Chronobiology and Chronotherapy of Hypertension – A Review

Hypertension occurs in over 90% of all patients with cardiovascular disease (CVD) in the United States and it is a major risk factor for end-organ damage, CVD and death. In the treatment of hypertension, investigation of chronobiology, chronopharmacology and chronotherapy began a few decades ago. Studies over the last decade have revealed that blood pressure (BP) and CVD are influenced by our behaviour such as what we eat and even conditioned by the time of day. Also, the ability of the night: day ratio of systolic BP predicts the risk for cardiovascular events more accurately compared with office BP measured only at once. Evidence clearly points to the fact that nocturnal BP is indeed the BP as it is most consistently correlated with prediction of cardiovascular risk and provides more close surveillance of safety. Circadian rhythm is a significant input into the regulation of BP. Hence, a circadian disorder such as hypertension requires chronopharmacotherapy. However, different medications have been studied for their chronopharmacology and potential chronotherapy. This article reviews the chronobiology of hypertension, and the chronopharmacology and chronotherapy of the various medications used in its management.