Abnormal nocturnal blood pressure falls in elderly hypertension: clinical significance and determinants.

Abnormal patterns of diurnal blood pressure variation have been reported to be related to advanced target organ damage and poor cardiovascular prognosis. We studied silent cerebrovascular disease and stroke events in older Japanese patients with different nocturnal blood pressure dipping. There was a J-shaped relationship of nocturnal dipping status with silent cerebral infarcts detected by brain magnetic resonance imaging at baseline, and with stroke incidence during the follow-up period. The extreme-dippers (with marked nocturnal blood pressure dipping) and the risers (with higher nocturnal blood pressure than awake blood pressure) had a higher prevalence of silent cerebral infarcts and a poorer stroke prognosis than those with appropriate nocturnal blood pressure dipping (dippers). The extreme-dippers tended to have predominant systolic hypertension and increased blood pressure variability. Several factors affect the diurnal blood pressure variation pattern. The non-dipping pattern is associated with autonomic nervous dysfunction and poor sleep quality due to nocturnal behavior and sleep apnea. The extreme-dippers might have increased arterial stiffness with reduced circulating blood volume in addition to an excessive morning surge due to alpha-adrenergic hyperactivity. Anti-hypertensive medication that normalizes the diurnal blood pressure variation might improve the cardiovascular prognosis in high-risk hypertensive patients.