Short Sleepers Risk Type 2 Diabetes and Heart Disease

A new study has found that people who sleep less than six hours a night may be three times more likely to develop incident-impaired fasting glycemia (IFG), a condition that leads to diabetes and heart disease.

Researchers at the University of Warwick (United Kingdom) and the State University of New York (Buffalo, USA) conducted a nested case-control study involving 1,455 participants who were free of type 2 diabetes and known cardiovascular disease at baseline (1996-2001), and who were re-examined during 2003-2004. All participants were aged between 35 and 79 years old, and all completed a clinical examination that included measures of resting blood pressure, height, and weight. They also completed questionnaires about their general health, wellbeing, and sleeping patterns. Average sleep duration was categorized as short (less than 6 hours), mid-range (6 to 8 hours), and long (over 8 hours).

The results, after adjustment for several diabetes risk factors, showed that the odds ratio (OR) of IFG among short sleepers was 3.0, compared to mid-range sleepers. No association was identified between long sleep and IFG. Adjustment for insulin resistance attenuated the association, but only among short sleepers. The study was published in the September 2010 issue of the Annals of Epidemiology.

"Previous studies have shown that short sleep duration results in a 28% increase in mean levels of the appetite stimulating hormone ghrelin so it can affect feeding behaviors,” said study coauthor Saverio Stranges, M.D., of the health sciences research institute at the University of Warwick. "Other studies have also shown that a lack of sleep can decrease glucose tolerance and increases the production of cortisol, a hormone produced in response to stress.”

The longer-term effects of sleep deprivation have been linked to weight gain, diabetes, high blood pressure, heart problems, depression, and substance abuse. There is a decrease in the amount of leptin, an appetite-suppressing hormone, as well as the rise in ghrelin. Too little sleep also interferes with the body's ability to regulate glucose and can cause inflammation leading to heart problems and a rise in blood pressure.

Related Links:
University of Warwick
State University of New York