Vitamin D deficiency is associated with ankle-brachial index but not arterial stiffness in an elderly community-dwelling Chinese population

Objective: Increased arterial stiffness, a sub-clinical symptom of target organ damage, has been associated with vitamin D deficiency. This study aimed to investigate the associations between total serum vitamin D level, arterial stiffness and atherosclerosis in a Chinese community-dwelling elderly population. Design and method: Study participants (n = 175; age range 60–100 (median 87) years; 91 males) were recruited from a community-dwelling elderly Chinese cohort. The levels of total serum 25-hydroxyvitamin D [25(OH)D], blood glucose, lipids and pressure were determined with clinical tests. Arterial stiffness was assessed with brachial ankle pulse wave velocity (baPWV), and the atherosclerosis status was evaluated with the ankle brachial index (ABI). Results: Vitamin D deficiency (< 30 ng/ml) was found in 87.4% of the cohort studied. For these subjects, total 25(OH)D was positively correlated with right (r = 0.230, p = 0.004) and left ABI (r = 0.212, p = 0.008), whereas there was no correlation with right and left baPWV (r = -0.136 and r = -0.137, p = 0.092 and p = 0.089, respectively). In univariate linear regression, age (standardized β = -0.158, p = 0.049) and calcium (standardized β = 0.211, P = 0.016) were significantly associated with right ABI but not left ABI in patients with vitamin D deficiency, whereas total serum 25(OH)D was positively associated with left (standardized β = 0.195, P = 0.025) and right ABI (standardized β = 0.094 P = 0.022) level. Multivariate regression suggested that total serum 25(OH)D was also independently correlated with left and right ABI with adjustment for sex, age and diastolic blood pressure. No significant association between total serum 25(OH)D level and the baPWV was found. Conclusions: The study suggested that serum total 25(OH) D may be favorably associated with ABI in the elderly population with vitamin D deficiency; however, in the elderly, it may not be correlated with arterial stiffness as measured by baPWV. More prospective larger scale studies are required to provide confirmation and validation of these findings in elderly populations.