Associations between airflow obstruction and the risks of morbidity on major chronic diseases in Chinese adults: a prospective cohort study

Abstract

Objective: To examine the prospective associations between airflow obstruction (AFO) and risks of major chronic diseases morbidity in Chinese adults. Methods: Samples of this study were from the China Kadoorie Biobank. A total of 486 996 participants aged 30 to 79 years (mean 51.5 years) at the baseline study, were included after excluding those who self-reported of having heart disease, stroke and cancer at baseline. AFO was defined under the Global Initiative on Obstructive Lung Disease (GOLD) criteria and forced expiratory volume per one second in percentage of the expected one (FEV(1)% P). Cox regression models were used to investigate the associations of AFO with incidence rates of ischemic heart disease, cerebrovascular disease and lung cancer after adjusted for potential confounders. Results: Over a period of 7 years through the follow-up program, the incident cases of ischemic heart disease, cerebrovascular disease and lung cancer appeared as 24 644, 36 336 and 3 218, respectively. Compared with people without AFO, the HR (95% CI) of GOLD-1 to GOLD-4 were 0.89 (0.78-1.01), 1.05 (0.98-1.12), 1.29 (1.18-1.40) and 1.65 (1.42-1.91) respectively for ischemic heart disease. The HR (95%CI) of GOLD-1 to GOLD-4 were 0.96 (0.70-1.26), 1.12 (0.96-1.31), 1.38 (1.14-1.65) and 1.48 (1.05-2.02) respectively for lung cancer. No statistically significant differences in the associations between GOLD level and cerebrovascular disease morbidity were found. However, each 10% decrease in FEV(1)% P was associated with 7.2% (95%CI: 6.4%-8.0%), 3.6% (95%CI: 3.0%-4.3%) and 10.5% (95%CI: 8.4%-12.6%) increased the risks of ischemic heart disease, cerebrovascular disease and lung cancer respectively. The results were persistant when stratified by smoking status. Conclusion: Higher degree of AFO seemed to be associated with the risks of ischemic heart disease, cerebrovascular disease and lung cancer morbidity among the Chinese adults.