Asthma risk: the inseparable synergy of obesity and metabolism.

Background: Obesity is a risk factor for asthma, but heterogeneity remains. The relationship between different metabolic obesity phenotypes and asthma has not been previously studied.

Methods: We used data from the National Health and Nutrition Examination Survey (NHANES), including a total of 50,544 participants. We compared the nationally weighted prevalence of asthma across different obesity statuses, metabolic conditions, and their combined states, and estimated asthma risk. Patients with asthma were identified through questionnaire data. Weighted chi-square tests were used to compare asthma prevalence between groups. Multivariable weighted logistic regression analyses were used to estimate asthma risk.

Results: In the total population, obesity (OR = 1.32,  < 0.001) and hypertension (OR = 1.19,  < 0.001) were risk factors for asthma, while hyperglycemia (OR = 1.09,  = 0.062) and dyslipidemia (OR = 0.96,  = 0.254) was not significantly associated with higher asthma risk. Compared to metabolically healthy non-obese individuals, metabolically healthy obese individuals had a higher risk of asthma. Furthermore, when obesity was combined with two or more metabolic risk factors, the risk of asthma was higher by 39% (OR = 1.39,  < 0.001). This effect was more pronounced in females(OR = 1.52 in females vs OR = 1.22 in females, both  < 0.05). Further analysis revealed that, in the total population, obesity combined with isolated hypertension was significantly associated with higher risk of asthma (OR = 1.49,  = 0.001). Moreover, among females, obesity combined with isolated hyperglycemia, hypertension or dyslipidemia was all associated with higher risk of asthma.

Conclusion: Both obesity and metabolic abnormalities independently increase asthma risk, and their combined effects pose an even greater threat, particularly among females. These findings highlight the importance of simultaneously addressing both obesity and metabolic abnormalities to reduce asthma risk.

Supplementary Information: The online version contains supplementary material available at 10.1186/s12890-025-03878-5.