Is the decline in the GH IGF 1 axis associated with age related changes in body composition and function?
Many of the body composition changes and differences in physical and psychological function that occur with aging seem consistent with a GH-IGF-1–deficient state. Indeed, the decrease in GH observed with aging (though milder) is associated with many of the same physiologic abnormalities seen in younger adults with GH deficiency, including:
• Reduced lean body and muscle mass
• Reduced strength and aerobic capacity
• Increased total, central, and intraabdominal (visceral) fat
• High incidence of metabolic syndrome
• Reduced bone mass and density
• Reduced or absent slow-wave (deep) sleep
• High incidence of mood disturbance (depression)
• Deterioration of memory and cognitive function
Despite the association of these changes to both aging in the elderly and GH deficiency in younger adults, causality is still unknown.
