Mediating role of inspiratory muscle strength in the relationship between abdominal obesity and lung function in young individuals: a cross-sectional study.

Abstract

This study aimed to explore the mediating role of inspiratory muscle strength between abdominal obesity and lung function in young people. Cross-sectional study. This survey was conducted in Peking University Health Science Center, Beijing, China. 404 subjects aged 18 and older. Forced expiratory volume in one second percent (FEV1%) predicted ≥80% was defined as the normal lung function. A total of 404 subjects were included, with maximal inspiratory pressure of 65.27±29.55 cmH₂O. Among them, 61 subjects (15.10%) had central obesity, 106 subjects (26.24%) had a FEV1% predicted <80%. Abdominal obesity was significantly associated with lung function (OR=5.356, 95% CI 2.391 to 11.999, p<0.001) and inspiratory muscle strength (OR=3.537, 95% CI 1.441 to 8.679, p=0.006). Even after adjusting for inspiratory muscle strength, the relationship between abdominal obesity and lung function remained significant (OR=4.723, 95% CI 2.076 to 10.749, p<0.001), and there was a significant association between inspiratory muscle strength and lung function (OR=0.322, 95% CI 0.176 to 0.591, p<0.001). The z-test confirmed that inspiratory muscle strength mediated the relationship between abdominal obesity and lung function (|z|=2.14, p<0.05). This study highlighted the mediating role of inspiratory muscle strength between abdominal obesity and lung function.