Lower body mass index is associated with a higher risk of giant cell arteritis: a systematic review and meta-analysis

Objective: To characterize the possible association between body mass index (BMI) and risk of giant cell arteritis (GCA). Methods: We conducted a systematic review of observational studies (case-control or cohort study) that (I) reported BMI of patients with GCA prior to the diagnosis of GCA compared with subjects without GCA and (II) provided relative risk (RR), odds ratio (OR) or hazard ratio (HR) with 95% confidence interval (CI) from its regression analysis. Meta-analysis of the included studies was then performed to estimate the pooled effect using generic variance method of DerSimonian and Laird. Results: Three studies encompassing 141 patients with GCA and 85,736 controls met our eligibility criteria and were included in the data analyses. We demonstrated a statistically significant inverse relationship between BMI and risk of subsequent development of GCA as the risk increased by 8% when BMI was reduced by 1.0 kg/m(2) (pooled OR of 0.92/kg/m(2); 95% CI, 0.88-0.96). Conclusions: Our study demonstrated a statistically significant inverse relationship between BMI and risk of subsequent development GCA. The pathophysiologic link behind this negative correlation is not well-characterized and further investigation is required.