Non-Dipper Pattern is a Determinant of the Inappropriateness of Left Ventricular Mass in Essential Hypertensive Patients

Background and Objectives: Inappropriately high left ventricular mass (iLVM) is known to be related to cardiovascular prognosis. A non-dipper pattern has a greater mean left ventricular (LV) mass than the dipper pattern in hypertensive patients. However, the appropriateness of LV mass in dipper or non-dipper patterns has not been adequately investigated. The aim of this study was to define the relationship between nocturnal dipping and the appropriateness of LV mass. Subjects and Methods: Using the ambulatory blood pressure monitoring (ABPM) database, the data of 361 patients who underwent ABPM and echocardiography was analyzed retrospectively. Appropriateness of LV mass was calculated as observed/predicted ratio of LV mass (OPR) using a Korean-specified equation. Nocturnal dipping was expressed as percent fall in systolic blood pressure (BP) during the night compared to the day. Results: Daytime, nighttime and 24 hours BP in hypertensive patients was 140.4${\pm}$14.8 mmHg, 143.7${\pm}$15.2 mmHg and 129.4${\pm}$20.0 mmHg, respectively. OPR was 106.3${\pm}$19.9% and nocturnal dipping was 10.2${\pm}$10.9 mmHg. In a multiple linear regression model, 24 hours systolic BP ($\beta$=0.097, p=0.043) and nocturnal dipping ($\beta$=-0.098, p=0.046) were independent determinants of OPR as well as age ($\beta$=0.130, p=0.025) and body mass index (BMI) ($\beta$=0.363, p<0.001). Odds ratio of the non-dipper pattern was 2.134 for iLVM (p=0.021) and 3.694 for obesity (p<0.001; BMI >25 kg/$m^{2}$). Conclusion: The non-dipper pattern is independently associated with iLVM in hypertensive patients as well as obesity.