Serum cytokines and critical illness-related corticosteroid insufficiency

Abstract

Little information exists regarding the association of specific cytokine levels and different subgroups of patients with critical illness-related corticosteroid insufficiency (CIRCI). Data from a previous prospective study on adrenal function in the ICU were used in this study. CIRCI was diagnosed when either the basal cortisol was less than 10 μg/ml or the Δ cortisol was less than 9 μg/ml. The patients with CIRCI were further divided into a low basal cortisol (LBC) group (basal cortisol < 10 μg/ml), and low Δ cortisol (LDC) group (basal cortisol ≥ 10 μg/ml and Δ cortisol < 9 μg/ml). Serum cytokine levels were compared among the normal (NOM), LBC, and LDC groups. The serum of 82 out of 123 (67%) patients included in the previous study was available for analysis; these patients were included in the present study. The overall incidence of CIRCI was 43.9% (36 out of 82 patients). Among patients with CIRCI, 16 (44.4%) were classified as the LBC group and 20 (55.6%) as the LDC group. The LDC group had significantly higher levels of IL-6 and IL-10 compared to both the NOM and LBC groups (p < 0.01). The LDC group also had significantly increased TNF-α (p = 0.002) compared to the LBC group. There were no significant differences in any of the cytokine levels between the NOM and LBC groups. Elevated cytokines were associated with adrenal dysfunction in a subset of patients meeting the criteria for CIRCI (normal or high basal cortisol and low Δ cortisol).