Higher Vitamin D Levels before Methotrexate Therapy Initiation Are Associated with Lower Subsequent Mortality in...

Area of Science:

• Rheumatology
• Endocrinology
• Public Health

Background:

• Vitamin D deficiency is linked to increased mortality in the general population.
• Previous studies suggest an association between vitamin D levels and mortality in rheumatoid arthritis (RA) cohorts.

Purpose of the Study:

• To investigate the association between pre-treatment 25-hydroxyvitamin D (25(OH)D) levels and all-cause mortality in RA patients initiating methotrexate (MTX).

Main Methods:

• Retrospective analysis of a national Veterans Affairs (VA) cohort of RA patients.
• Patients were stratified based on 25(OH)D levels (> 50 nmol/L vs. ≤ 50 nmol/L) before MTX initiation.
• Cox Proportional Hazard Model used to assess mortality risk, adjusting for traditional risk factors.

Main Results:

• The study included 15,109 RA patients.
• RA patients with 25(OH)D levels > 50 nmol/L showed a 28% reduced risk of mortality compared to those with levels ≤ 50 nmol/L (HR: 0.72, CI: 0.64-0.80, p < 0.001).
• This association remained significant after adjusting for traditional risk factors.

Conclusions:

• In a national RA cohort receiving methotrexate, higher pre-treatment 25(OH)D levels (> 50 nmol/L) are associated with lower subsequent all-cause mortality.
• Further research is needed to determine if vitamin D supplementation in deficient RA patients impacts mortality.