title: Insulin-like growth factor I (IGF-I) and cognitive decline in older persons.
abstract: Insulin-like growth factor I (IGF-I) deficiency may be involved in cognitive deficits seen with aging, and in neurodegenerative diseases such as Alzheimer's disease. The objective of this study was to investigate whether IGF-I is associated with cognitive performance and 3-year cognitive decline in 1318 subjects, aged 65-88 years. Cross-sectionally, IGF-I was directly related to information processing speed, memory, fluid intelligence, and Mini-Mental State Examination (MMSE) score, but these associations did not remain significant after adjustment for age and other factors. Analysis in quintiles of IGF-I revealed a threshold effect of low IGF-I on information processing speed, with lower speed in subjects in the lowest quintile of IGF-I (<9.4 nmol/l)(1) versus those in the other four quintiles (fully adjusted B=-0.89; 95% CI, -1.72 to -0.05). This threshold of low IGF-I was also observed for 3-year decline in information processing speed (adjusted RR=1.78; 95% CI, 1.19-2.68). In summary, this study suggests that IGF-I levels below 9.4 nmol/l are negatively associated with both the level and decline of information processing speed.
authors.affiliation: Institute for Research in Extramural Medicine (EMGO Institute), VU University Medical Center, 1081 BT, Amsterdam, The Netherlands. mg.dik.emgo@med.vu.nl
authors.forename: Miranda G
authors.initials: MG
authors.lastname: Dik
authors.forename: Saskia M F
authors.initials: SM
authors.lastname: Pluijm
authors.forename: Cees
authors.initials: C
authors.lastname: Jonker
authors.forename: Dorly J H
authors.initials: DJ
authors.lastname: Deeg
authors.forename: Marie Z
authors.initials: MZ
authors.lastname: Lomecky
authors.forename: Paul
authors.initials: P
authors.lastname: Lips
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D003072:Cognition Disorders / Q000097:blood* / Q000523:psychology; D016001:Confidence Intervals; D003430:Cross-Sectional Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000172:deficiency / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies
chemical_list: D007334:Insulin-Like Growth Factor I