Given the emerging knowledge that circadian rhythmicity exists in every
cell and all organ systems, there is increasing interest in the possible
benefits of chronotherapy for many diseases. There is a well-documented 24-h
pattern of blood pressure with a morning surge that may contribute to the
observed morning increase in adverse cardiovascular events. Historically,
antihypertensive therapy involves morning doses, usually aimed at reducing
daytime blood pressure surges, but an absence of nocturnal dipping blood
pressure is also associated with increased cardiovascular risk. To more
effectively reduce nocturnal blood pressure and still counteract the morning
surge in blood pressure, a number of studies have examined moving one or more
antihypertensives from morning to bedtime dosing. More recently, such studies of
chronotherapy have studied comorbid populations including obstructive sleep
apnea, chronic kidney disease, or diabetes. Here, we summarize major findings
from recent research in this area (2013-2017). In general, nighttime
administration of antihypertensives improved overall 24-h blood pressure
profiles regardless of disease comorbidity. However, inconsistencies between
studies suggest a need for more prospective randomized controlled trials with
sufficient statistical power. In addition, experimental studies to ascertain
mechanisms by which chronotherapy is beneficial could aid drug design and
guidelines for timed administration.