Obesity and sleep in adolescents

Over the past several decades, the prevalence of obesity in children and adolescents has grown to epidemic proportions. Concomitant with the increase in the prevalence of obesity, our society is facing a progressive reduction in sleep duration. The two secular trends mirror each other and it is possible that short sleep duration may be one of the modifiable contributing factors to the obesity pandemic. An inverse relationship between sleep duration and body weight have been reported in several epidemiologic studies. In addition, data from recent years indicate that short sleep duration and poor sleep quality affect glucose homeostasis. The mechanism linking short sleep duration with weight gain is unknown, but there is growing evidence that the two hormones, leptin and ghrelin as well as the orexin system are involved. The increase in both the prevalence of obesity and its severity has also translated into a corresponding increase in the prevalence of obesity-associated morbidities, such as type 2 diabetes mellitus and insulin resistance, dyslipidemia, systemic hypertension, atherosclerosis and ischemic heart disease, non alcoholic fatty liver/steatohepatitis, psychosocial complications and decreased quality of life, as well as obstructive sleep apnea syndrome (OSAS) and the obesity hypoventilation syndrome. The implications of OSAS in children and adolescents, especially obese, are broad and sometimes complex. If left untreated or alternatively if treated late, OSAS may lead to substantial morbidity that affects multiple target organs and systems and that may not be completely reversible with appropriate treatment, if the latter is instituted late.