Loss of the nocturnal decline in blood pressure in subjects with essential hypertension and microalbuminuria

Blood Press Monit. 1996 Dec;1(6):469-473.

Abstract

BACKGROUND: Microalbuminuria, a marker of early renal damage, predicts mortality in non-diabetic subjects. The loss of circadian blood pressure regulation is associated with the severity of essential hypertension and has been reported in hypertension due to renal disease. We therefore looked for a possible link between microalbuminuria and the smaller decrease in nocturnal blood pressure that occurs in essential hypertension.METHODS: The 24 h ambulatory blood pressure of 52 subjects with essential hypertension was measured and their urine tested for microalbuminuria (urinary albumin excretion of 30-300 mg/24 h). RESULTS: The subjects with (n = 10) and without (n = 42) microalbuminuria were comparable in clinical characteristics, antihypertensive treatments and serum creatinine. They had significantly different night-time systolic, diastolic and mean blood pressure decreases on ambulatory blood pressure monitoring. Two-factor analysis of variance showed that the day-night blood pressure decrease was linked to microalbuminuria status. The day-night blood pressure change of subjects with microalbuminuria differed from that of subjects without microalbuminuria independently from the daytime blood pressure level. CONCLUSION: Subjects with essential hypertension and microalbuminuria show a loss of nocturnal blood pressure decline. Whether microalbuminuria indicates a subtype of essential hypertension due to renal disease or severe hypertension with early renal damage remains to be clarified.