Objectives: Childhood obesity has been suggested to be associated with asthma and impairment of pulmonary functions, but the findings are conflicting. The aim of this study was to examine the relationship of body mass index (BMI) with asthma, asthma-like symptoms, and lung functions in Chinese schoolchildren.
Methods: Data from a survey of 2,179 children aged 10.04 +/- 0.85 years in Guangzhou, China were analyzed. Children's history of respiratory symptoms/diseases and other potential confounders were obtained by standardized questionnaires. Anthropometric and spirometry tests were performed in all subjects. Children were categorized as "normal weight," "overweight," and "obesity" using Chinese Obesity cut-off points based on age- and gender-specific BMI values.
Results: Being overweight was significantly associated with an increased risk of cough with cold (odds ratio, OR 1.60; 95% CI 1.01-2.55) in boys, and phlegm with cold (OR 2.46; 95% CI 1.25-4.85) and cough without cold (OR 2.91; 95% CI 1.05-8.08) in girls. Being obese was positively associated with an increased risk of phlegm with cold (OR 1.69; 95% CI 1.04-2.87) in boys, and wheezing (OR 3.82; 95% CI 1.28-11.42) and wheezing with cold in girls (OR 8.75; 95% CI 2.11-36.34). The forced vital capacity (FVC) increased with BMI in all children, overweight boys and obese girls also had significantly higher forced expiratory volume in 1 sec (FEV(1)) than those with normal weight.
Conclusions: Our findings demonstrate that overweight and obesity are high risks for children's respiratory symptoms and diseases. Pulmonary function was not adversely affected by obesity in schoolchildren.