The GH/IGF-I axis in obesity: influence of neuro-endocrine and metabolic factors

In this review we propose an integrated neuro-endocrine-metabolic point of view on the alterations (adaptations?) of GH/IGF-1 axis in obesity, summari zing the evidence from the literature, particularly focusing the data on hu mans and adding where possible results from our studies in this field, It is well-known that GH secretion is deeply impaired in overweight patient s: we reviewed the multiple mechanisms underlying this issue, considering e ither central (CNS-related, such as impairment of GHRH tone or increased so matostatin release) or peripheral tie metabolic: insulin, free fatty acids, glucose) factors. A central point of the debate about GH insufficiency in obesity is if it re presents a simple adaptive phenomenon or reflects a true impairment of the axis activity, Evaluation of IGF-I levels and generation in obesity was the mean used to address this question: a bulk of evidence on IGF-I balance in human obesity has been provided, but the matter is still uncertain and uns olved.