#6823 THE NUTRITIONAL AND NEPHROLOGICAL IMPACT OF A LOW-NORMAL PROTEIN HIGH CALORIE DIET ON THE ONCOLOGICAL SOLITARY KIDNEY: TIME FOR A NEW PERSPECTIVE?
Authors: Trevisani Francesco , Paccagnella Matteo , Fiorio Francesco , Laurenti Fabiana , Vago Riccardo , Marco Federico Di , Floris Matteo , Capitanio Umberto , Ghidini Michele , Salonia Andrea , Montorsi Francesco , Bettiga Arianna 
Published: June 2023

Abstract

Background and Aims
Nutritional therapy (NT) based on controlled protein intake represents a cornerstone in the management of chronic kidney disease (CKD). However the international guidelines do not precisely define an adequate protein intake for nephrological patients affected by cancer, the onco-nephrological ones. Among them, there is a precise asset where a personalized nutritional strategy can make the difference; the oncological patients who remain with a solitary kidney due to a radical nephrectomy for renal cancer. In fact, the acute decrease of GFR due to the loss of an entire kidney leads these patients to develop a mild to severe stage of CKD and this pathological condition should require a nephrological diet with protein restriction based upon GFR levels. However, in routinary clinical practice this cohort of patients tend to be followed by oncologists who apply a completely opposite nutritional approach with a high protein diet for the presence of cancer in order to avoid catabolism, malnutrition and sarcopenia. The aim of our study was to investigate whether a Low-Normal Protein High Calorie (LNPHC) diet in a nephrologist-nutritionist combined approach (NNCA) and aimed at CKD patients can also be effective in improving the nutritional status in solitary cancer kidney patients without compromising the renal function and metabolism.

Method
A consecutive cohort of 44 pts was enrolled in the Urological Department at San Raffaele Scientific Institute between 2018-2021. Inclusion criteria were: Age (&gt;18 years old), eGFR (&lt;60 ml/min/1.73), Malnutritional Screening Tool (MST&lt;2), Solitary kidney for radical nephrectomy for renal cancer, informed consent (signed). Each patient underwent an initial nephrological and nutritional evaluation and was subsequently subjected to a conventional CKD LNPHC diet integrated with aproteic foods (0,7-1 g/Kg/die: calories: 30-35 kcal per kg body weight/die) for a period of 6 months (+/- 2 moths). The diet was based on the estimated Glomerular Filtration Rate (CKD-EPI 2021 Creatinin formula), comorbidities and nutritional status. MST, Body Mass Index (BMI), Phase Angle (PA), Fat Mass percentage (FM%), Fat-Free Mass Index (FFMI), body cell mass index (BCMI), extracellular/intracellular water ratio (ECW/ICW), waist/hip circumference ratio (WHC), lab test exams and clinical variables were examined at baseline and after 6 months. Statistical analysis: Kruskal-Wallis rank sum test; Data analysis: R programming language and RStudio integrated development environment.

Results
Descriptive analysis is showed in Table 1. Our results clearly highlighted that LNPHC was able to generate a significant improvement in all the investigated nutritional parameters (Table 2 and 3) avoiding malnutrition or catabolism. Moreover, regarding the nephrological asset, LNPHC was responsible for a significant decrease of urea, the most important parameter influencing general status. The non-significant increase of serum creatinine and therefore decrease of eGFR was related to the augmented muscle mass (Table 4).

Conclusion
LNPHC represents a new important therapeutic strategy to apply in the onco-nephrological patients with solitary kidney due to renal cancer.