Ambulatory blood pressure and left ventricular mass in normotensive patients with autosomal dominant polycystic kidney disease

Higher left ventricular mass (LVM) has been found in early stages of autosomal dominant polycystic kidney disease (ADPKD). The mechanisms involved in the increase of LVM are unknown. To investigate whether LVM in ADPKD may be influenced by abnormal diurnal BP variations, the 24-h ambulatory BP profile was analyzed in a group of young normotensive ADPKD patients. Ambulatory BP monitoring and two-dimensional echocardiography were performed in 26 young normotensive ADPKD with normal renal function and in 26 healthy control subjects. LVM index was higher in ADPKD patients than in controls (90.8+/-19.6 g/m2 versus 73.9+/-16.1 g/m2, P = 0.001). Average 24-h and daytime systolic, diastolic, and mean BP were similar in both groups. Nighttime diastolic and mean BP, but not systolic BP, were greater in ADPKD patients. The average and percent nocturnal decrease of systolic BP was lower in ADPKD patients than in control subjects (10.0 mm Hg -3 to 24] versus 15.5 mm Hg -4 to 31], P = 0.009, and 9.0% -2 to 22] versus 14.2% -2 to 25], P = 0.016, respectively). On the basis of their profile BP patterns, 54% of ADPKD subjects and 31% of controls were classified as nondippers (P = 0.092). There were no differences between dippers and nondippers in left ventricular wall thickness, chamber dimensions, and mass indexes. In ADPKD patients, simple regression analysis showed that LVM index was correlated with 24-h, daytime, and nighttime systolic BP. On multiple regression analysis, the 24-h systolic BP was the only variable linked to LVM index. It is concluded that young normotensive ADPKD patients have higher LVM that is closely related to the ambulatory systolic BP. The nocturnal fall in BP is attenuated in these patients, although it is not associated with the higher LVH that they present.