Does age influence circulating adhesion molecules in the critically ill?

Abstract

Soluble adhesion molecules are regarded to be markers of inflammation, endothelial activation, or damage. The influence of age on plasma concentrations of circulating adhesion molecules should be serially studied in critically ill intensive care patients. Prospective and descriptive study over 5 days. Clinical investigation in a surgical intensive care unit of a university hospital. Thirty critically ill patients (Acute Physiology and Chronic Health Evaluation [APACHE] II score of > 15 points), with sepsis secondary to postoperative complications, were included in this study. Fifteen consecutive patients aged < 50 yrs and 15 consecutive patients aged > 70 yrs were prospectively studied. All patients were treated by the standard protocols of our intensive care unit, which did not differ between the groups. The patients received continuous analgesia-sedation and mechanical ventilation. Intensivists caring for the patients were not involved in the study and were blinded to data analysis. Hemodynamic parameters were extensively monitored in all patients. From arterial blood samples, plasma concentrations of soluble adhesion molecules (endothelial leukocyte adhesion molecule-1, intercellular adhesion molecule-1, vascular cell adhesion molecule-1, granule membrane protein-140) were measured on the day of admission (i.e., baseline values) and during the following 5 days. Three of the younger patients and six of the elderly patients died during the study period (p < .05). Oxygen delivery and consumption, and the other hemodynamic data, were without group differences throughout the study. Plasma concentrations of all adhesion molecules were beyond normal at baseline in both groups. These concentrations increased further during the first 2 to 3 days in both groups, with a significantly higher increase in the elderly patients (endothelial leukocyte adhesion molecule-1 to 179 +/- 32 ng/mL; intercellular adhesion molecule-1 to 1695 +/- 158 ng/mL; vascular cell adhesion molecule-1 to 1395 +/- 212 ng/mL; and granule membrane protein-140 to 888 +/- 119 ng/mL). In the younger patients, concentrations of soluble adhesion molecules decreased later in the study and almost reached baseline values on day 5. In the elderly patients, these concentrations remained significantly higher until the end of the study. The higher plasma concentrations of the measured adhesion molecules in elderly critically ill patients indicate that elderly patients are more prone than younger patients to a more pronounced activation or even damage of the endothelium. Further work needs to be done to determine the prognostic importance and to define the role of soluble adhesion molecules, particularly in the elderly critically ill patient.