University of Vigo’s HYGIA Study Reveals Taking Blood Pressure Meds at Night can Save a Life

University of Birmingham Study Analyzes Trials Evidencing Value in Pharmacists-Led CVD Interventions in Health System

A University of Vigo (Spain) researcher, Ramon Hermida, studied the consumption of hypertension medication at bedtime and found that this practice dramatically reduces health risks. Part of the HYGIA Study—including over 19,000 patients—designed in a clinical setting with the Galician Healthcare Service, to prospectively investigate whether cardiovascular risk reduction.

Health System Collaboration

In addition to the University of Vigo, the Galician Healthcare Service, a publicly funded healthcare system of Galicia, Spain, participated in the study.

The HYGIA Study

The HYGIA study was designed to prospectively investigate four elements including 1) the prognostic value of ambulatory blood pressure (BP) monitoring among patients primarily evaluated at primary care settings 2) the impact of changes in ambulatory BP during follow-up cardiovascular cerebrovascular, metabolic and renal risk in hypertensive patients 3) the influence of circadian time of treatment in cardiovascular, cerebrovascular, metabolic and renal risk in hypertensive patients and 4) the prevalence of an altered BP profile as a function of antihypertensive treatment, circadian time of treatment, age, and presence of diabetes, among other factors.

The study targeted 21,983 and ended up recruiting 19,084 hypertension patients (10,614 men and 8,40 women) randomly assigned to take the blood pressure-lowering medications first thing in the morning or in the evening. The study started in 2008 and concluded in 2018 and followed them for a median of six years.


With patients wearing ambulatory blood pressure-measure devices (24 hour monitoring), the investigators found that after factoring out a number of important variables, that the timing of when medications are taken makes a material difference.

For example those patients taking their medications nightly had considerably lower LDL cholesterol, higher HDL cholesterol and reduced sleeping blood pressure. The risks of dying is dramatically less—those taking their medications at bedtime are 45% less likely to die of cardiovascular causes overall, 56% less likely to die of cardiovascular disease; 61% less likely to die of hemorrhagic stroke and 46% less likely to die of ischemic stroke which remains the most common. Moreover bedtime medication led to 34% less likelihood of a heart attack and 49% reduction in risk of stroke.

University of Vigo

Established in 1990, University of Vigo is a public university in Spain.

Lead Research/Investigator

Ramon Hermida 

Call to Action: If you are taking antihypertensive medication, mention this study to your physician and see if they think it relevant to your situation.