Sleep plays an important role in the modulation of endocrine function and energy metabolism;hormone levels are markedly different during a sleepless night compared with a night of normal sleep.Sleep deprivation may change the levels of cortisol,growth hormone (GH) and thyrotropin (TSH) at night.In addition,sleep curtailment disturbs the balance of anorexigenic (leptin) and orexigenic (ghrelin) factors,and does harmful to glucose tolerance.