Irregular Sleep Could Hurt Your Heart

We know a bad night’s sleep can make us tired, irritable, and distracted the next day. It could also be harmful to your heart and increase your chance for developing heart disease.

A longitudinal cohort study recently published in the Journal of the American Heart Association studied over 2,000 older adults between the ages of 45 and 84 years in Minnesota, Maryland, Illinois, North Carolina, California, and New York. From 2010 to 2013, the researchers conducted sleep assessments in which the participants kept a sleep diary over seven consecutive days and wore a wristwatch that tracked their sleep and wake history. They also underwent assessments of their cardiovascular health.

The researchers found that the participants with a higher degree of sleep irregularity (defined as those that varied more than two hours within a week) were more likely to have higher rates of plaque buildup in arteries (atherosclerosis). As plaque accumulates, the walls of the blood vessels thicken, which reduces blood flow and decreases oxygen and other nutrients to the rest of the body. Atherosclerosis can lead to various heart conditions including heart attacks, strokes, coronary heart disease, angina, and carotid or peripheral artery disease.

The biggest surprise to researchers was that 30% of the study participants experienced irregular sleep patterns that varied more than 90 minutes over the course of the week. This is consistent with prior research that suggests that irregular sleep patterns are not confined to shift workers, but experienced by a large proportion of the general public.

Keeping a regular sleep schedule may be an important factor in preventing heart disease. The American Heart Association recommends seven to nine hours of sleep each night, and various sleep hygiene practices such as going to bed and waking up at the same time each day, turning off all screens an hour before bed, making sure the bedroom is dark and quiet, and avoiding caffeine in the afternoons can all help contribute to healthier sleep.