Nocturnal hypertension

Abstract

The importance of nighttime blood pressure and nighttime blood pressure dipping has been demonstrated for decades. Nighttime pressure may be elevated (nocturnal hypertension) in isolation or together with daytime hypertension. Nocturnal blood pressure (BP) has been shown to have a significant predictive value for cardiovascular disease. Abnormal circadian blood pressure patterns associated with elevated sleep blood pressure include non dipping and reverse dipping, both of which are associated with increased target-organ damage and adverse cardiovascular outcomes. Ambulatory BP monitoring is the recommended method for diagnosis of nocturnal hypertension and abnormal nighttime dipping. Home BP measurement is an important technique and a recent study showed that it is more reliable and more strongly associated with LV mass index than office and ambulatory BP measurements. As efficacy of the BP medications wanes during nighttime and early morning, control of nocturnal hypertension and morning hypertension can be difficult. As such, chronotherapy, the dosing of BP medication in the evening, has been an ongoing topic of interest in the field of hypertension. Some studies have shown that chronotherapy is effective in reducing nocturnal BP, improving non dipping and rising patterns to dipping patterns, and improving cardiovascular prognosis. However, criticism and concerns have been raised regarding the design of these studies, and the implausible clinical benefits in cardiovascular outcomes considering the degree of BP lowering from bedtime dosing. Studies have shown that there is no consistent evidence to suggest that routine administration of antihypertensive medications at bedtime can improve nocturnal BP and early morning BP control. It is unclear at this time whether routine bedtime dosing is beneficial for reducing cardiovascular outcomes.