Cardiovascular risk in aging and obesity: Is there a role for GH?

GH has significant impact in adults. In fact, patients with the GH deficiency (GHD) syndrome are now recognized as having an increased cardiovascular risk. The effects of human aging on GH secretion have been evaluated by a number of researchers. Studies of 24 h secretion of GH have shown variable reductions in most 24-h GH secretory parameters in middle-aged and in older men and women, resulting in a decrease in plasma levels of its anabolic mediator IGF-I. Obesity is also associated with several endocrine and metabolic abnormalities. These include decreased serum GH concentrations, reduced GH half-life, frequency of GH secretory episodes and daily GH production rate. The mechanism of the low GH in obesity is not completely understood nor is it clear whether its relationship with visceral adiposity is causal. The aim of this article will be to review the available clinical data concerning the potential involvement of "subclinical" or perhaps better "functional" GHD, which is observed in aging and obesity, in the increase in cardiovascular risk which characterizes these two conditions.