Short or poor quality sleep is associated with high blood-sugar levels in African-Americans with diabetes, according to new research.

This suggests that one inexpensive way to improve the health of those with type 2 diabetes might be to help them sleep longer and better.

"Sleep is modifiable," said Kristen Knutson, of the department of health studies at the University of Chicago and first author of the paper. "We've known for some time that skimping on sleep can impair glucose tolerance even for healthy people. Now we have evidence connecting chronic partial sleep deprivation and reduced blood-sugar control in patients with diabetes."

"Although we can't be certain whether sleep loss makes diabetes worse or the diabetes interferes with sleep, it only makes sense for everyone, but especially patients with diabetes, to give themselves the opportunity to get enough sleep," Knutson said.

The study focused on 161 African-Americans being treated at the University of Chicago Hospitals for type 2 diabetes. It was published in the Sept. 18, 2006, issue of the Archives of Internal Medici.

Researchers found that, on average, the 161 diabetes sufferers got very little sleep. Mean sleep duration was six hours a night. Only six percent reported getting eight hours of sleep on weeknights and only 22 percent reported getting at least seven hours. Seventy-one percent had poor sleep quality.

Many people with diabetes have painful complications that can interfere with sleep. Even after the researchers excluded 39 patients who reported pain, however, two out of three of the remaining 122 patients reported poor quality sleep.

Insufficient or poor quality sleep was closely associated with higher blood sugar.

Many previous studies have suggested that cutting back on sleep might increase diabetes risk, said Eve Van Cauter, Professor of Medicine at the University of Chicago and senior author of the study. The current study asks the question: is glucose control in subjects who already have diabetes adversely affected by too little sleep or poor sleep?

"Our findings suggest, at least in this study population, that short or poor sleep is associated with decreased blood-sugar control in patients who already have diabetes," she said. "The growing tendency to burn the candle at both ends may be a significant contributor to the current epidemic of diabetes. One way to slow down this epidemic may be to avoid building a chronic sleep debt."