The association between sleep duration and obesity in older adults

Abstract

Background: Reduced sleep has been reported to predict obesity in children and young adults. However, studies based on self-report have been unable to identify an association in older populations. In this study, the cross-sectional associations between sleep duration measured objectively and measures of weight and body composition were assessed in two cohorts of older adults.

Methods: Wrist actigraphy was performed for a mean (s.d.) of 5.2 (0.9) nights in 3055 men (age: 67-96 years) participating in the Osteoporotic Fractures in Men Study (MrOS) and 4.1 (0.8) nights in 3052 women (age: 70-99 years) participating in the Study of Osteoporotic Fractures (SOF). A subgroup of 2862 men and 455 women also underwent polysomnography to measure sleep apnea severity.

Results: Compared to those sleeping an average of 7-8 h per night, and after adjusting for multiple risk factors and medical conditions, a sleep duration of less than 5 h was associated with a body mass index (BMI) that was on average 2.5 kg/m(2) (95% confidence interval (CI): 2.0-2.9) greater in men and 1.8 kg/m(2) (95% CI: 1.1-2.4) greater in women. The odds of obesity (BMI >or= 30 kg/m(2)) was 3.7-fold greater (95% CI: 2.7-5.0) in men and 2.3-fold greater in women (95% CI: 1.6-3.1) who slept less than 5 h. Short sleep was also associated with central body fat distribution and increased percent body fat. These associations persisted after adjusting for sleep apnea, insomnia and daytime sleepiness.

Conclusions: In older men and women, actigraphy-ascertained reduced sleep durations are strongly associated with greater adiposity.

Figure 1. Association between body mass index and sleep duration among older men and women

The adjusted mean body mass index with 95% confidence interval is displayed by nocturnal sleep duration for male participants in MrOS and female participants in SOF. Analyses are adjusted for study site, age, race, level of education, smoking status, alcohol and caffeine consumption, use of benzodiazepines and antidepressants, depression, physical activity, history of diabetes, heart disease, and stroke. MrOS: Osteoporotic Fractures in Men Study; SOF: Study of Osteoporotic Fractures.

Figure 2. Association between waist circumference and sleep duration among older men and women

The adjusted mean waist circumference with 95% confidence interval is displayed by nocturnal sleep duration for male participants in MrOS and female participants in SOF. Analyses are adjusted for study site, age, race, level of education, smoking status, alcohol and caffeine consumption, use of benzodiazepines and antidepressants, depression, physical activity, history of diabetes, heart disease, and stroke. MrOS: Osteoporotic Fractures in Men Study; SOF: Study of Osteoporotic Fractures.

Figure 3. Association between percent body fat and sleep duration among older men

The adjusted mean percent fat mass with 95% confidence interval for whole body and trunk by nocturnal sleep duration in male participants of the Osteoporotic Fractures in Men Study. Analyses are adjusted for study site, age, race, level of education, smoking status, alcohol and caffeine consumption, use of benzodiazepines and antidepressants, depression, physical activity, history of diabetes, heart disease, and stroke.