Isolated HbA1c identifies a different subgroup of individuals with type 2 diabetes compared to fasting or post-challenge glucose in Asian Indians: The CARRS and MASALA studies.

AIMS: Guidelines recommend hemoglobin A1c (HbA1c) as a diagnostic test for type 2 diabetes, but its accuracy may differ in certain ethnic groups. METHODS: The prevalence of type 2 diabetes by HbA1c, fasting glucose, and 2 h glucose was compared in 3016 participants from Chennai and Delhi, India from the CARRS-2 Study to 757 Indians in the U.S. from the MASALA Study. Type 2 diabetes was defined as fasting glucose ≥ 7.0 mmol/L, 2-h glucose ≥ 11.1 mmol/L, or HbA1c ≥ 6.5%. Isolated HbA1c diabetes was defined as HbA1c ≥ 6.5% with fasting glucose < 7.0 mmol/L and 2 h glucose < 11.1 mmol/L. RESULTS: The age, sex, and BMI adjusted prevalence of diabetes by isolated HbA1c was 2.9% (95% CI: 2.2-4.0), 3.1% (95% CI: 2.3-4.1), and 0.8% (95% CI: 0.4-1.8) in CARRS-Chennai, CARRS-Delhi, and MASALA, respectively. The proportion of diabetes diagnosed by isolated HbA1c was 19.4%, 26.8%, and 10.8% in CARRS-Chennai, CARRS-Delhi, and MASALA respectively. In CARRS-2, individuals with type 2 diabetes by isolated HbA1c milder cardio-metabolic risk than those diagnosed by fasting or 2-h measures. CONCLUSIONS: In Asian Indians, the use of HbA1c for type 2 diabetes diagnosis could result in a higher prevalence. HbA1c may identify a subset of individuals with milder glucose intolerance.

Convergence of non-communicable diseases and tuberculosis: a two-way street?

The intersection of tuberculosis (TB) with non-communicable diseases (NCDs), including diabetes mellitus (DM), chronic lung disease (CLD), and cardiovascular disease (CVD), has emerged as a critical clinical and public health challenge. Rapidly expanding NCD epidemics threaten TB control in low- and middle-income countries, where the prevention and treatment of TB disease remain a great burden. However, to date, the notion that TB may adversely impact NCD risk and severity has not been well explored. This review summarizes biomedical hypotheses, findings from animal models, and emerging epidemiologic data related to the progression of DM, CLD and CVD during and after active TB disease. We conclude that there is sufficient empirical evidence to justify a greater research emphasis on the syndemic interaction between TB and NCD.

Ethnic Variations in Diabetes and Prediabetes Prevalence and the roles of Insulin Resistance and ß-cell Function: The CARRS and NHANES Studies.

AIMS: It is unclear how the prevalence of diabetes in Asian Indians in urban India compares to that of race/ethnic groups in the US that may have different underlying susceptibilities. Therefore we examined ethnic variations in the prevalence of type 2 diabetes, iIFG, iIGT, IFG+IGT, and the associated risk factors in Asian Indians in Chennai, India, and Whites, Blacks, and Hispanics in the United States. METHODS: Cross-sectional analyses, using representative samples of 4,867 Asian Indians aged 20-74 years from Chennai, India in the Centre for Cardiometabolic Risk Reduction in South-Asia study (CARRS) (2010-2011) and 6,512 US Whites, Blacks, and Hispanics aged 20-74 years from the National Health and Nutrition Examination Survey (NHANES) (2007-2012). RESULTS: The age-adjusted prevalence of type 2 diabetes was highest in Asian Indians (men; 29.0, 95% CI: 25.9, 31.0), women; (30.6, 95% CI, 27.5, 33.9)) and lowest in Caucasians (men; 12.2, 95% CI, 10.3, 14.4), women; 9.5 (7.9, 11.5). Asian Indians had the lowest prediabetes prevalence (men; 19.0 (17.2, 20.8); women 27.2, 95% CI, 22.8, 32.1)) and Caucasians had the highest (men; 46.5 (43.5, 49.6), women; 34.4, 95% CI, 31.7, 37.3). However, there were differences in prediabetes prevalence by gender and prediabetes state. The inclusion of HOMA-ß in standardized polytomous logistic regression models resulted in a greater odds of diabetes in Blacks and Hispanics compared to Asian Indians. CONCLUSIONS: The high prevalence of diabetes in Asian Indians may be due to innate susceptibilities for ß-cell dysfunction in this high risk population.