Vitamin D Deficiency Participates in Depression of Patients with Diabetic Peripheral Neuropathy by Regulating the Expression of Pro-Inflammatory Cytokines

Abstract

Objective

Vitamin D deficiency is associated with patients with diabetic peripheral neuropathy (DPN), and low levels of vitamin D are common in patients with depression. Depression is common in DPN patients and the definite pathogenesis remains unclear. This study aimed to determine vitamin D deficiency in the onset of depression in DPN and evaluate the effect of vitamin D supplementation on depression.

Methods

A total of 192 patients with DPN were enrolled in this study. Clinical and laboratory information was collected. Chemiluminescent immunoassay was used to measure the level of 25(OH)D. Enzyme-linked immunosorbent assay was employed to measure the concentrations of interleukin (IL)-1β, tumor necrosis factor-α (TNF-α), and IL-17A. Subjects with low 25(OH)D received 5000IU vitamin D daily for 12 weeks. Depression scores and levels of 25(OH)D, IL-1β, TNF-α, and IL-17A were re-evaluated after supplementation.

Results

The incidence of vitamin D deficiency and depression was high in DPN patients. Compared with vitamin D sufficient participants, Hamilton Depression Rating Scale (HAMD) scores and the levels of inflammatory markers IL-1β, TNF-α, and IL-17A were significantly higher in insufficient group (all p<0.05). HAMD score, IL-1β, TNF-α, and IL-17A were negatively correlated with 25(OH)D (all p<0.05). A linear relationship existed among IL-1β, TNF-α, IL-17A, and 25(OH)D (p<0.05). HAMD scores, IL-1β, TNF-α, and IL-17A were all reduced significantly after supplementation of vitamin D (p<0.05). Binary logistic analysis revealed that vitamin D insufficiency was an independent risk factor for depression in patients with DPN. Receiver operating characteristic (ROC) curve analysis showed a high sensitivity (87.20%) of 25(OH)D in discriminating DPN patients with depression.

Conclusion

Vitamin D deficiency participated in occurrence of depression in DPN patients and could be mediated, at least in part, by upregulation of pro-inflammatory cytokines. Vitamin D supplementation may be effective in improving depressive symptoms in DPN patients.

Keywords:

• vitamin D
• depression
• diabetic peripheral neuropathy
• interleukin-1 beta
• tumor necrosis factor-alpha
• interleukin-17A

Abbreviation

25(OH)D, 25-hydroxyvitamin D.

Consent for Publication

All authors and patients agree to publish this article.

Acknowledgments

The authors would like to acknowledge all study participants and researchers who have offered support throughout the project.

Author Contributions

All authors made a great contribution to the work, whether that is in the conception, design, execution, acquisition of data, analysis, and interpretation, or in all these areas; took part in drafting, revising or reviewing the article, gave final approval of the version to be published, have agreed on the journal to which the article has been submitted; and agree to be accountable for all aspects of the work.

Disclosure

All authors declared no conflicts of interest in this work.

Additional information

Funding

The work was supported by the Natural Science Foundation of the Higher Education Institutions of Anhui Province (Grant No. KJ2021B005).