Ambulatory blood pressure monitoring before and after treatment in secondary forms of hypertension

Objective: Studies using ambulatory blood pressure (BP) monitoring (ABPM) have reported that in some secondary forms of hypertension the normal nocturnal BP decrease is blunted. Design and method: The aim of our study was to compare the nocturnal BP decrease in patients with secondary hypertension before and after treatment. ABPM was performed using the validated Meditech ABPM-06. ABPM readings were obtained at 30-minute intervals for 24-hour in patients with secondary hypertension before and after treatment. The diagnosis of secondary hypertension was based on the history and laboratory data: plasma and urinary electrolytes, renal function, calcium-phosphorus system, the renin-angiotensin-aldosterone system, urinary free cortisol, suppressibility of cortisol after 1 mg dexamethasone, plasma adrenocorticotropic hormone, plasma D4 androstenedione, plasma dehydroepiandrosterone sulphate, plasma 17-alpha hydroxyprogesterone, plasma testosterone, and urinary metanephrine. BP decrease were studied in the following groups: 42 patients with primary aldosteronism (19 men and 23 women; mean age, 44±12 years), 25 patients with adrenal pheochromocytoma (11 men and 14 women; mean age, 42±13 years), and 55 patients with Cushing's syndrome (18 men and 37 women, mean age, 43±13 years). Results: Average systolic/diastolic BP decrease was: before 2/1 mmHg and after 8/6 mmHg treatment in patients with primary aldosteronism. Average systolic/diastolic BP decrease was: before 4/5 mmHg and after 9/12 mmHg treatment in patients with adrenal pheochromocytoma. Average systolic/diastolic BP decrease was: before 3/2 mmHg and after 11/9 mmHg treatment in patients with Cushing's syndrome. All differences in systolic/diastolic BP decrease were statistically significant, with a P value <.001 Conclusions: The results of our study confirm that secondary causes of hypertension lead to a reduced decrease in blood pressure during sleep. After proper treatment reduction in nighttime BP normalizes. A detailed analysis of ABPM can lead us to find the accurate etiology of hypertension.