How Lack of Sleep Increases Your Risk of Heart Attack

A chronic lack of sleep often associated with an increased risk for suffering a heart attack or stroke, and a new study describes a reason why.

The research paper, published in Experimental Physiology, reported that the habitual lack of sleep (less than seven hours per night) was associated with increased morbidity and mortality due in large part to an increased inflammatory burden. Additionally, circulating levels of microRNAs, which are recognized as biomarkers for cardiovascular function and play a key role in regulating vascular health. MicroRNAs act by suppressing gene expression of certain cell proteins.

“They are like cellular brakes, so if beneficial microRNAs are lacking that can have a big impact on the health of the cell,” commented senior author Christopher DeSouza, a professor of Integrative Physiology at the University of Colorado Boulder, in a press release about the study. “Why 7 or 8 hours seems to be the magic number is unclear.”

MicroRNA Likes More Sleep

The researchers looked at 24 adults (12 with normal sleep duration and 12 with short sleep duration). Half of the participants slept between seven and 8.5 hours, while the other half slept five to 6.8 hours nightly. Blood samples were drawn, and circulating levels of microRNA were assayed by RT-PCR. The microRNAs included miR‐34a, miR‐92a, miR‐125a, miR‐126, miR‐145, miR‐146a and miR‐150. Participants were non-smokers, had normal lipids, did not take medications, and were free of overt cardiovascular disease.

According to the paper, circulating levels of miR-125a, miR-126, and miR-146a were significantly reduced in participants with habitual lower sleep than in those with regular duration. There were no significant differences in circulating levels of the other measured microRNA types, however.

Prof. DeSouza’s lab will continue to conduct research into whether restoring normal sleep duration and habits could replenish microRNA levels.

“Don’t underestimate the importance of a good night’s sleep,” he added.