Association between Sleep Duration and Body Mass Index and Waist Circumference

Insufficient sleep may lead to adverse cardio-metabolic effects by influencing body weight, blood pressure, and glucose tolerance. We aimed to assess the relation between sleep duration and indices of obesity including body mass index (BMI) and waist circumference in a sample population in central Iran. We selected a sub-sample of 1770 individuals from Isfahan Healthy Heart Program. The data regarding the sleep duration was collected by using a validated questionnaire. The relation of sleep duration with BMI and waist circumference was examined by using categorical logistic regression with adjustment for sex, BMI, and daily calorie intake. Sleep duration time less than 5 hours/day compared with 7-8 hours/day increased the odds ratio for abdominal obesity in people aged under 60 years [OR=2.49 (95%CI 1.40-4.43)]. In individuals aged under 60 years, this relation was significant for both men, [OR=2.64 (95%CI 1.16- 6.02]) and women [OR=2.38 (95% CI 1.05-5.39)]. In addition, in women, sleep time > 9 hours was negatively related to waist circumference. Sleep duration time less than 5 hours per day increased odds ratio of overweight only in women [OR=1.75 (95% CI 1.07-2.85)]. Sleep duration time under 5 hours in people aged less than 60 years was positively associated with waist circumference. In women, sleep duration time over 9 hours was negatively associated with waist circumference. Only in women, sleep time under 5 hours /night increased BMI. Short sleep duration was associated with abdominal obesity and this was independent of its relation to BMI.