[Effect of weight reduction on respiratory function in obese children with asthma].

Background: Though the epidemiological relationship between obesity and asthma has been widely investigated, the mechanism is less known. Several studies have examined that weight loss improved lung function in adults. However, it has not been systematically studied in children. We investigated the effect of weight reduction on respiratory function in obese children with asthma.

Methods: We selected 10 obese children aged 7-13 years with physician diagnosed asthma who was subjected the weight reduction program in Fukuoka National Hospital in 2003-2007. Obesity was defined by BMI >90 percentile of the same age population. Before and after the program, they performed the spirometry. And they were measured the height, the weight, the %Fat, and the Fat volume. Logistic linear analysis was conducted to determine the correlation between relative change in each obesity markers and relative change in each respiratory parameter.

Results: Reduction of BMI, %Fat, and Fat volume correlated with relative changes in %FVC and %FEV1. Reduction of %Fat and Fat volume also correlated with relative changes in %PEF and %V50.

Conclusion: Reduction of BMI, %Fat, and Fat volume can improve respiratory function in obese children with asthma. Obesity may be contribute to aggravate the symptoms of asthma.