Urinary sodium excretion and ambulatory blood pressure findings in patients with hypertension.

Use of ambulatory blood pressure (BP) monitoring (ABPM) allows for identification of dipping, nondipping, extreme dipping, and reverse dipping of BP. Using office BP and ABPM, hypertension subtypes can be identified: sustained normotension (SNT), white-coat hypertension, masked hypertension, and sustained hypertension. The comparison of hemodynamic parameters and salt intake has not been investigated among these patient groups. Office BP, ABPM, augmentation index (AIx), pulse wave velocity (PWV), cardiac output (CO), and total peripheral resistance (TPR) were automatically measured. Estimation of salt intake was assessed by 24-hour urinary sodium excretion. Urinary sodium excretion was not different among groups. AIx, PWV, CO, and TPR were lowest in patients with SNT. CO was lowest while AIx adjusted for a heart rate of 75 beats per minute, PWV, and TPR were highest in the extreme dipper group. No relationship was detected between hypertension subtypes and urinary sodium excretion.