Too Much or Too Little Sleep
Increases Diabetes Risk
New Haven, Conn. Men who sleep too
much or too little are at an increased risk of developing Type 2 diabetes, according to a
study by the New England Research Institutes in collaboration with Yale School of Medicine
The data published in the March issue of
Diabetes Care were obtained from 1,709 men, 40 to 70 years old. The men were enrolled in
the Massachusetts Male Aging Study and were followed for 15 years with home visits, a
health questionnaire and blood samples.
Six to eight hours of sleep was found to
be most healthy. In contrast, men who reported they slept between five and six hours per
night were twice as likely to develop diabetes and men who slept more than eight hours per
night were three times as likely to develop diabetes, according to the lead author, H.
Klar Yaggi, M.D., professor in Yales Department of Internal Medicine, pulmonary
section. Previous data from the Nurses Health Study have shown similar results in women.
These elevated risks remained after
adjustment for age, hypertension, smoking status, self-rated health status and
education, Yaggi said.
He said researchers are just beginning to
recognize the hormonal and metabolic implications of too little sleep. Among the
documented effects, Yaggi said, are striking alterations in metabolic and endocrine
function including decreased carbohydrate tolerance, insulin resistance, and lower levels
of the hormone leptin leading to obesity. The mechanisms by which long sleep duration
increase diabetes risk requires further investigation.
There is a lot of interest in
determining whether sleep disturbances such as a reduced amount of sleep or disorders like
sleep apnea may actually worsen the metabolic syndrome, said Yaggi. Metabolic
syndrome is a cluster of risk factors including high blood pressure, obesity, high
cholesterol and insulin resistance which increase the risk for heart disease and stroke.
Co-authors include Andre Araujo and John
McKinlay. The research was supported in part by the National Institute on Aging, the
National Institute of Diabetes and Digestive and Kidney Disorders, the Yale Mentored
Clinical Research Scholars Program from the National Center for Research Resources, and a
career development award from the Veterans Affairs Health Services and Research and
Diabetes Care 29: 657-661 (March 2006)
Source: Yale University