Normal sleeping pattern may prevent heart disease

Individuals who reported a normal sleeping duration of 6–8 hours a night showed a lower chance of developing heart disease or stroke than those who slept for either shorter or longer durations, according to a secondary analysis of the Corinthia study presented at the ACC.20/WCC Virtual Meeting.

“Sleep is an essential physiological process, and disturbance of sleep duration may be associated with atherosclerosis,” said lead author Dr Evangelos Oikonomou from the National and Kapodistrian University of Athens, Greece.

A total of 2,043 participants (mean age 64 years) living in the Corinthia region of Greece were included in this present study. All subjects underwent ultrasonography to measure intima media thickness (IMT), the inner part of the arterial wall, and thickening reflects plaque build-up which is associated with increased stroke risk and other cardiovascular diseases. An IMT of >1.5 mm or protrusion of >50 percent was defined as an atherosclerotic plaque. Surveys were used to record total sleeping durations, which were categorized as normal (6–8 hours/night), short (<6 hours/night), and long (>8 hours/night). [ACC.20/WCC, abstract 1360-87]

Subjects who slept for normal duration had a significantly lower mean IMT, indicating lower carotid atherosclerosis burden, than those who slept for shorter or longer durations (0.98 vs 1.07 or 1.07 mm, respectively; p=0.001).

Individuals with normal sleep duration also had a significantly decreased carotid atherosclerotic plaque than those with short or long sleep durations (23 percent vs 30 percent or 29 percent; p=0.016).

After adjusting for potential confounders, subjects who reported short or long sleep durations were more likely to have an increased carotid atheromatic plaque at 54 percent or 39 percent, respectively, than those who reported normal sleep duration.

“We don’t fully understand the relationship between sleep and cardiovascular health. It could be that sympathetic nervous system withdrawal or a slowing [of this system] that occurs during sleep may act as a recovery phase for vascular and cardiac strain,” said Oikonomou.

“Moreover, short sleep duration may be associated with increased cardiovascular risk factors — for example, unhealthy diet, stress, being overweight, or greater alcohol consumption — whereas longer sleep duration may be associated with a less active lifestyle pattern and lower physical activity,” he added. “[Therefore,] the message, based on our findings, is ‘sleep well, but not too well.’ Getting too little sleep appears bad for your health but too much seems to be harmful as well”.

Oikonomou concluded that a balanced amount of sleep, 6–8 hours daily, could be an added cardioprotective factor for individuals living in modern western type societies, while shorter and longer sleep duration provides evidence of cardiovascular risk factor.