Diurnal Blood Pressure Changes in Primary Aldosteronism - A Study of Ambulatory Blood Pressure Monitoring and Neurohormonal Changes

The study was aimed to investigate the relationship between the 24-hour blood pressure and neurohormonal change in patients with secondary hypertension. Circadian blood pressure variation was studied in patients with chronic renal failure and primary aldosteronism. Ambulatory blood pressure was monitored every 10 minutes during daytime and every 30 minutes during nighttime. The daytime and nighttime systolic/diastolic blood pressures (SBP/DBP) in patients with primary hyperaldosteronism were significantly higher than those with primary hypertension (SBP:147 16 vs 125 11 mmHg, daytime; 142 23 vs 118 13 mmHg, nighttime; DBP: 96 18 vs 85 8 mmHg, daytime; 91 24 vs 81 9 mmHg, nighttime). In the renal form of secondary hypertension, the blood pressure did not reveal a significant difference with diurnal change in comparison with primary hypertension. The reduction in nocturnal blood pressure was less in primary hyperaldosteronism than in primary hypertension. Insufficient decrease of blood pressure during nighttime may warrant further investigation to diagnose secondary hypertension.