The geriatric nutritional risk index predicts complications after nephrectomy for renal cancer

Purpose: We examined if malnutrition, as defined by the Geriatric Nutritional Risk Index (GNRI), is independently associated with 30-day postoperative complications in patients undergoing nephrectomy for the treatment of renal cancer.

Materials and methods: Using the American College of Surgeons National Surgical Quality Improvement Program database from 2006-2019, we identified patients ≥65 years old who underwent nephrectomy for renal cancer. The following formula for GNRI was used to define preoperative nutritional status: 1.489 x serum albumin (g/L) + 41.7 x (current body weight [kg]/ ideal body weight [kg]). Based on the GNRI, patients were classified as having no (> 98), moderate (92-98), or severe malnutrition (< 92). After adjusting for potential confounders, multivariable logistic regression analyses were performed to assess the association between GNRI and 30-day postoperative complications. Odds ratios (OR) with 95% confidence intervals (CI) were reported.

Results: A total of 7,683 patients were identified, of which 1,241 (16.2%) and 872 (11.3%) had moderate and severe malnutrition, respectively. Compared to normal nutrition, moderate and severe malnutrition were significantly associated with a greater odds of superficial surgical site infection, progressive renal insufficiency, readmission, extended length of stay, and non-home discharge. Severe malnutrition was also associated with urinary tract infection (OR 2.10, 95% CI 1.31-3.35) and septic shock (OR 2.93, 95% CI 1.21-7.07).

Conclusion: Malnutrition, as defined by a GNRI ≤ 98, is an independent predictor of 30-day complications following nephrectomy. The GNRI could be used to counsel elderly patients with renal cancer prior to nephrectomy.