Very low protein diet supplemented with ketoanalogs improves blood pressure control in chronic kidney disease

• Published in: Kidney international Vol. 71; no. 3; pp. 245 - 251
• Main Authors: Bellizzi, V., Di Iorio, B.R., De Nicola, L., Minutolo, R., Zamboli, P., Trucillo, P., Catapano, F., Cristofano, C., Scalfi, L., Conte, G., on behalf of the ERIKA Study-group
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.02.2007; Elsevier Limited
• Subjects: Aged; Amino Acids, Essential - administration & dosage; Amino Acids, Essential - chemistry; Blood Pressure - drug effects; Chronic Disease; chronic kidney disease; Diet, Protein-Restricted; Female; Humans; hypertension; Hypertension, Renal - diet therapy; ketoanalogs; Ketones - administration & dosage; Ketones - chemistry; Kidney Diseases - complications; Male; Middle Aged; Prospective Studies; sodium intake; Treatment Outcome; very low protein diet; very low protein diet; chronic kidney disease; sodium intake; hypertension; ketoanalogs
• ISSN: 0085-2538; 1523-1755
• DOI: 10.1038/sj.ki.5001955

Blood pressure (BP) is hardly controlled in chronic kidney disease (CKD). We compared the effect of very low protein diet (VLPD) supplemented with ketoanalogs of essential amino acids (0.35g/kg/day), low protein diet (LPD, 0.60g/kg/day), and free diet (FD) on BP in patients with CKD stages 4 and 5. Vegetable proteins were higher in VLPD (66%) than in LPD (48%). LPD was prescribed to 110 consecutive patients; after run-in, they were invited to start VLPD. Thirty subjects accepted; 57 decided to continue LPD; 23 refused either diet (FD group). At baseline, protein intake (g/kg/day) was 0.79±0.09 in VLPD, 0.78±0.11 in LPD, and 1.11±0.18 in FD (P<0.0001). After 6 months, protein intake was lower in VLPD than LPD and FD (0.54±0.11, 0.78±0.10, and 1.04±0.21g/kg/day, respectively; P<0.0001). BP diminished only in VLPD, from 143±19/84±10 to 128±16/78±7mm Hg (P<0.0001), despite reduction of antihypertensive drugs (from 2.6±1.1 to 1.8±1.2; P<0.001). Urinary urea excretion directly correlated with urinary sodium excretion, which diminished in VLPD (from 181±32 to 131±36mEq/day; P<0.001). At multiple regression analysis (R2=0.270, P<0.0001), BP results independently related to urinary sodium excretion (P=0.023) and VLPD prescription (P=0.003), but not to the level of protein intake. Thus, in moderate to advanced CKD, VLPD has an antihypertensive effect likely due to reduction of salt intake, type of proteins, and ketoanalogs supplementation, independent of actual protein intake.