Cross-sectional versus Prospective Associations of Sleep Duration with Changes in Relative Weight and Body Fat Distribution

Abstract

A cross-sectional relation between short sleep and obesity has not been confirmed prospectively. The authors examined the relation between sleep duration and changes in body mass index and waist circumference using the Whitehall II Study, a prospective cohort of 10,308 white-collar British civil servants aged 35-55 years in 1985-1988. Data were gathered in 1997-1999 and 2003-2004. Sleep duration and other covariates were assessed. Changes in body mass index and waist circumference were assessed between the two phases. The incidence of obesity (body mass index: > or =30 kg/m(2)) was assessed among nonobese participants at baseline. In cross-sectional analyses (n = 5,021), there were significant, inverse associations (p < 0.001) between duration of sleep and both body mass index and waist circumference. Compared with 7 hours of sleep, a short duration of sleep (< or =5 hours) was associated with higher body mass index (beta = 0.82 units, 95% confidence interval (CI): 0.38, 1.26) and waist circumference (beta = 1.88 cm, 95% CI: 0.64, 3.12), as well as an increased risk of obesity (odds ratio(adjusted) = 1.65, 95% CI: 1.22, 2.24). In prospective analyses, a short duration of sleep was not associated with significant changes in body mass index (beta = -0.06, 95% CI: -0.26, 0.14) or waist circumference (beta = 0.44, 95% CI: -0.23, 1.12), nor with the incidence of obesity (odds ratio(adjusted) = 1.05, 95% CI: 0.60, 1.82). There is no temporal relation between short duration of sleep and future changes in measures of body weight and central adiposity.

Actigraphic sleep duration and fragmentation are related to obesity in the elderly: the Rotterdam Study

“…This study is the only other large cohort study that we are aware of using actigraphy to measure sleep duration. Stranges et al 34 could not confirm a longitudinal association between sleep duration and weight gain either, although they did find cross-sectional associations between sleep duration and BMI. Persons with more fragmented sleep had a higher BMI and more obesity, and the association of short sleep with obesity was substantially attenuated after adjustment for sleep fragmentation.…”

Sleep Duration and Weight Change in Midlife Women: The SWAN Sleep Study

“…Findings have been less consistent in prospective studies of adults (5,6). Of 14 published studies, 6 have reported associations between short sleep duration and subsequent weight gain in all subgroups examined (7-12), 4 found associations only in selected subgroups (13-16), and 4 found no association (17)(18)(19)(20).…”

“…Findings have been less consistent in prospective studies of adults (5,6). Of 14 published studies, 6 have reported associations between short sleep duration and subsequent weight gain in all subgroups examined (7-12), 4 found associations only in selected subgroups (13-16), and 4 found no association (17)(18)(19)(20).The inconsistency across prior prospective studies in adults may stem from several factors. All but one prior study (21) relied on self-reported sleep duration, usually measured with a single survey item, rather than objective measures such as sleep actigraphy (19).…”

Sleep, sleep-disordered breathing and metabolic consequences

“…Although cross-sectional studies from around the world show a consistent increased risk of obesity among short sleepers in children and adults [32], prospective data seem to fail to show this [33]. Causal inference is difficult due to lack of control for important confounders and inconsistent evidence of temporal sequence in prospective studies [27,32].…”