Hemoglobin A1c can identify more cardiovascular and metabolic risk profile in OGTT-negative Chinese population

Objective: To investigate the significance of hemoglobin A1c (HbA1c) in cardiovascular and metabolic risk stratification among diabetes and non-diabetes in southern Chinese.

Methods: Indigenous adults (aged more than or equal to 35 years) without known diabetes were enrolled in the cross-sectional survey. According to oral glucose tolerance test (OGTT), participants were categorized into OGTT-negative group and OGTT-positive group. Cardiovascular and metabolic risk profile was compared between different HbA1c levels (≥ 6.5% vs. < 6.5%) in each group.

Results: The prevalence of OGTT-diagnosed diabetes was 6.45% (422/6540). In OGTT-negative group, subjects with HbA1c ≥ 6.5% were older, had higher prevalence of coronary heart disease, current smoking, hypertension, obesity and abdominal obesity. They also had higher body weight, waist-hip ratio, body mass index, glucose levels (fasting plasma glucose, 2-hour plasma glucose and HbA1c), and lipid levels (total cholesterol and low density lipoprotein cholesterol). In OGTT-positive group, patients with HbA1c ≥ 6.5% identified less cardiovascular and metabolic risk file than that in OGTT-negative group.

Conclusions: Subjects with HbA1c ≥ 6.5% have more unfavorable cardiovascular and metabolic risk profile than those with HbA1c < 6.5%, especially in OGTT-negative population. More attention should be paid to this subgroup in clinical practice.