Association between body mass index and palindromic rheumatism risk and outcomes: a case-control study

Palindromic rheumatism (PR) is a periodic rheumatic disease characterized by recurrent attacks of pain and swelling, affecting articular and periarticular structures. Despite the evidence supporting the association between overweight and obesity with autoimmune rheumatic diseases, the relation between body mass index (BMI) and PR remains underexplored. Therefore, this research aimed to evaluate the possible association between BMI and PR risk and outcomes.

This cross-sectional study utilized data from the CTDRC-PR Cohort. The PR group consisted of adults (age ≥ 18 years) diagnosed with PR according to the Guerne & Weisman criteria. Healthy controls (HCs) were selected from the general population enrolled in the Azar Cohort Study.

Of the 229 patients followed in the CTDRC-PR cohort, 151 met the study inclusion criteria. Following 1:2 propensity score matching, the final analytical sample consisted of 147 PR patients and 294 matched HCs. No significant difference was observed in mean BMI between PR patients and HCs. In a multivariate logistic regression model adjusted for age, sex, marital status, and smoking status, BMI ≥ 25 kg/m² was associated with an increased risk of PR. No significant differences were found in demographic profiles, clinical presentation, disease activity levels, or rates of remission between overweight/obese PR patients and those with lean/normal weight.

The lack of association between BMI and PR risk or outcomes may reflect the unique immunological positioning of PR, which differs from classical autoimmune pathways sensitive to adiposity. It also underscores the limitations of BMI as a surrogate for metabolically active adipose tissue. Key Points • No significant difference was observed in mean BMI between PR patients and HCs. • In a multivariate logistic regression model adjusted for age, sex, marital status, and smoking status, neither overweight nor obesity was associated with an increased risk of PR.