Serum 25-hydroxyvitamin D levels and dermatomyositis: A 2-sample mendelian randomization study

Area of Science:

• Genetics
• Epidemiology
• Endocrinology

Background:

• Previous research indicates lower serum 25-hydroxyvitamin D [25(OH)D] levels in dermatomyositis (DM) patients.
• The precise causal link between 25(OH)D and DM risk has remained unclear.

Purpose of the Study:

• To investigate the potential causal relationship between 25(OH)D levels and the risk of developing DM using a Mendelian randomization approach.

Main Methods:

• Genome-wide association study (GWAS) data for 25(OH)D and DM were obtained.
• Single-nucleotide polymorphisms (SNPs) strongly associated with 25(OH)D served as instrumental variables.
• Inverse-variance weighted (IVW) method was the primary analysis, supported by MR-Egger regression and weighted median methods. Heterogeneity and sensitivity analyses were performed.

Main Results:

• The IVW analysis revealed a significant positive causal association between genetically predicted 25(OH)D levels and DM risk (OR=2.36, p=0.048).
• Other analytical methods indicated a potential protective effect of 25(OH)D on DM, though not statistically significant.
• Pleiotropy and heterogeneity analyses confirmed the robustness and reliability of the identified SNPs.

Conclusions:

• This study presents the first evidence supporting a causal relationship between 25(OH)D levels and DM.
• The findings underscore the clinical significance of assessing serum 25(OH)D and considering vitamin D supplementation in managing DM.