Association between serum 25-hydroxyvitamin D and carotid atherosclerotic plaque in Chinese type 2 diabetic patients

In this study, we investigated the distribution of vitamin D and its association with carotid atherosclerotic plaque (CP) in Chinese type 2 diabetic (T2D) patients. We performed a cross-sectional study in 210 T2D and 94 age-and gender-matched nondiabetic patients during winter months, by determining serum 25-hydroxyvitamin D (25(OH) D) levels in both diabetic and nondiabetic controls. We carried out measurements of B-mode ultrasonography of carotid arteries in each T2D patient. The 25(OH) D concentration was 26.25 nmol/L among the T2D patients. About 93.3% T2D patients suffered from hypovitaminosis D. First, we found a clear inverse correlation between the 25(OH) D concentration and CP (P<0.001). Second, an association between 25(OH) D and macrovascular disease was significant (P=0.005). In multivariate logistic regression analysis, decreasing 25(OH) D concentration was markedly associated with CP in T2D patients. Third, after adjusting for the confounding factors, we also observed a positive correlation between low levels of 25(OH) D in T2D patients with CP, when the following parameters were measured: old age (odds ratio [OR]=2.533, P=0.013); smoking (OR=3.872, P=0.001); and high level of low-density lipoprotein (LDL) cholesterol (OR=2.776, P=0.009).Thus, we concluded that high prevalence of hypovitaminosis D exists in Chinese T2D patients. Further, we found a significant association between low concentration of serum 25(OH) D and the existence of high body mass index, and high circulating LDL to be substantially positive predictors of patients with CP in T2D.