Serum cortisol levels in patients admitted to the department of medicine: Prognostic correlations and effects of age, infection, and comorbidity

BACKGROUND: In contrast to healthy adults or critically ill patients, data on serum cortisol levels in noncritically ill patients admitted to general internal medicine wards has not been well characterized. We aimed to describe the distribution and range of serum cortisol levels in patients admitted to the department of medicine, to discover whether old age, severe infections, or comorbidity induced a blunted hypothalamic-pituitary-adrenal (HPA) response and whether initial serum cortisol value had a prognostic significance. METHODS: Morning (8 am) serum cortisol level together with epidemiologic, clinical, and laboratory data were analyzed for 252 consecutive adult (age > or = 18 yrs) patients admitted to the department of internal medicine during a 6-weeks period. RESULTS: The mean serum cortisol level (541 +/- 268 nmol/L) was within the normal range. Only one patient had a low serum cortisol level of 72 nmol/L, whereas the majority of patients had either normal (80%) or increased (19%) serum cortisol levels. Older age, sepsis, prolonged duration of fever, higher comorbidity score, and higher serum creatinine level were each associated with significantly higher serum cortisol level. In addition, a higher serum cortisol level was significantly related to longer hospitalization and higher in-hospital mortality rate. CONCLUSIONS: Serum cortisol level positively correlated with age, disease severity, and outcome. All admitted patients, except one, had normal to high serum cortisol. Whether this increased cortisol level is an adequate HPA response or less than required for the disease-induced stress should be investigated in further studies.