Context: The association between hyperglycemic markers and cardiovascular risk is not consistent in nondiabetic subjects. Even less are the data regarding the associations in subjects with normal glucose tolerance (NGT).
Objective: Our objective was to assess the association of glycated hemoglobin A1c (HbA1c), fasting plasma glucose (FPG), and 2-h postchallenge glucose with carotid intima-media thickness (CIMT) in subjects with NGT.
Design, participants and measurements: This cross-sectional study included 1627 participants with NGT and aged 40 yr and above, who were randomly recruited from Songnan Community, Baoshan District, Shanghai. All participants received a 75-g oral glucose tolerance test, blood HbA1c assay, and CIMT measurements.
Results: Using multivariable linear regression, after adjustment for age, sex, smoking and drinking status, body mass index, blood pressure, and serum lipids, the increasing trend of CIMT was found in HbA1c quartiles (P = 0.016) rather than in FPG and postchallenge glucose quartiles. Furthermore, in a fully adjusted logistic model including FPG and postchallenge glucose as covariates, participants in the highest quartile of HbA1c, as compared with those in the lowest quartile, still conferred a 68% increased odds of elevated CIMT (≥ 0.70 mm).
Conclusions: In the population of NGT, HbA1c is significantly associated with CIMT independent of conventional cardiovascular risk factors, FPG, and postchallenge glucose. The results implied that HbA1c could be more informative of cardiovascular risk as compared with FPG and postchallenge glucose in subjects with NGT.