Serum 25-hydroxyvitamin D levels and peripheral neuropathy in patients with type 2 diabetes: a systematic review and meta-analysis
Vitamin D is a multifunctional pro-hormone and has widespread actions in human body. Several studies showed a possible association between vitamin D deficiency and diabetic peripheral neuropathy (DPN) in patients with type 2 diabetes, but no definite conclusion was available.
A systematic review and meta-analysis was performed to comprehensively assess the association between serum 25-hydroxyvitamin D [25(OH)D] levels and DPN in patients with type 2 diabetes. Data from eligible studies were pooled using meta-analysis.
Six studies that involved a total of 1,484 type 2 diabetic patients were finally included into the meta-analysis. Meta-analysis showed that there were obviously decreased serum 25(OH)D levels in DPN patients [weighted mean difference (WMD) = −6.36 ng/ml, 95 % confidence interval (95 % CI) −8.57 to −4.14, P < 0.00001]. Vitamin D deficiency was also significantly associated with increased risk of DPN in patients with type 2 diabetes [odds ratio (OR) 2.88, 95 % CI 1.84–4.50, P < 0.00001]. Meta-analysis of three studies with adjusted estimates showed that vitamin D deficiency was independently associated with increased risk of DPN in patients with type 2 diabetes (OR 2.68, 95 % CI 1.67–4.30, P < 0.0001). Sensitivity analysis showed that there was no obvious change in the pooled estimates.
Vitamin D is involved in the development of DPN in type 2 diabetic patients, and vitamin D deficiency is very likely to be associated with DPN in type 2 diabetic patients. Further studies are needed to validate the association between vitamin D deficiency and DPN.
KeywordsDiabetic peripheral neuropathy 25-Hydroxyvitamin D Meta-analysis
- 15.Celikbilek A, Gocmen AY, Tanik N, et al. (2014) Decreased serum vitamin D levels are associated with diabetic peripheral neuropathy in a rural area of Turkey. Acta Neurol Belg [Epub ahead of print]Google Scholar
- 16.Wells G, Shea B, O’connell D, et al. (2012) The Newcastle–Ottawa scale (NOS) for assessing the quality of nonrandomised studies in meta-analyses. Ottawa Health Research Institute WebsiteGoogle Scholar
- 24.Ahmadieh H, Azar ST, Lakkis N, Arabi A (2013) Hypovitaminosis d in patients with type 2 diabetes mellitus: a relation to disease control and complications. ISRN Endocrinol 2013:641098Google Scholar
- 26.Zhang JP, Xu N, Yi D et al (2014) Association between the level of serum vitamin D and peripheral neuropathy in type 2 diabetic patients [article in Chinese]. Chin J Endocrinol Metab 30(5):385–387Google Scholar
- 27.Maser RE, Lenhard MJ, Pohlig RT (2014) Vitamin D insufficiency is associated with reduced parasympathetic nerve fiber function in type 2 diabetes. Endocr Pract 1–22 [Epub ahead of print]Google Scholar