Severe Vitamin D Deficiency Is Associated With Increased Expression of Inflammatory Cytokines in Painful Diabetic Peripheral Neuropathy

• Published in: Frontiers in nutrition (Lausanne) Vol. 8; p. 612068
• Main Authors: Xiaohua, Gong, Dongdong, Luo, Xiaoting, Niu, Shuoping, Chen, Feixia, Shen, Huajun, Yang, Qi, Zhou, Zimiao, Chen
• Format: Journal Article
• Language: English
• Published: Switzerland Frontiers Media S.A 10.03.2021
• Subjects: IL-6; inflammatory cytokine; Nutrition; painful diabetic peripheral neuropathy; severe vitamin D deficiency; TNF–α; type 2 diabetes mellitus; type 2 diabetes mellitus; severe vitamin D deficiency; TNF–α; inflammatory cytokine; painful diabetic peripheral neuropathy; IL-6
• ISSN: 2296-861X; 2296-861X
• DOI: 10.3389/fnut.2021.612068

The exact pathogenic mechanism of the painful diabetic peripheral neuropathy (DPN) is poorly understood. Our study aimed to evaluate the association amongst vitamin D status, inflammatory cytokines, and painful DPN. A total of 483 patients were divided into three groups, i.e., diabetes without DPN (no-DPN, = 86), diabetes with painless DPN (painless DPN, = 176) and diabetes with painful DPN (painful DPN, = 221) groups. Basic information and laboratory results were collected. The concentrations of vitamin D (25-hydroxyvitamin D), high-sensitivity C-reactive protein, interleukin (IL)-2, IL-4, IL-6, IL-10, tumor necrosis factor-α (TNF-α), and interferon-γ (IFN-γ) were also measured. The prevalence of severe vitamin D deficiency (<10 ng/mL) was more common in the painful DPN group than in the painless DPN and no-DPN groups (25.8,12.5, and 8.1%, respectively, < 0.01). Cases in the painful DPN group had significantly higher concentrations of IL-6 ( < 0.01) and TNF-α ( < 0.01) than those in the two other groups. The multivariate logistic analysis showed that severe vitamin D deficiency, IL-6, and TNF-α were independent risks for painful DPN after adjusting for confounding factors. Furthermore, the vitamin D status had significantly negative correlations with IL-6 ( = -0.56, < 0.01) and TNF-α ( = -0.47, < 0.01) levels. Severe vitamin D deficiency was an independent risk factor for the painful DPN. Severe vitamin D deficiency status may play a role in the painful DPN pathogenesis through elevated IL-6 and TNF-α levels.