Objective: To describe the area specific differences in lung function indices and prevalence of airflow obstruction (AFO) in adults found by China Kadoorie Biobank (CKB) study, involving 512 495 adults, in 10 areas in China.
Methods: The detailed information on lung function indices (FEV, and FVC) and prevalence of AFO (diagnosed according to GOLD and LLN criteria) of subjects aged 30-79 years were analyzed, those with abnormal lung function indices at baseline survey were excluded.
Results: The FEV1 and FVC among males (2.66 L, 3.16 L) were higher than those among females (1.99 L, 2.35 L). The FEV1 and FVC were highest in Henan and Harbin. The prevalence of AFO diaonosed according to GOLD criteria was 5.13% in males, higher than that in females (3.75%). The prevalence of AFO was higher in rural area than in urban area (males: 6.32% vs. 3.47%; females: 4.26% vs. 2.97%). The prevalence of AFO was highest in Sichuan (13.34% in males, 10.70% in females), followed by that in Suzhou, Henan and Hunan. The prevalence of AFO diagnosed according to LLN criteria (6.93% in males, 6.29% in females) was higher than that diagnosed according to GOLD criteria, but the area specific difference was similar.
Conclusion: The lung function indices and the prevalence of AFO in adults varied greatly among the 10 areas covered by CKB study.