Correlation of radiographic damage and central obesity in ankylosing spondylitis: A cross sectional study

Abstract Background Cardiovascular complications remain the leading of many long-term complications in Ankylosing Spondylitis (AS), accounting for 40% of all-cause mortalities. Previous studies reported the high prevalence of metabolic syndrome in AS with its prevalence ranging from 27% to 54.5%. Among its components, central obesity was the most prevalent component seen in AS with its prevalence ranging from 45.8 to 90.9%. However, lack of study, differences of disease activity index used, and inability to exclude confounding risk factors, might have contributed with previous studies report's conflicting results. Thus, the correlation between severity of AS and central obesity remains controversy. Aim To investigate the correlation of AS's severity measured with radiographic damage and central obesity measured with Indonesian's Waist circumference and Body Mass Index (BMI) criteria with Indonesian's cut-off. Methods This is a cross-sectional study with consecutive sampling involving 28 AS patients aged 18–60 years old receiving csDMARDs. Exclusion criteria of this study were recent infections, recent anti-TNFα, history of end state renal disease, history of metabolic syndrome before Ankylosing Spondylitis diagnosis, current smokers, and current alcohol consumption. Radiographic damage was scored using modified Stokes Ankylosing Spondylitis Spinal Score (mSASSS) score. Statistical analysis was computed with SPSS v21.0 for mac OSX. Results There were 7 males and 21 females with average age 45.07 ± 10.46 years old. Average anthropometric measures of the subjects were: waist circumference 87.37 ± 11.91 cm, height 157.05 ± 8.57 cm, weight 62,28 ± 11,50 kg, and BMI 25.42 ± 5.23 kg/m 2 . The average mSASSS score was 22.39 ± 5.85 (κ:0.92, p = 0.00). Analysis with Pearson's correlation revealed positive correlation between mSASSS score and waist circumference (ρ:0.49, p = 0.02) and particulary female subjects (ρ:0.52, p = 0.01). Furthermore, revealed positive correlation between mSASSS score and BMI (ρ:0.389, p = 0.04). Conclusion Positive correlation between severity of AS measured with mSASSS score with central obesity measured with waist circumference and BMI was observed in Indonesian AS patients receiving csDMARDS. Further studies are needed to investigate the nature of the relationships regarding chronic inflammation's pathway of AS and central obesity.