SEATTLE —Patients with insomnia and objective short sleep duration have an increased risk for diabetes, researchers reported at the 23rd Annual Meeting of the Associated Professional Sleep Societies. According to Alexandros Vgontzas, MD, and colleagues, patients with insomnia who slept for five or fewer hours per night had nearly a threefold increased risk of diabetes (odds ratio [OR], 2.95), compared with persons who slept six or more hours. Persons with insomnia who slept for five to six hours per night also had an elevated risk of diabetes (OR, 2.07), when compared with those who slept six hours or more.
“Insomnia with objective short sleep duration is associated with activation of the hypothalamic-pituitary-adrenal axis, [which involves] increased cortisol secretion and activation of the autonomic system that may lead to the development of diabetes,” Dr. Vgontzas told Neurology Reviews. He is the Director of the Center for Sleep Disorder Medicine and Professor of Psychiatry at the Penn State College of Medicine in Hershey.
The study results were based on data from 1,741 men and women who were randomly selected from central Pennsylvania and then examined in a sleep laboratory. Participants with a complaint of insomnia for at least one year were defined as having insomnia, and those with a fasting blood sugar level greater than 126 mg/dL or treatment were defined as having diabetes.
Participants were grouped into three categories regarding polysomnographic sleep duration—those who slept for six or more hours, those who slept five to six hours, and those who slept for five or fewer hours. Logistic regression was used to calculate odds ratios for an association between diabetes and insomnia and short sleep duration. The investigators controlled for age, race, sex, BMI, smoking, alcohol use, depression, sleep- disordered breathing, and weight.
Dr. Vgontzas pointed out that although the findings suggest that people with insomnia have a lower risk for physical problems if their sleep duration is normal, they still are at risk for depression and the adverse behavioral effects of insomnia, and, therefore, should seek treatment.
Long and Short Sleep Linked With Diabetes Risk
According to results from a separate study, persons with short and long sleep duration have a higher risk for diabetes, and persons sleeping for more than eight hours per night have the highest risk, reported Girardin Jean-Louis, PhD, and colleagues.
Dr. Jean-Louis’s group analyzed data from 29,818 persons in the US who completed the 2005 National Health Interview Survey. Participants were between ages 18 and 85; 85% were white, and 56% were women. The researchers observed an OR of 1.24 for diabetes associated with short sleep (five or fewer hours per night) and 1.48 for diabetes associated with long sleep (nine or more hours per night). The prevalence of diabetes was 12% for blacks and 8% for whites, and the prevalence of obesity (BMI of 30 kg/m2 or greater) was 52% for blacks and 38% for whites.
“Both blacks and whites who were obese tended to have short sleep time,” said Dr. Jean-Louis, Associate Professor, State University of New York Downstate Medical Center, Brooklyn Health Disparities Research Center in New York.
“These findings suggest that race significantly influenced the risk of obesity conferred by short sleep duration,” he concluded. “As obesity is associated with diabetes and sleep apnea, more blacks [may be] at risk for sleep apnea and diabetes, which are both linked to cardiovascular disease.”
—Colby Stong