Among patients with type 2 diabetes (T2D), women are more likely than men to report peripheral neuropathic symptoms, according to study results published in BMJ Open Diabetes Research & Care. Conversely, researchers found no association between serum vitamin D levels and neuropathic pain in this study.
Chronic hyperglycemia may lead to neuropathic pain in patients with diabetes, and recent data have suggested vitamin D deficiency may serve as a risk factor for diabetic neuropathy. The goal of this study was to investigate the association between vitamin D deficiency and neuropathic pain in patients with T2D.
The cross-sectional study enrolled participants with T2D recruited from the outpatient endocrine clinic of King Abdullah University Hospital, in Ramtha, Jordan, between January and December 2017. Neuropathy status was assessed using the PainDETECT questionnaire (range, 0-38).
The study cohort included 239 patients (58.6% women; mean age, 56.51±9.03 years).
The mean neuropathy score according to the PainDETECT questionnaire was 13.29±7.48. On the basis of these results, 26.8% of participants had peripheral neuropathy. Vitamin D deficiency was detected in 67.8% of participants with T2D. Analysis demonstrated no significant association between vitamin D status and neuropathy status (P =.55). Furthermore, there was no association between vitamin D status and treatment for neuropathic pain (P =.78).
There was an association between peripheral neuropathy and the sex of patients with T2D, as 76.6% of participants with neuropathy were women and 23.4% were male (P <.01). Ordinal logistic regression found that female sex was the only significant predictor of neuropathic pain in patients with T2D (compared with male sex: odds ratio, 2.45; 95% CI, 1.29-4.67; P <.01).
The researchers acknowledged several limitations of the study, including determining neuropathy based on questionnaire results and not clinically, use of a single assessment tool for neuropathy, and the possibility that there may be a difference in pain threshold and tolerance levels in women compared with men.
“[W]e believe that the current study is the first report that did not find any association between vitamin D levels and neuropathic pain in participants with [T2D],” wrote the researchers.
Alkhatatbeh M, Abdul-Razzak KK. Neuropathic pain is not associated with serum vitamin D but is associated with female gender in patients with type 2 diabetes mellitus. BMJ Open Diab Res Care. 2019;7:e000690.