Association between body mass index (BMI) percentile and asthma in children of 5–12 years old: A case–control study using electronic medical records in Primary Health Care Corporation, Qatar 2016–2017

ABSTRACT Background: Over the last several decades, obesity and asthma prevalence have risen among children. The increase in overweight and obesity has been associated with an increased risk of asthma in children. Most epidemiological studies have proposed that a high body mass index (BMI) at infancy and early childhood increases the risk of asthma in children. A recently adopted electronic recording system for health service encounters in Primary Health Care Corporation of Qatar has provided a convenient opportunity to assess the possible link between asthma and obesity in children aged 5–12 years. Objectives: To calculate the prevalence rate of overweight and obesity among asthmatic children aged 5–12 years using primary health care centers during 2016–2017. To measure the strength of the association between BMI and asthma in children aged 5–12 years after adjusting for age, gender, and nationality. Methodology: This was a case–control study on the electronic health records of children aged 5–12 years who visited one of the primary health care centers during the two-year study period (2016–2017). A total of 9889 children with a diagnosis of asthma and valid BMI measurements were included in the case group, and an identical number of children who visited the health care centers for other reasons and had valid BMI measurements were randomly enrolled in the control group. Results: The prevalence of obesity (BMI-for-age Z-score >2) was significantly higher among asthmatics (24.9%) compared with non-asthmatic controls (17.7%). Asthma significantly increased the risk of being obese by 41% in bivariate analysis. The calculated risk estimate for the association between asthma and obesity increased to 70% after adjusting for the confounding effect of age, gender, and nationality. Conclusions: The present observational study based on a large sample of 5 to 12-year-old children documented a strong association between asthma and obesity (BMI-for-age Z-score 2 or above). This positive association between asthma and high BMI was stronger among older children, females, and Qatari nationals.