LEG VERSUS FOREARM FLOW - 24 H MONITORING IN 14 NORMOTENSIVE SUBJECTSAND IN 14 AGE-MATCHED HYPERTENSIVE PATIENTS CONFINED TO BED

A circadian blood pressure rhythm has been demonstrated in the majorit y of subjects, even if inactive during daytime. A rhythm of leg blood now and peripheral resistance, with higher values during sleep than du ring waking, has also been recently shown in subjects confined to bed. Doubts still persist on whether such a rhythm also exists in the fore arm, and whether or not its trend is similar to that found in the leg. In this study, leg and forearm blood flow and resistance were monitor ed noninvasively every 15 min for 22 h in 14 normotensives and 14 age- matched hypertensives confined to bed. A significant blood pressure fa ll (normotensives, -4.8%/-6.1%; hypertensives, -7.1%/-6.3%; all P < .0 001), heart rate decrease (-14.9 in the former, -10% in the latter; bo th P < .0001) and leg now increase (normotensives, +47.4%, hypertensiv es, +36.1%; both P < .0001) were found during sleep in all subjects, b ecause of a blood redistribution probably attributable to activation o f the cholinergic system. Forearm flow was significantly higher during sleep (+26.1%, P < .0001) in the normotensives, whereas in the hypert ensives a slight nocturnal decrease (-1.9%) was found. In conclusion, the hypertensives had lower leg and forearm now than the normotensives during sleep and similar during daytime. Peripheral resistance measur ed in the leg and in the forearm was greater in the former than in the latter, both during sleep and during waking. (C) 1998 American Journa l of Hypertension, Ltd.