Additional role of serum 25-hydroxyvitamin D3 levels in atherosclerosis in Chinese middle-aged and elderly men.

1. Perturbed serum vitamin D levels have been shown to be associated with increased risk of cardiovascular disease. The aim of the present study was to investigate the association of serum 25-hydroxyvitamin D3 (25(OH)D3) levels and B ultrasonography-detected carotid plaque and carotid intima-media thickness (C-IMT) in Chinese middle-aged and elderly men. 2. In all, 1001 men, aged 45-78 years, were enrolled in the study. Increased C-IMT was defined as any C-IMT value in the highest quartile of the study subjects (≥ 0.75 mm). 3. The study population had a median serum 25(OH)D3 level of 14.51 ng/mL (interquartile range (IQR) 10.84-18.67 ng/mL). Subjects with carotid plaques had lower serum 25(OH)D3 levels than those without (13.80 (IQR 10.82-17.68) vs 14.74 (IQR 10.87-19.08) ng/mL, respectively; P = 0.029), and decreasing serum 25(OH)D3 levels were accompanied by increased C-IMT in both groups (13.24 (IQR 9.91-16.81) vs 14.45 (IQR 11.40-18.51) ng/mL, respectively (P < 0.05) in those with plaque; 13.80 (IQR 9.99-17.09) vs 14.99 (IQR 11.17-19.43) ng/mL, respectively (P < 0.01) in those without plaque). Multivariate logistic regression analysis showed that serum 25(OH)D3 levels were independently associated with carotid plaque (odds ratio (OR) 0.972; 95% confidence interval (CI) 0.946-0.998; P = 0.032). In addition, serum 25(OH)D3 levels were identified as an independent protective factor for increased C-IMT among subjects with plaque (OR 0.900; 95% CI 0.849-0.955; P = 0.001) and those without plaque (OR 0.944; 95% CI 0.908-0.981; P = 0.004). 4. Collectively, these findings suggest that serum 25(OH)D3 levels are inversely associated with atherosclerosis in Chinese middle-aged and elderly men.