Children's lung function in relation to changes in socioeconomic, nutritional, and household factors over 20 years in Lanzhou.

Background: Lanzhou has experienced rapid urbanization, leading to changes in socioeconomic, nutritional, and household factors. These changes may affect children's lung function.

Methods: Two cross-sectional studies of school-age children (6-13 years of age) from the urban (Chengguan) (Period 1 in 1996 with n=390; Period 2 in 2017 with n=192) and the suburban (Xigu) (Period 1 n=344; Period 2 n=492) district were conducted. Demographic information, household factors, and nutrition status were obtained via a questionnaire survey. Forced vital capacity (FVC) and forced expiratory volume in the first second (FEV) were measured in each period. Student's t-test analysis of variance was used to assess the differences in FVC and FEV between Periods 1 and 2. Generalized linear models were used to analyze the associations between questionnaire derived factors and lung function. Analyses were done separately for girls and boys.

Results: Children had significantly lower mean FEV and FVC measures in Period 2 than in Period 1. This reduction was greater in children living in the urban area than those living in the suburban area. Obese children had significantly lower lung function but this was only statistically significant in Period 1.

Conclusions: Children's lung function (FVC and FEV) were lower in 2017 than in 1996. Rapid urbanization may have contributed to the decline of lung function. Obesity may be a risk factor for impaired lung function in children living in Lanzhou and possibly elsewhere.