Don’t lose sleep over it: That’s good advice when it comes to reducing your risk of developing type 2 diabetes, according to a new study.

Researchers at Columbia University followed about 9,000 people between the ages of 32 and 86, who had taken part in follow-up studies of the first National Health and Nutrition Examination Survey. The follow-up evaluation period spanned the years 1982 to 1992.

Participants who slept 5 or fewer hours, or 9 or more hours, were significantly more likely to have diabetes at the time of the follow-up study.

This study joins a host of others that demonstrate that people who aren’t getting enough sleep put themselves at a higher risk for diabetes. “Sleep should be given a higher priority, so that we make sure we get enough of it,” says study author James E. Gangwisch, PhD, of Columbia University. His study offers support to some other studies that showed mixed results or used smaller sample sizes, Gangwisch says. Also, the new study controls for several variables that could otherwise be causing the increased risk of diabetes, and examines the study subjects over a period of time rather than taking a cross-section at one point in time.

“There’s a relationship between short sleep duration and obesity and hypertension” [high blood pressure], Gangwisch says. “Even after we control for those, there’s still a significant relationship between sleep deprivation and diabetes. There’s a definite effect that makes sense because of the experimental studies that show that depriving subjects of sleep compromised their insulin sensitivity. That, over time, could lead to diabetes.”

Despite the fact that the 9-hour-plus sleepers also had a greater risk of diabetes, researchers concluded that there was not the same causal link. Instead, they attributed the higher rate of diabetes in the longer sleepers to other issues, including the inflammatory process that comes with insulin resistance, and sleep apnea. In other words, the diabetes was causing the sleep, not the other way around. “There’s no evidence to suggest that long sleep duration is bad for you in any way,” says Gangwisch.

He added that more research needs to be done to understand the mechanisms behind the relationship between sleep and diabetes. Until then, people may ward off diabetes and experience other health benefits by getting the recommended 7 to 9 hours of sleep a night. “Even if a person already does have diabetes, just like with diet and exercise, we should be trying to control sleep habits and to get adequate sleep,” Gangwisch says.