? It is one of the fundamental steps of finding out what is wrong with a person when they are ill. Read on to find out a bit more about diagnostics, and how the Randox Reagents R&D Scientists are helping to change healthcare globally!
What is a diagnostic test?
A diagnostic test is any kind of analysis performed on a patient sample (a sample is typically blood, urine or cerebrospinal fluid (CSF)), to aid in the diagnosis or detection of disease. The information found from a test can be used to:
- Diagnose disease
- Assess the extent of damage
- Monitor the effectiveness of treatment
- Confirm a person to be free from disease
Examples of substances that may be tested for the blood include proteins, nutrients, waste products, antibodies, hormones, salts, trace elements or vitamins. These are sometimes referred to as ‘analytes’, ‘markers’ or ‘biomarkers’.
This is where reagents come in…
A reagent is a substance which is mixed with the patient sample to create a chemical reaction to detect the biomarker. These reactions are analysed by machines known as analysers.
Using data gathered from both clinical symptoms and laboratory tests, the doctor will follow a sometimes painstaking process of analysis and elimination to perform a successful diagnosis!
On 9 March 2017, Randox Reagents are celebrating World Kidney Day! World Kidney Day is a global campaign aimed at raising awareness of the importance of our kidneys to our overall health. It aims to reduce the frequency and impact of kidney disease and its associated health problems worldwide.
This year, the World Kidney Day promotes education on the harmful consequences of obesity and its association with kidney disease, advocating healthy lifestyle and health policy measures that make preventive behaviours an affordable option.
With this in mind, throughout the week we have been sharing on social media some interesting facts on diagnostic tests which can help aid an early risk assessment of kidney disease in obese patients, allowing preventative action to be taken before any serious damage occurs. The tests of focus this week included cystatin C, adiponectin and microalbumin…
The creatinine test is routinely run for patients who are suspected for deteriorating kidney function, however this test has limitations. Cystatin C is an alternative test, and is particularly useful in patients where creatinine measurements are not suitable e.g. individuals who are obese, malnourished, have liver cirrhosis or reduced muscle mass. Importantly, unlike creatinine, cystatin C does not have a ‘blind area’ – up to 50% of kidney function can be lost before significant creatinine elevation occurs. Cystatin C is extremely sensitive to very small changes in kidney function and is therefore capable of detecting early stage kidney dysfunction. The cystatin C test therefore allows preventative measures to be taken much earlier and before significant kidney function decline.
There is substantial evidence that excess visceral fat is the main driving force for almost all of the disorders associated with the metabolic syndrome, including CKD.1,2 The adiponectin test from Randox can accurately assess levels of abdominal visceral fat, independent of age, race or fitness level.3,4 Assessing adiponectin, and therefore visceral fat levels, can help assess risk of CKD, as well as a range of other illnesses such as pre-diabetes, CVD and various cancers.
The microalbumin test detects very low levels of a blood protein called albumin, in urine. The detection of albumin in urine can be an indicator of kidney injury and can result in irreversible damage if left untreated. Low albumin concentrations in the urine are the earliest marker of kidney damage and therefore enable preventative measures to be taken. Microalbumin testing can identify individuals with diabetic nephropathy approximately 5-10 years earlier than proteinuria tests helping reduce the frequency of end stage renal disease.
Both World Kidney Day and Randox are working towards improving healthcare worldwide. With continuous investment in R&D, Randox are helping with the risk assessment and earliest detection of renal function problems. By assessing one’s risk of kidney problems (with the adiponectin test), it can give patients (obese and other) the tools to prevent kidney problems further on down the line. With early diagnosis (through the cystatin C and microalbumin tests) it will be possible to keep kidney problems from getting worse, therefore lowering the number of those diagnosed with CKD worldwide.
A study published on 21st February 2017 in the Journal of the American College of Cardiology has found that measuring apolipoproteins E, C-II and C-III can offer earlier detection of cardiovascular risk in comparison to routine apolipoprotein A-I and B tests.1
The lead author of the study, Professor Manuel Mayr, from King’s College London has said, “We directly compared the association of a broad panel of apolipoproteins to new onset of cardiovascular disease over a 10-year observation period, and found that while apoB was predictive, other apolipoproteins, namely apoE, apo C-II and apo C-III, were even better”. Professor Mayr further implied that the findings provide support that expanding current cardiac screening tests to include apolipoproteins could reduce risk of cardiovascular diseases.2
What are apolipoproteins?
Apolipoproteins are proteins that bind to lipids to form lipoproteins. Lipoproteins are made of proteins and fats, and serve the function of transporting insoluble fats, such as cholesterol and triglycerides, to be used by different cells. 3
There are six major types of apolipoprotein: A, B, C, D, E and H and the lipoproteins within these categories can vary in size, density and lipid composition. The study found that apolipoproteins E, C-II and C-III are linked to very low-density lipoproteins (vLDL) and have a stronger association with cardiovascular diseases in comparison to apolipoprotein A-I and apolipoprotein B.4
vLDL is strongly associated with the development of atherosclerosis, the build-up of fatty material inside the arteries, which is a major risk factor of cardiovascular diseases as it can lead to angina, heart attack, stroke or peripheral arterial disease.5
Why measure apo C-II, apo C-III and apo-E?
As highlighted by the authors of the study, cardiovascular risk assessment is commonly associated with only a few lipids within established lipoprotein classes, such as LDL.1 This emphasises the importance of carrying out detailed lipid testing to identify all subgroups to provide a complete cardiovascular risk assessment, as traditional biomarkers for lipids may only provide a limited overview. This can then allow for effective treatment to be provided at an earlier stage, which could subsequently reduce the risk of death by cardiovascular diseases.
Randox offer a range of routine and novel cardiac assays to provide a complete cardiac risk assessment, including: Apolipoprotein C-II / C-III / E / A-I / A-II / B, Adiponectin, HDL Cholesterol, HDL3 Cholesterol, LDL Cholesterol, sLDL Cholesterol, Total Cholesterol, TxBCardio™, H-FABP, Homocysteine, hsCRP, Lipoprotein (a), sPLA2-IIA, and Triglycerides. For more information, email: email@example.com.
1. Mayr, M. et al., Very-low-density lipoprotein-associated apolipoproteins predict cardiovascular events and are lowered by inhibition of APOC-III., Journal of the American College of Cardiology. Vol. 69, No. 7, 2017.
2. NIHR Biomedical Research Centre at Guy’s and St Thomas’ and King’s College London, Discovery could help doctors to spot cardiovascular disease at an earlier stage: Advanced technologies provide researchers with new insights into the warning signs for cardiovascular disease, ScienceDaily (2017) Available from: https://goo.gl/XkC23R [Accessed: 21 February 2017]
3. Kingsbury, K. J., Understanding the Essentials of Blood Lipid Metabolism, Medscape, (2017) Available from: https://goo.gl/AApW6S [Accessed: 23 February 2017]
4. Wallace, A., New technique could aid in earlier diagnosis of heart disease, UPI, (2017) Available from: https://goo.gl/xzxLdf [Accessed: 23 February 2017]
5. British Heart Foundation, Atherosclerosis, (2017) Available from: https://goo.gl/1qHxpk [Accessed: 23 February 2017}
So far in our inflammatory biomarker series, we have considered the clinical significance of measuring rheumatoid factor (RF) and C-reactive protein (CRP) to detect inflammation. Inflammation, either chronic or acute, is the body’s immune response to protect against harmful stimuli such as damaged cells, irritants or pathogens and can be present in a range of diseases and conditions.1 Measuring inflammatory biomarkers can assist clinicians in the identification of a particular disease or can provide a marker of treatment response. In this blog, we consider the role of antioxidants and identify relevant biomarkers which may be linked to inflammatory states.
What is an antioxidant?
An antioxidant is a molecule that inhibits the oxidation of other molecules. Oxidation is a chemical reaction that produces free radicals, which are groups of very reactive molecules that can interrupt important cellular processes. Antioxidants are commonly referenced with regards to food, however antioxidants are also found in the body in the form of enzymes. Their purpose is to protect against the effects of oxidative stress to reduce damage from free radicals.
What is the link between antioxidants and inflammation?
Oxidative stress and the inflammation associated with it are the cause of most human disease. This would suggest that free radicals are implicated in many disease states for example rheumatoid arthritis, asthma, stroke, or cancer. Therefore antioxidants are important to protect against oxidative damage, thus reducing the risk of inflammation. There are a number of antioxidants which play a protective role the body, such as ferritin, superoxide dismutase, transferrin, uric acid and glutathione reductase.
Ferritin is responsible for storing iron and releasing it when required. Ordinarily, ferritin is found inside blood cells with only a small amount circulating in the blood. Ferritin is clinically significant at both high and low levels. Low levels of ferritin can highlight an iron deficiency which causes anaemia. Whereas elevated levels of ferritin can be a result of conditions such as rheumatoid arthritis, haemochromatosis, liver disease, metabolic syndrome, type 2 diabetes and renal failure.2 As ferritin is an acute phase reactant, levels will be elevated in any inflammatory state within the body.3
Transferrin is a protein that is responsible for binding and transporting iron in the blood. Transferrin acts as a preventative antioxidant as it binds with free iron, removing it from the bloodstream. This is a critical function, as free iron can stimulate the production of harmful free radicals. As transferrin is a negative acute phase protein, lower levels are associated with inflammatory conditions.7
Superoxide is a by-product of oxygen metabolism and is one of the most damaging free radicals in the body as it can cause cell damage. Superoxide Dismutase (SOD) is an enzyme which catalyses the breakdown of superoxide into a less damaging oxygen or hydrogen peroxide. Therefore SOD preforms a vital defensive function to reduce oxidative stress.4 Extensive research exists which links oxidative stress to chronic inflammation, which can be a contributing factor to diabetes, arthritis, cardiovascular disease and cancer.5 Therefore if levels of superoxide dismutase are low, patients are at risk inflammation, for example, SOD levels are significantly less in rheumatoid arthritis patients.6
Glutathione reductase is found in red blood cells and plays a key role in maintaining cell function and preventing oxidative stress in human cells. Reduced levels of glutathione reductase can contribute to the prevalence of inflammatory states, suggesting that adequate levels of glutathione reductase are essential for optimal function of the immune system. 7, 8
Uric acid is a waste product produced when the body breaks down chemical compounds called purines. It is a scavenging antioxidant that acts by inactivating free radicals. Elevated levels of uric acid is commonly associated with gout, a type of arthritis which is caused when crystals of sodium urate form inside joints causing rapid and painful inflammation.9 Other research has indicated that elevated levels of uric acid is associated with increased risk of cardiovascular disease.
Total Antioxidant Status (TAS)
TAS is a measurement of antioxidant function rather than quantity and considers the cumulative effect of all antioxidants present. The antioxidant defence system has many components, and a deficiency in any of these components can cause a reduction in the overall antioxidant status of an individual.10 Reduction in total antioxidant status has been implicated in several disease states including cancer, CVD, Arthritis and Alzheimer’s disease.
As demonstrated above, different types of antioxidants can help reduce different types of inflammation. Antioxidant tests can be requested from any doctor, who may also review dietary intake, investigate any symptoms and advise if testing is required. If antioxidant levels are found to be inadequate, improving them can be easily done through dietary changes, and can help reduce a body’s overall inflammation.
For health professionals
Randox Laboratories offer a range of diagnostic reagents for antioxidant testing to assist in the diagnosis of inflammatory diseases. Randox offer a complete diagnostic package with applications for a range of biochemistry analysers and a selection of kit sizes, controls and calibrators available. Available tests include: Ferritin, Transferrin, Superoxide Dismutase (Ransod), Glutathione Reductase, Uric Acid, and Total Antioxidant Status (TAS).
- Nordqvist, C., Inflammation: Causes, Symptoms and Treatment. Medical News Today, 2015, https://goo.gl/rT4WS9 (accessed 16 January 2017)
- Koperdanova, M., Interpreting raised serum ferritin levels, British Medical Journal, 2015, https://doi.org/10.1136/bmj.h3692 (accessed 2 February 2017)
- Nall, R. Ferritin Level Blood Test, Health Line, 2015, https://goo.gl/XGcW9P (accessed 2 February 2017)
- Yasui, K. and Baba, A., Therapeutic potential of superoxide dismutase (SOD) for resolution of inflammation. Inflammation Research. Vol.55, No.9, pp.359-363, 2006, 1007/s00011-006-5195-y (accessed 2 February 2017)
- Reuter, S., Gupta, S.C., Chaturvedi, M.M., Aggarwal, B.B., Oxidative stress, inflammation and cancer: How are they linked? Free Radic Biol Med. 2010, 1; 49(11):1603-1616 https://goo.gl/Uez3JZ (accessed 2 February 2017)
- Bae SC, Kim SJ, Sung MK., Inadequate antioxidant nutrient intake and altered plasma antioxidant status of rheumatoid arthritis patients. J Am Coll Nutr. 2003 Aug;22(4):311-5
- Reynolds, B., Glutathione for inflammatory respsonse, FX Medicine, 2015, Available from: https://goo.gl/2YAv5l (accessed 3 February 2017)
- Morris, G., Anderson, G., Dean, O. et al., The glutathione system: a new drug target in neuroimmune disorders. Mol Neurobiol 2014;50(3):1059-1084, Available from: https://goo.gl/PDSgwv (accessed 3 February 2017)
- Malaghan Institute, Uric acid – a new look at an old marker of inflammation, Malaghan Institute of Medical Research, 2013, Available from: https://goo.gl/P6NfXP
- Li, Y., Browne, R.W., Bonner, M.R., Deng, F., Tian, L., Mu, L., Positive Relationship between Total Antioxidant Status and Chemokines Observed in Adults. Oxid Med Cell Longev. 2014, Available from: https://goo.gl/rmj5MB (accessed 9 February 2017)
We are encouraging you to #LoveYourHeart this Valentine’s Day! Read on to find out why your heart health should matter to you this #HeartMonth!
Fact: Did you know people with diabetes are 2 to 4 times more likely to develop cardiovascular disease than people without diabetes?¹
Good diabetes control is imperative! If you have diabetes take control and monitor your treatment to ensure you are safe from complications such as cardiovascular disease…
Many complications associated with diabetes include kidney disease, eye disease, cardiovascular disease and diabetic ketoacidosis (a life threatening condition that can develop in insulin dependent diabetics).
If you have diabetes, being physically active and controlling your weight and blood pressure will help manage your blood sugar level; and therefore help manage the risk of cardiac diseases.
However a few simple routine tests may also be carried out to ensure normal kidney function. Normal kidney function in a diabetic patient means that diabetes is being controlled well, however if kidney function begins to deteriorate then you will know that measures need to be taken to control diabetes better.
Speciality tests to assess kidney function which can be requested include:
- Cystatin C – a sensitive marker of kidney function used for detection of early renal dysfunction in diabetic patients. It is important to note that Creatinine is the routine test for renal dysfunction, however it has a blind range which means it is unable to detect elevated Creatinine levels found in stage 2 and halfway through stage 3 renal dysfunction; as a result 50% of kidney function can be lost before elevated Creatinine levels can be seen. The Cystatin C test is a much more sensitive marker and can detect early stages of renal dysfunction, allowing treatment to begin before it is too late.
- Beta-2 Microglobulin – this test is used when kidney damage has occurred to distinguish between the two most commonly affected sites, glomeruli and renal tubules.
Fact: Cardiovascular Diseases are the number one cause of death globally, with more people dying annually from CVDs than any other cause.² In the UK alone, 41,000 people under the age of 75 die from CVD each year.³
If you are worried about your cardiovascular health, or whether you are at risk of a heart attack or stroke, ask your doctor for a cardiovascular risk assessment. Routinely they will run lipid tests such as Total Cholesterol, HDL Cholesterol, LDL Cholesterol and Triglycerides to assess your overall cholesterol and triglyceride levels, and allow corrective action to be taken.
Look out for hidden risk factors!
Specific tests you may also want to discuss with your doctor include:
- sLDL Cholesterol and Lipoprotein(a) to assess for genetically inherited risks of cardiovascular disease – even if your cholesterol levels are safe you may still be at risk of cardiovascular disease as a result of familial traits
- Adiponectin to assess the level of abdominal visceral fat, of which high levels can increase your cardiovascular risk. Please note that abdominal visceral fat levels or body fat cannot be determined by BMI score, which assesses whether weight is within a healthy range. As such, the Adiponectin test provides a clearer indication of health and is a good predictor of cardiovascular risk
- TxBCardio to assess response to Aspirin therapy for the prevention of cardiovascular disease. Up to 30% of patients receiving Aspirin therapy suffer unknowingly from Aspirin resistance. This test enables treatment to be modified and corrected
Asking your doctor for these tests creates an opportunity for corrective action to be taken and can have significant benefits for your health.
Fact: Approximately one woman dies from heart disease every minute, of which 64% had no previous symptoms.4
Sixty-four percent of women who die suddenly of coronary heart disease had no previous symptoms. Because these symptoms vary greatly between men and women, they’re often misunderstood. Media has conditioned us to believe that the telltale sign of a heart attack is extreme chest pain. But in reality, women are somewhat more likely to experience shortness of breath, nausea/vomiting and back or jaw pain. Other symptoms women should look out for are dizziness, lightheadedness or fainting, pain in the lower chest or upper abdomen and extreme fatigue.
Being aware of these signs can aid early detection, and greatly increase chances of surviving a heart attack!
So don’t forget to #LoveYourHeart this Valentine’s Day! Randox can provide a vast range of specialised blood tests to allow the most accurate diagnosis of diabetes, cardiac risk and associated complications. From all of us here at Randox we wish you an enjoyable Valentine’s Day!
What are inflammatory biomarkers?
The purpose of measuring an inflammatory biomarker is to detect inflammation, which can assist clinicians in the identification of a particular disease or provide a marker of treatment response. Inflammation, either chronic or acute, is the body’s immune response to protect against harmful stimuli such as damaged cells, irritants or pathogens.1 When inflammation occurs in the body, extra protein is released from the site of inflammation and circulates in the bloodstream.2 It is these proteins, or antibodies, which clinicians are testing for in the blood as they can indicate if inflammation is present.
Like many inflammatory biomarkers, such as rheumatoid factor (RF), C-reactive protein (CRP) or erythrocyte sedimentation rate (ESR), further tests will be required as testing for these tests alone does not provide a clearly defined diagnosis. However inflammatory biomarker tests can provide clinicians with a good indication of what may be wrong with a patient, which is why they are commonly tested for in a clinical setting.
What is Rheumatoid Factor?
Rheumatoid factor (RF) is an autoantibody which can target and damage healthy body tissue and in turn cause inflammatory symptoms.3 It is uncommon for this antibody to be present in healthy individuals, which is why it is a beneficial test to aid the diagnostic process. In particular, rheumatoid factor can be used as an inflammatory biomarker to assist in the diagnosis of rheumatoid arthritis (RA). However the rheumatoid factor antibody can also be present in healthy individuals or patients with systemic lupus erythematosus, liver cirrhosis, Sjögren’s Syndrome, Hepatitis and other conditions.4 If a test detects rheumatoid factor levels above 14 IU/ml, this is considered abnormally high.3
What is Rheumatoid Arthritis?
Rheumatoid arthritis is an autoimmune disease which attacks the lining tissue of joints, resulting in chronic inflammation. This disease commonly affects the hands, feet and wrists, with symptoms causing pain, fatigue and loss of bodily function and over time may even lead to multiple organ damage.5 Although diagnosis of rheumatoid arthritis requires a physical examination, testing for rheumatoid factor can be beneficial to assist in the diagnosis of this disease. Other blood tests that can be used to detect biomarkers associated with rheumatoid arthritis include C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), IgA, IgG, IgM and anti-cyclic citrullinated peptide (anti-CCP).
For health professionals
Randox Laboratories offer a leading portfolio of diagnostic reagents which includes a test for rheumatoid factor, with applications available for a range of biochemistry analysers. With a measuring range of 6.72 – 104 lU/ml, this assay can comfortably detect levels outside the normal range. Randox offer a complete diagnostic package for the screening of rheumatoid factor with a range of kit sizes, controls and calibrators available. Other inflammatory biomarker tests available from Randox include CRP, High Sensitivity CRP, Full Range CRP, IgA, IgG and IgM.
1. Nordqvist, C. Inflammation: Causes, Symptoms and Treatment. Medical News Today, https://goo.gl/rT4WS9 (accessed 16 January 2017)
2. Harding, M., Blood Tests to Detect Inflammation, Patient, 2015, https://goo.gl/F4OGrz, (accessed 16 January 2017)
3. Shiel, W. C., Rheumatoid Factor (RF), MedicineNet, 2016, https://goo.gl/XPA69u 2016 (accessed 16 January 2017)
4. Rheumatoid Arthritis Organisation, Rheumatoid Factor Test, Rheumatoid Arthritis Organisation, 2016, https://goo.gl/JujE5a
5. Gibofsky, A. Overview of Epidemiology, Pathophysiology and Diagnosis of Rheumatoid Arthritis. The American Journal of Managed Care. Vol.18, No.13. p.295-302, 2012