2 research outputs found
Divergent effects of central melanocortin signalling on fat and sucrose preference in humans.
Melanocortin-4-receptor (MC4R)-expressing neurons modulate food intake and preference in rodents but their role in human food preference is unknown. Here we show that compared with lean and weight-matched controls, MC4R deficient individuals exhibited a markedly increased preference for high fat, but a significantly reduced preference for high sucrose food. These effects mirror those in Mc4r null rodents and provide evidence for a central molecular circuit influencing human macronutrient preference.This work was supported by the Wellcome Trust (to A.A.v.d.K., P.C.F., I.S.F.), the National Institute for Health Research Cambridge Biomedical Research Centre (to S.O’R., I.S.F.), the Bernard Wolfe Health Neuroscience Fund (to A.A.v.d.K., I.S.F., P.C.F.) and the European Research Council (I.S.F.). This work was supported by the NeuroFAST consortium which is funded by the European Union’s Seventh Framework Programme (FP7/2007-2013) under grant agreement no 245009.This is the final version of the article. It first appeared from Nature Publishing Group via http://dx.doi.org/10.1038/ncomms1305
The Sleep/Wake Cycle is Directly Modulated by Changes in Energy Balance.
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.Wellcome Trust, National Institute for Health Research Cambridge Biomedical Research Centre, European Research Council, Bernard Wolfe Health Neuroscience Fund, Swiss National Science Foundation (Grant IDs: PBLAP3-145870, P3SMP3-155318), European Society of Endocrinology (Grant ID: IESP), German Research Foundation (Grant ID: TR-SFB 654, B01), NeuroFAST consortium which is funded by the European Union’s Seventh Framework Programme (FP7/2007-2013) (Grant ID: 245009)This is the author accepted manuscript. The final version is available from the Associated Professional Sleep Societies, LLC via http://dx.doi.org/10.5665/sleep.609