Impact of obstructive sleep apnea and hypertension on left ventricular hypertrophy in Japanese patients

The incidence of cardiovascular disease and mortality rates are high among patients with left ventricular hypertrophy (LVH). Obstructive sleep apnea (OSA) has been reported to increase left ventricular mass (LVM) and cause LVH. The prevalence of hypertension, a major cause of increased LVM, is high in OSA; however, it is still unknown whether OSA is an independent factor that increases LVM in addition to triggering LVH. This study investigated out-of-office blood pressure (BP) via ambulatory BP monitoring (ABPM) in patients with OSA diagnosed by polysomnography (PSG) and sought to determine the effects of OSA and hypertension on LVM. A total of 432 patients with OSA underwent ABPM and echocardiography. These patients were stratified into four groups according to their left ventricular mass index (LVMI) quartiles, and the component factors influencing LVMI, such as patient background, sleep data and all-day BP data, were analyzed. This study included 356 men and 76 women. The mean age was 54.6 +/- 13.2 years, the mean body mass index was 26.7 +/- 4.6 kg m(-2) and the mean apnea-hypopnea index (AHI) was 37.9 +/- 22.5. Multivariate analysis indicated that antihypertensive agent use (beta = 0.143, P = 0.002), an AHI >= 15/h (beta = 0.100, P = 0.045) and 24-h systolic BP (beta = 0.252, P<0.001) were significant independent factors for increased LVM. The significant LVMI component factors in OSA patients were an AHI >= 15/h and 24-h systolic BP. The results of this study demonstrated that both elevated BP and OSA were independently associated with increased LVM.