[Absence of nocturnal dipping is associated with stroke and myocardium infarction]

The arterial hypertension varies in according to the circadian cycle, presenting physiologic fall of blood pressure (BP) during sleep (dipping). The absence of this fall or its increase associates to higher incidence of target-organ damages.

To analyze the prevalence of dipping in hypertensive individuals, to correlate dipping to the blood pressure levels, clinic, and socio-demographic factors, and biochemical characteristics and to associate it cardiovascular events (stroke and myocardial infarction).

Hypertensive individuals were submitted to the ambulatory blood pressure monitoring. Presence of dipper was defined as fall >10% of the systolic BP of the day for sleep.

163 evaluated patients were divided in dippers (D, n=53) and nondippers (ND, n=110). Between the groups there was not significant difference to the age, sex, race, time of hypertension, glycemia, LDL-cholesterol, total cholesterol, triglycerides, schooling, smoking, and history of diabetes. D presented BP higher than the ND during the day and lower during sleep. ND had higher body mass index (BMI) (p=0.0377), lower level of HDL-cholesterol (p=0.0189), and higher pulse pressure during sleep (p=0.0025). History of stroke alone (p=0,046) and combined with myocardial infarction (p=0.032) were more frequent in nondippers individuals. In the logistic regression, only ND was associated independently with stroke or myocardial infarction.

ND was associated in an independent way with the target-organ damages analyzed, what demonstrates its importance and strengthens the necessity of more aggressive treatment with objective to reach BP goals e, consequently, to prevent the development of new cardiologic and cerebrovascular events.