Association of general and central obesity with asthma attacks: A cross-sectional study based on NHANES 2021-2023

Obesity has been linked to increased asthma severity, but its direct role in triggering asthma attacks remains unclear. This study examined how general and central obesity are associated with asthma attacks using recent data from the National Health and Nutrition Examination Survey (NHANES).

This cross-sectional study analysed NHANES data from August 2021 to August 2023 by the National Centre for Health Statistics for adults aged 18 and older with active asthma. The main outcome was self-reported asthma attacks in the past year. The exposures were body mass index (BMI; categorised as normal, overweight, or obese) and central obesity, defined by waist circumference. Survey-weighted logistic regression accounted for the complex sampling design and adjusted for variables including age, sex, race/ethnicity, education, poverty-income ratio, physical activity, alcohol use, diabetes, and hypertension.

Out of 908 adults with active asthma, 436 reported experiencing at least one attack. Fully adjusted models showed that being overweight was not significantly associated with asthma attacks (adjusted OR 1.14, 95% CI 0.49-2.62), while obesity had a higher but statistically non-significant association (adjusted OR 1.56, 95% CI 0.89-2.72). Central obesity was not independently linked to asthma attacks (adjusted OR 0.95, 95% CI 0.55-1.65). Female sex and hypertension consistently correlated with increased odds of attacks.

Among current U.S. adults with asthma, body measurements alone do not serve as strong independent predictors of asthma attacks after full adjustment, although the results did show a positive trend. The risk of an asthma attack likely involves a complex interplay of social, clinical, and biological factors beyond obesity alone.