Impaired lung function is associated with non-alcoholic fatty liver disease independently of metabolic syndrome features in middle-aged and elderly Chinese

BACKGROUND: Associations between lung function and non-alcoholic fatty liver disease (NAFLD) have been reported. However, evidence from large-scale populations about the relationship is scarce. The objective of the study was to evaluate the relationship between lung function and NAFLD in middle-aged and elderly Chinese. METHODS: A total of 1842 participants aged 40 years or older were recruited from Chongming District, Shanghai, China. Lung function, evaluated by forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) was measured with standard spirometry. The NAFLD was evaluated by ultrasonography. RESULTS: The subjects with NAFLD had lower FVC (% predicted) (0.85 ± 0.26 vs. 0.90 ± 0.28, p < 0.001) and FEV1 (% predicted) (0.93 ± 0.29 vs. 0.98 ± 0.34, p < 0.001) than non-NAFLD. After adjusting for potential risk factors, the lowest quartile of FVC (% predicted) and FEV1 (% predicted) was associated with increased prevalence of NAFLD, with the fully adjusted odds ratio of 1.37 and 1.24 (95% confidence interval [CI] 1.18–1.97, p < 0.001, 95% CI 1.11–1.87, p = 0.009), respectively. CONCLUSIONS: Impaired lung function is associated with non-alcoholic fatty liver disease, independent of conventional metabolic risk factors.