The effect of continuous nutritional support on adipokine and ghrelin levels in critically ill patients

Introduction: Altered levels of adipokines, which may be influenced by energy availability, have been demonstrated in critically ill patients. These patients frequently undergo fasting and underfeeding. This study investigated the effect of continuous nutritional support on adipokine levels in critically ill patients. Materials and Methods: Patients admitted to the intensive care unit were randomized to receive nutritional support with an energy target determined either by (i) repeated indirect calorimetry measurements (study group), or (ii) a weight-based formula (25 Kcal/kg/day; control group). Adipokine levels (serum leptin, resistin, ghrelin, and adiponectin) were measured on days 1 and 7. Both cumulative energy balance (energy balance at discharge from intensive care unit or after 7 days) and maximal negative energy balance (most negative energy balance observed during the study) were assessed. Results: The daily energy balance (p=0.001), cumulative energy balance (p=0.01), and maximal negative energy balance (p=0.01) were significantly positive for the study group and negative for the control group. There were no significant between-group differences in adipokine levels on day 1 or day 7. In the control group, serum ghrelin increased significantly over time (p<0.05) and a trend for an increase in resistin (p<0.065) was noted. For the whole group, a more positive cumulative energy balance and a lower maximal negative energy balance were associated with a significantly smaller increase in serum ghrelin levels (p=0.008 and p=0.035, respectively) and a smaller increase in resistin levels (p=0.061 and p=0.027, respectively). Conclusions: A positive cumulative energy balance in critically ill patients appears to influence the levels of ghrelin and, to a lesser extent, resistin. The clinical significance of this finding requires further investigation.