Sleep and heart disease
J Women's Health (2013) DOI:10.1089/jwh.2012.3918
Sleeping for more than 10 hours while experiencing symptoms of insomnia is associated with an almost doubling in the risk of CHD, according to a study of 86,329 women aged between 50 and 79 years.
Over 10.3 years and after adjusting for potential confounders, women with high insomnia scores were 19 per cent and 11 per cent more likely to develop CHD and CVD respectively.
Sleeping for five hours or less or for at least 10 hours increased the risk of CHD by 25 per cent and CVD by 19 per cent after adjusting for age and race. However, these differences were not significant after adjusting for additional factors, such as smoking, body mass index, physical activity, alcohol, depression and other co-morbidities.
Sleep duration and insomnia interacted significantly to increase the risk of CHD and CVD. For example, compared to those sleeping between seven and eight hours women with high insomnia scores who slept for at least ten hours were 93 per cent more likely to develop CHD, even after adjusting for all the factors.
The authors suggest several factors that could account for the link including poor physical health, depression, and conditions linked to low socioeconomic status, such as obesity, mental illness and heart disease.