Harvard study reveals how lack of sleep increases heart disease risk

A new study out of Harvard University details an association between lack of adequate, restful sleep and increased risk of developing cardiovascular disease. Though the risk has been known for years, the new Harvard research looks at the chemical changes that pave the way for health problems, pointing toward an increase in white blood cell levels that promote clogged arteries.READ: Why broken sleep makes you tired and promotes CVD

Traditional cardiovascular disease risk factors include a lifestyle lacking in exercise, as well as smoking and eating a poor diet. However, past research has also found an association between lack of sleep and increased CVD risk. This risk applies in cases where sleep quality is poor, as well, such as in night-shift workers who may struggle to get restful sleep during daytime hours.

Cardiovascular disease is a major public health issue, claiming around 17.7 million lives every year around the world, according to Harvard. A key component in CVD is atherosclerosis, which is a hardening of the arteries often caused by plaque build-up. The plaque can be composed of what is often called 'bad' cholesterol, but white blood cells can contribute to narrowed arteries by becoming tangled in the fibers connecting plaque together.

Harvard's study looks at how sleep deprivation contributes to increased cardiovascular disease risk. Poor sleep quality and quantity decreases the production of hypocretin, a protein, which prompts blood marrow to boost production of a different protein called CSF-1. Increased CSF-1 then causes an increase in white blood cells, which contributed to the development of larger plaques with more WBCs in sleep-deprived mice.

When supplemented with hypocretin, the researchers noted that sleep-deprived mice experienced a decrease in atherosclerosis. Future research involving humans, not mice, is necessary to determine whether people experience similar effects from sleep deprivation, however.