Some studies have suggested that there could be an association between the duration of sleep in humans and development of the obesity. We have analyzed the group of the probands (n = 3970, 2038 males and 1932 females, aged 18-65 years), with permanent address in the Central or South Bohemia. We ascertained the relationship between the duration of their sleep (obtained per questionnaire) and body mass index, weight, height, the value of systolic and diastolic blood pressure, heart rate, waist and hip circumference, the values of total-, high density- and low density- cholesterol, thyroid hormone and body exercise performed. The optimal values of the body mass index (and optimal body weight) were associated with the duration of sleep 7 hours per night (P < 0.001). This association was found both in males and females and in both districts. Other anthropometrical and biochemical parameters were not associated with the sleep duration., V. Adámková ... [et al.]., and Obsahuje seznam literatury
Sleep is regulated by complex biological systems and environmental influences, neither of which is fully clarified. This study demonstrates differential effects of partial sleep deprivation (SD) on sleep architecture and psychomotor vigilance task (PVT) performance using two different protocols (sequentially) that each restricted daily sleep to 3 hours in healthy adult men. The protocols differed only in the period of sleep restriction; in one, sleep was restricted to a 3-hour block from 12:00 AM to 3:00 AM, and in the other, sleep was restricted to a block from 3:00 AM to 6:00 AM. Subjects in the earlier sleep restriction period showed a significantly lower percentage of rapid-eye-movement (REM) sleep after 4 days (17.0 vs. 25.7 %) and a longer latency to the onset of REM sleep (L-REM) after 1 day (78.8 vs. 45.5 min) than they did in the later sleep restriction period. Reaction times on PVT performance were also better (i.e. shorter) in the earlier SR period on day 4 (249.8 vs. 272 ms). These data support the view that earlier-night sleep may be more beneficial for daytime vigilance than later-night sleep. The study also showed that cumulative declines in daytime vigilance resulted from loss of total sleep time, rather than from specific stages, and underscored the reversibility of SR effects with greater amounts of sleep., H. Wu ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy