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Abstract: TH-PO929

Evaluation of Protein Malnutrition in CKD Patients on Low-Protein Diet

Session Information

Category: Health Maintenance, Nutrition, and Metabolism

  • 1500 Health Maintenance, Nutrition, and Metabolism


  • Bologna, Arianna, IRCCS Ospedale San Raffaele, Milano, Lombardia, Italy
  • Foligno, Nadia Edvige, IRCCS Ospedale San Raffaele, Milano, Lombardia, Italy
  • Vezzoli, Giuseppe, IRCCS Ospedale San Raffaele, Milano, Lombardia, Italy

Low-protein diet is considered crucial to slow down kidney function deterioration in patients with chronic kidney disease and control metabolic variables such as serum phosphate, urea and bicarbonate. However, low-protein diet may result in malnutrition if patients do not respect nutritional prescription.
Thus, the present study examined the risk of protein malnutrition in CKD patients who started a low-protein diet.


Anthropometric variables, blood variables, nutrient intake and body composition were measured in 40 patients with CKD stage 4-5 (M/F 23/17; age 70±15 years; body weight 70±17 kg) before and after 3-months of a low-protein diet (0.6 g/kg; energy intake 30 Kcal/kg). Nutrient intake was estimated with a food frequency questionnaire; body fat mass (FM), free-fat mass (FFM) and skeletal muscle mass normalized to height2 (SMI) were assessed using bioimpedentiometry analysis.


In the whole sample, after a 3-month diet protein intake decreased from 0.85±0.24 to 0.71±0.20 g/kg (p<0.001) without a decrease in calory intake (22.3±5.9 and 21.5±4.9 kcal/kg).
The diet induced a decrease in body weight (70±17 to 69±16 kg; p<0.001), BMI (26.5±6.4 to 25.9±6.2 kg/m2; p=0.001), FM (21±10 to 20±10 kg; p=0.003), serum urea (168±48 to 134±43 mg/dl; p<0.001).
Eight patients (20%; 4 diabetics) had a protein intake lower than 0.6 g/kg after 3-months of diet. Compared with patients having a higher protein intake, these patients showed lower protein intake at baseline (0.71±0.21 vs 0.89±24 g/kg; p=0.05) and serum albumin (36.3±2.7 vs 40.5±3.2 g/l; p=0.012). Their protein intake after the diet was significantly lower than that at baseline (0.53±0.2 vs 0.71±0.21 g/kg; p=0.016). They also showed a significant decrease in SMI (9.5±1.9 to 8.5±1.8; p=0.003).
Conversely, the other 32 patients did not change SMI (9.2±2 to 9,2±2 kg/m2), but significantly decreased FM (23±11 to 21±11 kg; p=0.002) and increased phase angle (4.2±0.9 to 4.6±0.9; p=0.017).


Protein malnutrition may occur during a low-protein diet in CKD patients with a low consumption of proteins before starting this diet.
Nutritional analysis is necessary to identify CKD patients at risk of protein malnutrition and to adequately follow up CKD patients on low protein diet.