Body mass index is related with the presence of syndesmophyte in axial spondyloarthritis: Data from the Korean College of Rheumatology BIOlogics (KOBIO) registry.

OBJECTIVE

We investigated whether body mass index (BMI) is associated with parameters of disease activity and clinical manifestations in axial spondyloarthritis (axSpA).

METHODS

Demographic, clinical, and radiological features and disease activity indexes from 789 axSpA patients (619 males and 170 females) were obtained from the Korean College of Rheumatology BIOlogics (KOBIO) registry. BMI (kg/m2) was classified into normal (BMI <23.0), overweight (23.0 ≤ BMI <25.0), and obese (BMI ≥25.0). Disease activity indexes included Bath ankylosing spondylitis disease activity index (BASDAI), erythrocyte sediment rate (ESR), C-reactive protein (CRP), and ankylosing spondylitis disease activity score (ASDAS).

RESULTS

The mean BMI in patients with axSpA was 23.3 ± 3.5. 50.2% of all patients were overweight or obese. Overweight/obese patients had more syndesmophyte and less peripheral arthritis than those in normal BMI patients (p < 0.001 and p < 0.030, respectively). BMI was not associated with disease activity indexes in axSpA patients. Patients with syndesmophyte had higher BMI than those without syndesmophyte (24.2 ± 3.6 vs. 22.9 ± 3.3, p < 0.001). Multivariate logistic regression analysis showed that increased BMI was closely related with the presence of syndesmophyte (OR = 1.086, 95% CI 1.031-1.143, p = 0.002)

Conclusions

Our results imply that increased BMI is significantly associated with the presence of syndesmophyte, but not with disease activity in axSpA.