Sleep disturbances in midlife unrelated to 32-year diabetes incidence: the prospective population study of women in Gothenburg.

OBJECTIVE To study the relation between diabetes incidence and sleep problems in a population-based sample of women followed for 32 years. RESEARCH DESIGN AND METHODS The researchers conducted a prospective population study initiated in 1968-1969, with follow-ups in 1974-1975, 1980-1981, 1992-1993, and 2000-2001 in Gothenburg, Sweden. A total of 1,462 women born in 1908, 1914, 1918, 1922, and 1930, representative of women of the same ages in the general population, initially participated (90% participation rate). Reported sleep duration, sleep problems, and use of sleeping medication were related to incident diabetes from 1968 to 2000. Associations between sleep problems and diabetes were corrected for waist-to-hip ratio (WHR), BMI, subscapular skinfold, fasting blood glucose and serum lipid concentrations, blood pressure, heart rate, smoking, physical activity, education, and socioeconomic status. Additionally, associations between BMI, WHR, and sleep problems were examined. RESULTS Over 32 years, 126 women (8.7%) developed diabetes. Associations between diabetes and initial sleep problems were tested in a Cox regression analysis, taking into consideration factors associated (P < 0.1) with diabetes. Sleep problems in 1968 did not increase risk of developing diabetes during the following 32 years. Obesity, particularly centralized, was associated with sleep problems. CONCLUSIONS No association between sleep problems and developing diabetes was seen in this 32-year follow-up of middle-aged women. Obesity, on the other hand, known to cause increased risk of diabetes, was associated with current sleep problems.