Association of glycated hemoglobin with carotid intimal medial thickness in Asian Indians with normal glucose tolerance

Aim: To assess the association of glycated hemoglobin (HbA1c) levels with carotid intimal medial thickness (CIMT) in Asian Indians with normal glucose tolerance (NGT). Methods: Subjects with NGT were recruited from the Chennai Urban Rural Epidemiology Study carried out on a representative population of Chennai, South India. All subjects had fasting plasma glucose <100 mg/dl (5.6 mmol/l) and 2-h post load plasma glucose <140 mg/dl (7.8 mmol/l). HbA1c was measured using the Biorad Variant machine. CIMT was measured on the right common carotid artery using high-resolution B-mode ultrasonography. Results: The study group included 1383 NGT subjects, of whom 760 (54.9%) were women. The mean CIMT value in the 1st quartile of HbA1c (<5.2%) was 0.65 and it increased significantly to 0.73 in the last quartile of HbA1c (>5.8) (p<0.001). Regression analysis showed that HbA1c had a strong association with CIMT after adjusting for age, gender, waist circumference, systolic and diastolic blood pressure. LDL cholesterol, serum triglycerides. HOMA-IR and smoking (beta - 0.046, p=0.047). Conclusion: Even among subjects with NGT, there is a significant increase in CIMT with increasing levels of HbA1c, showing the value of using HbA1c for diagnosis of glucose intolerance. (C) 2012 Elsevier Inc. All rights reserved.