Cytokines and IGF-I in delirious and non-delirious acutely ill older medical inpatients.
BACKGROUND
therapeutic use of cytokines can induce delirium, and delirium often occurs during infections associated with elevated levels of cytokines. This study examined the association of demographic, clinical and biological factors (IL-1alpha, IL-1beta, IL-1RA, IL-6, TNF-alpha, IFN-gamma, LIF, IGF-I, APOE genotype) with the presence and severity of delirium.


METHODS
in an observational prospective longitudinal study, patients aged 70+ were recruited from an elderly medical unit and assessed every 3-4 days (maximum assessments 4). At each time, the scales MMSE, DRS, CAM, APACHEII were administered and blood was withdrawn to estimate the above biological factors. Mixed effects (PQL) and GEE were used to analyse the repeated measurements and investigate the associations at the individual and population average levels.


RESULTS
a total of 205 observations on 67 individuals were analysed. Lower levels of IGF-I, and lower levels of circulating IL-1RA, are significantly (P < 0.05) associated with delirium, while the remaining of cytokines, severity of illness and possession of epsilon 4 allele had a non-significant effect. This has been shown by both statistical methods. Similarly lower levels of IGF-I, and high levels of IFN-gamma, are statistically significantly (P < 0.05) associated with higher DRS scores (more severe delirium).


CONCLUSIONS
this study finds that (i) low levels of both neuroprotective factors (IGF-I, IL-1RA) are associated with delirium, (ii) high IFN-gamma and low IGF-I have significant effects on delirium severity and (iii) otherwise the pro-inflammatory cytokines studied, APOE genotype and severity of illness do not appear to be associated, in older medically ill patients, with either delirium or severity of it.
Adamis
Dimitrios
D
Research and Academic Institute of Athens, Athens, Greece. dimaadamis@yahoo.com
Lunn
Mary
M
Martin
Finbarr C
FC
Treloar
Adrian
A
Gregson
Norman
N
Hamilton
Gillian
G
Macdonald
Alastair J D
AJ
D018806:APACHE; D000208:Acute Disease; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D053327:Apolipoprotein E4 / Q000235:genetics; D015415:Biomarkers / Q000097:blood; D003071:Cognition; D016207:Cytokines / Q000097:blood*; D003693:Delirium / Q000097:blood* / Q000235:genetics / Q000276:immunology / Q000523:psychology; D005260:Female; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000032:analysis*; D007371:Interferon-gamma / Q000097:blood; D053590:Interleukin 1 Receptor Antagonist Protein / Q000097:blood; D008137:Longitudinal Studies; D008297:Male; D011446:Prospective Studies
D053327:Apolipoprotein E4; D015415:Biomarkers; D016207:Cytokines; C507763:IL1RN protein, human; D053590:Interleukin 1 Receptor Antagonist Protein; D007334:Insulin-Like Growth Factor I; D007371:Interferon-gamma