Objective: The aim of our systematic review and meta-analysis was to investigate whether overweight/obesity are associated with higher disease activity measures in patients with axial spondyloarthritis (SpA).
Methods: MEDLINE, PubMed, and Web of Science were searched using key terms corresponding to population (axial SpA patients), exposure (overweight/obesity), and outcome (Bath Ankylosing Spondylitis Disease Activity Index [BASDAI] and Ankylosing Spondylitis Disease Activity Score [ASDAS]). Predefined inclusion criteria were adult patients with axial SpA, exposure classified according to body mass index (BMI), BASDAI/ASDAS reported for each BMI group, and observational studies. The Newcastle-Ottawa Scale for cohort, cross-sectional, and case-control studies was used for quality check. Random-effects meta-analysis was used to pool results, which were expressed as the mean difference (MD) in BASDAI and ASDAS between BMI groups, with 95% confidence intervals (95% CIs).
Results: A total of 10 articles were included in the meta-analysis. The MD in BASDAI between normal BMI and overweight/obese patients was -0.38 (95% CI -0.56, -0.21; P < 0.0001); the MD in ASDAS between the same groups was -0.19 (95% CI -0.29, -0.09; P < 0.0001). The MD in BASDAI between normal BMI and overweight patients was -0.09 (95% CI -0.33, 0.15; P = 0.45), and the MD between normal BMI and obese patients was -0.78 (95% CI -1.07, -0.48; P < 0.0001). For ASDAS, the MD between normal BMI and overweight patients was -0.02 (95% CI -0.19, 0.15; P = 0.79), and the MD between normal BMI and obese patients was -0.42 (95% CI -0.60, -0.23; P < 0.0001).
Conclusion: Overweight and obese patients with axial SpA tend to present higher disease activity scores compared to patients with a normal BMI. This difference seems to be clinically meaningful only for the comparison between obese patients and patients with normal BMI, and more for BASDAI than ASDAS.
© 2020, American College of Rheumatology.