Low 25-Hydroxyvitamin D Level Is Associated with Peripheral Arterial Disease in Type 2 Diabetes Patients

Patients with type 2 diabetes have an increased risk of atherosclerosis and vascular disease. Vitamin D deficiency is associated with vascular disease and is prevalent in diabetes patients. We undertook this study to determine the association between 25-hydroxyvitamin D (25[OH]D) levels and prevalence of peripheral arterial disease (PAD) in type 2 diabetes patients.

A total of 1028 type 2 diabetes patients were recruited at Nanjing Medical University Affiliated Nanjing Hospital from November 2011 to October 2013. PAD was defined as an ankle-brachial index (ABI) < 0.9. Cardiovascular risk factors (blood pressure, HbA1c, lipid profile), comorbidities, carotid intima-media thickness (IMT) and 25(OH)D were assessed.

Overall prevalence of PAD and of decreased 25(OH)D (<30 ng/mL) were 20.1% (207/1028) and 54.6% (561/1028), respectively. PAD prevalence was higher in participants with decreased (23.9%) than in those with normal (15.6%) 25(OH)D (≥30 ng/mL, p <0.01). Decreased 25(OH)D was associated with increased risk of PAD (odds ratio [OR], 1.69, 95% CI: 1.17-2.44, p <0.001) and PAD was significantly more likely to occur in participants ≥65 years of age (OR, 2.56, 95% CI: 1.51 -4.48, vs. 1.21, 95% CI: 0.80-1.83, p-interaction = 0.027). After adjusting for known cardiovascular risk factors and potential confounding variables, the association of decreased 25(OH)D and PAD remained significant in patients <65 years of age (OR, 1.55; 95% CI: 1.14-2.12, p = 0.006).

Low serum 25(OH)D levels were significantly associated with a higher prevalence of PAD in type 2 diabetes patients <65 years of age. It may increase the risk of PAD independent of other known cardiovascular risk factors.