A recent study published in the Journal of the American Heart Association has found that frequent irregularities in sleep duration may increase the risk of developing atherosclerosis, a condition characterized by plaque build-up in the arteries. The study analyzed the sleep data of 2000 adults over the age of 45 and found that going to sleep at different times and frequently changing the amount of time spent sleeping are both risk factors that could potentially lead to hardening of the arteries. Lead author of the study Kelsie Full, an assistant professor at Vanderbilt University’s Division of Epidemiology, noted that “maintaining regular or habitual sleep durations, or sleeping close to the same total amount of time each night, may play an important role in preventing cardiovascular disease.”
The study participants were from different parts of the United States and included various racial and ethnic groups. The results showed that those with greater sleep duration irregularity were more likely to have a high burden of atherosclerosis. Additionally, the researchers observed an association between greater sleep timing irregularity and high coronary artery calcium (CAC). The team hypothesized that the reason why there is a strong association between sleep irregularities and atherosclerosis is due to repeated disruptions to the brain’s circadian rhythm and desynchronization of sleep–wake timing. As the brain’s internal clock regulates most major cardiovascular functions, disruption of the circadian rhythms may lead to an increased risk of atherosclerosis progression.