Soy Protein as a Part of a Low-protein Diet is a New Direction in Cardio- and Nephroprotection in Patients With 3b-4 Stages of Chronic kidney Disease

Abstract

It has been established that the use of a low-protein diet (LPD) in combination with ketoanalogues of essential amino acids (KA) can contribute to cardio and nephroprotection in chronic kidney disease (CKD). Moreover, it has been shown that partial replacement of the animal protein with soy protein (SP) in the diet contributed to more pronounced nephro and cardioprotection in CKD, however, the data, available in the literature, are mainly represented by experimental studies.

Aim of the study: We conducted a prospective randomized controlled clinical study that compared the effects of 2 types of diets on the main parameters of nephro and cardioprotection in patients with CKD.

Materials and methods: The study included 85 CKD 3b-4 stages G3b-4 patients, compliant to LPD (0.6 g of protein/kg of body weight) + KA (1 tablet/5 kg of body weight). 43 patients (Group 1) received LPD with substitution of animal protein with soy (60% SP + 40% of other vegetable proteins) + KA, and 42 patients (control group (Group 2) received conventional LPD (60% animal protein +40% of vegetable protein) + KA, within 12 months.

Results: Substitution of animal protein with SP in diet of patients with CKD to a greater extent delayed the decrease in eGFR (-5.9% vs -11.3%, P = .048), the increase in left ventricle hypertrophy (+4.7% vs +12.3%, P = .042), as well as the increase in central systolic blood pressure (+2.6% vs +13.0%, P = .021), augmentation index (+7.6% vs +23.3%, P = .010), slowed down the decrease in lean body mass in males (+0.9% vs -11.2%, P = .017) and females (-1.8% vs -10.3%, P = .024), increase in phosphorus (-10.3% vs +13.0%, P = .029), cholesterol (-10.7% vs -3.4% P = .047) and urea (+6.3% vs +19.6%, P = .035) serum levels.

Conclusion: The use of LPD with substitution of animal protein with SP + KA provides more pronounced effect on nephro and cardioprotection as well as maintenance of nutritional status, than conventional LPD + KA in patients with CKD 3b-4 stages.

Keywords: CKD; LPD; ketoanalagues of essential amino acids (КA); soy protein.