People who get fewer than six hours of sleep at night are prone to abnormal blood sugar levels, possibly putting them at risk for diabetes, U.S. researchers said on Wednesday.

They said people in a study who slept less than six hours were 4.5 times more likely to develop abnormal blood sugar readings in six years compared with those who slept longer.

“This study supports growing evidence of the association of inadequate sleep with adverse health issues,” said Lisa Rafalson of the University at Buffalo in New York, who presented her findings at the Conference on Cardiovascular Disease Epidemiology and Prevention in Palm Harbor, Florida.

Several studies have shown negative health consequences related to getting too little sleep. In children, studies showed it raises the risk of obesity, depression and high blood pressure. In older adults, it increases the risk of falls. And in the middle aged, it raises the risk of infections, heart disease, stroke and cancer.

Adults typically need between seven and nine hours of nightly sleep, according to the U.S. Centers for Disease Control and Prevention.

Rafalson and colleagues wanted to see if lack of sleep might be raising the risk for type 2 diabetes, the kind that is being driven by rising rates of obesity and sedentary lifestyles. It develops when the body makes too much insulin and does not efficiently use the insulin it makes, a condition known as insulin resistance.

Using data from a large, six-year study, they identified 91 people whose blood sugar rose during the study period and compared them to 273 people whose glucose levels remained in the normal range.

They found the short sleepers were far more likely to develop impaired fasting glucose - a condition that can lead to type 2 diabetes - during the study period than those who slept six to eight hours.

That difference held even after adjusting for age, obesity, heart rate, high blood pressure, family history of diabetes and symptoms of depression.

“Our findings will hopefully spur additional research into this very complex area of sleep and illness,” Rafalson said in a statement.

CHICAGO (Reuters)