NOCTURNAL OSCILLATIONS IN PLASMA-RENIN ACTIVITY DURING SLEEP IN HYPERTENSIVE PATIENTS - THE INFLUENCE OF PERINDOPRIL

In previous studies, we established a strong concordance between nocturnal oscillations in plasma renin activity (PRA) and REM-NREM sleep cycles. To determine whether this relation persists in the case of moderate essential hypertension and if it is influenced by antihypertensive therapies affecting renin release, six normal subjects and six hypertensive patients were studied. The normal subjects underwent one control night. The hypertensive patients were studied during a first night when a placebo was given. Four of them underwent a second night following a single dose of an angiotensin-converting enzyme (ACE) inhibitor, perindopril; and a third night, 45 days later, with the antihypertensive treatment. In addition, two of the patients underwent two night-studies, after a single and repeated doses of a beta-blocker, atenolol, to see whether preventing renin release modified the sleep structure. The relationship between the nocturnal PRA oscillations and the sleep stage patterns persisted in hypertensive patients receiving placebo. In patients who had low PRA levels, the increases associated with NREM sleep were small. However, the mean relative amplitude of the oscillations, expressed as a percentage of the nocturnal mean, was about 60%, which was similar to that in normotensive subjects. Active renin and PRA oscillations were closely coupled. ACE activity profiles displayed damped fluctuations and no systematic relationship with sleep stages. Perindopril, in single or repeated doses led to striking increases in PRA and amplified the nocturnal oscillations without disturbing their relationship to specific sleep stages. Atenolol almost supressed PRA fluctuations, while regular REM-NREM sleep cycles persisted. These results indicate that the relation between PRA oscillations and sleep stage alternation persists in moderate essential hypertension, and is preserved during perindopril therapy which increases the oscillation amplitude. © 1990, Italian Society of Endocrinology (SIE). All rights reserved.