OBJECTIVE: The goal of our study was to investigate the potential relationship between Lipid Accumulation Product (LAP) and prevalence of asthma. DESIGN: Cross-sectional study. SETTING: The National Health and Nutrition Examination Survey (2003-2018). PARTICIPANTS: The study included a total of 13,993 participants, all of whom had complete data on both asthma and LAP. BACKGROUND: The Lipid accumulation product (LAP) index is a potential estimator of visceral fat accumulation. Overweight and obesity are the risk factors for asthma. However, no research investigated the possible correlation between LAP and the incidence of asthma. METHODS: We undertook a cross-sectional analysis to investigate the link between LAP and asthma, utilizing data from the National Health and Nutrition Examination Surveys (NHANES 2003-2018). To address the complex, multistage, and clustered survey design, sample weights were incorporated into all the statistical analyses. The association between LAP and the prevalence of asthma was examined through multivariable logistic regression. Additionally, the linear correlation between these variables was assessed via smoothed curve fitting and threshold effect analyses. Subgroup analysis was conducted to identify any vulnerable populations. RESULTS: The study included 13,993 participants, of whom 1965 (14.0 %) were diagnosed with asthma. Following adjustment for all covariates, a notable positive correlation emerged between the LAP index and asthma according to a multivariate logistic regression analysis. A heightened prevalence of asthma was observed with each unit increase in LnLAP (OR = 1.17, 95 % CI = 1.09-1.27, P <
0.002). Compared to individuals in the lowest LAP quartile, those in the highest quartile had a 34 % increased probability of developing asthma. (OR 1.34, 95 % CI 1.13-1.60, P = 0.002). Additionally, smoothed curve-fitting analysis revealed a nonlinear correlation between the LAP index and asthma. Through threshold effect analysis, the inflection point was established at 114.495. CONCLUSION: The study found a positive association between the LAP index and asthma in adults, suggesting that LAP may serve as a potential biomarker for early detection of asthma and assessment of treatment efficacy.