The association between short sleep and obesity after controlling for demographic, lifestyle, work and health related factors

Objective: The relationship between short sleep and obesity remains unclear, and a possible explanation is that many studies have not included sufficient control variables in the analyses. We examined the association between sleep and being overweight or obese after adjusting for the confounding contributions of 17 variables. Methods: A random sample of 1162 Australian adults from three regional cities in central Queensland, Australia, participated in a telephone survey. A series of increasingly complex multinomial logistic regression models were employed to assess the association between short sleep (<= 6 h) being overweight (body mass index [BMI] 25-29.99 kg/m(2)) and obesity (BMI, >= 30 kg/m(2)), while controlling for several demographic, lifestyle, work, and health-related variables. Results: The results suggested obesity was significantly associated with short sleep, age, male gender, lower education level, less physical activity, more sitting time, working longer hours, drinking more alcohol, having diabetes mellitus (DM), and having hypertension. Being overweight was significantly associated with age, male gender, smoking, and working more than 43 hours per week. Conclusions: After adjustment of several confounding variables, a significant association between short sleep and obesity was obtained, but there was no association between short sleep and being overweight. Additional studies applying comprehensive analytic models and stronger research designs are needed to confirm our findings. Crown Copyright (c) 2013 Published by Elsevier B.V. All rights reserved.