Cytokines and acute phase response in delirium

This study aimed to examine the expression patterns of pro- and anti-inflammatory cytokines in elderly patients with and without delirium who were acutely admitted to the hospital.

All consecutive patients aged 65 years and older, who were acutely admitted to the Department of Internal Medicine of the Academic Medical Center, Amsterdam, a tertiary university teaching hospital, were invited. Members of the geriatric consultation team completed a multidisciplinary evaluation for all study participants within 48 h after admission, including cognitive and functional examination by validated measures of delirium, memory, and executive function. C-reactive protein and cytokines (IL-1beta, IL-6, TNF-alpha, IL-8, and IL-10) were determined within 3 days after admission.

In total, 185 patients were included; mean age was 79 years; 42% were male; and 34.6% developed delirium within 48 h after admission. Compared to patients without delirium, patients with delirium were older and had experienced preexistent cognitive impairment more often. In patients with delirium, significantly more IL-6 levels (53% vs. 31%) and IL-8 levels (45% vs. 22%) were above the detection limit as compared with patients who did not have delirium. After adjusting for infection, age, and cognitive impairment, these differences were still significant.

Proinflammatory cytokines may contribute to the pathogenesis of delirium in acutely admitted elderly patients.