24-HOUR BLOOD-PRESSURE PROFILE IN ADDISONS-DISEASE

The purpose of this study was to evaluate the circadian blood pressure rhythmicity in patients with primary adrenal insufficiency. Ten newly diagnosed and untreated patients with Addison's disease, 17 addisonia n patients (including the previous 10) following an adequate regimen o f corticosteroid replacement therapy, and 15 healthy subjects as a con trol group were studied. Twenty-four-hour ambulatory blood pressure an d heart rate were measured automatically every 30 min using a Takeda T M-2420 recorder. The runs test, used for detecting blood pressure diur nal rhythm, was compatible with a rhythm in 2 of 10 patients with untr eated Addison's disease, in 13 of 17 patients with treated Addison's d isease, and in 13 of 15 normals. Six of eight addisonian patients show ing no evidence of blood pressure rhythm in the untreated state acquir ed circadian periodicity during therapy. An analysis of blood pressure readings by Fourier series with four harmonics showed that blood pres sure mesor was lower in untreated than in treated addisonian and norma l subjects (P <.05). The nocturnal fall was smaller for systolic and d iastolic blood pressure in untreated than in treated addisonian and no rmal subjects (P <.05). Adrenocortical insufficiency is often characte rized by loss of circadian blood pressure rhythm, and normal rhythm ca n be reestablished by replacement therapy. Lack of cortisol rhythm or persistent activation of the renin-angiotensin system and sympathetic tone may play a role in this phenomenon.