A new study finds that too much sleep, as well as too little sleep, is linked to leading chronic diseases, such as diabetes, coronary heart disease, obesity and anxiety in those aged 45 and over.
The study defines too much sleep as 10 hours or more, and too little as 6 hours or less.
Researchers from the Centers for Disease Control and Prevention (CDC) report their findings in the October issue of the journal SLEEP.
Study co-author Dr. Janet B. Croft, a senior chronic disease epidemiologist in the Division of Population Health at the CDC, says:
"Some of the relationships between unhealthy sleep durations and chronic diseases were partially explained by frequent mental distress and obesity."
For their study, the researchers examined data on over 54,000 people aged 45 and over living in 14 states of the US.
The data showed 31% of the participants were "short sleepers" who slept an average of 6 hours or less in a 24-hour period, over 65% were "optimal sleepers" who slept 6 to 9 hours on average, and 4% were "long sleepers" who slept an average of 10 hours or more.
When they analyzed the relationships between sleep and health, the team found that compared with optimal sleepers, short sleepers tended to suffer more from coronary heart disease, stroke and diabetes, as well as obesity and frequent mental distress.
Dr. M. Safwan Badr, president of the American Academy of Sleep Medicine (AASM), says:
"Sleeping longer doesn't necessarily mean you're sleeping well."
He says people should understand that sleep affects health: a healthy, balanced lifestyle is not just about following a good diet and staying fit, but also getting the right quantity and quality of sleep.
Dr Badr says:
"It's critical that adults aim for 7 to 9 hours of sleep each night to receive the health benefits of sleep, but this is especially true for those battling a chronic condition."
He says people with chronic diseases often suffer from common sleep conditions like apnea and insomnia, which affects their ability to get a good night's sleep. If you wake up exhausted, then you need to get help to identify the problem:
"If you are diagnosed with a sleep illness, treating it could significantly improve disease symptoms and your quality of life."
The researchers call for further studies to look at how mental health and keeping to a normal weight may interact with sleep duration to prevent chronic diseases.
Another study published recently found yoga helped menopausal women with insomnia.