Diurnal blood pressure variability in mineralocorticoid excess syndrome

Noninvasive 24-h blood pressure (BP) monitoring has demonstrated a diurnal blood pressure profile in most individuals that is characterized by higher arterial pressures during wakefulness and lower pressures at night during sleep. Recently, reports suggest that this typical diurnal variation is absent in syndromes of autonomic dysfunction and in some forms of secondary hypertension. We investigated the 24-h BP, BP variability, and adrenal steroid concentrations in a patient with deoxycorticosterone (DOC)-secreting adrenal adenoma prior to and following adrenalectomy. Preoperatively, when the patient had a ten-fold increase in serum concentrations of DOC, there was no fall in nocturnal BP despite a marked reduction in heart rate during sleep. Postoperatively, when the concentrations of DOC and other adrenal steroids returned to normal values, the 24-h BP profile normalized with restoration of the nocturnal reduction in pressure. These findings document the effects of mineralocorticoid overproduction on diurnal BP regulation. Intensive investigation of individuals with a well-defined etiology of hypertension and the absence of diurnal variation of BP may lead to further hypotheses that will define the role of both autonomic and nonautonomic factors in BP control.