title: Clinical implications of the reduced activity of the GH-IGF-I axis in older men.
abstract: During the last decade, a significant body of evidence has accumulated, indicating that IGF-I might play a role in several pathological conditions commonly seen during aging, such as atherosclerosis and cardiovascular disease (CVD), cognitive decline, dementia, sarcopenia and frailty. A vascular protective role for IGF-I has been suggested because of its ability to stimulate nitric oxide production from endothelial and vascular smooth muscle cells. In cross sectional studies, low IGF-I levels have been associated with unfavorable CVD risk factors profile, such as atherosclerosis, abnormal lipoprotein levels and hypertension, while in prospective studies, lower IGF-I levels predict future development of ischemic heart disease. The fall in IGF-I levels with aging correlates with cognitive decline and it has been suggested that IGF-I plays a role in the development of dementia. IGF-I is highly expressed within the brain and is essential for normal brain development. IGF-I has anti-apoptotic and neuroprotective effects and promotes projection neuron growth, dendritic arborization and synaptogenesis. Collectively, these data are consistent with a causal link between the age-related decline in GH and IGF-I levels and cognitive deficits in older persons. Finally, there is evidence of a relationship between declining GH and IGF-I levels and age-related changes in body composition and physical function. However, few studies have documented a precise role of IGF-I in the development of sarcopenia, frailty and poor mobility. We have recently documented that serum IGF-I is significantly associated with measures of muscle strength and physical performance in men and to a lesser extent in women. In conclusion, IGF-I is a pleiotropic hormone that in older persons may positively affect the cardiovascular system, the central nervous system and physical function.
authors.affiliation: Department of Internal Medicine and Biomedical Sciences, Section of Geriatrics, University of Parma, 43100 Parma, Italy. gpceda@unipr.it
authors.forename: G P
authors.initials: GP
authors.lastname: Ceda
authors.forename: E
authors.initials: E
authors.lastname: Dall'Aglio
authors.forename: M
authors.initials: M
authors.lastname: Maggio
authors.forename: F
authors.initials: F
authors.lastname: Lauretani
authors.forename: S
authors.initials: S
authors.lastname: Bandinelli
authors.forename: C
authors.initials: C
authors.lastname: Falzoi
authors.forename: W
authors.initials: W
authors.lastname: Grimaldi
authors.forename: G
authors.initials: G
authors.lastname: Ceresini
authors.forename: F
authors.initials: F
authors.lastname: Corradi
authors.forename: L
authors.initials: L
authors.lastname: Ferrucci
authors.forename: G
authors.initials: G
authors.lastname: Valenti
authors.forename: A R
authors.initials: AR
authors.lastname: Hoffman
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002318:Cardiovascular Diseases / Q000209:etiology; D013006:Growth Hormone / Q000378:metabolism*; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D008297:Male; D008569:Memory Disorders; D009043:Motor Activity / Q000502:physiology
chemical_list: D007334:Insulin-Like Growth Factor I; D013006:Growth Hormone