Published online Sep 19, 2020. doi: 10.5498/wjp.v10.i9.212
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
Delirium is a common disorder in elderly medical inpatients, in surgical wards, and Intensive care units with serious adverse outcomes.
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.
To investigate the relationship of the occurrence of delirium during hospitalisation (prevalent and incident) with the serum levels of IGF-I and GH.
Observational, prospective, longitudinal study of older people who consecutively admitted to medical wards of a general hospital.
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.
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
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.