Excess weight may be a risk for rheumatoid arthritis in women

Takeaway

• Higher body mass index (BMI) in middle age, BMI in early adulthood and waist circumference were associated with an increased risk of rheumatoid arthritis (RA).
• The positive association between BMI in middle age and RA was restricted to women.

• Findings suggest that prevention strategies targeting weight reduction and maintenance of a healthy weight may reduce the burden of RA.

Study design

• 13 cohort studies met eligibility criteria after a search across PubMed and Embase databases.
• Random effects models were used to estimate summary relative risk (RR) for RA in relation to different measures of adiposity.
• Funding: None disclosed.

• The summary RR per 5 kg/m² increase in BMI was 1.11 (95% CI, 1.05-1.18; I², 50%).
• In subgroup analyses, a positive association was seen between BMI in middle age and RA in women (RR, 1.15; 95% CI, 1.08-1.21) but not in men (RR, 0.89; 95% CI, 0.73-1.09; I², 58%).
• The summary RR per 5 kg/m² increase in BMI in early adulthood (at age 18 years) and per 10 cm increase in waist circumference was 1.17 (95% CI, 1.01-1.36) and 1.13 (95% CI, 1.02-1.25), respectively.

• Heterogeneity among included studies.
• Some studies included self-reported anthropometric measurements.