The present knowledge of the effects of GH and IGF-1 deficiency on aging and lifespan suggests that untreated patients with congenital isolated IGF-1 deficiency seem to reach old age despite marked obesity, development of hyperlipidemia, and a tendency to develop diabetes and its complications, probably because the risk for cancer, a frequent cause of death in the general population, seems to be reduced in these patients [12]. This evidence concerns the gene GH1 and obesity due to melanocortin 4 receptor deficiency.