Acute responses of gastrointestinal hormones to both oral and parenteral intradialytic nutrition.

INTRODUCTION: Intradialytic nutrition (IDN) has been used to improve the nutritional status of malnourished hemodialysis (HD) patients. OBJECTIVE: To evaluate the different effects of parenteral IDN (IDPN) and oral IDN (IDON) on nutrition-related gastrointestinal hormones. PATIENTS AND METHODS: Seven clinically stable HD patients with malnutrition were included. All patients were treated for 1 month with either IDPN or IDON, with a 4-week period of no nutritional support between each type of therapy. On the first day of each nutritional support (IDON or IDPN) we analyzed the acute responses of insulin, ghrelin, and glucagon-like peptide 1 (GLP-1). We compared the areas under the secretory curves (AUC) and the maximum peaks of serum glucose, insulin, ghrelin, and GLP-1. A group of 6 clinically stable HD patients without any type of IDN served as the control group. RESULTS: The acute responses of glucose and insulin to IDN were significantly higher with IDPN than with IDON. The AUC of glucose (602 ± 81 vs. 495 ± 81 mg/dl/h, p < 0.01) and insulin (232 ± 103 vs. 73.8 ± 69 µU/ml/h, p < 0.01) as well as the maximum peaks of glucose (228 ± 41 vs. 177 ± 47 mg/dl, p < 0.05) and insulin (104 ± 46 vs. 29 ± 24 µU/ml, p < 0.01) were significantly higher after IDPN than after IDON. Ghrelin decreased after both IDPN and IDON; however, the decrease was significantly higher with IDPN compared to IDON. The ghrelin nadir was significantly lower in IDPN than in IDON (0.77 ± 0.5 vs. 1.5 ± 0.3, p < 0.05) although the AUC of ghrelin was not significantly different. GLP-1 was significantly increased at 1 h after starting both IDPN and IDON with no significant differences between the groups. CONCLUSION: IDPN induces a higher increase in serum glucose and insulin levels and a greater reduction in serum ghrelin concentrations compared with an equivalent orally administered nutritional supplement.