Complaints of poor sleep are common in older populations. Insomnia reduces quality of

life and is often a factor in decisions to seek health care. Sleep complaints often lead to overmedication and sedation of the elderly, with the numerous potential attendant problems, including increased morbidity and mortality. Finally, cognition also declines with advancing age, particularly those cognitive functions that involve novel problem solving and psychomotor processing speed, with its own related impact on the older individual’s ability to function independently. Interventions that could at least stabilize or possibly improve functional capacity, sleep quality, and cognitive function theoretically Inhibitors,research,lifescience,medical have the potential to prolong an older individual’s ability to live independently, and interest in their possible utility is growing rapidly. There is increasing evidence that the functioning of many of these systems may be improved through stimulation Inhibitors,research,lifescience,medical of the “somatotrophic” or growth hormone (GH)-insulinlike growth factor-I (IGF-I) axis. Levels

of GH and IGF-I Inhibitors,research,lifescience,medical rise rapidly at puberty, remain high during early adulthood, and then decline progressively with aging. It has been suggested that with age there is a “somatopause” of GH-IGF-I anabolic status in both sexes, which is reversible by GH restoration or stimulation therapies. Because the aging pituitary remains capable of synthesizing and secreting increased amounts of GH if appropriately stimulated, several recent studies have examined the effects of

VEGFR assay administering GH secretagogues (GHSs) – factors that stimulate Inhibitors,research,lifescience,medical GH secretion – as an alternative to GH treatment. These secretagogues include analogs of the endogenous hypothalamic GHS, growth hormone-releasing hormone (GHRH). Here we briefly review the evidence for such somatotrophic interventions. We also report preliminary findings on the effects of chronic GHRH treatment on the somatotrophic hormones, body composition, functional status, sleep, and cognitive function of healthy older men and women from two major GHRH intervention studies, one recently completed and the other ongoing. Aging, Inhibitors,research,lifescience,medical somatotrophic hormones, and body composition GH is secreted by the pituitary under the hypothalamic control of at least Nature Reviews Genetics three peptide systems: somatostatin (somatotropin-rcleasc inhibiting factor [SRIF]), which inhibits GH secretion; GHRH; and a second recently characterized secretogogue, ghrelin.1 The combined influences of these systems yield a pulsatile pattern of GH secretion in peripheral blood. GH exerts its effects by binding to its own receptor as well as by stimulating the synthesis of IGF-I. The liver is the primary contributor to levels of IGF-I in the systemic circulation, but IGF-I is generated in many GH target tissues, and local effects may be more important than those of circulating IGF-I of hepatic origin.1 With aging, there are declines in the GH-IGF-I axis2 and in lean body mass.