Readers and friends often leave messages asking whether it is better for patients with high blood pressure to take antihypertensive drugs in the morning or at night, and our evaluation of "better" is nothing more than two aspects, one is that the stability of blood pressure lowering is better, and the other is that the incidence of cardiovascular events is lower.
There are many clinical trial studies on the timing of antihypertensive drugs, and different studies have given different answers. In view of the routine fluctuation of human blood pressure, waking up in the morning is a dangerous period for the peak of human blood pressure, therefore, many hypertension guidelines recommend taking antihypertensive drugs after waking up in the morning to reduce the cardiovascular risk caused by the morning peak of hypertension.
However, some studies in recent years have found that taking high blood pressure at night has a stronger effect on lowering blood pressure and protecting the cardiovascular system. In a systematic review and meta-analysis study of a large randomized clinical trial published in May 2023 in the Journal of Hypertension, a sub-journal of the AHA, the investigators reviewed and analyzed 72 randomized clinical studies and found that taking antihypertensive drugs at night significantly improved ambulatory blood pressure values at 24/48 hours, significantly reduced systolic and diastolic blood pressure, and decreased the number of cardiovascular events.
Such studies have made many friends realize that taking antihypertensive drugs at night may be a better time to take drugs that are more conducive to lowering blood pressure and reducing the risk of cardiovascular disease, but different studies have given different results. In October 2022, a randomized controlled clinical experimental study published in The Lancet, which followed 26,000 participants for up to 5.2 years, showed that there was no significant difference in the incidence of cardiovascular events in patients with hypertension when taking antihypertensive drugs in the morning and evening, with the proportion of cardiovascular events per 100 in the morning medication group being 0.72 compared to 0.69% in the night medication group. In other words, taking antihypertensive drugs in the morning or at night will not have a significant impact on the incidence of cardiovascular diseases.
The results of such a study will confuse many friends, whether it is better to take blood pressure medication in the morning, or to take blood pressure medication at night, or both, which time is convenient to take at that time? The latest study on the timing of antihypertensive drugs published in The Lancet Clinical Medicine on May 13 may give us new inspiration.
Speaking of this study, it is actually a subgroup analysis of the 2022 TIME study that we shared earlier, through the subgroup analysis, the investigators came up with different results on the best time to take antihypertensive drugs than the total study.
In this study, the researchers selected 5,358 of the 26,000 participants to take the online questionnaire, these participants were randomly assigned, 2,778 chose to take the drug in the morning, while the remaining 2,580 people were assigned to the evening dose, the study analyzed the association between the sleep time of patients who took the drug in the morning and those who were given the drug in the evening, and the median time point of these patients was 3:07 a.m., of which the median time point was 30 minutes earlier, which was considered sleep" Earlier", and those with a 30-minute delay in the median time point were assigned as "late". To put it simply, the more than 5,300 people are divided into two groups according to their sleep time, one is used to getting up early, the other is used to going to bed late, and some are intermediate.
Through cross-analysis of sleep habits, timing of medication and the incidence of cardiovascular events, the researchers found that individual sleep habits are closely related to the choice of the best time to take antihypertensive drugs. The results of the analysis showed that patients who slept late and chose to take antihypertensive drugs in the morning had a significant increase in the risk of cardiovascular and cerebrovascular events such as non-fatal myocardial infarction and hospitalization for stroke, while the risk associated with late sleep patients who took the drug at night did not increase. Specific research data show that for people who are accustomed to going to bed late and those who take medication in the morning, the risk of cardiovascular and cerebrovascular events increases by 46% for every 1 hour of delayed median sleep time!
On the other hand, the risk of hospitalization for myocardial infarction caused by taking antihypertensive drugs in the morning was significantly lower than that of those who took drugs at night.
In terms of separate analysis of stroke risk, there was no interaction between the risk of stroke and the time of taking medication, and sleep time was the main factor affecting the incidence of stroke hospitalization.
The results of such studies tell us that for hypertensive patients, if they are accustomed to going to bed early and waking up early, considering taking antihypertensive drugs after waking up in the morning may be a better time to take the drug to reduce the cardiovascular and cerebrovascular risks, while for hypertensive patients who are accustomed to going to bed late, taking antihypertensive drugs at night may bring higher cardiovascular and cerebrovascular benefits.
The authors of the study pointed out that the results of the study show that it is clinically important for individual sleep habits as a therapeutic target for choosing the time to take antihypertensive drugs, which is a strong supplement to the literature on time therapy for hypertension and an important research result for precision medicine for hypertension. Aligning the timing of administration of antihypertensive drugs with an individual's circadian rhythm type may reduce the incidence of non-fatal cardiovascular and cerebrovascular hospitalization events compared to a "mismatched" dosing time regimen. Future studies need to determine whether cardiovascular risk can be reduced by synchronizing the timing of antihypertensive therapy with the individual's circadian rhythm type.
The correlation between this sleep time and the timing of taking medication can also be preliminarily explained through physiological mechanisms, people who are accustomed to going to bed early and getting up early, the general sympathetic nerve is activated after waking up in the morning, which will lead to vasoconstriction, increased heart rate, and blood pressure will also rise. In this case, taking the medicine at night can better control the risk of high blood pressure at night.
Of course, in real life, many friends' sleep may not be so regular, sometimes they will go to bed early and get up early, sometimes they will go to bed late and get up early or go to bed late and get up late, in this case, you should still understand your own blood pressure fluctuation law, and reasonably choose the time of taking antihypertensive drugs in combination with the actual situation, for example, through ambulatory blood pressure monitoring, you can find that you have a friend with high blood pressure problems at night, taking medicine at night may be more beneficial than taking medicine in the morning, and if you have high blood pressure problems in the morning no matter what time you get up, then choose to take medicine after getting up, It might just be a better choice.
Bibliography:
Pigazzani, F., Dyar, K. A., Morant, S. V., Vetter, C., Rogers, A., Flynn, R. W., ... et al. (2024). Effect of timed dosing of usual antihypertensives according to patient chronotype on cardiovascular outcomes: the Chronotype sub-study cohort of the Treatment in Morning versus Evening (TIME) study. EClinicalMedicine, 72, 102633.