Sleeping fewer than seven hours is associated with a higher risk of developing high blood pressure over time, according to a new study.
While the association between sleep patterns and high blood pressure has been reported, evidence about the nature of this relationship has been inconsistent, according to researchers. In this meta-analysis, researchers pooled data from 16 studies spanning 23 years, evaluating hypertension incidence in 1,044,035 people who did not have a prior history of high blood pressure over a median follow-up of five years (follow-up ranged from 2.4 to 18 years).
Short sleep duration was significantly associated with a higher risk of developing hypertension and the association was found to be even stronger for those getting less than five hours of sleep.
"Based on the most updated data, the less you sleep -- that is less than seven hours a day -- the more likely you will develop high blood pressure in the future," warned study principal investigator Kaveh Hosseini, MD. "We saw a trend between longer sleep durations and a greater occurrence of high blood pressure, but it was not statistically significant. Getting seven to eight hours of sleep, as is recommended by sleep experts, may be the best for your heart too."
The study found that sleeping less than seven hours was associated with a 7% increased risk of developing high blood pressure, which spiked to 11% when reported sleep duration was less than five hours.
While the study did not look at why this might be the case, Hosseini said that disrupted sleep could be to blame. For example, he said lifestyle habits or comorbid conditions such as overeating, alcohol use, nightshift work, certain medication use, anxiety, depression, sleep apnea or other sleep disorders may be factors.
Researchers were surprised there were no age-based differences in the association between sleep duration and hypertension given that sleep patterns tend to shift with age. The age of the participants ranged from 35.4 years to 60.9 years and more than half (61%) were female. When compared with men, females who reported less than seven hours of sleep had a 7% greater risk of developing high blood pressure.
"Getting too little sleep appears to be riskier in females," Hosseini said. "The difference is statistically significant, though we are not sure it's clinically significant and should be further studied. What we do see is that lack of good sleep patterns may increase the risk of high blood pressure, which we know can set the stage for heart disease and stroke."