The researchers analyzed data from 133,353 women free of diabetes, cardiovascular disease and cancer, with participants from two cohorts: NHS 30-55 years and NHS II 25-42 years. At the time of study inclusion, 5.9% and 4.8% of women in the NHS and NHS II cohorts, respectively, had sleep difficulties (difficulty falling asleep or staying asleep all or most of the time). During the subsequent 10-year follow-up, 6,407 women developed type 2 diabetes. After correcting for factors such as baseline lifestyle, the researchers found that women with sleep difficulties had a 45% higher risk of diabetes than normal women (aHR 1.45 (1.33 to 1.58)). After correction for hypertension, depression, and BMI, HR=1.22(1.12to1.34). Women with the following four sleep conditions had four times the risk of developing type 2 diabetes (4.17(2.93to5.91)): difficulty sleeping, frequent snoring, sleeping less than six hours per night, sleep apnea (NHS) or shift work (NHS II). Women with two of these conditions have twice the risk of developing diabetes, while the risk rises to three times with all three conditions. Previous studies have shown that sleep difficulties are detrimental to metabolism and can lead to obesity, hypertension and depression, while the current study suggests that sleep deprivation can lead to impaired glucose regulation. The researchers concluded that good sleep patterns are very important and that adequate sleep may prevent type 2 diabetes.