Association of body mass index with asthma occurrence and persistence in adolescents: A retrospective study of NHANES (2011-2018)

Abstract

Objective: To investigate the association of body mass index (BMI) with asthma and analyze the risk factors of asthma persistence among overweight/obese adolescents and those with a high risk for obesity.

Methods: In this cross-sectional study, adolescents aged 11-17 years with complete general information and asthma diagnoses were selected from the National Health and Nutrition Examination Survey database. For adolescents without self-reported asthma, we performed matching according to age and sex at a case-to-control ratio of 1:3. Logistic regression analysis was employed to identify independent predictors of asthma occurrence followed by constructing a nomogram and comparing its efficacy to independent factors in predicting asthma occurrence. Besides, associations of BMI with asthma occurrence and persistence were evaluated. Finally, we obtained risk factors for asthma persistence in overweight/obese individuals and those at a high risk for obesity.

Results: Totally 753 adolescents with asthma and 2259 adolescents without asthma were included to analyze the occurrence of asthma. BMI and Hispanic Ethnicity were independent predictors of asthma occurrence and were included in nomogram construction. BMI had an efficiency comparable to that of the nomogram model in predicting asthma occurrence, which is superior to that of Hispanic Ethnicity. Of the 753 adolescents diagnosed with asthma, 464 were still diagnosed with asthma of at least a year's duration. Interestingly, BMI may have the ability to predict asthma persistence. Further, Hispanic Ethnicity and household income were significantly related to asthma occurrence among overweight/obese and high-risk obese individuals.

Conclusions: High BMI could independently predict increased asthma occurrence. Additionally, BMI may play an essential role in predicting asthma persistence. This study may help improve the diagnosis and reduce the occurrence of asthma.

Keywords: Adolescents; Asthma; BMI; Nomogram.

Fig. 1

The flowchart of the study population.

Fig. 2

Nomogram construction and evaluation. (A) Nomogram construction to predict the risk of asthma. For HE, 1: Mexican American, 2: Other Hispanic, 3: Non-Hispanic White, 4: Non-Hispanic Black, 5: Other Race. (B) Nomogram evaluation by the calibration curve. Abbreviations: BMI, body mass index; HE, Hispanic Ethnicity.

Fig. 3

Evaluation of the nomogram model and two independent predictors. The ability of the three models in predicting asthma occurrence using (A) receiver operating characteristic analysis and (B) decision curve analysis. Abbreviations: HE, Hispanic Ethnicity; BMI, body mass index; AUC, the area under the curve. Model 1, Hispanic Ethnicity; model 2, body mass index; model 3, nomogram.

Fig. 4

The ability of body mass index (BMI) in predicting asthma persistence. (A) Receiver operating characteristic analysis. (B) Decision curve analysis. Abbreviations: AUC, the area under the curve; 95% CI, 95% confidence interval; BMI, body mass index.

Fig. 5

Possible mechanisms of body mass index involvement in asthma.