Ambulatory blood pressure monitoring provides a unique tool in the evaluation of night-time blood pressure (BP), having a critical role in the detection of a blunted nocturnal fall and of elevated night-time BP. Both nondipping status and nocturnal hypertension are associated with increased cardiovascular risk and target organ damage. The aim of our study was to investigate the impact of both nondipping status and nocturnal hypertension on left ventricular mass (LVM), assessed by means of echocardiography in a consecutive cohort of untreated participants.
A total of 937 individuals were assessed by means of ambulatory blood pressure monitoring and echocardiography. Participants were divided into dippers and nondippers with or without systolic nocturnal hypertension (SNH). SNH was defined as night-time systolic blood pressure of 120 mmHg or more, and nondipping status was defined as an average reduction in systolic blood pressure at night less than 10% compared with the daytime BP.
Dippers and nondippers with SNH presented significantly higher values of left ventricular mass index compared with dippers and nondippers without SNH, respectively. Multiple regression analysis revealed that age (β=0.182, P<0.001), male gender (β=0.168, P<0.001), body mass index (β=0.080, P=0.011), and nocturnal SBP (β=0.174, P=0.037) were significant and independent determinants of LVM. Nondipping status was not found as an independent factor associated with LVM (P=0.136).
Nocturnal hypertension rather than nondipping status seems to be an independent factor associated with left ventricular mass index. The concomitant presence of both nondipping status and nocturnal hypertension is associated with higher LVM, indicating an enhanced cardiovascular risk.