Excessive Napping and Diabetes Share Connection

Scientists have discovered in a new scientific investigation that older people who tend to nap a lot are at a higher risk of developing type II diabetes. The investigation, which was conducted in China, also showed that excessive sleeping causes impaired fasting glucose. Details of the new study appear in the March 1 issue of the respected scientific publication Sleep, PhysOrg reports. The most statistically-significant correlations were recorded in people who napped four to six times per week. They had a 36 percent higher chance of developing diabetes type II than control groups.

People who slept for short periods of time every day of the week exhibited a 28 percent increase in their risk of developing the metabolic disorder. In type II diabetes, the body becomes unable to metabolize the hormone insulin, which is crucially important for breaking down glucose (sugars). Without this control mechanism, the chemicals accumulate, leading to disastrous side-effects. The researchers behind the study say that they controlled for possible influences going the other way, as in if diabetes caused excessive sleepiness, and argue that they found no such correlation. It would indeed appear that excessive napping during the daytime causes the terrible disease.

“In many non-Mediterranean, Western countries a large proportion of those that nap are generally older or have other conditions that cause tiredness and create an urge to nap. The napping can therefore be a marker of disease,” says University of Birmingham reader in epidemiology Neil Thomas, PhD, the lead author of the new paper. He argues that, in China, napping is a norm of sorts, and that it is practiced by people of all ages. Chinese youngsters learn this habit during their infancy, and practice it throughout their lives. In the Western world, aging, deteriorating health status or nighttime complaints, rather than the force of habit, are the main drivers of napping among adults.

The research was conducted on about 19,567 patients, who were recruited between 2003 and 2005, as well as 2005 and 2006. Of these participants, some 5,595 were male, with an average age of 64 years, while the rest were women, aged on average 61 years. This community study took place in Guangzhou, China, and was conducted by a collaboration of researchers, based at the Guangzhou Number 12 People's Hospital and the Universities of Birmingham and Hong Kong. Additional data on the patients were collected from the Guangzhou Biobank Cohort Study.