Visceral fat reflects disease activity in patients with ankylosing spondylitis.

PURPOSE Response to infliximab treatment diminishes as body mass index (BMI) increases in patients with ankylosing spondylitis (AS). The purpose of the study was to determine if diminished response to infliximab treatment in patients with AS could be associated with increased visceral adipose tissue rather than increased BMI. METHODS Twenty six AS patients (21 males and five females) who fulfilled the modified New York criteria and who were currently receiving infliximab treatment were enrolled in the study. Pain was measured by the visual analogue scale (VAS). The disease activity and functional status were assessed by the Bath AS Disease Activity Index (BASDAI) and the Bath AS Functional Index (BASFI). The Bath AS Metrology Index (BASMI) was used to evaluate mobility restrictions. Weight and visceral body composition were measured without shoes in light indoor clothes using a bio-impedance meter. RESULTS There was a significant correlation between visceral adipose tissue amount and disease activity under infliximab treatment. In correlation analysis, visceral fat showed significant correlations between BASDAI (r=0.545, p=0.004) and VAS (r=0.458, p=0.019). Total body fat also showed a significant correlation with BASDAI (r=0.463, p=0.017). CONCLUSION A significant correlation was found between visceral adipose tissue amount and disease activity in patients with AS.