Vitamin D deficiency increases the risk of peripheral neuropathy in Chinese patients with type 2 diabetes

Background Vitamin D deficiency was reported to be associated with diabetic peripheral neuropathy. But the association in Chinese population and the screening value of vitamin D deficiency for diabetic peripheral neuropathy were unknown. Methods A total of 861 patients with type 2 diabetes were recruited in this cross‐sectional study. Vitamin D deficiency was defined as serum circulating 25‐hydroxyvitamin D(25(OH)D) level < 20 ng/mL. Peripheral neuropathy was evaluated by neurological symptoms, neurological signs, neurothesiometer and electromyogram. Results The patients with diabetic peripheral neuropathy had significantly lower serum 25(OH)D concentration (15.59 ± 7.68 ng/mL) and higher prevalence of vitamin D deficiency (80%) than patients with signs of diabetic peripheral neuropathy (17.66 ± 7.50 ng/mL; 64.5%) and non‐DPN patients (18.35 ± 6.60; 61.7%) (all p  < 0.01). Spearman's correlation analysis showed that serum circulating 25(OH)D level was closely associated with DPN ( r  = 0.121) and signs of DPN ( r  = 0.111) (both p <  0.01). After adjusting for all potential confounders, VDD was still linked with increased risk of DPN [odds ratio 2.59 (1.48–4.53)] ( p <  0.01). Logistical regression analysis further revealed that VDD was an independent risk factor for DPN ( β  = 0.88) ( p <  0.01). Receiver operating characteristic analysis indicated that serum 25(OH)D < 17.22 ng/mL hinted the signs of DPN and serum 25(OH)D < 16.01 ng/mL predicted the occurrence of DPN (both p <  0.01). Conclusions Vitamin D deficiency is an independent risk factor for diabetic peripheral neuropathy and may be a potential biomarker for peripheral neuropathy in Chinese patients with type 2 diabetes. Copyright © 2016 John Wiley & Sons, Ltd.