Health In Focus
  • Bedtime may be the best time to take your blood pressure (BP) medicines
  • It significantly lowers the risk of death arising from cardiovascular complications
  • This could substantially reduce the mortality rate due to heart disease

High blood pressure (hypertension) can be controlled much better if the anti-hypertensive medications are taken at bedtime rather than in the morning, finds a new study from the University of Vigo in Spain. The study indicates that those hypertensive patients who took their medications at bedtime had a significantly lower risk of cardiovascular complications, including death or disability, compared to those who took the medications in the morning, which is currently the accepted norm.

The findings of the study, termed 'Hygia Chronotherapy Trial', have been published in the European Heart Journal. This is the largest trial so far that has investigated the influence of the time of day of taking blood pressure-lowering medications on the risk of cardiovascular complications.
Bedtime Could be the Ideal Time to Take Blood Pressure Medicines: Here’s Why

The study, which is a part of the Hygia Project, was led by Professor Ramón C. Hermida, PhD, who is the Founder and Director of the Laboratory of Bioengineering and Chronobiology at the University of Vigo, Pontevedra, Spain.

The importance of the Hygia Chronotherapy Project is summed up in the words of Hermida, who says: "Current guidelines on the treatment of hypertension do not mention or recommend any preferred treatment time. Morning ingestion has been the most common recommendation by physicians based on the misleading goal of reducing morning blood pressure levels. However, the Hygia Project has reported previously that average systolic blood pressure when a person is asleep is the most significant and independent indication of cardiovascular disease risk, regardless of blood pressure measurements taken while awake or when visiting a doctor. Furthermore, there are no studies showing that treating hypertension in the morning improves the reduction in the risk of cardiovascular disease."

Key Features of the Hygia Chronotherapy Trial

  • The Hygia Chronotherapy Trial was conducted between 2008 and 2018
  • A network of 40 primary care centers with 292 doctors was involved in the study
  • Ambulatory blood pressure (BP) was monitored over a 48-hour time span at least once a year during the course of the study
  • Ambulatory BP monitoring provided information of the average BP over a period of 48 hours as well as the fall in BP during sleep
  • The trial included patients of Caucasian Spanish origin, aged 18 years and above
  • 19,084 hypertensive patients (10,614 men and 8,470 women) were included in the trial, who were randomized into the following two groups:
    • Group 1: Patients who took their medicines at bedtime
    • Group 2: Patients who took their medicines in the morning
  • The patients followed a routine of daytime activity and night-time sleep
  • Patients were followed-up for an average of 6.3 years for any cardiovascular complications, including the following:
  • Analysis of data took into account the following factors that could influence the results:

Key Findings of the Hygia Chronotherapy Trial

  • Patients in Group 1 (bedtime medication) had 45 percent lesser risk of suffering cardiovascular complications than patients in Group 2 (morning medication)
  • Reduction in the risk of death from various types of cardiovascular complications in patients belonging to Group 1 are as follows:
    • Heart and blood vessel problems: 66 percent
    • Stroke: 49 percent
    • Myocardial infarction: 44 percent
    • Heart failure: 42 percent
    • Coronary revascularization: 40 percent
  • 1,752 patients died from heart and blood vessel problems or experienced other cardiovascular complications
  • Patients in Group 1 (bedtime medication) had significantly lower average BP throughout the day and night, compared to patients in Group 2 (morning medication)
  • The BP of patients in Group 1 (bedtime medication) dipped more at night, compared to patients in Group 2 (morning medication)
  • Progressive decrease in night-time systolic BP during follow-up was the single-most important predictor of reduced cardiovascular disease risk

Limitations of the Hygia Chronotherapy Trial

The major limitations of the trial include the following:
  • The trial was conducted only in Caucasian Spanish patients and hence, requires to be validated in patients of other ethnicities
  • The trial needs to be conducted in night-shift workers to see if the results varied
  • Patients were not stratified according to the type or class of anti-hypertensive medications being taken

Current Status of the Hygia Project

The Hygia Project is currently conducting the THADEUS Trial (Treatment of Hypertension During Sleep), which aims to determine the best BP level during sleep that could significantly reduce the risk of cardiovascular complications.

Concluding Remarks

Hermida concludes: "The results of this study show that patients who routinely take their anti-hypertensive medication at bedtime, as opposed to when they wake up, have better-controlled blood pressure and, most importantly, a significantly decreased risk of death or illness from heart and blood vessel problems."

Reference :
  1. Bedtime Hypertension Treatment Improves Cardiovascular Risk Reduction: The Hygia Chronotherapy Trial - (

Source: Medindia

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