(HealthDay News) — Women who experience a big increase in hours of sleep each night may face an increased risk of type 2 diabetes, new research suggests. The study appeared online Nov. 2 in Diabetologia.

Elizabeth Cespedes, Sc.D., a research postdoctoral fellow at Kaiser Permanente Division of Research in Oakland, Calif., and colleagues tracked 59,031 American women. The women were nurses between the ages of 55 and 83. The researchers looked for changes in sleep patterns from 1986 to 2000. Then they looked for any connections between sleep changes and cases of type 2 diabetes diagnosed between 2000 and 2012. In that time period, 3,513 women were diagnosed with diabetes.

After the researchers adjusted their statistics to account for changes in factors such as obesity, they found the only statistically significant relationship was in those who added two or more hours of sleep each night. Women whose sleep time grew by two or more hours had 15 percent greater odds of developing type 2 diabetes.

“Some scientists argue that long sleep is a symptom of underlying sleep disorders, depression, or ill health, and that it is these factors, and not long sleep, that increase the risk of diabetes,” Cespedes told HealthDay. But, the researchers tried to account for those factors and still saw “a relationship between large increases in sleep duration and increased risk of diabetes,” she said.

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