title: Decreasing sleep-time blood pressure determined by ambulatory monitoring reduces cardiovascular risk.
abstract: OBJECTIVE
  We investigated whether reduced cardiovascular risk is more related to the progressive decrease of asleep or awake blood pressure.
  
  
  BACKGROUND
  Independent studies have concluded that elevated sleep-time blood pressure is a better predictor of cardiovascular risk than awake or 24-h blood pressure means. However, the impact on cardiovascular risk of changes in these ambulatory blood pressure characteristics has not been properly investigated.
  
  
  METHODS
  We prospectively studied 3,344 subjects (1,718 men and 1,626 women), 52.6 ± 14.5 years of age, during a median follow-up of 5.6 years. Those with hypertension at baseline were randomized to ingest all their prescribed hypertension medications upon awakening or ≥1 of them at bedtime. Blood pressure was measured for 48 h at baseline and again annually or more frequently (quarterly) if treatment adjustment was required.
  
  
  RESULTS
  With data collected at baseline, when asleep blood pressure was adjusted by awake mean, only the former was a significant predictor of outcome in a Cox proportional hazards model also adjusted for sex, age, and diabetes. Analyses of changes in ambulatory blood pressure during follow-up revealed a 17% reduction in cardiovascular risk for each 5-mm Hg decrease in asleep systolic blood pressure mean (p < 0.001), independently of changes in any other ambulatory blood pressure parameter.
  
  
  CONCLUSIONS
  The sleep-time blood pressure mean is the most significant prognostic marker of cardiovascular morbidity and mortality. Most importantly, the progressive decrease in asleep blood pressure, a novel therapeutic target that requires proper patient evaluation by ambulatory monitoring, was the most significant predictor of event-free survival. (Prognostic Value of Ambulatory Blood Pressure Monitoring in the Prediction of Cardiovascular Events and Effects of Chronotherapy in Relation to Risk [the MAPEC Study]; NCT00295542).
authors: Bioengineering and Chronobiology Laboratories, University of Vigo, Vigo, Pontevedra, Spain. rhermida@uvigo.es
authors: Ramón C
authors: RC
authors: Hermida
authors: Diana E
authors: DE
authors: Ayala
authors: Artemio
authors: A
authors: Mojón
authors: José R
authors: JR
authors: Fernández
mesh_terms: D000328:Adult; D000368:Aged; D000959:Antihypertensive Agents / Q000008:administration & dosage / Q000627:therapeutic use; D001794:Blood Pressure; D018660:Blood Pressure Monitoring, Ambulatory; D002318:Cardiovascular Diseases / Q000453:epidemiology*; D002940:Circadian Rhythm; D005260:Female; D006801:Humans; D006973:Hypertension / Q000188:drug therapy; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012307:Risk Factors; D012890:Sleep / Q000502:physiology*; D013030:Spain / Q000453:epidemiology
chemical_list: D000959:Antihypertensive Agents