Association of hemoglobin A(1c) and glycated albumin with carotid atherosclerosis in community-dwelling Japanese subjects: the Hisayama Study

BACKGROUND: It is not clear which glucose measure is more useful in the assessment of atherosclerosis. We investigated the associations of hemoglobin A(1c) (HbA(1c)), glycated albumin (GA), 1,5-anhydroglucitol (1,5-AG), fasting plasma glucose (FPG), and 2-hour postload glucose (PG) with carotid intima-media thickness (IMT) in community-dwelling Japanese subjects. METHODS: A total of 2702 subjects aged 40–79 years underwent a 75-g oral glucose tolerance test and measurements of HbA(1c), GA, 1,5-AG, and carotid IMT by ultrasonography in 2007–2008. Carotid wall thickening was defined as a maximum IMT of >1.0 mm. The crude and multivariable-adjusted linear and logistic regression models were used to analyze cross-sectional associations between levels of glycemic measures and carotid IMT. RESULTS: The crude average of the maximum IMT increased significantly with rising quartiles of HbA(1c), GA, FPG, and 2-hour PG levels in subjects with and without glucose intolerance (GI), while no clear association was observed for 1,5-AG. After adjustment for other confounding factors, positive trends for HbA(1c), GA, and FPG (all p for trend < 0.05), but not 2-hour PG (p = 0.07) remained robust in subjects with GI, but no such associations were found in those without GI. When estimating multivariable-adjusted β values for the associations of 1 SD change in glycemic measures with the maximum IMT in subjects with GI, the magnitude of the influence of HbA(1c) (β = 0.021), GA (β = 0.024), and FPG (β = 0.024) was larger than that of 2-hour PG (β = 0.014) and 1,5-AG (β = 0.003). The multivariable-adjusted odds ratios for the presence of carotid wall thickening increased significantly with elevating HbA(1c), GA, and FPG levels only in subjects with GI (all p for trend < 0.001). Among subjects with GI, the area under the receiver operating characteristic curve significantly increased by adding HbA(1c) (p = 0.04) or GA (p = 0.04), but not 1,5-AG, FPG, or 2-hour PG, to the model including other cardiovascular risk factors. CONCLUSIONS: In community-dwelling Japanese subjects with GI, elevated HbA(1c), GA, and FPG levels were significantly associated with increased carotid IMT, and HbA(1c) and GA provided superior discrimination for carotid wall thickening compared to 1,5-AG, FPG, and 2-hour PG, suggesting that HbA(1c) and GA are useful for assessing carotid atherosclerosis. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12933-015-0247-7) contains supplementary material, which is available to authorized users.