Cortisol, interleukins and S100B in delirium in the elderly.

In independent studies delirium was associated with higher levels of cortisol, interleukin(IL)s, and S100B. The aim of this study was to simultaneously compare cortisol, IL-6, IL-8, and S100B levels in patients aged 65years and older admitted for hip fracture surgery with and without delirium. Cortisol, IL-6, IL-8, and S100B were assayed in repeated blood samples. 120 patients (mean age 84years, 62 patients with delirium) were included. Highest levels of IL-8 (27.1, 95% Confidence Interval (CI): 13.6-53.1pg/ml) and cortisol (666, 95% CI: 475-859nmol/L) were before delirium, but of IL-6 (84.3, 95% CI: 46.5-151.4pg/mL) and S100B (0.18, 95% CI: 0.12-0.24 microg/L) during delirium. In multivariable analysis cortisol, LogIL-6, and LogS100B were significantly associated with delirium, but adjusted for pre-existing cognitive impairment, only LogS100B remained significantly associated. Cortisol, IL-6 and S100B may have a role in the pathogenesis of delirium, but S100B is the strongest independent marker.