Pre-operative protein feeding to stimulate muscle and bone synthesis in older patients undergoing elective hip surgery

Aging is associated with a gradual loss of skeletal muscle mass and function, termed sarcopenia. Periods of hospitalization and immobilization can increase the rate of muscle loss. Dietary protein supplementation represents an effective strategy to preserve skeletal muscle mass by stimulating muscle protein synthesis. In line, we propose that pre-operative feeding forms an effective nutritional strategy to stimulate muscle protein synthesis during surgery and, as such, improves subsequent recovery.

Protein feeding prior to surgery enhances muscle and bone protein synthesis rates in the post-prandial period when compared to the non-feeding condition in older patients undergoing total hip arthroplasty.

Timepoints in this study:

1. Evening prior to surgery: Informed consent, DEXA-scan, questionnaires, placement of naso-duodenal tube;

2. Morning prior to surgery: placement of two intravenous catheters, infusion of stable isotope amino acids, administration of protein-rich supplement, blood draws every hour, questionnaire.

3. Surgery: muscle and bone collection, blood draws every hour

1. This study will be conducted in older patients attending the department of Orthopedics with a scheduled total hip arthroplasty.

2. Subjects are randomized into a feeding and non-feeding group (no intervention).

3. Continuous stable isotope infusions will be applied in both groups to measure muscle and bone protein synthesis rates.

4. Subjects in the feeding group will receive a protein-rich supplement via enteral administration prior to surgery.

5. During the pre- and perioperative period, 6 venous bloodsamples, a muscle biopsy and bone sample will be taken to measure turnover rates.