Sleep duration and central obesity in women - Differences between short sleepers and long sleepers

Objective: To assess characteristics of short sleepers and long sleepers and to assess association between sleep duration and central obesity in a population-based sample of women. Method: Non-pregnant women >= 20 years that were randomly selected from the population-registry of Uppsala, Sweden, answered a questionnaire (n =6461) including questions on sleeping habits and somatic disorders. Results: There was a U-shaped association between sleep duration and waist circumference. Short sleeping women (<5 h) had a waist circumference of 89.2 +/- 14.9 cm (mean +/- SD) decreasing to 82.9 +/- 11.9 cm for women sleeping 7-<8 h and increasing to 89.0 +/- 16.7 cm for women sleeping >= 10 h. Both short sleepers and long sleepers were more often physically inactive, smokers, ill or taking medication, and psychologically distressed than normal sleepers (6-<9 h). In women <50 years both short and long sleep duration were risk factors for central obesity. Short sleep duration remained a risk factor for central obesity, whereas the association with long sleep duration did not reach statistical significance after adjustments. Conclusions: Short sleepers and long sleepers showed differences in characteristics compared to normal sleepers. Furthermore, we showed an independent association between short sleep duration and central obesity, which was strongest in younger women. It is important to identify short sleepers, especially in younger women. (C) 2012 Elsevier B.V. All rights reserved.