Daily Variation of Blood Pressure in Patients with Cushing's Syndrome

Abstract

The circadian rhythm of blood pressure (BP) was compared between patients with Cushing's syndrome and those with essential hypertension. In patients with essential hypertension, clear nocturnal falls in systolic and diastolic BP and heart rate (HR) were observed, and there was a positive correlation between HR and systolic or diastolic BP. On the other hand, in patients with Cushing's syndrome, there was no nocturnal fall in BP and instead a rise in some cases. In all cases with Cushing's syndrome there was a nocturnal fall in HR, and consequently no significant correlation between HR and BP in these patients. The present results imply that the normal circadian rhythm of blood pressure may be regulated at least in part by the hypothalamo-pituitary-adrenal system. © 1987, Tohoku University Medical Press. All rights reserved.