Comorbidities according to airflow limitation severity: data from comprehensive health examination in Japan

OBJECTIVES The present study aimed to investigate the relationship between airflow limitation (AL) severity and comorbidities in comprehensive health examination. METHODS This cross-sectional study included 6661 men and 6044 women aged 40-89 who underwent a lung function test during medical checkups. AL was defined as forced expiratory volume in 1 s/forced vital capacity of < 0.7. Logistic regression analysis was used to assess the association between AL severity and the presence of comorbidities. RESULTS When compared with the normal lung function group, subjects with AL had a higher prevalence of lung cancer (odd ratio (OR) 9.88, 95% confidence interval (CI) 3.88-25.14) in men, hypertension (OR 1.63, 95% CI 1.26-2.10) in women, diabetes and hyperglycemia (OR 1.23, 95% CI 1.02-1.49 in men, OR 1.61, 95% CI 1.18-2.20 in women) in men and women after adjusting for potential confounders. In men, lung cancer and MetS (the Joint Interim Statement: JIS) were significantly associated with moderate-to-very severe AL after adjustment. In women, hypertension, diabetes and hyperglycemia, MetS (JIS), and MetS (the Japanese Committee of the Criteria for MetS: JCCMS) were significantly associated with mild AL after adjustment. Hypertension was significantly associated with moderate-to-very severe AL after adjustment in women. CONCLUSIONS Significant relationships were found between AL severity and the presence of comorbid lung cancer in men, hypertension in women, diabetes and hyperglycemia, and MetS in men and women. Knowledge of comorbidities associated with AL should be widely publicized to raise the awareness of chronic obstructive pulmonary disease (COPD).