Background: Usually, there is a physiological fall in nocturnal blood pressure among all individuals, both hypertensive and normotensive individuals. The lack of nocturnal blood pressure (BP) fall may be associated with the risk of developing cardiovascular complications in hypertensive patients. Cardiovascular and hormonal factors associated with the lack of nocturnal blood pressure fall was studied in individuals aged over 55, those most exposed to this kind of complications.
Methods: A total of 108 individuals aged over 55 and with a wide range of BP (59 normotensive and 49 light-moderate hypertensive with no previous treatment) were studied. Two groups were established: dipper and non-dipper, with a fall over 10% in nocturnal SBP and DBP or not, respectively. Patients included in the study underwent serum hormonal measurements (renin, aldosterone, endoteline-1, atrial natriuretic peptide, free epinephrine and norepinephrine), continuous blood pressure monitoring for 24 hours (CBPM) and echocardiography with measurement of left ventricular mass (LVM), cardiac output, and peripheral vascular resistances (PVR) (determined in function of mean blood pressure and cardiac output).
Results: Fifty-one individuals were dipper and 57 were non-dipper. Significantly higher cholesterol (p < 0.05) and free norepinephrine (p < 0.001) levels among dipper compared with non-dipper individuals were observed. Non-dipper individuals had PVR significantly higher than dipper individuals (p < 0.05). Values of diurnal BP, other hormonal measurements, and CBPM did not differ significantly between the two groups.
Conclusions: Non-dipper individuals aged over 55 have lower circulating free norepinephrine values and higher peripheral vascular resistances than dipper individuals, irrespective of diurnal blood pressure values. The left ventricular mass does not differ significantly between the two groups.