Causal relationship between vitamin D and stress urinary incontinence: Two-sample Mendelian randomization study

Area of Science:

• Urology
• Nutritional Science
• Genetic Epidemiology

Background:

• Observational studies suggest a link between vitamin D and stress urinary incontinence (SUI), but causality remains uncertain.
• Existing research presents conflicting evidence, necessitating further investigation into the vitamin D-SUI relationship.

Purpose of the Study:

• To investigate the potential causal relationship between vitamin D and SUI using a robust Mendelian randomization (MR) approach.
• To clarify the role of vitamin D levels, deficiency, and supplementation in the etiology of SUI.

Main Methods:

• Utilized publicly available genome-wide association study summary data for SUI and vitamin D status in European populations.
• Employed inverse variance-weighted (IVW), MR-Egger, weighted median, and weighted mode regression methods for causal inference.
• Conducted sensitivity analyses, including heterogeneity and pleiotropy assessments, to ensure result validity.

Main Results:

• Mendelian randomization analysis revealed no statistically significant causal association between vitamin D levels and SUI (IVW OR: 0.999, P=0.786).
• No causal link was detected for vitamin D deficiency (IVW OR: 1.000, P=0.646) or vitamin D supplementation (IVW OR: 1.000, P=0.064) with SUI.
• No evidence of significant heterogeneity or horizontal pleiotropy was observed, supporting the robustness of the findings.

Conclusions:

• The study does not support a causal relationship between vitamin D status and stress urinary incontinence.
• The observed association in observational studies may be due to confounding factors or other unmeasured mediators.
• Further research, including clinical trials, is warranted to fully elucidate the complex interplay between vitamin D and SUI.