Analytical evaluation of the Bio-Rad Variant II automated HbA1C analyzer

Higgins, Trefor; Blakney, George B; Dayton, Jan

doi:10.1016/s0009-9120(01)00229-6

Cited by 24 publications

(20 citation statements)

References 5 publications

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“…The advantages of this test are that it can be measured at any time of the day with a very small blood sample (5 l). The disadvantages are that A1C cannot be measured in the presence of hemoglobin variants by several methods, costs, and the difficulty in standardization (35).…”

Section: Discussionmentioning

confidence: 99%

Association of A1C With Cardiovascular Disease and Metabolic Syndrome in Asian Indians With Normal Glucose Tolerance

et al. 2007

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OBJECTIVE -This study examines the association of A1C with cardiovascular disease (CVD) risk factors, coronary artery disease (CAD), and metabolic syndrome in Asian Indians with normal glucose tolerance (NGT). RESEARCH DESIGN AND METHODS-This cross-sectional study recruited subjects from phase III of the Chennai Urban Rural Epidemiology Study (CURES), an epidemiological study in a representative population of Chennai (formerly Madras) in South India, conducted between January 2003 and June 2004. Included were 1,644 subjects with NGT, i.e., fasting plasma glucose Ͻ100 mg/dl (5.6 mmol/l) and 2-h postload plasma glucose Ͻ140 mg/dl (7.8 mmol/l). A1C was measured using the Biorad Variant machine. Metabolic syndrome was defined based on modified Adult Treatment Panel III guidelines.RESULTS -The mean Ϯ SD A1C value in the study cohort was 5.5 Ϯ 0.4%. A1C showed a significant association with BMI (␤ ϭ 0.017, P Ͻ 0.001), systolic (␤ ϭ 0.002, P ϭ 0.028) and diastolic (␤ ϭ 0.202, P ϭ 0.017) blood pressure, waist circumference (␤ ϭ 0.007, P Ͻ 0.001), serum cholesterol (␤ ϭ 0.002, P Ͻ 0.001), triglycerides (␤ ϭ 0.001, P Ͻ 0.001), LDL cholesterol (␤ ϭ 0.002, P Ͻ 0.001), fasting insulin (␤ ϭ 0.009, P Ͻ 0.001), and homeostasis model assessment of insulin resistance (␤ ϭ 0.047, P Ͻ 0.001) after adjusting for age and sex. Regression analysis showed that A1C had a strong association with metabolic syndrome that persisted after adjusting for age and sex (odds ratio [OR] 2.9 [95% CI 2.08 -4.00]; P Ͻ 0.001). A1C also had a strong association with CAD (2.6 [1.23-5.63]; P ϭ 0.01), but the significance was lost when adjusted for age and sex.CONCLUSIONS -There is a strong association of A1C with prevalent CVD risk factors in Asian-Indian subjects with NGT. Diabetes Care 30:1527-1532, 2007T he DCCT (Diabetes Control and Complications Trial) and UKPDS (UK Prospective Diabetes Study) demonstrated the importance of A1C in the development of long-term diabetes microvascular complications (1,2). Further, both studies elegantly demonstrated significant reductions in the risk of developing microvascular complications for every percentage of reduction in A1C levels (1,2). However, the association of A1C with cardiovascular disease (CVD) is less clear (3)(4)(5)(6)(7)(8).CVD is the principal cause of mortality globally, particularly in type 2 diabetic subjects, as their CVD mortality risk is equal to that of subjects without diabetes who had a previous episode of myocardial infarction (9). Recent prospective studies have shown that A1C is associated with CVD and mortality (10). This association has also recently been extended to nondiabetic subjects, as the relationship of CVD with glycemia is believed to be a continuum without a threshold effect (5-8).However, there is uncertainty as to the nature of the relationship, as some studies report no statistically significant association (3) between A1C and CVD in nondiabetic males while others do (4 -8).Asian Indians are known to have very high rates of premature coronary artery disease (CAD) and diab...

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Section: Discussionmentioning

confidence: 99%

Association of A1C With Cardiovascular Disease and Metabolic Syndrome in Asian Indians With Normal Glucose Tolerance

et al. 2007

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“…Nonesterified fatty acids (NEFAs) were measured using the WAKO kit adopted for use on a centrifugal analyzer (25). A1C was determined in whole blood using the Variant II A1C cation-exchange HPLC kit system (26). Fluoxetine and norfluoxetine were determined by gas chromatography with electron-capture detection based on a modification described by Torok-Both et al (27).…”

Section: Methodsmentioning

confidence: 99%

Effects of a Selective Serotonin Reuptake Inhibitor, Fluoxetine, on Counterregulatory Responses to Hypoglycemia in Healthy Individuals

et al. 2008

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OBJECTIVE-Hypoglycemia commonly occurs in intensivelytreated diabetic patients. Repeated hypoglycemia blunts counterregulatory responses, thereby increasing the risk for further hypoglycemic events. Currently, physiologic approaches to augment counterregulatory responses to hypoglycemia have not been established. Therefore, the specific aim of this study was to test the hypothesis that 6 weeks' administration of the selective serotonin reuptake inhibitor (SSRI) fluoxetine would amplify autonomic nervous system (ANS) and neuroendocrine counterregulatory mechanisms during hypoglycemia. RESEARCH DESIGN AND METHODS-A total of 20 healthy (10 male and 10 female) subjects participated in an initial single-step hyperinsulinemic (9 pmol ⅐ kg Ϫ1 ⅐ min Ϫ1 )-hypoglycemic (means Ϯ SE 2.9 Ϯ 0.1 mmol/l) clamp study and were then randomized to receive 6 weeks' administration of fluoxetine (n ϭ 14) or identical placebo (n ϭ 6) in a double-blind fashion. After 6 weeks, subjects returned for a second hypoglycemic clamp. Glucose kinetics were determined by three-tritiated glucose, and muscle sympathetic nerve activity (MSNA) was measured by microneurography.RESULTS-Despite identical hypoglycemia (2.9 Ϯ 0.1 mmol/l) and insulinemia during all clamp studies, key ANS (epinephrine, norepinephrine, and MSNA but not symptoms), neuroendocrine (cortisol), and metabolic (endogenous glucose production, glycogenolysis, and lipolysis) responses were increased (P Ͻ 0.01) following fluoxetine.CONCLUSIONS-This study demonstrated that 6 weeks' administration of the SSRI fluoxetine can amplify a wide spectrum of ANS and metabolic counterregulatory responses during hypoglycemia in healthy individuals. These data further suggest that serotonergic transmission may be an important mechanism in modulating sympathetic nervous system drive during hypoglycemia in healthy individuals. Diabetes 57:2453-2460, 2008 S everal reports have indicated that fluoxetine could have metabolic effects and influence carbohydrate metabolism (1-3). In fact, there have been three case studies reporting the occurrence of hypoglycemia related to the use of selective serotonin reuptake inhibitors (SSRIs) in depressed patients with and without diabetes (4 -6). However, although SSRIs are potent inhibitors of neuronal serotonin uptake, they also have the ability to block norepinephrine transport (7). This could increase sympathetic outflow activity (2,8). Baudrie and Chaouloff (9) have previously reported an increased hyperglycemic response to 2-deoxy-D-glycose in conscious rats following serotononergic receptor antagonists, implying increased counterregulation in these animals.A subsequent study by Perry and Fuller (2) demonstrated that systemic injection of the SSRI fluoxetine in rats resulted in threefold increases of hypothalamic norepinephrine release, thereby providing a mechanistic basis for SSRIs to modulate sympathetic nervous system activity. A later study by Bymaster et al. (3) examined the specificity of five different SSRIs (fluoxetine, citalopram, fluvoxamine, paroxe...

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“…Por não possuírem resolução suficiente para separar as frações glicadas, eles medem a fração glicada total (HbA 1 ). Nos últimos anos, eles têm sido substituídos por sistemas de HPLC mais robustos e automatizados (35)(36)(37)(38). O método de HPLC por troca iônica foi utilizado pelo DCCT (3) e é recomendado como método de referência interino para a dosagem de GHb até que os órgãos internacionais decidam sobre o método de referência definitivo (27,39).…”

Section: Métodos Para Dosagem Da Ghbunclassified

Glico-hemoglobina (HbA1c): aspectos clínicos e analíticos

Camargo

Gross

2004

Arq Bras Endocrinol Metab

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RESUMOA glico-hemoglobina (GHb) é um parâmetro importante no controle glicêmico de pacientes com DM. Vários estudos clínicos mostraram claramente que a melhora no controle glicêmico está fortemente associada com a diminuição no desenvolvimento e/ou progressão das complicações em diabetes melito tipos 1 e 2. A medida exata e precisa da GHb é uma questão importante para os laboratórios clínicos. Vários fatores afetam os resultados e podem levar a resultados errôneos. Nesta revisão, discutimos os problemas da padronização da determinação da GHb para monitorar a terapia diabética e também os principais fatores interferentes. Os métodos para GHb podem ser diferentemente afetados pelas interferências. O efeito da interferência pode ser clinicamente mais relevante com o pior controle glicêmico. O laboratório deve estar atento para estes fatores para evitar confusão na interpretação clínica dos resultados, e os clínicos devem contatar o laboratório sempre que houver discrepância entre a impressão clínica e o resultado laboratorial. Glycohemoglobin (GHb) has a key role in the assessment of glycemic control in diabetic patients. Several studies have clearly shown that improved glycemic control is strongly associated with decreased development and/or progression of diabetic complications in both type 1 and 2 diabetes mellitus. Therefore, accurate determination of GHb concentration is an important issue for clinical laboratories. Several factors may affect and lead to erroneous results. We discuss the problems of standardization of GHb measurements for monitoring glycemic control and also consider the potential interfering factors on GHb measurements. Moreover, GHb assays may be affected by interference in different ways. The effect of interference may be more clinically relevant with poor metabolic control. Laboratory staff must be aware of all pitfalls to avoid adding more confusion to the clinical interpretation of HbA 1c values and physicians should contact laboratories if discrepancies between clinical impressions and laboratory data are observed.

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Analytical evaluation of the Bio-Rad Variant II automated HbA1C analyzer

Cited by 24 publications

References 5 publications

Association of A1C With Cardiovascular Disease and Metabolic Syndrome in Asian Indians With Normal Glucose Tolerance

Association of A1C With Cardiovascular Disease and Metabolic Syndrome in Asian Indians With Normal Glucose Tolerance

Effects of a Selective Serotonin Reuptake Inhibitor, Fluoxetine, on Counterregulatory Responses to Hypoglycemia in Healthy Individuals

Glico-hemoglobina (HbA1c): aspectos clínicos e analíticos

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