Association between Overweight/Obesity and Clinical Activity in Rheumatoid Arthritis.

Introduction: The effect of overweight/obesity on clinical status in rheumatoid arthritis (RA) is still a controversial topic.

Aim: To assess the association between body composition and clinical status in RA patients.

Methods: A prospective, comparative, cross-sectional study was performed on 123 (98.4% women, 86.3% FR+, 9.3±8.7 duration years) RA patients diagnosed according to ACR/EULAR 2010 criteria who were assessed for inflammatory activity (DAS 28), functional status (HAQ-Di), and type of treatment. Body composition was evaluated by BMI, waist, hip, and middle arm girths, waist/hip ratio, skin fold measurements, and bioelectrical impedance analysis.

Results: The prevalence of overweight and obesity (BMI-WHO cut-off points) was 30.9% and 45.5% respectively. Using Stavropoulos-Kalinoglou cut-off points, each corresponding prevalence increased to 31.7% and 58.5%, respectively. Pooled patients in the overweight/obesity classification (Stavropoulos-Kalinoglou classification) exhibited a significantly higher number of swollen joints as compared to subnormal/normal body composition subjects (3.8±3.3 vs. 1.9±2.5; p=.02). Swollen joint count showed significant positive correlation with 6 out of 11 body composition parameters: BMI; arm and hip girths, triceps skin fold, body fat average determined by bioelectrical impedance analysis, and skin fold measurements.

Conclusions: Prevalence of obesity in RA varies according to BMI cut-off points. Overweight and obesity were associated with higher inflammatory activity characterized by a higher count of tender and swollen joints. A positive correlation was found between swollen joint amount and the majority of the body fat mass indicators assessed. Body composition assessment/improvement should be an important part of the routine care of RA patients.