Abstract
Background: Vitamin D deficiency is seen more frequently in diabetic patients with distal symmetrical polyneuropathy . Unfortunately, there is a shortage of data concerning prediabetic individuals with peripheral neuropathy (PN). Therefore, we aimed to study the association of vitamin D deficiency with PN severity and to determine the effect of vitamin D supplementation on PN in prediabetics. Methods : A case-control study was conducted consisting of 178 prediabetic individuals recruited from the outpatient department of the National Institute of Diabetes and Endocrinology, Cairo, Egypt. All patients were screened for PN using clinical examination and Douleur Neuropathique 4 diagnostic questionnaire (DN4). They were divided into 89 patients with and 89 patients without PN (group A and B). Group A was assessed for neuropathic severity using the Short-Form McGill Pain Questionnaire (SF-MPQ). In addition, 25-hydroxyvitamin D, ionized calcium, phosphorus, parathyroid hormone (PTH), glycated hemoglobin (HbA1c), fasting blood glucose (FBG), 2-hour post 75g glucose (2h-75g glucose) and lipid profile were measured. Prediabetic patients with PN were given vitamin D3 200.000 IU IM monthly for three months. After three months, clinical assessment, DN4, SF-MPQ and all laboratory measures were repeated. Results: Vitamin D level was negatively correlated with neuropathy score and severity (r = -0.65, -0.47, p <0.001) among group A. Moreover, vitamin D level was an independent predictor of neuropathic severity (odds ratio -0.18, 95% CI -0.33 -0.03, P ≤ 0.05). Supplementation of vitamin D resulted in a highly significant improvement in glycemic parameters and lipid profile, p ≤ 0.001. Interestingly, neuropathy score and severity before vitamin D supplementation were (6.4 ± 1.6 and 28.3 ± 7.2) and after became (2.5 ± 0.9 and 17 ± 6.3, p ≤ 0.001). Conclusion: Vitamin D deficiency is an independent risk factor for PN. Correction of vitamin D deficiency improves glycemic parameters, PN score and severity.
Full text
