Nonprotein calorie supplement improves adherence to low-protein diet and exerts beneficial responses on renal function in chronic kidney disease.

OBJECTIVE: Malnutrition is common in patients with chronic kidney disease (CKD) who are on low-protein diets and is a powerful predictor of morbidity and mortality in CKD. Studies have shown that patients on low-protein diets often have difficulty meeting nutritional energy requirements. Our study evaluated the effects of a nonprotein calorie (NPC) supplement on renal function and nutritional status in patients on a low-protein diet. DESIGN: This was a prospective, randomized, open-label, controlled clinical trial. SUBJECTS: A total of 109 patients with CKD (men, 67%; mean age, 54.5 ± 13 years) with stage 3 to 4 disease were randomly assigned to the intervention group (n = 55) or the control group (n = 54). INTERVENTION: All participants received individualized dietary counseling aimed at achieving a daily protein intake of 0.6 to 0.8 g and a daily energy intake of 30 to 35 kcal/kg. The intervention group consumed a 200-kcal NPC supplement daily. The control group received dietary counseling only. MAIN OUTCOME MEASURE: The estimated glomerular filtration rate (eGFR) was calculated using the 4-variable Modification of Diet in Renal Disease (MDRD) Study equation. Urine protein excretion, dietary protein and energy intake, and serum levels of creatinine, urea nitrogen, cholesterol, triglycerides, and albumin were assessed at baseline, at 12 weeks, and at 24 weeks. RESULTS: Dietary protein intake and urine protein excretion levels decreased significantly in the intervention group and were significantly lower than those of the control group. In addition, serum levels of creatinine and urea nitrogen decreased significantly, and eGFR increased significantly in the intervention group compared with baseline assessments. No significant differences were observed in the control group. CONCLUSIONS: The NPC supplement improved patient adherence to the low-protein diet and reduced urine protein excretion in patients with CKD.

Nutrition support for acute kidney injury 2020-consensus of the Taiwan AKI task force.

BACKGROUND: We used evidence-based medicine to suggest guidelines of nutritional support for Taiwanese patients with acute kidney injury (AKI). METHODS: Our panel reviewed the medical literature in group meetings to reach a consensus on answering clinical questions related to the effects of the nutritional status, energy/protein intake recommendations, timing of enteral, and parenteral nutrition supplementation. RESULTS: Markers of the nutritional status of serum albumin, protein intake, and nitrogen balance had positive relationships with low mortality. A forest plot of the comparison of mortality between a body mass index (BMI) of <18.5 and ≥18.5 kg/m2 was produced using data from seven observational studies which showed that a lower BMI was associated with higher mortality. The energy recommendation of 20-30 kcal/kg body weight (BW)/day was determined to be valid for all stages of AKI. The protein recommendation for noncatabolic AKI patients is 0.8-1.0 g/kg BW/day, and 1.2-2.0 g/kg BW/day is the same as that for the underlying disease that is causing AKI. Protein intake should be at least 1.5 g/kg BW/day and up to 2.5 g/kg BW/day in patients receiving continuous renal replacement therapy. Considering that patients with AKI often have other critical comorbid situations, early enteral nutrition (EN) is suggested, and parenteral nutrition is needed when >60% energy and protein requirements cannot be met via the enteral route in 7-10 days. Low energy intake is suggested in critically ill patients with AKI, which should gradually be increased to meet 80%-100% of the energy target. CONCLUSION: By examining evidence-based research, we provide practicable nutritional guidelines for AKI patients.

Soy protein hydrolysate ameliorates cardiovascular remodeling in rats with L-NAME-induced hypertension.

Pepsin-digested soy protein hydrolysate has been reported to be responsible for many of the physiological benefits associated with soy protein consumption. In the present study, we investigated the effects of soy protein hydrolysate with angiotensin-converting enzyme (ACE) inhibitory potential on the blood pressure and cardiovascular remodeling in rats with N(omega)-nitro-L-arginine methyl ester hydrochloride (L-NAME)-induced hypertension. Rats were fed a diet containing L-NAME (50 mg/kg body weight) with or without soy protein hydrolysate (1%, 3% or 5%) for 6 weeks. We found that ingestion of soy protein hydrolysate retarded the development of hypertension during the 6-week experimental period without affecting the amount of food intake. Although there was no difference in plasma ACE activity or tissue nitric oxide levels, ACE activity in the heart of rats consuming soy protein hydrolysate was significantly lower than that of the control group. Moreover, cardiac malonaldehyde and tumor necrosis factor-alpha concentrations were also lower in the soy protein hydrolysate group. No difference in plasminogen activator inhibitor-1 level was found in plasma or cardiovascular tissue. In the histopathological analysis, we also found that soy protein hydrolysate ameliorated inflammation and left ventricle hypertrophy in the heart. These findings suggest that soy protein hydrolysate might not only improve the balance between circulating nitric oxide and renin-angiotensin system but also show beneficial effects on cardiovascular tissue through its ACE inhibitory activity.

Variable effects of soy protein on plasma lipids in hyperlipidemic and normolipidemic hemodialysis patients.

BACKGROUND: Hyperlipidemic factors contribute to the high cardiovascular risk in hemodialysis patients. Soy protein has decreased some atherogenic lipid concentrations in subjects with normal renal function. This study evaluates the effect of soy protein on serum lipid profiles in hyperlipidemic and normolipidemic hemodialysis patients. METHODS: Nineteen hyperlipidemic and 18 normolipidemic hemodialysis patients were enrolled in a randomized, double-blind, placebo-controlled, clinical trial. After a 4-week run-in phase, subjects in each category were randomly assigned to 2 groups. Thirty grams of isolated soy protein or milk protein was consumed daily as a beverage at breakfast or postdialysis for 12 weeks. RESULTS: In hyperlipidemic subjects, soy protein intake significantly decreased total cholesterol levels by 18.6% (95% confidence interval [CI], -11.4 to -25.8; P = 0.04), triglyceride levels by 43.1% (95% CI, -34.0 to -52.2; P = 0.02), non-high-density lipoprotein cholesterol levels by 23.6% (95% CI, -14.7 to -32.5; P < 0.01), apolipoprotein B levels by 15.4% (95% CI, -5.4 to -25.4; P = 0.01), and insulin levels by 49.8% (95% CI, -23.3 to -66.1; P < 0.01). Low-density lipoprotein cholesterol concentration was decreased significantly (-25.8%; 95% CI, -8.3 to -42.7; P = 0.01), and high-density lipoprotein cholesterol level was increased significantly (17%; 95% CI, 2 to 32.0; P = 0.03), but there was no significant difference compared with the milk protein group (-5.5% +/- 16.9% and 7.0% +/- 11.8%, respectively). There were no significant changes in serum lipid and lipoprotein concentrations in normolipidemic subjects. CONCLUSION: These results indicate soy protein substitution has lipid-lowering effects in hyperlipidemic hemodialysis patients. However, soy protein intake had little effect on plasma lipid levels in normolipidemic hemodialysis patients.

Effects of various soya protein hydrolysates on lipid profile, blood pressure and renal function in five-sixths nephrectomized rats.

Studies have demonstrated that isolated soya protein (ISP) can slow the progression of renal injury, reduce blood pressure and improve the serum lipid profile in experimental animals and human subjects. The mechanisms and components of soya responsible have not been fully established. The present study was designed to evaluate the effects of the hydrophilic supernatant fraction (SF) and the hydrophobic precipitate fraction (PF) isolated from soya protein hydrolysate on renal function, lipid metabolism and blood pressure in five-sixths nephrectomized rats. Experimental animals were subjected to a nephrectomy and allocated to four groups (180 g casein/kg, 180 g ISP/kg, 100 g casein/kg with 80 g SF/kg, and 100 g casein/kg with 80 g PF/kg). The SF group had the most significant decreases in blood pressure and total cholesterol, as well as a significantly retarded progression of the experimentally induced renal disease, compared with the other groups. The PF group exhibited a significantly increased faecal excretion of total steroids. The serum creatinine, level of proteinuria, total cholesterol and LDL-cholesterol concentrations, and blood pressure were significantly reduced, and HDL-cholesterol was significantly increased, in the ISP and PF groups compared with the casein group, but no significant differences were observed between the ISP and PF groups. These results suggest that both soya protein hydrolysate fractions favourably affected chronic renal failure induced by a five-sixths nephrectomy, and the hydrophilic fraction of soya protein hydrolysate had the most pronounced effect on attenuating hypertension and slowing the progression of renal disease.

Effect of soya protein on serum lipid profile and lipoprotein concentrations in patients undergoing hypercholesterolaemic haemodialysis.

Clinical trials have shown that soya protein reduces the concentrations of some atherogenic lipids in subjects with normal renal function. The present study examined the effects of soya protein on serum lipid concentrations and lipoprotein metabolism in patients on hypercholesterolaemic haemodialysis. Twenty-six hypercholesterolaemic (total cholesterol > or =6.21 mmol/l) patients on haemodialysis were studied in a randomized, double-blind, placebo-controlled clinical trial. After a 4-week run-in phase, the subjects were randomly assigned to two groups. Isolated soya protein or milk protein 30 g was consumed daily as a beverage at breakfast or post-dialysis for 12 weeks. Soya protein substitution resulted in significant reductions in total cholesterol (17.2 (sd 8.9 )%), LDL-cholesterol (15.3 (sd 12.5 )%), apo B (14.6 (sd 12.1 )%) and insulin (23.8 (sd 18.7) %) concentrations. There were no significant changes in HDL-cholesterol or apo A-I. These results indicate that replacing part of the daily protein intake with soya protein has a beneficial effect on atherogenic lipids and favourably affects lipoprotein metabolism in hypercholesterolaemic patients undergoing haemodialysis.

Effects of dietary protein on renal function and lipid metabolism in five-sixths nephrectomized rats.

The objective of the present experiment was to examine the effect of substituting different quantities of soyabean protein for casein on renal function and lipid metabolism in rats with chronic renal failure induced by a five-sixths nephrectomy. Experimental animals were subjected to a nephrectomy and fed either casein or soyabean protein (200 or 100 g/kg diet). The diets were isoenergetic with identical fat, Na, K and P contents. Rats ingesting 200 g casein/kg diet showed a significantly (P<0.05) accelerated course of chronic renal failure, while the soyabean-protein groups showed retarded progression of the experimentally induced renal disease and hypercholesterolaemic effects. Rats in the low-soyabean-protein diet (100 g/kg) also demonstrated increased serum albumin and decreased serum triacylglycerol, total cholesterol concentrations and blood urea-N; however, the low-casein diet significantly (P<0.05) increased serum triacylglycerol. Results of the present study show that the replacement of casein by soyabean protein was related to the rate of progression of renal failure and improvement in lipid profiles in serum of five-sixths nephrectomized rats.