Observational Study
Copyright ©The Author(s) 2020. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Psychiatr. Sep 19, 2020; 10(9): 212-222
Published online Sep 19, 2020. doi: 10.5498/wjp.v10.i9.212
Delirium, insulin-like growth factor I, growth hormone in older inpatients
Dimitrios Adamis, Iulian Coada, Piet Eikelenboom, Che-Sheng Chu, Karen Finn, Vincent Melvin, John Williams, David James Meagher, Geraldine McCarthy
Dimitrios Adamis, Iulian Coada, Vincent Melvin, Geraldine McCarthy, Department of Psychiatry, Sligo/Leitrim Mental Health Services, Sligo F91 CD34, Ireland
Dimitrios Adamis, Department of Psychiatry, Research and Academic Institute of Athens, Athens 11742, Greece
Dimitrios Adamis, David James Meagher, Department of Psychiatry, University Hospital Limerick, Limerick V94 F858, Ireland
Piet Eikelenboom, Department of Psychiatry, GGZinGeest and VuMC, Amsterdam 1081 HV, the Netherlands
Che-Sheng Chu, Department of Psychiatry and Center for Geriatric and Gerontology, Kaohsiung Veterans General Hospital, Kaohsiung 81362, Taiwan
Karen Finn, Department of Biopharmaceutical and Medical Science, School of Science and Computing, Galway-Mayo Institute of Technology, Galway H91 T8NW, Ireland
John Williams, Department of Pathology, Sligo University Hospital, Sligo F91 H684, Ireland
Author contributions: Adamis D was involved in the conceptualization of the project, data curation, statistical analysis, supervision of the project, writing-original draft; Coada I was involved in data entry, curation, writing-original draft; Eikelenboom P was involved in the conceptualization, supervision of the project, writing-original draft; Chu C was involved in the conceptualization, supervision, and writing-original draft; Finn K was involved in the biochemical analysis, data entry, data curation, writing-original draft; Melvin V was involved in the clinical data collection, data entry and curation, writing-original draft; Williams J was involved in the conceptualization, biochemical analysis, supervision, funding acquisition and writing the original draft; Meagher D was involved in the conceptualization, supervision, and writing the original draft; McCarthy G was involved in the conceptualization, supervision, funding acquisition and writing the original draft; all authors have contributed read and approve the final manuscript.
Supported by Research Seed grant from the Research and Education Foundation, Sligo University Hospital, Sligo, Ireland.
Institutional review board statement: The study has been approved from the Sligo University Hospital ethical committee.
Informed consent statement: The informed consents were waived.
Conflict-of-interest statement: All authors have no any conflicts of interest.
Data sharing statement: No sharing of data.
STROBE statement: The authors have read the STROBE Statement, and the manuscript was prepared and revised according to the STROBE Statement.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Corresponding author: Dimitrios Adamis, MD, MSc, Academic Research, Department of Psychiatry, Sligo/Leitrim Mental Health Services, Clarion Road, Sligo F91 CD34, Ireland. dimaadamis@yahoo.com
Received: December 30, 2019
Peer-review started: December 27, 2019
First decision: April 2, 2020
Revised: June 16, 2020
Accepted: August 24, 2020
Article in press: August 24, 2020
Published online: September 19, 2020
Research background

Delirium is a common disorder in elderly medical inpatients, in surgical wards, and Intensive care units with serious adverse outcomes.

Research motivation

To understand delirium is important to understand the underline mechanisms by which body and brain are linked and how brain responses to bodily homeostatic stress is mediated. We have notice from our previous research work that the severity of physical illness is not a risk factor for delirium at least in older populations and perhaps delirium is associated with deficits in the immunoreactivity of the brain (low cerebral reserve). Low levels of neuroprotective factors may possibly explain the onset of delirium rather than the actual trigger or “insult” factor. A number of studies have investigated the relationship between Insulin-like growth factor I (IGF-I) and delirium with conflicting results. A relevant also factor is the Growth Hormone (GH) which is related to IGF-I via negative feedback. Therefore in the present study we included also the GH.

Research objectives

To investigate the relationship of the occurrence of delirium during hospitalisation (prevalent and incident) with the serum levels of IGF-I and GH.

Research methods

Observational, prospective, longitudinal study of older people who consecutively admitted to medical wards of a general hospital.

Research results

We found that low cognitive function, low levels of IGF-I and high levels of GH were significantly associated with any delirium (prevalence, incident, or fluctuating) during the study period.

Research conclusions

The involvement of GH in delirium is a new finding from the present study. Also the finding of the low levels of IGF-I and the association of delirium confirms some of the previous studies. Those findings together with the association of cognitive decline with delirium strength the primary hypotheses that low brain reserves are possible the predisposing factor for delirium. Those findings needs further replication in other studies and especially in surgical samples

Research perspectives

If the above findings are replicated in future studies then the next step is clinical trials with small doses of IGF-I for prevention of delirium.