Unlike the standard blood-pressure reading taken in a doctor's office, this round-the-clock tracking -- called ambulatory blood-pressure monitoring (ABPM) -- gives a clearer picture of a person's blood pressure both during the day and the important sleep-time period.
After more than five years of follow-up, those who took at least one of their blood-pressure pills at night seemed to reap significant benefits. Sixty-two percent had controlled blood pressure over the 24-hour period, compared to 53 percent of those who took all their pills in the morning. Moreover, only 34 percent of this group were "nondippers," vs. 62 percent of the morning-medications group, the study authors said.
Those who routinely took at least one of their blood-pressure medicines at night experienced only one-third of the cardiovascular events -- including angina, stroke and heart attack -- suffered by those who swallowed all their blood-pressure pills in the morning, the study found.
"The results of the study indicate that the way we diagnose and treat hypertension needs to be completely reevaluated," said Michael Smolensky, co-author of an accompanying journal article and an adjunct professor in the department of biomedical engineering at the University of Texas at Austin.
One reason blood-pressure medications are more effective when taken before bed: They prevent the release of chemicals synthesized during the sleep span that raise blood pressure to abnormal levels, said Smolensky, the journal's editor. Synchronizing blood-pressure medications to the circadian body clock "optimizes the medications' therapeutic benefit and sometimes lessens their unwanted side effects," he said.
This is not the first study to show the benefits of night-time dosing of blood-pressure medications, Smolensky said. "However, it is the first in which ABPM was done very frequently
All rights reserved