Energy metabolism differs between sleep stages and begins to increase prior to awakening

• Published in: Metabolism, clinical and experimental clinical and experimental, 2017-04, Vol.69, p.14-23
• Main Authors: Kayaba, Momoko, Park, Insung, Iwayama, Kaito, Seya, Yumi, Ogata, Hitomi, Yajima, Katsuhiko, Satoh, Makoto, Tokuyama, Kumpei
• Format: Article
• Language: English
• Subjects: Adult; Asian Continental Ancestry Group; Body Composition - physiology; Calorimetry, Indirect; Carbohydrate Metabolism - physiology; Endocrinology & Metabolism; Energy Metabolism - physiology; Female; Humans; Male; Metabolic chamber; Oxidation-Reduction; Polysomnography; Semi-parametric regression; Sleep - physiology; Sleep stage; Sleep Stages - physiology; Sleep, REM - physiology; Sleeping metabolic rate; Time after sleep onset; Wakefulness - physiology; Young Adult
• ISSN: 0026-0495; 1532-8600
• DOI: 10.1016/j.metabol.2016.12.016

Abstract Purpose Human sleep is generally consolidated into a single prolonged period, and its metabolic consequence is to impose an extended period of fasting. Changes in sleep stage and homeostatic sleep drive following sleep onset may affect sleeping metabolic rate through cross talk between the mechanisms controlling energy metabolism and sleep. The purpose of this study was to isolate the effects of sleep stage and time after sleep onset on sleeping metabolic rate. Methods The sleeping metabolic rate of 29 healthy adults was measured using whole room indirect calorimetry, during which polysomnographic recording of sleep was performed. The effects of sleep stage and time after sleep onset on sleeping metabolic rate were evaluated using a semi-parametric regression analysis; A parametric analysis was used for the effect of sleep stage and a non-parametric analysis was used for the effect of time. Results Energy expenditure differed significantly between sleep stages: wake after sleep onset (WASO) > stage 2, slow wave sleep (SWS), and REM; stage 1 > stage 2 and SWS; and REM > SWS. Similarly, carbohydrate oxidation differed significantly between sleep stages: WASO > stage 2 and SWS; and stage 1 > SWS. Energy expenditure and carbohydrate oxidation decreased during the first half of sleep followed by an increase during the second half of sleep. Conclusions This study identified characteristic phenotypes in energy expenditure and carbohydrate oxidation indicating that sleeping metabolic rate differs between sleep stages.