Can Taking Blood Pressure Pills at Night Improve Heart Health?

High blood pressure, also known as hypertension, is a risk factor for cardiovascular disease, stroke, kidney disease, vision loss, and dementia. As it commonly comes with no noticeable symptoms, hypertension is often called the silent killer; up to one in five people do not even know they have the disorder. 

Nearly half of adults in the U.S. have been diagnosed with hypertension, yet only one-quarter of them have their blood pressure under control. Therefore, it’s crucial to get checked regularly to ensure that you are keeping your blood pressure in the optimal range. 

Although there are natural ways to lower blood pressure, millions of Americans take one of the dozens of antihypertensive medications, including beta-blockers, diuretics, ACE inhibitors, and calcium channel blockers, amongst others. To better treat people who are on hypertension medications, researchers are looking to chronotherapy to assess if taking drugs at different times produces beneficial effects.

As the name suggests, chronotherapy medication involves tailoring drug dosages to better match the circadian rhythm, which is the body’s internal 24-hour clock. Chronotherapy can increase the effectiveness of medications and reduce adverse effects if the right timing is discovered.

A recently published study may have discovered the right timing for high blood pressure, with the results favoring antihypertensive medications being taken at bedtime rather than in the morning. This article will detail the results, implications, and takeaways from that research. 

The Study: Chronotherapy and Blood Pressure Medication

Published in the European Heart Journal in October 2019, the Hygia Chronotherapy Trial was a prospective study that included 19,084 Spanish adults who were taking one or more medications for hypertension and were 60 years old, on average. 

The researchers aimed to determine if taking their medications at bedtime, as opposed to upon waking, led to better blood pressure control and a reduction in the risk of cardiovascular-related events, such as heart attack, stroke, or heart failure.

Over a median follow-up period of 6.3 years, the participants had ambulatory blood pressure monitoring (ABPM) done for a 48-hour period at least once per year, along with in-office blood pressure measurements and bloodwork. 

ABPM is considered a better alternative to measuring blood pressure at in-office visits, as “white coat syndrome” commonly spikes blood pressure abnormally. ABPM allows physicians to observe more natural patterns, as the monitor checks blood pressure every 20 to 30 minutes, including during sleep. 

The Results 

The general findings of this study showed that those who took their blood pressure medications at bedtime had better blood pressure control and a significantly reduced risk of several cardiovascular-related outcomes.

At the end of the trial, those in the bedtime medication group were taking significantly fewer antihypertensive drugs; their physicians were able to alter dosages throughout the study based on lower blood pressure readings. 

The researchers controlled for many variables that could also play a role in cardiovascular disease risk, including age, sex, cholesterol levels, smoking status, type 2 diabetes, and chronic kidney disease.

Compared to those in the morning medication group, the bedtime group had significantly improved blood pressure readings and blood work in the following areas: 

• Improved kidney health, as measured by reduced creatinine and increased estimated glomerular filtration rate (eGFR).
• Improved cholesterol panels, with reduced LDL cholesterol and increased HDL cholesterol.
• Reduced systolic and diastolic blood pressure, both at in-office visits and with 48-hour ABPM averages.

The researchers also looked at the hazard ratio (HR) of various cardiovascular-related outcomes; the HR is the relative risk of an event happening at any point in time.

The participants in the bedtime medication group, compared to the upon-waking medication group, had significant HR reductions with many cardiovascular events, including: 

• 45% reduced risk of having a cardiovascular-related event, including a heart attack, stroke, or heart failure
• 66% reduced risk of dying from a cardiovascular-related event
• 49% reduced risk of stroke
• 44% reduced risk of having a coronary event, which includes cardiovascular disease death, heart attack, and coronary revascularization
• 42% reduced risk of heart failure 

The Implications

This was the first randomized controlled trial to assess the effects of medication timing on ambulatory blood pressure and the risk of having cardiovascular events. The results were markedly in favor of taking antihypertensive medications at bedtime rather than first thing in the morning. 

Other chronotherapy research has reported that taking ambulatory blood pressure while asleep is a better predictor of cardiovascular disease than waking or 24-hour average blood pressures. Blood pressure naturally dips in relation to the circadian rhythm, with a normal “dipping” being a 10 to 20% difference in daytime average systolic blood pressure to the nighttime average. A dip below 10% is considered abnormal and is a risk factor for having adverse cardiovascular events. 

In this study, the strongest predictor of reduced cardiovascular disease risk was the progressive decline in sleeping systolic blood pressure in the bedtime medication group. This may indicate that the 45% reduction in the HR for cardiovascular-related events is linked to targeting the body’s biological “dipping” patterns in the night.

Although these results are impressive, more research will need to be done before official changes to blood pressure dosage recommendations are made; this trial was limited in ethnic heterogeneity, as the population studied was primarily made up of Caucasian Spanish individuals.

This study provides evidence that taking antihypertensive medications before bedtime may be more beneficial to controlling blood pressure than taking it in the morning, as well as for reducing the risk of developing or dying from various cardiovascular-related events, including heart attack, stroke, and heart failure. 

If you’re taking a medication for high blood pressure, consult your doctor first before altering when you take your dose.

Key Takeaways

• Taking the full dose of blood pressure medication at bedtime rather than in the morning may be linked to improved blood pressure control.
• In this randomized controlled trial, those in the bedtime group also had significantly reduced risk of several cardiovascular-related outcomes, including heart disease, heart attack, stroke, and heart failure. 
• Uncontrolled blood pressure is a major risk factor for cardiovascular disease, kidney disease, and dementia. Thus, altering the timing of the dosage could greatly reduce this risk and improve heart health. 

Bloomfield D, Park A. Night time blood pressure dip. World J Cardiol. 2015;7(7):373‐376. doi:10.4330/wjc.v7.i7.373

Bowles NP, Thosar SS, Herzig MX, Shea SA. Chronotherapy for Hypertension. Curr Hypertens Rep. 2018;20(11):97. Published 2018 Sep 28. doi:10.1007/s11906-018-0897-4

Hermida RC, Ayala DE, Smolensky MH, Fernández JR, Mojón A, Portaluppi F. Chronotherapy with conventional blood pressure medications improves management of hypertension and reduces cardiovascular and stroke risks. Hypertens Res. 2016;39(5):277‐292. doi:10.1038/hr.2015.142