Insulin-like growth factor I (IGF-I) and cognitive decline in older persons

• Published in: Neurobiology of aging Vol. 24; no. 4; pp. 573 - 581
• Main Authors: Dik, Miranda G, Pluijm, Saskia M.F, Jonker, Cees, Deeg, Dorly J.H, Lomecky, Marie Z, Lips, Paul
• Format: Journal Article
• Language: English
• Published: London Elsevier Inc 01-07-2003; Elsevier Science
• Subjects: Aged; Aged, 80 and over; Analysis of Variance; Biological and medical sciences; Cognition; Cognition Disorders - blood; Cognition Disorders - psychology; Confidence Intervals; Cross-Sectional Studies; Development. Senescence. Regeneration. Transplantation; Elderly; Female; Follow-Up Studies; Fundamental and applied biological sciences. Psychology; Humans; Insulin-Like Growth Factor I - deficiency; Insulin-Like Growth Factor I - metabolism; Longitudinal studies; Male; Middle Aged; Prospective Studies; Serum IGF-I; Vertebrates: nervous system and sense organs; LASA; GH; IGF-I; AD; AVLT; RCPM; Cognition; CV; MMSE; Serum IGF-I; Longitudinal studies; VUmc; Elderly; BMI; Human; Senescence; Follow up study; Insulin like growth factor 1
• ISSN: 0197-4580; 1558-1497
• DOI: 10.1016/S0197-4580(02)00136-7

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
1nmol/l∼67ng/ml.
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.