Association between inflammation-associated cytokines, serum albumins, and mortality in the elderly.

Objective: To investigate the association between serum albumin, prealbumin, various serum inflammation associated-cytokines, and mortality in older geriatric recuperative care patients.
Design: A prospective cohort study.
Setting: A geriatric rehabilitation unit of a university-affiliated Department of Veterans Affairs hospital.
Participants: Participants were 53 geriatric patients (mean age 78 +/- 7.3, 96% male) admitted to a Geriatric Evaluation and Management (GEM) unit. Patients with documented near-terminal medical disorder, overt infections, and any systemic or localized inflammatory disorders were excluded.
Measurements: Inflammation-associated cytokines (IL-8, IL-1beta, IL-6, IL-10, TNF-alpha), albumin, prealbumin, and C-reactive protein were measured at hospital discharge and each subject was then tracked for 1 year.
Main Results: By Cox Proportional-Hazards Regression analysis, the strongest predictor of mortality within 6 months of study entry was the serum IL-6. For each log increase in IL-6, there was nearly a 9-fold greater 6-month mortality risk (RR 8.99, 95% CI 1.65 to 49.03). The association between albumin and mortality was no longer significant after controlling for IL-6. There was a strong inverse correlation between IL-6 and both albumin (R2 0.39, P < .001) and prealbumin (R2 0.41, P < .001).
Conclusion: Subclinical inflammation appears to be an important factor contributing to low serum albumins in older recuperative care patients and may confound the association between albumin and mortality in this population. More in-depth studies of these associations are warranted.