1813-LB: Serum 25-hydroxyvitamin D Levels in Relation to the Risk of Diabetic Foot Ulcer in Chinese Patients with Type 2 Diabetes

Vitamin D deficiency is not only related to bone-related diseases but also associated with cardiovascular disease, diabetes, cancer and autoimmune diseases. Previous studies show that vitamin D deficiency increases risk of macrovascular diseases and different type of infections in patients with diabetes. Data on the relationship between vitamin D and diabetic foot ulcer (DFU) is limited among Chinese patients with type 2 diabetes. In this retrospective cross-sectional study, we enrolled 5483 patients (2378 men and 3105 women aged 30 to 89 yrs) with type 2 diabetes at Qingdao Endocrine and Diabetes Hospital from Jan 1, 2017 to Oct 31, 2019. Serum 25-hydroxyvitamin D (25(OH)D) level was measured by electrochemiluminescence assay. Vitamin D deficiency was defined as Serum 25(OH)D level < 20 ng/mL according to the Endocrine Society Clinical Practice Guideline 2011. DFU was diagnosed according to guidelines on the diagnosis and treatment of foot infection in persons with diabetes (IWGDF 2019).The prevalence of DFU was 8.1% in this cohort. Patients with DFU had lower serum 25(OH)D concentration (15.33±4.51 ng/mL v.s 18.54±3.82 ng/mL, P<0.05) compared with those without DFU. The prevalence of vitamin D deficiency was higher in patient with DFU than those without the complication (84.5% v.s 70.1%, P<0.05). We did not find gender difference on the prevalence of vitamin D deficiency. In the logistical regression model, vitamin D deficiency was associated with increased risk of DFU, after adjustment of age, gender, duration of diabetes, smoking, body mass index, systolic blood pressure, fasting glucose, HbA1c, fasting C-peptide, and total cholesterol, the corresponding odds ratio (95% CI) was 1.36 (1.01-3.37) (P<0.05). Vitamin D deficiency, a common hypovitaminosis in Chinese patients with type 2 diabetes, is independently associated with increased risk for DFU. Whether vitamin D supplementation improves healing of DFU deserves further study.