Background The aim of this cross-sectional study was to investigate the association between airflow obstruction and the metabolic syndrome (MS) or its components in Japanese men.
Methods The study included 7,189 male subjects, aged 45-88 years, who underwent spirometric lung function tests at a medical check-up. The spirometric criteria for diagnosis of airflow obstruction were forced expiratory volume in 1 second (FEV₁)/forced vital capacity (FVC) <70%. The severity of airflow obstruction was defined according to the Global Initiative for Chronic Obstructive Lung Disease (GOLD) guideline.
Results The prevalence of airflow obstruction was 9.0% and the frequency of MS was 25.6%. In logistic regression models adjusting for age, body mass index, smoking, and alcohol, the risk of MS was higher in subjects with airflow obstruction of GOLD stage II-IV compared to those with normal lung function [odds radio (OR), 1.33; 95% confidence interval (95% CI), 1.01-1.76)]. Of the MS components, waist circumference (OR, 1.76; 95% CI, 1.24-2.50) and blood pressure (OR, 1.37; 95% CI, 1.08-1.74) were associated with airflow obstruction of GOLD stage II-IV, after controlling for potential confounders.
Conclusion Airflow obstruction of GOLD stage II-IV might be associated with MS, waist circumference and blood pressure components in Japanese men.