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Journal of Aging Research
Volume 2011, Article ID 951403, 11 pages
Review Article

Insulin-Like Growth Factor I and the Pathogenesis of Delirium: A Review of Current Evidence

1Research and Academic Institute of Athens, 27 Themistokleous Street and Akadimias, 10677 Athens, Greece
2HSPR Department, Institute of Psychiatry, Kings College, Room HO.09, David Goldberg Building, de Crespigny Park, London SE5 8AP, UK
3Psychiatry Graduate Entry Medical School, University of Limerick, Castletroy, Limerick, Ireland
4Department of Psychiatry, Midwestern Regional Hospital, Dooradoyle, Limerick, Ireland

Received 15 March 2011; Revised 26 April 2011; Accepted 12 May 2011

Academic Editor: James M. Harper

Copyright © 2011 Dimitrios Adamis and David Meagher. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Delirium is a frequent complication in medically ill elderly patients that is associated with serious adverse outcomes including increased mortality. Delirium risk is linked to older age, dementia, and illness that involves activation of inflammatory responses. IGF-I is increasingly postulated as a key link between environmental influences on body metabolism with a range of neuronal activities and has been described as the master regulator of the connection between brain and bodily well-being. The relationships between IGF-I and ageing, cognitive impairment and inflammatory illness further support a possible role in delirium pathogenesis. Five studies of IGF-I in delirium were identified by a systematic review. These conflicting findings, with three of the five studies indicating an association between IGF-1 and delirium occurrence, may relate to the considerable methodological differences in these studies. The relevance of IGF-I and related factors to delirium pathogenesis can be clarified by future studies which account for these issues and other confounding factors. Such work can inform therapeutic trials of IGF-I and/or growth hormone administration.