Individuals who sleep less than 6 hours and more than 10 hours per day may have an increased risk for metabolic syndrome, according to research published in BMC Public Health, reports Healio.

“Both short and long sleep duration have been consistently studied as a risk factor for obesity, hyperglycemia and hypertension,” Claire E. Kim,from Seoul National University College of Medicine, Korea, and colleagues wrote.

Kim and colleagues conducted a cross-sectional study to determine how sleep duration affects metabolic syndrome among adults aged 40 to 69 years (n = 133,608; 44,930 men).

The researchers determined sleep duration by asking participants “In the past year, on average, how many hours/minutes of sleep (including daytime naps) did you take per day?” Sleep was categorized into four categories: less than 6 hours, 6 to 8 hours, 8 to 10 hours and 10 hours or more.