Overnight weight loss: relationship with sleep structure and heart rate variability

Background: Weight loss can be caused by a loss of body mass due to metabolism and by water loss as unsensible water loss, sweating, or excretion in feces and urine. Although weight loss during sleep is a well-known phenomenon, it has not yet been studied in relation to sleep structure or autonomic tonus during sleep. Our study is proposed to be a first step in assessing the relationship between overnight weight loss, sleep structure, and HRV (heart rate variability) parameters.Methods: Twenty-five healthy volunteers received a 487 kcal meal and 200 ml water before experiment. Volunteers were weighed before and after polysomnography. Absolute and relative weight indices were calculated. Time and frequency domain analysis of heart rate variability was assessed during stages 2, 4, and REM. Nonparametric linear regression analysis was performed between night weight loss parameters, polysomnographic, and HRV ariables. Results: HF correlated positively with weight loss during stage 4. Slow wave sleep duration correlated positively with weight loss and weight loss rate. The duration of Stage 2 correlated negatively with absolute and relative weight loss. Conclusions: Weight loss during sleep is dependent upon sleep stage duration and sleep autonomic tonus. Slow-wave sleep and sleep parasympathetic tonus may be important for weight homeostasis

Sleep promoters and insomnia

The purpose of this updating manuscript is to briefly describe the profile, clinical use and indication of some of the most used sedative and hypnotic compounds. About 2/3 of all hypnotic prescriptions go to chronic use. Benzodiazepines are among the most prescribed drugs worldwide. Women, elderly, psychiatric and medical disease patients are among chronic users of hypnotics. Zolpidem is now the most prescribed hypnotic in most countries. It appears to be safer, compared to benzodazepines, and might be an option for long-term and controlled use (as needed). Sedative antidepressants are also among the most prescribed drug for sedation in insomnia patients in USA and UK. Sedative effect and use of trazodone, mirtazapine, doxepine, amitryptilin are described. The authors also discuss the use of melatonin and its sleep properties, and the rational use of sedative antipsychotics for chronic insomnia, particularly in psychiatric patients. Finally, some phytotherapeutic compounds are mentioned.O objetivo deste artigo de atualização é o de descrever brevemente o perfil, a utilização clínica e a indicação de alguns dos sedativos e compostos hipnóticos mais utilizados. Cerca de 2/3 de todas as prescrições hipnóticas vão para o uso crônico. Os benzodiazepínicos estão entre as drogas mais prescritas mundialmente. As mulheres, os idosos e os pacientes psiquiátricos e clínicos estão entre os usuários crônicos de hipnóticos. O zolpidem é, atualmente, o hipnótico mais prescrito na maioria dos países. Parece ser mais seguro em comparação aos benzodiazepínicos e poderia ser uma opção para o uso de longo prazo e controlado (quando necessário). Os antidepressivos sedativos encontram-se também entre as medicações mais prescritas para sedação em pacientes com insônia nos EUA e no Reino Unido. São descritos efeito sedativo e uso de trazodona, mirtazapina, doxepina e amitriptilina. Os autores também discutem o uso de melatonina e suas propriedades sedativas e o uso racional de antipsicóticos sedativos para insônia crônica, em especial em pacientes psiquiátricos. Finalmente, alguns compostos fitoterápicos são mencionados.Universidade Federal de São Paulo (UNIFESP)Universidade de São Paulo Hospital das Clínicas Centro para Estudos do Sono Instituto de PsiquiatriaHospital Saint AntoineUNIFESPSciEL

Is exercise an alternative treatment for chronic insomnia?

The purposes of this systematic/critical review are: 1) to identify studies on the effects of exercise on chronic insomnia and sleep complaints in middle-aged and older adults and to compare the results of exercise with those obtained with hypnotic medications and 2) to discuss potential mechanisms by which exercise could promote sleep in insomniac patients. We identified studies from 1983 through 2011 using MEDLINE, SCOPUS and Web of Science. For systematic analyses, only studies assessing the chronic effects of exercise on sleep in people with sleep complaints or chronic insomnia were considered. We used the following keywords when searching for articles: insomnia, sleep, sleep complaints, exercise and physical activity. For a critical review, studies were selected on the effects of exercise and possible mechanisms that may explain the effects of exercise on insomnia. We identified five studies that met our inclusion criteria for systematic review. Exercise training is effective at decreasing sleep complaints and insomnia. Aerobic exercise has been more extensively studied, and its effects are similar to those observed after hypnotic medication use. Mechanisms are proposed to explain the effects of exercise on insomnia. There is additional documented evidence on the antidepressant and anti-anxiety effects of exercise. Exercise is effective to decrease sleep complaints and to treat chronic insomnia. Exercise presented similar results when compared with hypnotics; however, prospective studies comparing the effects of exercise with medical and non-medical treatments are warranted before including exercise as a first-line treatment for chronic insomnia are necessary