Diurnal blood pressure variationin pheochromocytoma, primary aldosteronism and Cushing's syndrome

We examined circadian blood pressure (BP) variation (expressed as a relative night-time BP decline) in subjects with primary aldosteronism (78 patients), pheochromocytoma (n=45) and Cushing's syndrome (n=18). Subjects with aldosterone-producing adenoma (n=21) and pheochromocytoma (n=27) were also investigated after the tumour removal. In all, 65 patients with essential hypertension served as a control group. The night-time BP decline was significantly attenuated in all three forms of endocrine hypertension compared to the control group (primary aldosteronism P<0.0001, pheochromocytoma P<0.0001 for systolic and diastolic BP and Cushing's syndrome P<0.0001/<0.001 vs essential hypertension). In the case of pheochromocytoma, the absence of the night-time BP decrease was more prominent compared to the primary aldosteronism group (P=0.003/0.001) and for the diastolic BP also in comparison with the Cushing's syndrome group (P=0.03). Tumour removal led in both groups to the restoration of the previously altered circadian rhythm (aldosterone-producing adenoma: P=0.0005/0.0009; pheochromocytoma: P=0.001/0.0007). Our study demonstrates a blunted circadian BP variation in all forms of adrenal hypertension in comparison with essential hypertension. This reduction of the night-time BP decrease was more prominent in pheochromocytoma than in primary aldosteronism or Cushing's syndrome.