Gastro-Intestinal Tolerance and Renal Safety of Protein Oral Nutritional Supplements in Nursing Home Residents: A Randomized Controlled Trial.

Background/objective: High protein oral nutritional supplements (ONS) are regularly prescribed to undernourished patients; however usage of these in older adults is being discussed, as their renal function might have declined with age. Therefore, the aim of the current study was to evaluate the effects of 8 week long consumption of high protein ONS on the renal function of nursing home residents in need of supplementation. Furthermore, within the same setup, differences in gastro-intestinal tolerance between a standard and a more concentrated version of an ONS were investigated.

Design: Randomized, controlled, single-blind, parallel-group, multi-country trial (NTR2565).

Setting: Nursing home.

Participants: 67 nursing home residents in need of ONS (energy-dense, small volume group n=32; standard volume group n=35).

Intervention: Protein supplementation was provided by either a standard (200ml, 300kcal, 20g protein) or an energy-dense, small volume (125ml, 300kcal, 18g protein) ONS during the 8 week long study.

Measurements: Primary outcome was gastro-intestinal tolerance, assessed by daily stool frequency and consistency, and occurrence and intensity of self-reported gastro-intestinal symptoms. Safety was measured via the occurrence of (serious) adverse events, vital signs, as well as liver- and kidney function monitoring.

Results: No clinically relevant and, except for flatulence, no statistically significant differences in gastro-intestinal tolerance were observed between groups. No significant difference between groups was found for estimated glomerular filtration rate (eGFR) and urinary albumin/creatinine ratio at baseline and week 8, nor for the changes from baseline. Adverse events and the changes in monitored renal parameters over the study period did not point to a deterioration of renal function.

Conclusion: High protein ONS seems to be well-tolerated and safe; there is no indication that it affects renal function in nursing home residents, including patients with stage 3 chronic kidney disease, under the conditions tested. Results did not suggest a difference in the effect on renal function between standard and energy-dense small volume ONS format.