A1C cut points to define various glucose intolerance groups in Asian Indians

Hyperinsulinemia: an early biomarker of metabolic dysfunction

Introduction

Hyperinsulinemia in the absence of impaired glucose tolerance and normal HbA1c is considered indicative of pre-diabetes. Very few Indian studies have focused on hyperinsulinemia particularly in young adults. The present study aimed to determine whether hyperinsulinemia may be present despite HbA1c being normal.

Methods

This was a cross-sectional study conducted on adolescents and young adults aged 16-25 years living in Mumbai, India. The participants attended various academic institutions and were those who underwent screening as the first step of a clinical trial for studying the efficacy of almond intake in prediabetes.

Results

Among this young population (n=1313), 4.2% (n=55) of the participants were found to be prediabetic (ADA criteria) and 19.7% of them had HbA1c levels between 5.7%-6.4%. However, almost, 30.5% had hyperinsulinemia inspite of normal blood glucose levels and normal HbA1c. Among those with HbA1c<5.7 (n=533), 10.5% (n=56) participants had fasting insulin>15 mIU/L and a higher percentage (39.4%, n=260) had stimulated insulin above 80 mIU/L. These participants had higher mean anthropometric markers than those with normal fasting and/or stimulated insulin.

Conclusion

Hyperinsulinaemia in the absence of impaired glucose tolerance and normal HbA1c may provide a much earlier indicator of detection for risk of metabolic disease and progression to metabolic syndrome and diabetes mellitus.

Concordance in incidence of diabetes among persons with prediabetes detected using either oral glucose tolerance test or glycated haemoglobin

AIMS

To study the concordance in the incidence of type 2 diabetes (T2DM) between cohorts with prediabetes, selected either by oral glucose tolerance test (OGTT) or glycosylated haemoglobin (HbA1c) at two years in a real world situation.

METHODS

Two cohorts with impaired glucose tolerance (IGT) were selected from the non-interventional arm of the Indian diabetes prevention programmes; a group selected by using OGTT (Cohort 1, n = 498), another selected based on the HbA1c criterion (Cohort 2, n = 504). Clinical and biochemical data collected for 24 months at 6 monthly intervals were used in assessing the cumulative incidence of T2DM using the respective diagnostic criteria. Intra and inter group comparisons were analysed using appropriate statistical tests. A multiple logistic regression analysis was used to identify the variables significantly associated with the incidence of diabetes.

RESULTS

Incidence of diabetes in both cohorts were similar at 12 and 24 months with either of the two criteria (25.3% with glucose and 27.5% with HbA1c, p = 0.41 at 24 months). The multivariate analysis confirmed the results. Only baseline waist circumference was positively associated with the incidence.

CONCLUSION

Both OGTT and HbA1c have similar utility and validity in identifying persons with IGT. Persons identified with either of the criterion had similar incidence of T2DM among Asian Indians.

Revised Glycemic Index for Diagnosing and Monitoring of Diabetes Mellitus in South Indian Population

Aim: To find the optimal threshold of fasting plasma glucose (FPG) and glycated hemoglobin (HbA1c) for diagnosis of diabetes mellitus (DM) and to evaluate the association with diabetic retinopathy (DR) in the South Indian population.

Settings and Design: A retrospective population-based study.

Methods and Materials: A total of 909 newly detected type 2 DM patients were selected from our two previously conducted studies, which include an urban and a rural population of South India. All underwent estimation of fasting, postprandial plasma glucose (PPG), and other biochemical tests. A comprehensive and detailed ophthalmic examination was carried out. The fundi of patients were photographed using 45°, four-field stereoscopic photography. Based on receiver operating characteristic (ROC) curves, sensitivity and specificity were derived.

Results: The optimal cut-off values determined by maximizing the sensitivity and specificity of FPG and HbA1c using the Youden index were ≥ 6.17 mmol/L and ≥ 6.3%, respectively. By distributing the cut-off points into deciles and comparing them to the WHO criteria, we found that our HbA1c level of 6.60% was more than the WHO threshold (6.5%), with higher sensitivity (81.6%) and lower specificity (48.3%). The FPG level of 6.80 mmol/L was lower to the WHO criteria (7 mmol/L) with increased sensitivity (77.0%) and lower specificity (45.7%). Prevalence of DR by HbA1c levels between 6.5% and 6.9% was 15.3%. The prevalence of DR was more in the FPG category between 6.4 and 6.9 mmol/L and ≥ 7.5 mmol/L.

Conclusion: Our population-based data indicate that for the South Indian population HbA1c value of ≥63 % and FPG value of ≥6.17 mmol/L may be optimal for diagnosing DM with a high level of accuracy and will be useful for the identification of mild and moderate DR.

Variations in glycated haemoglobin with age among individuals with normal glucose tolerance: Implications for diagnosis and treatment-Results from the ICMR-INDIAB population-based study (INDIAB-12)

AIM

To report on glycated haemoglobin (HbA1c) values among individuals with normal glucose tolerance (NGT) at different age groups, using data acquired from a large national survey in India.

MATERIALS AND METHODS

Data on glycaemic parameters at different age groups were obtained from the Indian Council of Medical Research-INdia DIABetes (ICMR-INDIAB) study, in adults aged ≥ 20 years representing all parts of India. Age-wise distribution of HbA1c was assessed among individuals with NGT (n = 14,222) confirmed by an oral glucose tolerance test using the World Health Organization (WHO) criteria. Results were validated in another large epidemiological study (n = 1077) conducted in Chennai, India.

RESULTS

Among NGT individuals, HbA1c increased gradually with age from 5.16 ± 0.71% (33 mmol/mol) in the age group of 20-29 years to 5.49 ± 0.69% (37 mmol/mol) in those aged 70 + years. In the validation study, conducted in another study population, HbA1c was 5.35 ± 0.43% (35 mmol/mol) in age group of 20-29 years and 5.74 ± 0.50% (39 mmol/mol) in those aged 70 and above. In the INDIAB study, for every decadal increase in age, there is a 0.08% increase in HbA1c and this increase was more significant in females (females: 0.10% vs. males: 0.06%) and in urban (urban: 0.10% vs. rural: 0.08%) population.

CONCLUSIONS

HbA1c levels increase steadily with age. This suggests that age-specific cutoffs be used while utilizing HbA1c to diagnose diabetes and prediabetes, so as to minimize the risk of overdiagnosis and unnecessary initiation of treatment in elderly people who could have physiological increase in HbA1c levels.

Burden of Type 2 Diabetes and Associated Cardiometabolic Traits and Their Heritability Estimates in Endogamous Ethnic Groups of India: Findings From the INDIGENIUS Consortium

To assess the burden of type 2 diabetes (T2D) and its genetic profile in endogamous populations of India given the paucity of data, we aimed to determine the prevalence of T2D and estimate its heritability using family-based cohorts from three distinct Endogamous Ethnic Groups (EEGs) representing Northern (Rajasthan [Agarwals: AG]) and Southern (Tamil Nadu [Chettiars: CH] and Andhra Pradesh [Reddys: RE]) states of India. For comparison, family-based data collected previously from another North Indian Punjabi Sikh (SI) EEG was used. In addition, we examined various T2D-related cardiometabolic traits and determined their heritabilities. These studies were conducted as part of the Indian Diabetes Genetic Studies in collaboration with US (INDIGENIUS) Consortium. The pedigree, demographic, phenotypic, covariate data and samples were collected from the CH, AG, and RE EEGs. The status of T2D was defined by ADA guidelines (fasting glucose ≥ 126 mg/dl or HbA1c ≥ 6.5% and/or use of diabetes medication/history). The prevalence of T2D in CH (N = 517, families = 21, mean age = 47y, mean BMI = 27), AG (N = 530, Families = 25, mean age = 43y, mean BMI = 27), and RE (N = 500, Families = 22, mean age = 46y, mean BMI = 27) was found to be 33%, 37%, and 36%, respectively, Also, the study participants from these EEGs were found to be at increased cardiometabolic risk (e.g., obesity and prediabetes). Similar characteristics for the SI EEG (N = 1,260, Families = 324, Age = 51y, BMI = 27, T2D = 75%) were obtained previously. We used the variance components approach to carry out genetic analyses after adjusting for covariate effects. The heritability (h²) estimates of T2D in the CH, RE, SI, and AG were found to be 30%, 46%, 54%, and 82% respectively, and statistically significant (P ≤ 0.05). Other T2D related traits (e.g., BMI, lipids, blood pressure) in AG, CH, and RE EEGs exhibited strong additive genetic influences (h² range: 17% [triglycerides/AG and hs-CRP/RE] - 86% [glucose/non-T2D/AG]). Our findings highlight the high burden of T2D in Indian EEGs with significant and differential additive genetic influences on T2D and related traits.

Impact of triglycerides and waist circumference on insulin resistance and β-cell function in non-diabetic first-degree relatives of type 2 diabetes

BACKGROUND

Although there is abundant evidence indicating the relative contribution of insulin resistance (HOMA-IR) and β-cell dysfunction (HOMA-β) among first-degree relatives (FDRs) of Type 2 DM patients, few studies reported the association between HOMA-IR and HOMA-β with metabolic syndrome. Our objective was to evaluate the impact of metabolic syndrome factors on HOMA-IR, HOMA-β and glycoproteins in non-diabetic FDRs.

METHODS

In this study, 103 Yemeni male subjects aged 25-42 years, with BMI < 25 kg/m² were examined, 39 of whom were normal subjects with no family history of diabetes served as control and 64 subjects were non-diabetic FDRs of Type 2 DM patients.

RESULTS

Both glycoproteins, glycated haemoglobin (HbA1c) and fructosamine as well as insulin, HOMA-IR and HOMA-β were significantly (p = 4.9 × 10^-9; 6.0 × 10^-8; 6.6 × 10^-12; 1.3 × 10^-7; 5.5 × 10^-12, respectively) higher in non-diabetic FDRs as compared to control group. Fasting plasma glucose, though within normal range, were significantly (p = 0.026) higher in non-diabetic FDRs. Linear regression analysis showed that both TG and WC are the main metabolic syndrome factors that significantly increased HOMA-IR (B = 0.334, p = 1.97 × 10^-6; B = 0.024, p = 1.05 × 10^-5), HOMA-β (B = 16.8, p = 6.8 × 10^-5; B = 0.95, p = 0.004), insulin (B = 16.5, p = 1.2 × 10^-6; B = 1.19, p = 8.3 × 10^-6) and HbA1c (B = 0.001, p = 0.034; B = 0.007, p = 0.037).

CONCLUSION

Triglyceride and WC are the important metabolic syndrome factors associated with insulin resistance, basal β-cell function and insulin levels in non-diabetic FDR men of Type 2 DM patients. Moreover, FDRs showed insulin resistance with compensatory β-cell function (hyperinsulinaemia) suggesting that insulin resistance precede the development of pancreatic β-cell dysfunction in individuals at risk of Type 2 DM.

Differential risk factor profile of diabetes and atherosclerosis in rural, sub-urban and urban regions of South India: The KMCH-Non-communicable disease studies

AIMS

South Asia has emerged rapidly as an epicentre of non-communicable diseases (NCDs) specifically diabetes and cardiovascular diseases. The prevalence rate, risk factors and aetiology of NCDs in different socio-demographic settings are not clearly understood. This study was performed to assess the prevalence of diabetes and atherosclerosis and their risk factors in urban, sub-urban and rural communities of South India.

METHODS

Three communities [Nallampatti (rural), Thadagam (sub-urban) and Kalapatti (urban)] in South India were selected for participation in the KMCH-NCD Studies. Study volunteers were administered a detailed questionnaire, underwent anthropometric measurements, clinical measurements including blood pressure, glycated haemoglobin (HbA_1c ), non-fasting lipid profile and serum creatinine. Carotid intima-media thickness was measured using B-mode ultrasound. Multiple logistic regression analyses were performed to understand the association of risk factors with diabetes and atherosclerosis.

RESULTS

A total of 2976 native participants, ≥20 years of age were screened. The prevalence of diabetes was 16%, 26% and 23% respectively in the rural, sub-urban and urban study populations. Association of obesity with diabetes was observed in only urban population while hypertension and dyslipidaemia showed association in both urban and semi-urban populations. Association of diabetes with atherosclerosis was observed in urban and semi-urban populations. Hypertension in semi-urban and obesity and dyslipidaemia in urban population showed association with atherosclerosis.

CONCLUSIONS

Diabetes and atherosclerosis burden reported in the three different communities were higher than previous reports, especially in rural and sub-urban regions. No traditional risk factor is identified to be associated with prevalence of diabetes and atherosclerosis in rural population. These findings suggest an urgent need for investigation into the role of non-traditional risk factors like environmental or occupational exposures may help to better understand the aetiology of diseases in non-urbanized communities.

Performance of diabetes screening tests: an evaluation study of Iranian diabetes screening program

BACKGROUND

Type 2 diabetes is a common non-communicable disease that is responsible for about 9% of all deaths and a 25% reduction in life expectancy. However, nearly half of the diabetic patients are not aware of their disease. In this regard, to identify un-known diabetic patients, diabetes screening is of great importance. This study was conducted to evaluate the performance of two commonly used diabetes screening tests that are currently recommended by the Iranian diabetes screening program for (DSP).

METHODS

The validity of the two diabetes screening tests were measured among 1057 participants who were older than 30 years of age. The studied screening tests included capillary fasting blood glucose (CBG) and glycated hemoglobin (HbA1c). The golden standard for measuring the validity of the tests was venous fasting plasma glucose (VPG).

RESULTS

According to the results, the sensitivity of CBG and HbA1c tests was 69.01% and 84.5%, and the specificity of the tests were 95.7% and 79.3%, respectively. Positive and negative predictive values were 53.84% and 97.72% for CBG and 22.72% and 98.61% for HbA1c, respectively. The recommended cut points for CBG and HbA1c were 116.5 mg/dl and 7.15%, respectively. Using these values as the new cut points, sensitivity and specificity of CBG and HbA1c changed to 80.30% and 89.10%, and 77.50% and 94.20%, respectively.

CONCLUSIONS

Compared to several other countries, the performance of Iranian DSP is relatively better. The Receiver Operating Characteristic Curve suggested new cut points for significantly better performance of DSP.

Diagnostic accuracy of tests for type 2 diabetes and prediabetes: A systematic review and meta-analysis

AIM

This systematic review aimed to ascertain the diagnostic accuracy (sensitivity and specificity) of screening tests for early detection of type 2 diabetes and prediabetes in previously undiagnosed adults.

METHODS

This systematic review included published studies that included one or more index tests (random and fasting tests, HbA1c) for glucose detection, with 75-gram Oral Glucose Tolerance Test (or 2-hour post load glucose) as a reference standard (PROSPERO ID CRD42018102477). Seven databases were searched electronically (from their inception up to March 9, 2020) accompanied with bibliographic and website searches. Records were manually screened and full text were selected based on inclusion and exclusion criteria. Subsequently, data extraction was done using standardized form and quality assessment of studies using QUADAS-2 tool. Meta-analysis was done using bivariate model using Stata 14.0. Optimal cut offs in terms of sensitivity and specificity for the tests were analysed using R software.

RESULTS

Of 7,151 records assessed by title and abstract, a total of 37 peer reviewed articles were included in this systematic review. The pooled sensitivity, specificity, positive (LR+) and negative likelihood ratio (LR-) for diagnosing diabetes with HbA1c (6.5%; venous sample; n = 17 studies) were 50% (95% CI: 42-59%), 97.3% (95% CI: 95.3-98.4), 18.32 (95% CI: 11.06-30.53) and 0.51 (95% CI: 0.43-0.60), respectively. However, the optimal cut-off for diagnosing diabetes in previously undiagnosed adults with HbA1c was estimated as 6.03% with pooled sensitivity of 73.9% (95% CI: 68-79.1%) and specificity of 87.2% (95% CI: 82-91%). The optimal cut-off for Fasting Plasma Glucose (FPG) was estimated as 104 milligram/dL (mg/dL) with a sensitivity of 82.3% (95% CI: 74.6-88.1%) and specificity of 89.4% (95% CI: 85.2-92.5%).

CONCLUSION

Our findings suggest that at present recommended threshold of 6.5%, HbA1c is more specific and less sensitive in diagnosing the newly detected diabetes in undiagnosed population from community settings. Lowering of thresholds for HbA1c and FPG to 6.03% and 104 mg/dL for early detection in previously undiagnosed persons for screening purposes may be considered.

Glycated hemoglobin (HbA1c) as diagnostic criteria for diabetes: the optimal cut-off points values for the Pakistani population; a study from second National Diabetes Survey of Pakistan (NDSP) 2016-2017

AIM

Glycated hemoglobin (HbA1c) cut-off values as diagnostic tool in diabetes and prediabetes with its concordance to oral glucose tolerance test (OGTT) in Pakistani population.

METHODOLOGY

Data for this substudy was obtained from second National Diabetes Survey of Pakistan (NDSP) 2016-2017. With this survey, 10 834 individuals were recruited and after excluding known subjects with diabetes, 6836 participants fulfilled inclusion criteria for this study. Demographic, anthropometric and biochemical parameters were obtained. OGTT was used as standard diagnostic tool to screen population and HbA1c for optimal cut-off values. Participants were categorized into normal glucose tolerance (NGT), newly diagnosed diabetes (NDD) and prediabetes.

RESULTS

Out of 6836 participants, 4690 (68.6%) had NGT, 1333 (19.5%) had prediabetes and 813 (11.9%) had NDD by OGTT criteria with median (IQR) age of 40 (31-50) years. Optimal HbA1c cut-off point for identification of diabetes and prediabetes was observed as 5.7% ((AUC (95% CI)=0.776 (0.757 to 0.795), p<0.0001)) and 5.1% ((AUC (95% CI)=0.607 (0.590 to 0.624), p<0.0001)), respectively. However, out of 68.6% NGT subjects identified through OGTT, 24.1% and 9.3% participants were found to have prediabetes and NDD, respectively by using HbA1c criteria. By using both OGTT and HbA1c criteria, only 7.9% and 7.3% were observed as prediabetes and diabetes, respectively.

CONCLUSION

Findings from second NDSP demonstrated disagreement between findings of OGTT and HbA1c as diagnostic tool for Pakistani population. As compared with international guidelines, HbA1c threshold for prediabetes and NDD were lower in this part of world. HbA1c as diagnostic tool might require ethnic or regional-based modification in cut-off points, validated by relevant community-based epidemiological surveys.

Changes in blood pressure associated with lead, manganese, and selenium in a Bangladeshi cohort

BACKGROUND

Heavy metal contamination is widespread in Bangladesh. Previous studies have observed lead increases blood pressure over time. However, the role of other metal contaminants and essential micronutrients, which could also adversely affect blood pressure or act as protective factors, is understudied.

OBJECTIVES

We therefore evaluated the associations of lead, manganese, and selenium with blood and pulse pressure trajectories.

METHODS

We prospectively followed placebo-assigned participants nested within a randomized trial for the prevention of arsenic-related skin cancer (n = 255). Blood lead, manganese, and selenium were measured at baseline; blood pressure was measured at baseline and at 3 biennial follow-up examinations. Mixed-effect linear regression models were used to estimate associations with average annual changes in systolic, diastolic, and pulse pressure.

RESULTS

In models simultaneously adjusted for baseline blood lead, manganese, and selenium concentrations in addition to other potential confounders, lead was linearly associated with increases in systolic blood pressure, but not with diastolic blood pressure or pulse pressure. A non-linear association was observed for manganese, such that mid-range concentrations were associated with decreases in systolic, diastolic, and pulse pressure. Baseline selenium concentrations in the highest quartile were also associated with longitudinal decreases in both systolic and diastolic blood pressure, while null associations were observed with pulse pressure. In exploratory analyses, the combination of mid-range manganese and high selenium concentrations completely offset lead-associated increases in blood and pulse pressure.

CONCLUSIONS

The results indicate a direct, linear association of lead exposure with systolic blood pressure, and manganese and selenium exposures within certain ranges may have a blood pressure-lowering effect in this population.

Development of type 2 diabetes mellitus in people with intermediate hyperglycaemia

BACKGROUND

Intermediate hyperglycaemia (IH) is characterised by one or more measurements of elevated blood glucose concentrations, such as impaired fasting glucose (IFG), impaired glucose tolerance (IGT) and elevated glycosylated haemoglobin A1c (HbA1c). These levels are higher than normal but below the diagnostic threshold for type 2 diabetes mellitus (T2DM). The reduced threshold of 5.6 mmol/L (100 mg/dL) fasting plasma glucose (FPG) for defining IFG, introduced by the American Diabetes Association (ADA) in 2003, substantially increased the prevalence of IFG. Likewise, the lowering of the HbA1c threshold from 6.0% to 5.7% by the ADA in 2010 could potentially have significant medical, public health and socioeconomic impacts.

OBJECTIVES

To assess the overall prognosis of people with IH for developing T2DM, regression from IH to normoglycaemia and the difference in T2DM incidence in people with IH versus people with normoglycaemia.

SEARCH METHODS

We searched MEDLINE, Embase, ClincialTrials.gov and the International Clinical Trials Registry Platform (ICTRP) Search Portal up to December 2016 and updated the MEDLINE search in February 2018. We used several complementary search methods in addition to a Boolean search based on analytical text mining.

SELECTION CRITERIA

We included prospective cohort studies investigating the development of T2DM in people with IH. We used standard definitions of IH as described by the ADA or World Health Organization (WHO). We excluded intervention trials and studies on cohorts with additional comorbidities at baseline, studies with missing data on the transition from IH to T2DM, and studies where T2DM incidence was evaluated by documents or self-report only.

DATA COLLECTION AND ANALYSIS

One review author extracted study characteristics, and a second author checked the extracted data. We used a tailored version of the Quality In Prognosis Studies (QUIPS) tool for assessing risk of bias. We pooled incidence and incidence rate ratios (IRR) using a random-effects model to account for between-study heterogeneity. To meta-analyse incidence data, we used a method for pooling proportions. For hazard ratios (HR) and odds ratios (OR) of IH versus normoglycaemia, reported with 95% confidence intervals (CI), we obtained standard errors from these CIs and performed random-effects meta-analyses using the generic inverse-variance method. We used multivariable HRs and the model with the greatest number of covariates. We evaluated the certainty of the evidence with an adapted version of the GRADE framework.

MAIN RESULTS

We included 103 prospective cohort studies. The studies mainly defined IH by IFG5.6 (FPG mmol/L 5.6 to 6.9 mmol/L or 100 mg/dL to 125 mg/dL), IFG6.1 (FPG 6.1 mmol/L to 6.9 mmol/L or 110 mg/dL to 125 mg/dL), IGT (plasma glucose 7.8 mmol/L to 11.1 mmol/L or 140 mg/dL to 199 mg/dL two hours after a 75 g glucose load on the oral glucose tolerance test, combined IFG and IGT (IFG/IGT), and elevated HbA1c (HbA1c5.7: HbA1c 5.7% to 6.4% or 39 mmol/mol to 46 mmol/mol; HbA1c6.0: HbA1c 6.0% to 6.4% or 42 mmol/mol to 46 mmol/mol). The follow-up period ranged from 1 to 24 years. Ninety-three studies evaluated the overall prognosis of people with IH measured by cumulative T2DM incidence, and 52 studies evaluated glycaemic status as a prognostic factor for T2DM by comparing a cohort with IH to a cohort with normoglycaemia. Participants were of Australian, European or North American origin in 41 studies; Latin American in 7; Asian or Middle Eastern in 50; and Islanders or American Indians in 5. Six studies included children and/or adolescents.Cumulative incidence of T2DM associated with IFG5.6, IFG6.1, IGT and the combination of IFG/IGT increased with length of follow-up. Cumulative incidence was highest with IFG/IGT, followed by IGT, IFG6.1 and IFG5.6. Limited data showed a higher T2DM incidence associated with HbA1c6.0 compared to HbA1c5.7. We rated the evidence for overall prognosis as of moderate certainty because of imprecision (wide CIs in most studies). In the 47 studies reporting restitution of normoglycaemia, regression ranged from 33% to 59% within one to five years follow-up, and from 17% to 42% for 6 to 11 years of follow-up (moderate-certainty evidence).Studies evaluating the prognostic effect of IH versus normoglycaemia reported different effect measures (HRs, IRRs and ORs). Overall, the effect measures all indicated an elevated risk of T2DM at 1 to 24 years of follow-up. Taking into account the long-term follow-up of cohort studies, estimation of HRs for time-dependent events like T2DM incidence appeared most reliable. The pooled HR and the number of studies and participants for different IH definitions as compared to normoglycaemia were: IFG5.6: HR 4.32 (95% CI 2.61 to 7.12), 8 studies, 9017 participants; IFG6.1: HR 5.47 (95% CI 3.50 to 8.54), 9 studies, 2818 participants; IGT: HR 3.61 (95% CI 2.31 to 5.64), 5 studies, 4010 participants; IFG and IGT: HR 6.90 (95% CI 4.15 to 11.45), 5 studies, 1038 participants; HbA1c5.7: HR 5.55 (95% CI 2.77 to 11.12), 4 studies, 5223 participants; HbA1c6.0: HR 10.10 (95% CI 3.59 to 28.43), 6 studies, 4532 participants. In subgroup analyses, there was no clear pattern of differences between geographic regions. We downgraded the evidence for the prognostic effect of IH versus normoglycaemia to low-certainty evidence due to study limitations because many studies did not adequately adjust for confounders. Imprecision and inconsistency required further downgrading due to wide 95% CIs and wide 95% prediction intervals (sometimes ranging from negative to positive prognostic factor to outcome associations), respectively.This evidence is up to date as of 26 February 2018.

AUTHORS' CONCLUSIONS

Overall prognosis of people with IH worsened over time. T2DM cumulative incidence generally increased over the course of follow-up but varied with IH definition. Regression from IH to normoglycaemia decreased over time but was observed even after 11 years of follow-up. The risk of developing T2DM when comparing IH with normoglycaemia at baseline varied by IH definition. Taking into consideration the uncertainty of the available evidence, as well as the fluctuating stages of normoglycaemia, IH and T2DM, which may transition from one stage to another in both directions even after years of follow-up, practitioners should be careful about the potential implications of any active intervention for people 'diagnosed' with IH.

Effect of moderate-intensity aerobic exercise on glycosylated haemoglobin among elderly patients with type 2 diabetes & peripheral neuropathy

Aerobic exercise has been known to improve glycosylated haemoglobin (HbA1c) levels and insulin sensitivity in patients with type 2 diabetes mellitus (T2DM). The present study was undertaken to evaluate the effect of eight week moderate-intensity aerobic (heart rate reserve 40-60%) exercise on glycaemic control in elderly patients with T2DM and diabetic peripheral neuropathy (DPN). The participants (n=87) were randomly assigned to an eight-week programme by a computer-generated random number table to the study or control group, respectively. There were 47 participants in the control group and 40 participants in the study group after randomization. There was a significant difference in the mean values of glycated haemoglobin (HbA1c) at baseline and 8th week between the two groups. Moderate-intensity aerobic exercise of eight weeks duration helped in achieving enhanced glycaemic control in the T2DM patients with DPN.

Fasting Plasma Glucose and the HbA1c Are Not Optimal Screening Modalities for the Diagnosis of New Diabetes in Previously Undiagnosed Asian Indian Community Participants

Objectives

There is no definitive consensus on the screening algorithm in high-risk communities for diabetes. The aims of our study were to determine the prevalence of undiagnosed diabetes in a high-risk community using the oral glucose tolerance test (OGTT), as well as determine the value of anthropometric measurements and other measures of glycemia in the detection of diabetes.

Method

All participants from the Phoenix Lifestyle project without known diabetes, and who had undergone an OGTT were selected for study. Anthropometric measurements were collected according to accepted guidelines. Diabetes was diagnosed if fasting plasma glucose (FPG) ≥7.0 mmol/l, if 2-hour plasma glucose level during OGTT was ≥ 11.0 mmol/l, or if HbA1c ≥ 6.5%.

Results

The prevalence of newly diagnosed diabetes was 14.3% (11.7 % age standardized) (women=15.4%; men=11.8%). The prevalence rates were underestimated using FPG criteria, but overestimated when using the HbA1c. The AUC (area under the receiver-operator characteristics curve) was highest for FPG (.879), HbA1c (.855), then anthropometry measures (BMI=.621; waist circumference=.627). For diabetes, at levels >6.3, the discriminant ability (DA) of HbA1c was highest (79%), while a cut-point of ≥5.5mmol/l for FPG yielded a DA= 81.5% (82% sensitivity; 81%; specificity of 81%). There was a low level of agreement between the FPG (Kappa = .506), HbA1c (Kappa = .537), and the OGTT. Age- and sex-adjusted independent determinants of diabetes using stepwise backward logistic regression were age, triglyceride levels and a positive family history for diabetes.

Conclusion

Neither the HbA1c nor the FPG approached adequate predictive accuracy in the diagnosis of diabetes. In view of the high prevalence of undiagnosed diabetes, this study underscores the need for ongoing national surveillance data.

Ethnic dependent differences in diagnostic accuracy of glycated hemoglobin (HbA1c) in Canadian adults

AIM

Previous studies have shown varying sensitivity and specificity of hemoglobin A1c (HbA1c) to identify diabetes and prediabetes, compared to 2-h oral glucose tolerance testing (OGTT) and fasting plasma glucose (FPG), in different ethnic groups. Within the Canadian population, the ability of HbA1c to identify prediabetes and diabetes in First Nations, Métis and Inuit, East and South Asian ethnic groups has yet to be determined.

METHODS

We collected demographic, lifestyle information, biochemical results of glycemic status (FPG, OGTT, and HbA1c) from an ethnically diverse Canadian population sample, which included a purposeful sampling of First Nations, Métis, Inuit, South Asian and East Asian participants.

RESULTS

Sensitivity and specificity using Canadian Diabetes Association (CDA) recommended cut-points varied between ethnic groups, with greater variability for identification of prediabetes than diabetes. Dysglycemia (prediabetes and diabetes) was identified with a sensitivity and specificity ranging from 47.1% to 87.5%, respectively in Caucasians to 24.1% and 88.8% in Inuit. Optimal HbA1c ethnic-specific cut-points for dysglycemia and diabetes were determined by receiver operating characteristic (ROC) curve analysis.

CONCLUSIONS

Our sample showed broad differences in the ability of HbA1c to identify dysglycemia or diabetes in different ethnic groups. Optimal cut-points for dysglycemia or diabetes in all ethnic groups were substantially lower than CDA recommendations. Utilization of HbA1c as the sole biochemical diagnostic marker may produce varying degrees of false negative results depending on the ethnicity of screened individuals. Further research is necessary to identify and validate optimal ethnic specific cut-points used for diabetic screening in the Canadian population.

Comparison of Hemoglobin A1c with Fasting and 2-h Plasma Glucose Tests for Diagnosis of Diabetes and Prediabetes among High-risk South Indians

BACKGROUND

Glycosylated hemoglobin (HbA1c) has not been evaluated extensively for diabetes and prediabetes diagnosis and short-term variability of fasting plasma glucose (FPG), 2-h PG post-75 g glucose load (2 hPG) and HbA1c has not been studied among Indians.

OBJECTIVES

The study aimed to compare the sensitivity of HbA1c, FPG and 2 hPG for diabetes and prediabetes diagnosis as per the American Diabetes Association criteria, assess short-term variability of three tests and determine optimal HbA1c cutoffs for diabetes and prediabetes diagnosis among high-risk south Indians.

METHODS

This diagnostic accuracy study, conducted at a tertiary care teaching hospital located in South India, enrolled 332 adults at high risk for diabetes and subjected them to testing (FPG, 2 hPG, and HbA1c) twice at 2-3 weeks interval. Sensitivity of three tests for diagnosing diabetes and prediabetes was determined based on the final diagnosis of normoglycemia/prediabetes/diabetes made with six test results for each participant. Optimal HbA1c cutoffs for diabetes and prediabetes were determined based on the final diagnosis of glycemic status made with four test results of FPG and 2 hPG.

RESULTS

FPG, 2 hPG, and HbA1c, at American Diabetes Association recommended values, had sensitivity of 84.4%, 97%, and 93.8% respectively for diabetes diagnosis. HbA1c had lowest short-term variability (CVw = 1.6%). Receiver operating characteristic curve plotted with mean (of two values) HbA1c for each participant showed optimal HbA1c cutoffs of 6.5% for diabetes (area under curve [AUC] =0.990, sensitivity = 95.8%, specificity = 96.2%, accuracy = 95.2%) and 5.9% for prediabetes (AUC = 0.893, sensitivity = 84.3%, specificity = 80%, accuracy = 75.6%) diagnosis respectively. HbA1c <5.6% had 100% negative predictive value to exclude prediabetes/diabetes.

CONCLUSIONS

HbA1c ≥6.5% is a convenient and reliable alternative to plasma glucose tests to diagnose diabetes among high-risk South Indians. HbA1c ≥5.9% is optimal for prediabetes diagnosis and value <5.6% excludes prediabetes/diabetes.Abbreviations used in the manuscript: ADA: American Diabetes Association, AUC: Area under curve, CVw: Within-person coefficient of variation, FPG: Fasting plasma glucose, 2 hPG: Two-hour plasma glucose post-75 g oral glucose load, HbA1c: Glycosylated haemoglobin, IFG: Impaired fasting glucose, IGT: Impaired glucose tolerance, NPV: Negative predictive value, PPV: Positive predictive value; PG: Plasma glucose, ROC: Receiver operating characteristic.

The 1h post glucose value best predicts future dysglycemia among normal glucose tolerance subjects

AIM

To analyse the OGTT glycemic parameters - fasting, 1h and 2h plasma glucose values singly and in various combinations; with respect to their prediction of future dysglycemia in subjects with normal glucose tolerance (NGT).

METHODS

Electronic medical records of individuals who underwent an OGTT between 1991 and 2016 at a tertiary diabetes centre were analysed. NGT subjects who had at least one more follow up OGTT (n=1356) were selected for the study. Regarding their prediction of future dysglycemia, the glycemic parameters-Fasting plasma glucose (FPG), 1h plasma glucose (1HrPG) and 2h plasma glucose (2HrPG) were analysed separately and also in different combinations. HbA1c and the combined use of HbA1c and FPG were also compared. Receiver operating characteristic (ROC) curve analysis was performed to assess the capability of various glycemic parameters to discriminate between NGT and dysglycemia. The WHO criteria were used to define dysglycemia as the presence of prediabetes (Impaired fasting glucose and/or Impaired glucose tolerance) or diabetes.

RESULTS

318(23.4%) developed prediabetes (median follow up 3.5years) and 134(10%) developed diabetes (median follow up 5.6years). The 1hrPG had a significantly higher AUC (0.684, 0.716) compared to FPG (0.560 and 0.593) and 2hrPG (0.644 and 0.618) for prediabetes and diabetes respectively. Adding the FPG or the 2hrPG to the 1HrPG did not significantly improve the AUC beyond 1HrPG alone. The 1HrPG also predicted diabetes better than HbA1c as well as the combined use of HbA1c and FPG.

CONCLUSION

The 1HrPG value during OGTT is a good predictor of future dysglycemia among NGT subjects.

Use of HbA1c to diagnose type 2 diabetes mellitus among high risk Sri Lankan adults

AIM

Even though, glycosylated hemoglobin (HbA1c) was found to be effective in predicting diabetes especially in Caucasians there is limited evidence of its diagnostic utility in high risk Sri Lankan adults. This study aimed to determine the optimal HbA1c cut-off points for detecting diabetes in a high risk population in Sri Lanka.

MATERIALS AND METHODS

This community based study consisted of 254 previously healthy adults with history of diabetes in one or more first-degree relatives. Fasting plasma glucose (FPG) , glucose tolerance test (GTT) and HbA1c were measured in all and GTT was used as a reference to diagnose diabetes. Receiver operating characteristic curve was created to find the optimum HbA1c cut-off value to predict diabetes.

RESULTS

Prevalence of diabetes was 12.2% (n=31) with FPG and 16.1% (n=41) with GTT. Prevalence rose to 27.6% (P<0.01) when HbA1c with cut-off of ≥6.5% was used as the diagnostic test. The ROC curves showed the HbA1c threshold of 6.3% provided the optimum balance between sensitivity (80.5%) and specificity (79%). In compared to GTT, FPG had only a modest sensitivity (65%) in diagnosing diabetes in this high risk population.

CONCLUSION

Our study showed that optimum HbA1C cut-off for detecting diabetes was 6.3% and it had better sensitivity, but lower specificity than FPG. This study further showed that the prevalence of diabetes would become double if HbA1c is used over FPG to screen this high risk population.

Noncommunicable disease in rural India: Are we seriously underestimating the risk? The Nallampatti noncommunicable disease study

AIM

To assess the prevalence of noncommunicable diseases in a true rural farming population in South India and compare the data with the landmark contemporary Indian Council of Medical Research-India Diabetes (ICMR-INDIAB) study.

METHODS

Local Ethics Committee approval and informed consent was obtained from all participants. Inclusion criteria were participants, aged ≥20 and ≤85 years, from Nallampatti, a classical farming village from Tamil Nadu state, India. All participants were administered a detailed questionnaire, had anthropometric measurements including height, weight, and waist circumference. Bloods were drawn for random blood glucose, glycated hemoglobin (HbA1c), nonfasting lipid profile, Cystatin C, uric acid, and hemoglobin. All participants had carotid intima-media thickness (CIMT) done by high-resolution B-mode carotid ultrasound.

RESULTS

More than 50% of the population had either diabetes or prediabetes based on HbA1c. Nearly, 40% of the population had hypertension with suboptimal control in those with known hypertension. Nearly, a third of the population had dyslipidemia, elevated cystatin C levels, and abnormal CIMT. The burden was higher than the comparable ICMR-INDIAB study in rural Tamil Nadu.

CONCLUSION

One-third to one-half of this rural farming population is at risk of cardiovascular disease, with poor control of preexisting cardiovascular risk factors. Current Indian data may underestimate the risk in different ethnic populations and regions of India. Long-term follow-up of this cohort for the incident cardiovascular disease will shed light on the true cardiovascular risk in a typical South Indian rural farming population.

Derivation & validation of glycosylated haemoglobin (HbA 1c ) cut-off value as a diagnostic test for type 2 diabetes in south Indian population

Background & Objectives:

Glycosylated haemoglobin (HbA_1c) has been in use for more than a decade, as a diagnostic test for type 2 diabetes. Validity of HbA_1c needs to be established in the ethnic population in which it is intended to be used. The objective of this study was to derive and validate a HbA_1c cut-off value for the diagnosis of type 2 diabetes in the ethnic population of Rayalaseema area of south India.

Methods:

In this cross-sectional study, consecutive patients suspected to have type 2 diabetes underwent fasting plasma glucose (FPG) and 2 h post-load plasma glucose (2 h-PG) measurements after a 75 g glucose load and HbA_1c estimation. They were classified as having diabetes as per the American Diabetes Association criteria [(FPG ≥7 mmol/l (≥126 mg/dl) and/or 2 h-PG ≥11.1 mmol/l (≥200 mg/dl)]. In the training data set (n = 342), optimum cut-off value of HbA_1c for defining type 2 diabetes was derived by receiver-operator characteristic (ROC) curve method using oral glucose tolerance test results as gold standard. This cut-off was validated in a validation data set (n = 341).

Results:

On applying HbA_1c cut-off value of >6.3 per cent (45 mmol/mol) to the training data set, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for diagnosing type 2 diabetes were calculated to be 90.6, 85.2, 80.8 and 93.0 per cent, respectively. When the same cut-off value was applied to the validation data set, sensitivity, specificity, PPV and NPV were 88.8, 81.9, 74.0 and 92.7 per cent, respectively, although the latter were consistently smaller than the proportions for the training data set, the differences being not significant.

Interpretation & conclusions:

HbA_1c >6.3 per cent (45 mmol/mol) appears to be the optimal cut-off value for the diagnosis of type 2 diabetes applicable to the ethnic population of Rayalaseema area of Andhra Pradesh state in south India.

The 1-hour post-load glucose level is more effective than HbA1c for screening dysglycemia

AIM

To assess the performance of HbA1c and the 1-h plasma glucose (PG ≥ 155 mg/dl; 8.6 mmol/l) in identifying dysglycemia based on the oral glucose tolerance test (OGTT) from a real-world clinical care setting.

METHODS

This was a diagnostic test accuracy study. For this analysis, we tested the HbA1c diagnostic criteria advocated by the American Diabetes Association (ADA 5.7-6.4 %) and International Expert Committee (IEC 6.0-6.4 %) against conventional OGTT criteria. We also tested the utility of 1-h PG ≥ mg/dl; 8.6 mmol/l. Prediabetes was defined according to ADA-OGTT guidelines. Spearman correlation tests were used to determine the relationships between HbA1c, 1-h PG with fasting, 2-h PG and indices of insulin sensitivity and β-cell function. The levels of agreement between diagnostic methods were ascertained using Cohen's kappa coefficient (Κ). Receiver operating characteristic (ROC) curve was used to analyze the performance of the HbA1c and 1-h PG test in identifying prediabetes considering OGTT as reference diagnostic criteria. The diagnostic properties of different HbA1c thresholds were contrasted by determining sensitivity, specificity and likelihood ratios (LR).

RESULTS

Of the 212 high-risk individuals, 70 (33 %) were identified with prediabetes, and 1-h PG showed a stronger association with 2-h PG, insulin sensitivity index, and β-cell function than HbA1c (P < 0.05). Furthermore, the level of agreement between 1-h PG ≥ 155 mg/dl (8.6 mmol/l) and the OGTT (Κ[95 % CI]: 0.40[0.28-0.53]) diagnostic test was stronger than that of ADA-HbA1c criteria 0.1[0.03-0.16] and IEC criteria (0.17[0.04-0.30]). The ROC (AUC[95 % CI]) for HbA1c and 1-h PG were 0.65[0.57-0.73] and 0.79[0.72-0.85], respectively. Importantly, 1-h PG ≥ 155 mg/dl (8.6 mmol/l) showed good sensitivity (74.3 % [62.4-84.0]) and specificity 69.7 % [61.5-77.1]) with a LR of 2.45. The ability of 1-h PG to discriminate prediabetes was better than that of HbA1c (∆AUC: -0.14; Z value: 2.5683; P = 0.01022).

CONCLUSION

In a real-world clinical practice setting, the 1-h PG ≥ 155 mg/dl (8.6 mmol/l) is superior for detecting high-risk individuals compared with HbA1c. Furthermore, HbA1c is a less precise correlate of insulin sensitivity and β-cell function than the 1-h PG and correlates poorly with the 2-h PG during the OGTT.

Standardising HbA1c-based diabetes diagnosis: opportunities and challenges

Globally, the incidence of diabetes mellitus is rising at an alarming rate and has become a health crisis that threatens the economies of all nations. Therefore, diagnosing diabetes has become an important issue in the management of diabetes. Glycated hemoglobin (HbA1c) is now recommended as a means to diagnose diabetes, but its use still has limitations. In this article, the biology, measurement, standardization, and opportunities and challenges of the use of HbA1c to diagnose diabetes are reviewed. More specifically, its use in China and the Asian region is discussed in detail.

Predictive Value of Glycated Hemoglobin and Body Mass Index for Pretreatment Neuropathy in Patients With Multiple Myeloma

BACKGROUND

Peripheral neuropathy (PN) is detected in up to 62% patients with multiple myeloma (MM) at diagnosis. No specific risk factor for pretreatment neuropathy has been identified.

PATIENTS AND METHODS

We evaluated 29 sequential patients with MM attending our tertiary care center for peripheral neuropathy at diagnosis using symptoms, clinical examination, and nerve conduction studies (NCSs). Total Neuropathy Score, reduced (TNSr) and Total Neuropathy Score, clinical (TNSc) were calculated, and a score of ≥ 2 in each scale was considered diagnostic of PN. The study was approved by our institutional review board.

RESULTS

We found that 51.7% (n = 15) and 17.2% (n = 5) of patients had pretreatment neuropathy by TNSr and TNSc scales, respectively. Higher glycated hemoglobin (HbA1C) (P = .022), higher body mass index (BMI) (P = .008), higher serum creatinine levels (P = .023), and higher blood urea levels (P = .006) were associated with neuropathy by TNSr in univariate analysis. Higher blood urea levels (P = .023), higher serum creatinine levels (P = .003), and higher serum β2-microglobulin levels (P = .013) were associated with neuropathy by TNSc in univariate analysis. Higher HbA1c levels (P = .036; odds ratio [OR], 9.46) and BMI (P = .028; OR, 1.78) were associated with neuropathy by TNSr on binomial logistic regression analysis. Cutoffs of 5.6% (sensitivity, 60%; specificity, 71.4%) and 23.7 kg/m(2) (sensitivity, 80%; specificity, 71.4%) were obtained for HbA1c (area under the curve [AUC], 0.75) and BMI (AUC, 0.79), respectively, on receiver operating characteristic (ROC) curve analysis to predict neuropathy. The combination of HbA1c ≥ 5.6% and BMI ≥ 23.7 kg/m(2) had higher odds of neuropathy by TNSr (OR, 27.0; 95% confidence interval [CI], 2.0-368.4) when compared with either factor alone.

CONCLUSION

Use of TNSr, which incorporates electrophysiological abnormalities in addition to clinical manifestations, improves the detection rate of neuropathy. We found that high HbA1c and high BMI together are risk factors for neuropathy at diagnosis in patients with MM.

Unfavorable inflammatory profile in adults at risk of type 2 diabetes identified by hemoglobin A1c levels according to the American Diabetes Association criteria

AIMS

We aimed to evaluate the inflammatory profile of individuals with prediabetes defined by HbA1c levels, according to the new American Diabetes Association criteria, and to determine the ability of HbA1c to identify individuals with subclinical inflammation independently of the contribution of other metabolic parameters such as fasting, 1- or 2-h post-load glucose (PG) levels.

METHODS

High sensitivity C-reactive protein (hsCRP), erythrocyte sedimentation rate (ESR), fibrinogen, white blood cells (WBC) count and complement C3 (C3) were assessed, and oral glucose tolerance test (OGTT) was performed in 711 adults.

RESULTS

Subjects were stratified into three groups according to their HbA1c levels. Poor agreement existed between HbA1c and 2-h PG criteria for identification of individuals with prediabetes (κ coefficient = 0.300). As compared with subjects having HbA1c <5.7 % (39 mmol/mol), individuals with prediabetes (HbA1c 5.7-6.4 %, [39-46 mmol/mol]) exhibited a significant increase of the concentration of five inflammatory markers (hsCRP, ESR, fibrinogen, WBC count, C3) as well as of a cluster of inflammatory markers, as measured by an inflammatory score after adjusting for sex, age, smoking, fasting, 1- and 2-h PG levels. In multiple regression models including sex, age, body mass index, smoking habit, fasting, 1- and 2-h PG levels, and HOMA index, HbA1c levels were significant independent contributors to each of the five inflammatory markers examined.

CONCLUSIONS

These data suggest that HbA1c is a reliable marker of glucose homeostasis, and may identify individuals at increased risk of diabetes with unfavorable inflammatory profile independently from fasting and 2-h PG levels.

Cross-sectional comparison of point-of-care with laboratory HbA₁c in detecting diabetes in real-world remote Aboriginal settings

OBJECTIVES

To determine if point-of-care (POC) glycated haemoglobin (HbA₁c) is sufficiently accurate in real-world remote settings to predict or exclude the diagnosis of diabetes based on laboratory HbA1c measurements.

DESIGN

Cross-sectional study comparing POC capillary HbA₁c results with corresponding venous HbA₁c levels measured in a reference laboratory.

PARTICIPANTS

Aboriginal patients ≥15 years old who were due for diabetes screening at the participating clinics were invited to participate. Two hundred and fifty-five Aboriginal participants were enrolled and 241 were included in the analysis.

SETTING

6 primary healthcare sites in the remote Kimberley region of Western Australia from September 2011 to November 2013.

MAIN OUTCOME MEASURES

Concordance and mean differences between POC capillary blood HbA₁c measurement and laboratory measurement of venous blood HbA₁c level; POC capillary blood HbA1c equivalence value for screening for diabetes or a high risk of developing diabetes; sensitivity, specificity and positive-predictive value for diagnosing and screening for diabetes; barriers to conducting POC testing.

RESULTS

Concordance between POC and laboratory results was good (ρ=0.88, p<0.001). The mean difference was -0.15% (95% limits of agreement, -0.67% to 0.36%). POC HbA₁c measurements ≥6.5%, 48 mmol/mol had a specificity of 98.2% and sensitivity of 73.7% for laboratory measurements ≥6.5%. The POC equivalence value for screening for diabetes or a high risk of developing diabetes was ≥5.7%, 39 mmol/mol (sensitivity, 91%; specificity, 76.7% for laboratory measurements ≥6.0%, 42 mmol/mol). Staff trained by other clinic staff 'on the job' performed as well as people with formal accredited training. Staff reported difficulty in maintaining formal accreditation.

CONCLUSIONS

POC HbA₁c testing is sufficiently accurate to be a useful component in screening for, and diagnosing, diabetes in remote communities. Limited local training is adequate to produce results comparable to laboratory results and accreditation processes need to reflect this.

Comparison of fasting plasma glucose and glycated hemoglobin for diagnosing diabetes in a Taiwanese population

BACKGROUND

The purposes of this study were to examine the impact of using glycated hemoglobin (HbA1c) as a diagnostic criterion for (pre)diabetes and to determine the appropriate HbA1c cutoff value in a Taiwanese population.

METHODS

We used a dataset from the Clinical Informatics Research & Development Center of Taichung Veteran General Hospital. Fasting plasma glucose (FPG) and HbA1c test results were obtained from outpatient laboratory reports produced from January 1, 2011, to April 30, 2012. A total of 4920 blood tests were analyzed. For each potential HbA1c cutoff value, the sensitivity, specificity, positive and negative predictive values, and area under the receiver operator characteristic curve (AUC) were calculated at FPG levels of 100 and 126 mg/dL. Two-sample t- and chi-sqaured tests were used to compare differences in characteristics between individuals matching the definitions of diabetes set by the American Diabetes Association (ADA) in 2009 and 2010.

RESULTS

Among the 4920 study subjects, 580 people had an FPG value < 126 mg/dL and an HbA1c ≥ 6.5%. After the diagnostic criterion of HbA1c percentage was applied, the numbers of patients with normoglycemia and prediabetes decreased, whereas the number of diabetic patients increased. For FPG levels of 100 and 126 mg/dL, the HbA1c cutoff points were 5.95% and 6.35%, respectively.

CONCLUSIONS

More patients were diagnosed with diabetes when HbA1c was added as a diagnostic criterion. HbA1c thresholds of 5.95% and 6.35% were highly specific for prediabetes and diabetes, respectively, in Taiwanese adults.

Performance of glycated haemoglobin (HbA1c) as a screening test for diabetes and impaired glucose tolerance (IGT) in a high risk population--the Brazilian Xavante Indians

AIMS

To examine the properties of HbA1c to detect diabetes and IGT in adult Brazilian Xavante Indians, a high risk population for diabetes.

METHODS

The survey was carried out between October 2010 and January 2012 and based on a 75 g oral glucose tolerance test (OGTT). Basal and 2h capillary glycaemia were measured by HemoCue Glucose 201+; HbA1c using an automated high-performance liquid chromatography analyzer (Tosoh G7).

RESULTS

630 individuals aged ≥ 20 years were examined and 80 had a previous diagnosis of diabetes. Sensitivity, specificity and accuracy for HbA1c ≥ 6.5% (≥ 48 mmol/mol) were 71.3%, 90.5% and 87.2%. The areas under the ROC curve (AUC) was 0.88 (95%CI: 0.83-0.93). To identify IGT, HbA1c values between 5.7% and 6.4% (39-47 mmol/mol) presented sensitivity, specificity and accuracy of 87.2%, 24.7% and 51.4%, with an AUC of 0.62 (95%CI: 0.57-0.67).

CONCLUSIONS

The ADA/WHO proposed cut-off of 6.5% (48 mmol/mol) for HbA1c was adequate to detect diabetes among the Xavante. However, the performance of the ADA proposed cut-off points for pre-diabetes, when used to detect IGT was inadequate and should not be recommended.

Low positive predictive value of hemoglobin A1c for diagnosis of prediabetes in clinical practice

BACKGROUND

Positive predictive value (PPV) of hemoglobin A1c (HbA1c) for diagnosis of prediabetes in clinical practice has not been well studied.

METHODS

In a prospective study, patients diagnosed with prediabetes based on HbA1c (5.7%-6.4%) underwent a 75-g oral glucose tolerance test (OGTT) as the gold standard test to diagnose dysglycemia. Demographics, anthropometrics, comorbidity, concomitant prescription medications and biochemical data were collected.

RESULTS

We identified 66 patients with HbA1c-based prediabetes with a mean HbA1c of 6.00 ± 0.20%. However, based on the OGTT, 32 had normal glucose tolerance (NGT), 26 had prediabetes and 8 had diabetes yielding a PPV of HbA1c of 39.4%. In univariate analysis, the patients with the OGTT-based prediabetes administered more medications for associated medical problems compared with the NGT group (5.9 ± 2.2 versus 2.6 ± 1.8, P < 0.0001). After adjustment for baseline variables, the medication use remained significantly different between OGTT-based prediabetes and NGT groups (P = 0.041).

CONCLUSIONS

PPV of HbA1c for diagnosis of prediabetes in clinical setting is low. Patients with HbA1c of 5.7% to 6.4% should undergo OGTT to confirm diagnosis of dysglycemia.

Screening with HbA1c identifies only one in two individuals with diagnosis of prediabetes at oral glucose tolerance test: findings in a real-world Caucasian population

OBJECTIVE

Discordance between HbA1c and OGTT in screening pre-diabetes may occur because of lack of laboratory standardization, distinct underlying pathophysiological processes or different ethnicity. We evaluated HbA1c efficacy for screening OGTT-defined IFG and IGT conditions in a large Caucasian population using the newly revised IFCC protocol.

RESEARCH DESIGN AND METHODS

A total of 501 consecutive subjects were screened for pre-diabetic conditions with OGTT with 75 g of glucose. Testing for HbA1c, lipid profile and fasting insulin levels was also performed. For detecting differences between continuous variables, ANOVA followed by Tukey's honestly significant difference (HSD) post hoc test was used. Logistic regression and ROC curve analysis were also performed for assessing HbA1c screening efficacy.

RESULTS

ROC curve analysis showed that optimal HbA1c cut-off for detecting IFG was 5.6 % (sensitivity of 78 % and specificity of 63 %), while for IGT, the optimal cut-off was 5.9 % (sensitivity of 46 % and specificity of 84 %), with AUCs < 0.8. Screening with HbA1c identified 53.4 % of the 193 patients with IFG and/or IGT diagnosed at OGTT. As regards surrogate markers of insulin resistance, we observed a trend towards higher values of HOMA-IR and lower QUICKI values in subjects with IFG than in those with IGT. Patients with pre-diabetes at both tests had similar values of HOMA and QUICKI, compared with those with altered OGTT only.

CONCLUSIONS

IFCC-aligned HbA1c assay proved scarcely effective in detecting IFG and/or IGT in a large Caucasian population, identifying only half of the patients with abnormal OGTT. Moreover, adding HbA1c screening to OGTT may be of little benefit in identifying subjects with a worse metabolic profile.

Using hemoglobin A1C as a predicting model for time interval from pre-diabetes progressing to diabetes

OBJECTIVE

The early identification of subjects at high risk for diabetes is essential, thus, random rather than fasting plasma glucose is more useful. We aim to evaluate the time interval between pre-diabetes to diabetes with anti-diabetic drugs by using HbA1C as a diagnostic tool, and predicting it using a mathematic model.

METHODS

We used the Taipei Medical University Affiliated Hospital Patient Profile Database (AHPPD) from January-2007 to June-2011. The patients who progressed and were prescribed anti-diabetic drugs were selected from AHPPD. The mathematical model used to predict the time interval of HbA1C value ranged from 5.7% to 6.5% for diabetes progression.

RESULTS

We predicted an average overall time interval for all participants in between 5.7% to 6.5% during a total of 907 days (standard error, 103 days). For each group found among 5.7% to 6.5% we determined 1169.3 days for the low risk group (i.e. 3.2 years), 1080.5 days (i.e. 2.96 years) for the increased risk group and 729.4 days (i.e. 1.99 years) for the diabetes group. This indicates the patients will take an average of 2.49 years to reach 6.5%.

CONCLUSION

This prediction model is very useful to help prioritize the diagnosis at an early stage for targeting individuals with risk of diabetes. Using patients' HbA1C before anti-diabetes drugs are used we predicted the time interval from pre-diabetes progression to diabetes is 2.49 years without any influence of age and gender. Additional studies are needed to support this model for a long term prediction.

Comparison of fasting plasma glucose and haemoglobin A1c point-of-care tests in screening for diabetes and abnormal glucose regulation in a rural low income setting

AIMS

Glycated haemoglobin (HbA1C) has been suggested to replace glucose tests in identifying diabetes and pre-diabetes. We assessed agreement between fasting plasma glucose (FPG) and HbA1C rapid tests in classifying abnormal glucose regulation (AGR), and their utility for preventive screening in rural Africa.

METHODS

A population-based survey of 795 people aged 35-60 years was conducted in a mainly rural district in Uganda. FPG was measured using On-Call® Plus glucometers, and classified using World Health Organization (WHO) and American Diabetes Association (ADA) criteria. HbA1C was measured using A1cNow® kits and classified using ADA criteria. Body mass index and blood pressure were measured. Percentage agreement between the two tests was computed.

RESULTS

Using HbA1C, 11.3% of participants had diabetes compared with 4.8% for FPG. Prevalence of HbA1C-defined pre-diabetes (26.4%) was 1.2 times and 2.5 times higher than FPG-defined pre-diabetes using ADA (21.8%) and WHO (10.1%) criteria, respectively. With FPG as the reference, agreement between FPG and HbA1C in classifying diabetes status was moderate (Kappa=22.9; Area Under the Curve (AUC)=75%), while that for AGR was low (Kappa=11.0; AUC=59%). However, agreement was high (over 90%) among negative tests and among participants with risk factors for type 2 diabetes (obesity, overweight or hypertension). HbA1C had more procedural challenges than FPG.

CONCLUSIONS

Although low in the general sample, agreement between HbA1C and FPG is excellent among persons who test negative with either test. A single test can therefore identify the majority at lower risk for type 2 diabetes. Nurses if trained can conduct these tests.

Prediabetes: the effects on arterial thickness and stiffness in obese youth

OBJECTIVE

Adults with prediabetes are at increased risk to develop cardiovascular disease. Whether prediabetes in adolescents is associated with early markers of cardiovascular disease is not known. We sought to 1) compare the cardiovascular risk profiles among adolescents and young adults with prediabetes with those with normal glucose tolerance and 2) determine whether prediabetes is independently associated with noninvasive measures of arterial thickness and stiffness.

RESEARCH DESIGN AND METHODS

We studied 102 obese youth with prediabetes and 139 obese youth with normal glucose tolerance in a cross-sectional study. Prediabetes or at increased diabetes risk was diagnosed by a fasting blood glucose level of ≥100 to 125 mg/dL, 2-hour oral glucose tolerance test value of ≥140 to 199 mg/dL, or a hemoglobin A1c (HbA1c) value of ≥5.7% to 6.4%. Arterial thickness and stiffness were measured by carotid intima-media thickness (IMT), augmentation index, pulse wave velocity, and brachial distensibility (BrachD).

RESULTS

Nearly 50% of youth were diagnosed with prediabetes by HbA1c. Youth with prediabetes had worse metabolic profiles with higher BMI z score, systolic blood pressure, and fasting insulin; increased carotid IMT; and lower BrachD compared with normal glucose-tolerant youth (P < .05). Multivariate regression analysis found prediabetes was a significant determinant of internal carotid IMT and BrachD (P < .05). After excluding youth diagnosed by HbA1c, the prediabetes group was borderline significant for internal carotid IMT (.1 > P ≥ .05) only.

CONCLUSIONS

Youth with prediabetes have worse cardiometabolic risk factors and evidence of increased arterial thickness and stiffness. Interventions to prevent prediabetes are crucial to reduce the development of early arterial disease.

Addressing a growing community's health needs: project SAHNA (South Asian Health Needs Assessment)

Limited data and research is available on the health issues faced by the South Asian population, especially for those living in the Washington, DC metropolitan area. Online and in-person surveys were administered to a convenience sample (n = 709) of South Asians living in the metropolitan Washington DC region. The survey gathered information on socio-demographics and acculturation; health care access and utilization; sources of health information; perceptions of community health; physical activity and smoking. While over 70% of participants had a routine physical exam in the last 12 months, foreign born and less acculturated adults were less likely to have had a routine visit in the last 12 months. Internet (76.9%) and physicians (76.1%) are key sources of health information for South Asians. Only 29% of South Asians are engaging in the recommended amount of physical activity per week. The results of this study provide guidance for future work in addressing the health and well-being of South Asian communities in the United States.

Evaluation of HbA1c criteria for diagnosis of diabetes mellitus: a retrospective study of 12 785 type 2 Saudi male patients

Recently, American Diabetic Association has recommended glycated hemoglobin (HbA1c ≥6.5%) as an alternate to fasting plasma glucose (FPG ≥7.0 mmol/L) for diagnosis of diabetes. However, studies from different groups showed inconsistent results with the use of HbA1c criteria. We examined the validity of HbA1c cut-point of 6.5% for diagnosis of diabetes. A total of 12 785 male diabetic patients (FGP ≥7.0 mmol/L), aged 56.27 ± 13.32 years were included. The average values of FPG and HbA1c of all the 12 785 patients were 10.127 ± 0.026 mmol/L and 8.729 ± 0.013%, respectively. Sub-grouping of patients into different age categories showed significantly high levels of FPG (10.934 ± 0.123 mmol/L) in the youngest group (age, ≥20-35 years) as compared to FPG (ranged from 10.021 ± 0.052 to 10.190 ± 0.050 mmol/L) in patients with other age categories. The level of HbA1c was highest in the youngest group (8.809 ± 0.056%) and lowest in the oldest group (8.653 ± 0.082%). There was a significant correlation between FPG and HbA1c (R = 0.571, p < 0.001). There were 484 patients below the diagnostic threshold (HbA1c <6.5%), resulting in 3.78% false negative predictions. Majority of the false negative patients were in the age group of 40-75 years and had borderline FPG (7.0-8.0 mmol/L) and HbA1c (6.0-6.5%). These findings suggest that Saudi individuals with HbA1c between 6.0% and 6.5% may be considered as "probable diabetic" and their status should be verified by combined FPG and HbA1c criteria.

Elevated HbA1c and fasting plasma glucose in predicting diabetes incidence among older adults: are two better than one?

OBJECTIVE

To determine which measures-impaired fasting glucose (IFG), elevated HbA1c, or both-best predict incident diabetes in older adults.

RESEARCH DESIGN AND METHODS

From the Health, Aging, and Body Composition study, we selected individuals without diabetes, and we defined IFG (100-125 mg/dL) and elevated HbA1c (5.7-6.4%) per American Diabetes Association guidelines. Incident diabetes was based on self-report, use of antihyperglycemic medicines, or HbA1c ≥6.5% during 7 years of follow-up. Logistic regression analyses were adjusted for age, sex, race, site, BMI, smoking, blood pressure, and physical activity. Discrimination and calibration were assessed for models with IFG and with both IFG and elevated HbA1c.

RESULTS

Among 1,690 adults (mean age 76.5, 46% men, 32% black), 183 (10.8%) developed diabetes over 7 years. Adjusted odds ratios of diabetes were 6.2 (95% CI 4.4-8.8) in those with IFG (versus those with fasting plasma glucose [FPG] <100 mg/dL) and 11.3 (7.8-16.4) in those with elevated HbA1c (versus those with HbA1c <5.7%). When FPG and HbA1c were considered together, odds ratios were 3.5 (1.9-6.3) in those with IFG only, 8.0 (4.8-13.2) in those with elevated HbA1c only, and 26.2 (16.3-42.1) in those with both IFG and elevated HbA1c (versus those with normal FPG and HbA1c). Addition of elevated HbA1c to the model with IFG resulted in improved discrimination and calibration.

CONCLUSIONS

Older adults with both IFG and elevated HbA1c have a substantially increased odds of developing diabetes over 7 years. Combined screening with FPG and HbA1c may identify older adults at very high risk for diabetes.

Current concepts in blood glucose monitoring

Blood glucose monitoring has evolved over the last century. The concept of adequate glycemic control and minimum glycemic variability requires an ideal, accurate and reliable glucose monitoring system. The search for an ideal blood glucose monitoring system still continues. This review explains the various blood glucose monitoring systems with special focus on the monitoring systems like self- monitored blood glucose (SMBG) and continuous glucose monitoring system (CGMS). It also focuses on the newer concepts of blood glucose monitoring and their incorporation in routine clinical management of diabetes mellitus.

Evaluation of performance of A1c and FPG tests for screening newly diagnosed diabetes defined by an OGTT among tuberculosis patients-a study from India

AIM

The methods used for diagnosis of diabetes have limitations particularly in situations associated with stress hyperglycemia. Aim of this study was to evaluate the performance of A1c and fasting plasma glucose (FPG) tests for screening newly diagnosed diabetes (NDD) defined by OGTT among tuberculosis (TB) cases in India.

METHODS

A total of 983 subjects aged ≥18 years with TB were selected from 7 TB units - 4 urban, 2 rural and 1 semi-urban areas of Tamil Nadu, India, during August 2010-March 2011. Screening for diabetes was carried out by 2-h 75g OGTT. Classification of glucose intolerance status was based on WHO criteria. HbA1c was measured by high performance liquid chromatography using Bio-Rad turbo machine. HbA1c≥47.5mmol/mol was used for diagnosis of diabetes. FPG was estimated by glucose-oxidase method. Known cases of subjects with diabetes were excluded and final analysis was done using data of 779 individuals. The performance of A1c and FPG tests was evaluated against the results of OGTT using receiver operating characteristic curve analysis.

RESULTS

Prevalence of NDD was 10.8%. The areas under the curve (AUC) were 0.754 [95% confidence interval (CI) 0.68-0.83] (p<0.001) for A1c and 0.662 (95% CI 0.58-0.74) for FPG (p<0.001) in NDD subjects. The HbA1c cut-off point of ≥47.5mmol/mol gave a sensitivity of 59.1% and specificity of 91.7%, and the respective values were 34.8% and 97.5% for FPG in subjects with NDD.

CONCLUSION

HbA1c performed better than FPG as a screening tool for newly diagnosed diabetes among subjects with TB.

The diagnostic threshold of HbA1c and impact of its use on diabetes prevalence-a population-based survey of 6898 Han participants from southern China

OBJECTIVE

The objective of this study is to determine the diagnostic threshold of HbA1c for diabetes and the impact of using it on diabetes prevalence.

METHODS

A population-based stratified study was conducted in 2010 among community-dwelling adults aged ≥35years in southern China. Participants without previously-diagnosed diabetes (PDD) took oral glucose tolerance test (OGTT) and HbA1c assay. HbA1c diagnostic threshold was determined by receiver operating characteristic curve.

RESULTS

A total of 6989 participants with mean age of 52years were recruited. The area under curve of HbA1c was 0.903 (95% CI: 0.883-0.922), with optimal cut-off value at 6.25% (sensitivity 75.6% and specificity 91.9%). There were 449 (6.42%) patients with PDD and 422 (6.04%), 815 (11.66%) and 918 (13.13%) new cases diagnosed by OGTT, HbA1c ≥6.25% or either, respectively. When either HbA1c or OGTT was used, newly-diagnosed diabetes prevalence increased by 117.4%.

CONCLUSIONS

Diabetes is prevalent in southern China. Near half of the patients go undetected with current diagnostic criteria. HbA1c ≥6.25% may be the diagnostic threshold value but needs further verification. The introduction of HbA1c threshold into diabetes diagnosis in China will cause a substantial increase in diabetes prevalence and great challenge on the public healthcare system.

The usefulness of glycated hemoglobin A1c (HbA1c) for identifying dysglycemic states in individuals without previously diagnosed diabetes

PURPOSE

We investigated HbA1c's validity as a screening parameter for excluding dysglycemic states in the studied population.

MATERIAL/METHODS

Sensitivity and specificity of HbA1c in some cut-off points were compared with diagnoses based on the oral glucose tolerance test (OGTT) in individuals diagnosed between 2009-2010. Receiver operating characteristic (ROC) analysis for HbA1c was conducted. HbA1c and OGGT measures were done in 441 people (253 women, 187 men, average age 40.1 years (18-79 years)). Based on the OGGT test 37 individuals were diagnosed as diabetic, 28 as impaired glucose tolerant (IGT) and 63 as having impaired fasting glycemia (IFG).

RESULTS

A cut-off value of 6.5% HbA1c classifies diabetic subjects with a sensitivity of 45.9% and specificity of 97.5%. In the investigated population the best cut-off point (the highest sum of the sensitivity and specificity) was 5.9% HbA1c (sensitivity 86.6%, specificity 73%). HbA1c values excluding the risk of dysglycemic states have shown false negative rate in 31.9% when HbA1c was 5.5% and 10.6% when HbA1c was 5.0%.

CONCLUSIONS

Our results indicate that in the investigated population the evaluation of the prevalence of type 2 diabetes using HbA1c values proposed by the American Diabetes Association (ADA) has unsatisfactory sensitivity and detects less than a half of cases of diabetes based on the OGTT diagnoses. HbA1c 5.7% does not have sufficient specificity to identify individuals not being at risk of any disorder of glucose metabolism.

Prevalence of diabetes in Malaysia and usefulness of HbA1c as a diagnostic criterion

AIM

The prevalence of diabetes mellitus among Malaysians aged ≥ 30 years of age has increased by more than twofold over a 20-year period. This study aimed to determine the current status and to evaluate the diagnostic usefulness of the HbA(1c) cut-off point of 48 mmol/mol (6.5%).

METHODS

Using a two-stage stratified sampling design, participants aged ≥ 18 years were recruited from five zones selected to represent Malaysia. An oral glucose tolerance test was performed on all those not known to have diabetes.

RESULTS

A total of 4341 subjects were recruited. By World Health Organization criteria, the prevalence of diabetes mellitus was 22.9%; of that percentage, 10.8% was known diabetes and 12.1% was newly diagnosed diabetes. Diabetes was most prevalent amongst Indians (37.9%) and Malays (23.8%). Prevalence of new diabetes mellitus was only 5.5% (95% CI 4.9-6.3) when based on the HbA(1c) diagnostic criteria of 48 mmol/mol (6.5%) and, although the cut-off point was highly specific (98.1%), it was less sensitive (36.7%) compared with 45 mmol/mol (6.3%), which showed the optimal sum of sensitivity (42.5%) and specificity (97.4%) in identifying new diabetes mellitus.

CONCLUSION

This study recorded an overall diabetes prevalence of 22.6%, almost a twofold increase from 11.6% reported in 2006. This was likely attributable to the higher prevalence of new diabetes (12.1%) diagnosed following an oral glucose tolerance test. An HbA(1c) of 45 mmol/mol (6.3%) was found to be a better predictive cut-off point for detecting new diabetes in our multi-ethnic population.

Diagnostic accuracy of HbA1c in diabetes between Eastern and Western

BACKGROUND

In 2010, the American Diabetes Association recommended the use of HbA1c as a diagnostic criterion for diabetes. However, HbA1c is not an accepted diagnostic tool for diabetes in Eastern Asia, because genetic differences compromise the standardization of the diagnostic cut-off point.

OBJECTIVES

This study evaluated differences in the use of HbA1c for diagnosing diabetes in Eastern and Western populations and investigated whether HbA1c cut-off point of ≥ 6.5% is diagnostic of diabetes in patients from Eastern Asia.

METHODS

Literature was obtained from MEDLINE, EMBASE and Cochrane databases. The pooled sensitivity and specificity of each HbA1c cut-off point were extracted and compared between Western and Eastern populations. Differences in the cut-off point for diagnosing diabetes in each region were compared by examining differences in the area under summary receiver operating characteristic (SROC) curves.

RESULTS

Twelve publications from Eastern countries (n = 59,735) and 13 from Western countries (n = 22,954) were included in the analysis. Areas under SROC curves in the Eastern and Western groups were 0.9331 and 0.9120, respectively (P = 0.98). The cut-off point of the highest Youden index was 6.0%. At the HbA1c cut-off point of 6.5%, the pooled sensitivity and specificity were 58.7% and 98.4% for Eastern countries and 65.5% and 98.1% for Western countries, respectively.

CONCLUSIONS

HbA1c exhibits the same diagnostic value for diabetes in Eastern and Western populations. In both populations, HbA1c levels > 6.0% identify the population at high risk of diabetes, and HbA1c > 6.5% is diagnostic of clinically established diabetes.

Screening South Asians for type 2 diabetes and prediabetes: (1) comparing oral glucose tolerance and haemoglobin A1c test results and (2) comparing the two sets of metabolic profiles of individuals diagnosed with these two tests

BACKGROUND

The glycated haemoglobin A1c (HbA1c) level may be used for screening for type 2 diabetes and prediabetes instead of a more burdensome oral glucose tolerance test (OGTT). However, among the high-risk South Asian population, little is known about the overlap of the methods or about the metabolic profiles of those disconcordantly diagnosed.

METHODS

We included 944 South Asians (18-60 years old), whom we screened with the HbA1c level and the OGTT in The Hague, the Netherlands. We calculated the area under the receiver-operator characteristic curve (AUROC) with a 95% confidence interval of HbA1c using the American Diabetes Association classifications, and determined the sensitivity and specificity with 95% confidence intervals at different thresholds. Moreover, we studied differences in metabolic characteristics between those identified by HbA1c and by the OGTT alone.

RESULTS

The overlap between HbA1c and OGTT classifications was partial, both for diabetes and prediabetes. The AUROC of HbA1c for OGTT defined diabetes was 0.86 (0.79-0.93). The sensitivity was 0.46 (0.29-0.63); the specificity 0.98 (0.98-0.99). For prediabetes, the AUROC was 0.73 (0.69-0.77). Each of the 31 individuals with diabetes and 353 with prediabetes identified with the HbA1c level had a high body mass index, large waist circumference, high blood pressure, and low insulin sensitivity, all of which were similar to the values shown by those among the 19 with diabetes or 62 with prediabetes who only met the OGTT criteria, but not the HbA1c criteria.

CONCLUSIONS

The HbA1c level identified a partially different group than the OGTT did. However, both those identified with the HbA1c level and those identified with the OGTT alone were at increased metabolic risk.

TRIAL REGISTRATION

Dutch Trial Register: NTR1499.