Insulinlike growth factor-1, insulinlike growth factor binding protein-1, and cognitive function in older men and women.
OBJECTIVE
To assess the association between insulinlike growth factor (IGF)-1 and IGF binding protein (IGFBP)-1 with three cognitive function tests in a healthy elderly population.


METHODS
Cross-sectional analyses from the Rancho Bernardo Cohort Study.


METHODS
Southern California community of Rancho Bernardo.


METHODS
Men (n=636) and women (n=899) from the Rancho Bernardo study (median age 74) were assessed between 1988 and 1992 for cognitive function using the Mini-Mental State Examination (MMSE), Verbal Fluency (VF) test, and Trail-Making Test Part B (Trails B). Blood samples were obtained at the same time for IGF-1 and IGFBP-1 levels. The association between biomarkers and cognitive function tests was assessed by dichotomizing tests at the clinically relevant cutoff using logistic regression and according to tertiles and continuous IGF-1 and IGFBP-1 levels using multivariate linear regression analyses.


RESULTS
The mean MMSE, VF and Trails B scores indicated better cognitive function with higher IGF-1 tertile. Multivariate analyses showed that VF and MMSE were each significantly associated with IGF-1 in a dose-response manner for men (P for trend=.001), but no cognitive function tests were related to IGF-1 in women. For men, the highest IGFBP-1 tertile was inversely and significantly different from the lowest tertile for the MMSE test only (P for trend=.02).


CONCLUSIONS
IGF-1 was independently and positively related to MMSE and VF in men, and IGFBP-1 was inversely associated with MMSE in men. Sex differences in the association should be further investigated.
Al-Delaimy
Wael K
WK
Department of Family and Preventive Medicine, School of Medicine, University of California at San Diego, La Jolla, California 92093, USA. waldelaimy@ucsd.edu
von Muhlen
Denise
D
Barrett-Connor
Elizabeth
E
D000368:Aged; D015415:Biomarkers / Q000097:blood*; D003071:Cognition; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D018969:Insulin-Like Growth Factor Binding Proteins / Q000097:blood*; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D008297:Male; D012044:Regression Analysis
D015415:Biomarkers; D018969:Insulin-Like Growth Factor Binding Proteins; D007334:Insulin-Like Growth Factor I