The Sleep/Wake Cycle is Directly Modulated by Changes in Energy Balance

Abstract

Study Objectives: The rise in obesity has been paralleled by a decline in sleep duration in epidemiological studies. However, the potential mechanisms linking energy balance and the sleep/wake cycle are not well understood. We aimed to examine the effects of manipulating energy balance on the sleep/wake cycle. Methods: Twelve healthy normal weight men were housed in a clinical research facility and studied at three time points: baseline, after energy balance was disrupted by 2 days of caloric restriction to 10% of energy requirements, and after energy balance was restored by 2 days of ad libitum/free feeding. Sleep architecture, duration of sleep stages, and sleep-associated respiratory parameters were measured by polysomnography. Results: Two days of caloric restriction significantly increased the duration of deep (stage 4) sleep (16.8% to 21.7% of total sleep time; P = 0.03); an effect which was entirely reversed upon free feeding (P = 0.01). Although the apnea-hypopnea index stayed within the reference range (< 5 events per hour), it decreased significantly from caloric restriction to free feeding (P = 0.03). Caloric restriction was associated with a marked fall in leptin (P < 0.001) and insulin levels (P = 0.002). The fall in orexin levels from baseline to caloric restriction correlated positively with duration of stage 4 sleep (Spearman rho = 0.83, P = 0.01) and negatively with the number of awakenings in caloric restriction (Spearman rho =-0.79, P = 0.01). Conclusions: We demonstrate that changes in energy homeostasis directly and reversibly impact on the sleep/wake cycle. These findings provide a mechanistic framework for investigating the association between sleep duration and obesity risk.

Intensifying sleep slow oscillations does not improve metabolic control in healthy men

“…Food intake has been found in the majority of previous studies to be stimulated by sleep deprivation (e.g., St-Onge et al, 2011;Calvin et al, 2013;Markwald et al, 2013;Nedeltcheva and Scheer, 2014). In the present study, stimulating slow oscillatory activity during SWS, a sleep stage that is malleable by dietary changes (Collet et al, 2016;St-Onge et al, 2016) but to our knowledge has not yet been directly demonstrated to regulate appetite, did not reduce (and on a non-significant level rather increased) energy intake. Santiago et al 13 Against the background of previous observations in young, healthy men that slow oscillation auditory stimulation modulates cognitive (Ngo et al, 2013) as well as endocrine parameters (Besedovsky et al, 2017), we expected this intervention to improve metabolic control in our healthy participants, although it might be argued that its highly selective nature and moderate impact may per se limit effects in the healthy organism.…”

Time-Restricted Eating and Metabolic Syndrome: Current Status and Future Perspectives

“…Misalignment between circadian timing system and daily rhythms of food intake or sleep–wake behavior as a result of genetic, environmental or behavioral factors can contribute to circadian rhythm disruption which adversely impacts metabolic homeostasis and cardiovascular function [ 17 , 21 , 78 , 84 , 85 , 86 , 87 ]. Circadian disruption results in abnormal constant activation or suppression of metabolic regulatory mechanisms, which can cause abnormal glucose metabolism with defective glucose tolerance and insulin resistance [ 17 , 18 , 19 , 20 ].…”

Molecular Mechanisms of Sleep Homeostasis in Flies and Mammals

“…Indeed, it appears that sleep deprivation induced by starvation does not even lead to buildup of sleep drive and so does not impair performance on learning tasks (Thimgan et al 2010). In humans, however, starvation seems to have very different effects, increasing the time spent in the deepest stage of slow wave sleep without changing total sleep time (Collet et al 2016).…”

“…As is now widely recognized, sleep loss has systemic effects on metabolic pathways. Whether these, in turn, modulate sleep remains debatable, although energy balance can influence sleep (Collet et al 2016). In addition, sleep -wake states alter cellular metabolism, which has also been implicated in sleep function.…”