Obesity, smoking tied to higher disease activity in early axSpA

Smoking and body mass index (BMI) contribute to a higher disease activity (DA) in early axial spondyloarthritis (axSpA) over 1 year, while alcohol consumption appears to reduce DA, suggests a recent study. Of note, the magnitude of these associations may differ between men and women.

A team of investigators recorded the Ankylosing Spondylitis Disease Activity Score (ASDAS) of patients with chronic back pain onset at age <45 years, with pain for ≥3 months and ≤2 years, at inclusion, 3, and 12 months. All participants had axSpA based on a high physician’s level of confidence at baseline.

Using mixed linear regression models, the investigators estimated differences in ASDAS over 1 year by BMI (normal <25 kg/m², overweight 25–29.9 kg/m², and obese ≥30 kg/m²), smoking history (never/previous/current), and alcohol consumption (none, 0.1–2 units/week, 3–5 units/week, and ≥ 6 units/week) at baseline.

A total of 344 patients (mean age 30.3 years, 49.4 percent men) were included in the analysis. In women, obesity correlated with higher ASDAS (0.60, 95 percent confidence interval [CI], 0.28‒0.91) compared to normal BMI.

In both sexes, alcohol consumption seemed to reduce DA over 1 year, with a significant association only in women with the highest alcohol consumption (mean difference, ‒0.55, 95 percent CI, ‒1.05 to ‒0.04).

Moreover, smoking tended to increase ASDAS over 1 year compared to never smoking in both sexes. However, the differences reached statistical significance only in female former smokers.

Multivariable analysis, adjusted for all lifestyle factors and other confounders, confirmed these results.