Dietary protein intake in older adults undergoing cardiac surgery.

BACKGROUND

Older adults undergoing major surgery have increased protein requirements in the postoperative period, but there are limited data describing actual protein intake following cardiac surgery.

METHODS AND RESULTS

We performed a prospective sub-study within a registry of older adults ≥60 years of age undergoing cardiac surgery at a tertiary care centre. A dietician administered a food frequency questionnaire before surgery and 1-4 months after surgery. In-hospital food intake was recorded by direct observation for 3 days in the early postoperative period. Food intake was analyzed to calculate the protein intake per kilogram of body weight per day (g/kg/d) during the three phases of care, compared to the dietary reference intake. Frailty was measured by a questionnaire and physical performance tests before surgery. There were 22 patients (8 females, 14 males; 59% frail) enrolled in the study with a mean age of 72.0 ± 7.8 years. The mean protein intake was 1.3 ± 0.5 g/kg/d, 0.7 ± 0.3 g/kg/d, and 1.3 ± 0.6 g/kg/d in the preoperative, early postoperative, and postdischarge periods, respectively (P < 0.0001 for early postoperative compared to other periods). Compared to the targeted dietary reference intake of 1.5 g/kg/d, there was a mean protein deficit of 0.8 g/kg/d in the early postoperative period. Only one patient (5%) met the protein dietary reference intake in the early postoperative period.

CONCLUSION

In older adults undergoing cardiac surgery, dietary protein intake was substantially lower than the recommended target in the early postoperative period. Strategies to improve protein intake, particularly in frail older patients, may be considered as a therapeutic target.