Impact of obstructive sleep apnea on blood pressure and cardiovascular risk factors in Japanese men: A cross-sectional study in work-site group.

It has been shown that obstructive sleep apnea (OSA) is related to hypertension and cardiovascular disease; however, the prevalence of OSA in general population and the impact of it on blood pressure especially in Japan has not been well determined. We have conducted a screening test for OSA from 2003 to 2011. In addition, a cross-sectional analysis was performed in 2012 to determine the association of OSA and cardiovascular risk factors in Japanese men (18-69 years of age; mean age, 44.4 ± 0.2). The study group consisted of 2208 male employees, and OSA was evaluated by using the 4% oxygen desaturation index and apnea-hypopnea index (AHI). The prevalence of mild-to-moderate (5≤AHI<30) and severe (AHI≥30) OSA in the studied subjects were 7.1%, and 6.1%, respectively. Among the 135 severe OSA subjects, 105 (77.8%) had been treated with continuous positive airway pressure. Both systolic and diastolic blood pressures (DBP) were significantly increased in the subjects with severe OSA compared with those without OSA. These associations in DBP remained observed after adjustment for age, body mass index (BMI), estimated glomerular filtration rate, HbA1c, current alcohol intake, current smoking habits, and OSA treatment. DBP in severe OSA subjects were significantly increased in 1807 subjects who were not treated for hypertension or OSA. However, the levels of blood pressures were not decreased by OSA treatment. These results suggest that the prevalence of OSA is relatively high in middle-aged Japanese men and that blood pressures were elevated in the subjects with severe OSA.