[Nutritional management of kidney diseases in children]

The prevalence of various kidney diseases in children remains high in recent decades. Adequate nutrition management can enhance the effectiveness of drug treatment, slow the frequency of relapses andprevent the progression of the disease. The article is devoted to modern approaches to diet therapy in various kidney diseases in children with the defeat of tubular and glomerular appa ratus. For the first time the therapeutic diets for children with various kidney diseases are presented. Particular attention is paid to diet therapy in nephrotic syndrome (steroid-responsive and steroid-refractory). Dietary approaches with modern formulas for enteral nutrition in cases of steroid therapy complications in children with renal insufficiency (in predialysis stage and on dialysis) are described. Differentiated nutritional approaches for patients with different types of crystalluria are separately presented.

Effect of combined treatment of oral sorbent with protein-restricted diet on change of reciprocal creatinine slope in patients with CRF

BACKGROUND

Low-protein diet (LPD) is one therapy and AST-120, an oral carbon adsorbent, is the other therapy to reduce blood levels of indoxyl sulfate in patients with chronic renal failure (CRF). Based on the different mechanisms of reducing indoxyl sulfate levels, the addition of AST-120 to an LPD was investigated.

METHODS

Seven hundred twenty-two patients with chronic glomerulonephritis (CGN) and 162 patients with diabetic nephropathy (DN) were stratified by protein intake: less than 0.50 g/kg/d (0.50-g/kg/d group), 0.51 to 0.65 g/kg/d (0.65-g/kg/d group), and 0.66 to 0.80 g/kg/d (0.80-g/kg/d group). To analyze the effect of combined AST-120 therapy (6 g/d) in patients on LPD therapy, the slope of the reciprocal of serum creatinine (1/Cr slope), which represents progression of CRF, was applied.

RESULTS

(1) In patients with CGN, the addition of AST-120 with an LPD was as follows: the 1/Cr slope in the 0.50-g/kg/d (n = 152), 0.65-g/kg/d (n = 318), and 0.80-g/kg/d (n = 252) groups changed significantly from -430 x 10(-5) to -83 x 10(-5), -333 x 10(-5) to -102 x 10(-5), and -431 x 10(-5) to -116 x 10(-5) dL/mg/wk. (2) In patients with DN, the addition of AST-120 with an LPD was as follows: the 1/Cr slope in the 0.65-g/kg/d (n = 74) and 0.80-g/kg/d (n = 68) groups changed significantly from -602 x 10(-5) to -125 x 10(-5) and -646 x 10(-5) to -185 x 10(-5) dL/mg/wk.

CONCLUSION

It is suggested that the addition of AST-120 to a mild LPD provides the comparable effect with a strict LPD in the point of suppressing the progress of CRF.

Clinical application of the polyunsaturated n-3 fatty acids usage in pediatric practice

The investigation of the effectiveness of a diet supplemented with n-3 PUFA in children with glomerulonephritis was done. Patients receiving "Polyen" achieved better clinical remission, more rapid decrease of hypercholesterolemia, and hypercoagulation than the patients from the control group. We can recommend "Polyen" usage in the treatment of glomerulonephritis in children.

Protein intake in renal disease

The dietary protein intake (DPI) of 766 patients (aged 7 to 88 yr) was determined from 24-h urinary urea and protein excretion by urea kinetic modelling. Five hundred sixty-five patients had a normal serum creatinine concentration, and of these 565, 385 patients had no dietary modification advised and 180 were advised to follow a low-protein diet. The remaining 201 patients had an increased serum creatinine concentration; 148 of these 201 patients had been advised to restrict their DPI. Patients with a normal serum creatinine concentration who had no dietary restriction had a significantly higher DPI than those advised to restrict their protein intake (1.08 +/- 0.01 versus 0.96 +/- 0.02 g/kg per day (mean +/- SEM), P < 0.01). Similarly, patients with abnormal renal function who were advised to follow a low-protein diet had a reduced DPI (0.93 +/- 0.01 versus 0.87 +/- 0.02 g/kg per day; P < 0.05). A lower DPI correlated with level of renal dysfunction, independent of dietary advice (P < 0.0001). In the overall population, DPI correlated with body mass index (BMI; P < 0.0001) and serum albumin (P < 0.0001), and inverse correlations were evident between age (P < 0.0001), blood glucose level (P < 0.01), serum cholesterol level (P < 0.0001), and triglyceride levels (P < 0.0001) independently of renal function. Fifty-two patients were assessed within the 3 months before the commencement of dialysis, and 47 were reassessed within 3 months after the commencement of dialysis. Despite advice regarding an increase in dietary protein after the commencement of dialysis, this increase failed to occur within the 3 months of commencement of dialytic therapy (0.79 +/- 0.04 versus 0.82 +/- 0.03 g/kg per day); P = 0.64). However, 6 to 9 months after the commencement of dialysis, a significant increase in protein intake was evident (1.04 +/- 0.04 g/kg per day; P < 0.005 versus both prior measurements). Hence a low DPI in renal impairment occurs independently of dietary advice, but compliance with such advice is evident because patients advised to consume a low-protein diet had significantly lower protein intake than did patients receiving no dietary advice. Adaptation to a high-protein diet after instigation of dialysis is unsuccessful in the short term, irrespective of whether or not advice is given regarding a low-protein diet before dialysis is initiated. However, 6 to 9 months after the commencement of dialysis, a significant increase in protein intake occurs, which in the hemodialysis population correlates with dialysis delivery.

L-arginine may mediate the therapeutic effects of low protein diets

We have previously shown beneficial effects of dietary protein restriction on transforming growth factor beta (TGF-beta) expression and glomerular matrix accumulation in experimental glomerulonephritis. We hypothesized that these effects result from restriction of dietary L-arginine intake. Arginine is a precursor for three pathways, the products of which are involved in tissue injury and repair: nitric oxide, an effector molecule in inflammatory and immunological tissue injury; polyamines, which are required for DNA synthesis and cell growth; and proline, which is required for collagen production. Rats were fed six isocaloric diets differing in L-arginine and/or total protein content, starting immediately after induction of glomerulonephritis by injection of an antibody reactive to glomerular mesangial cells. Mesangial cell lysis and monocyte/macrophage infiltration did not differ with diet. However, restriction of dietary L-arginine intake, even when total protein intake was normal, resulted in decreased proteinuria, decreased expression of TGF-beta 1 mRNA and TGF-beta 1 protein, and decreased production and deposition of matrix components. L-Arginine, but not D-arginine, supplementation to low protein diets reversed these effects. These results implicate arginine as a key component in the beneficial effects of low protein diet.

Treatment of proteinuric patients with a vegetarian soy diet and fish oil

Our aim was to determine whether a longer period of treatment with a vegetarian soy diet with addition of fish oil supplements would accentuate the beneficial effects on hyperlipidemia and proteinuria of nephrotic patients we found in a previous study. After an 8-week baseline period on free diet, patients were randomly allocated either on soy diet alone (SD) or to SD plus 5 g/day of fish oil (SD + FO) orally for two months. Then they crossed over to the other treatment for two additional months. They finally resumed eating the free diet for 3 months. We selected 20 outpatients with chronic glomerulonephritis, proteinuria in the nephrotic range, fasting serum cholesterol > 250 mg/dl, mean serum creatinine concentrations 1.75 +/- 0.23 mg/dl. Serum lipid profile, urinary protein loss and nutritional parameters were monitored. With the soy diet, we obtained a significant decrease both of hyperlipidemia and of proteinuria. The effect of the soy diet on proteinuria increased over the 4 months. The addition of a moderate amount (5 g/day) of fish oil in a randomized cross-over design had no further beneficial effect. Stability of serum albumin, transferrin and the body mass index documented good nutritional status. In conclusion, the dietary manipulation with our vegetarian soy diet confirmed the beneficial effects on hyperlipidemia and proteinuria of nephrotic patients. Such effects persisted and even ameliorated after 4 months of diet. The addition of moderate oral supplements of fish oil did not potentiate the beneficial effect.

Fish oil has protective and therapeutic effects on proteinuria in passive Heymann nephritis

Passive Heymann nephritis (PHN) is a rat model of membranous nephropathy induced by injecting anti-Fx1A. The onset of proteinuria in PHN is caused by complement-mediated injury to glomerular epithelial cells (GEC) accompanied by enhanced glomerular eicosanoid production. In addition, sublethal injury by complement of rat GECs in culture leads to phospholipase activation, phospholipid hydrolysis and release of arachidonic acid and dienoic prostanoids. Based on these findings, we undertook to determine if substituting arachidonic acid (omega-6) in GEC membrane phospholipids with omega-3 fatty acids derived from fish oil would alter the development and course of proteinuria in PHN. We found that rats fed a diet containing 10% fish oil for four weeks prior to antibody injection developed 50 to 60% less proteinuria between two and six weeks after anti-Fx1A than rats fed an equivalent diet containing 10% safflower oil, and had substantial enrichment of glomerular phospholipids with omega-3 fatty acids and displacement of arachidonic acid. This outcome was associated with a 50% reduction in release of glomerular thromboxane B2 (stable metabolite of thromboxane A2) in the fish oil group. More importantly, when PHN rats with well established proteinuria while on regular chow were randomized to three dietary groups, those fed fish oil had a 25 to 50% decline in proteinuria as compared to those fed lard or safflower oil. This difference was evident within two weeks of randomization and persisted until the end of the study after eight weeks. In neither study could the differences in urine protein excretion be accounted for by protein or calorie deprivation, or by differences in blood pressure, renal function, immune response to sheep IgG, or glomerular deposition of IgG or complement. Thus, our results indicate that dietary fish oil has protective and therapeutic effects with regard to proteinuria in PHN. These benefits may relate to alterations in membrane phospholipid composition in favor of omega-3 fatty acids and release of less reactive trienoic eicosanoids.

Effects of a low-protein diet on urinary glycosaminoglycan excretion in adriamycin-treated rats

Adriamycin (ADR) induces glomerular damage in rats with persistent severe proteinuria which reaches a peak 15 days after a single 5 mg/kg intravenous (i.v.) injection. We studied in ADR-treated rats the effects of a low-protein (6%) diet (LPD) supplemented with keto acids on urinary protein and glycosaminoglycan (GAG) excretion and glomerular GAG contents. Animals were divided into three groups: group 1 was used as control, and groups 2 and 3 received a single i.v. injection of ADR; group 2 was fed a standard diet (21% protein) and group 3 an LPD. After ADR, group 2 developed heavy proteinuria and showed a progressive increase in urinary GAG excretion starting a few days after the beginning of proteinuria onset and persisting throughout the experiment. After ADR, group 3 (LPD treatment) did not develop proteinuria, and the level of urinary GAGs was comparable to that of controls. The glomerular GAG level in ADR-treated rats was greatly reduced as compared to controls; this decrease was partly eliminated in rats on an LPD. These results suggest that an LPD has a direct effect on cellular GAG production and turnover in ADR-induced glomerulonephritis.

Effect of changes in daily protein intake on renal function in chronic renal insufficiency: differences in reaction according to disease entity

Protein restriction is advocated in patients with chronic renal insufficiency (CRI) in an attempt to slow down further renal function deterioration, with the most obvious effect in patients with chronic glomerulonephritis (GN) and diabetic nephropathy, and much less in other disease entities, such as adult polycystic kidney disease (APKD), tubulointerstitial nephritis (TIN) and nephrosclerosis (NS). The mechanism by which protein restriction slows down the progression of renal failure remains unclear. Decline of hyperfiltration has been implicated. Whether long-term protein restriction in patients with CRI is associated with a decrease in hyperfiltration is not clear. We studied the effects of prolonged protein intake variation (isocaloric diets in 4-week periods of low (goal: 30-40 g protein daily) and high protein intake (goal: 80-90 g daily) on renal function in 51 patients with CRI. Patients were divided into subgroups according to the underlying renal disease (GN, n = 17; APKD, n = 9; TIN, n = 12; NS, n = 13). Glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) were measured at the end of each study period. Overall, GFR rose from 39 (9-90) to 46 (9-100) ml/min/1.73 m2 (median and ranges, p < 0.01), and ERPF from 158 (39-558) to 171 (32-676) ml/min/1.73 m2 (p < 0.01). GFR rose significantly in GN (15%, range -23 to 51%), APKD (5%, range -10 to 33%), and NS (8%, range -8 to 25%). ERPF only rose significantly in GN (14%, range -45 to 47%) and APKD (9%, range -9 to 25%).(ABSTRACT TRUNCATED AT 250 WORDS)

[The effect of omega-3 polyunsaturated fatty acids on the clinico-biochemical indices and kidney nitrogen-excreting function in patients with chronic kidney failure]

The addition of fish oil (20 g for 3 weeks) to diets of 7 patients with chronic renal failure (CRF) contributed to correction of metabolic derangement and nitrogen release, to alleviation of clinical symptoms. The most pronounced positive shifts were reported in early CRF. This gives evidence for a preventive value of diets supplemented with fish oil which secure delay of terminal CRF.

Dietary protein restriction rapidly reduces transforming growth factor beta 1 expression in experimental glomerulonephritis

Dietary protein restriction has been shown to slow the rate of loss of kidney function in humans with progressive glomerulosclerosis due to glomerulonephritis or diabetes mellitus. A central feature of glomerulosclerosis is the pathological accumulation of extracellular matrix within the diseased glomeruli. Transforming growth factor beta 1 (TGF-beta 1) is known to have widespread regulatory effects on extracellular matrix and has been implicated as a major cause of increased extracellular matrix synthesis and buildup of pathological matrix within glomeruli in experimental glomerulonephritis. In the present study, it is shown that administration of a low protein diet to rats rapidly reduces the elevated expression of TGF-beta 1 mRNA and TGF-beta 1 protein that is known to occur within glomeruli after induction of glomerulonephritis. Compared to a normal protein diet, glomerulonephritic rats receiving the low protein diet did not develop an increase in glomerular extracellular matrix and showed significantly less proteinuria. Glomeruli isolated from glomerulonephritic rats fed the normal protein diet showed a marked increase in proteoglycan synthesis on day 7 of disease and were demonstrated to be secreting increased amounts of TGF-beta 1 into the medium, whereas glomeruli at the same point in time isolated from rats on a low protein diet showed no increase in proteoglycan production or TGF-beta 1 secretion. These results suggest that a mechanism of the rapid therapeutic effect of a low protein diet on experimental glomerulonephritis is through suppression of TGF-beta 1 expression and prevention of the induction of extracellular matrix synthesis within the injured glomeruli.

Elevated dietary protein intake impairs the renal hemodynamic response to hyperaminoacidemia in patients with primary glomerular diseases

We have evaluated the renal hemodynamic response to a mixed amino acid infusion in 7 control subjects and in 8 patients with primary glomerulonephritis (GN). In order to evaluate the role of dietary protein intake in this response, GN patients were maintained for 3 weeks on two separate dietary regimens providing 130 +/- 5 g of protein/day (study 1) and 60 +/- 3 g of protein/day (study 2), respectively. Normal subjects were studied while consuming a free diet. In GN patients, following the reduction in dietary protein intake basal RPF and GFR decreased from 589 +/- 109 to 422 +/- 81 ml/1.73 m2/min (p less than 0.01, vs. study 1) and from 75 +/- 7 to 70 +/- 8 ml/1.73 m2/min (p = NS). Filtration fraction rose from 0.14 +/- 0.02 to 0.19 +/- 0.03 (p less than 0.05). In study 1, during amino acid infusion GFR and RPF did not change significantly from baseline (75 +/- 7 vs. 66 +/- 8 ml/1.73 m2/min at 180 min and 589 +/- 109 vs. 567 +/- 102 ml/1.73 m2/min, respectively). These results are at variance with data obtained in normal controls in whom both GFR and RPF rose significantly following hyperaminoacidemia. In contrast, when dietary protein intake was reduced, a normal renal hemodynamic response to amino acid infusion was restored (GFR went from 70 +/- 8 to 90 +/- 18 ml/1.73 m2/min and RPF from 422 +/- 81 to 517 +/- 90 ml/1.73 m2/min, both p less than 0.05 vs. basal), both absolute and percentage increases were similar to what was observed in controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Dietary marine lipids suppress murine autoimmune disease

Dietary marine lipids reduce both mortality and the severity of glomerulonephritis in inbred murine strains which develop spontaneous autoimmune disease. The protective effects of marine lipids appear to be accounted for by the major n-3 fatty acids in these preparations, 20:5 and 22:6. The n-3 fatty acids in dietary fish oil are extensively incorporated into several lipid classes in the spleen of autoimmune mice, including phosphatidylinositol, phosphatidylethanolamine, plasmalogens and saturated ether-linked phospholipids as well as diacylphosphoglycerides. The effects of dietary marine lipids on autoimmune disease in experimental models are highly specific. Careful controlled trials will be required to establish the role of dietary marine lipids in the therapy of human autoimmune disease.

Importance of early initiation of dietary protein restriction for the prevention of experimental progressive renal disease

The effect of dietary protein restriction on the progress of renal dysfunction was investigated in rats with adriamycin (ADR)-induced progressive glomerular disease. Dietary protein was reduced from 20% (normal diet) to 5% (low protein) immediately after (ADR-0w), 8 weeks (ADR-8w) or 16 weeks (ADR-16w) after the repeated injection of ADR. In the unrestricted (ADR-UR) group rats were fed 20% of protein throughout the 24-week experiment. Massive urinary protein developed immediately after ADR injection and significantly decreased by reducing dietary protein in all the groups (ADR-0w, ADR-8w, ADR-16w). However, plasma protein and serum albumin were low irrespective of the improvement of urinary protein. BUN and serum creatinine were unchanged in ADR-0w and ADR-8w groups, while they were increased in ADR-16w and ADR-UR groups. Glomerular sclerosis and tubular atrophy were much less severe in ADR-0w and ADR-8w than in ADR-16w and ADR-UR groups. The results indicate that dietary protein restriction checks the further progress of renal dysfunction. The importance of the time when protein intake should be reduced is discussed.

[Phosphorus-calcium metabolism and dietetic correction of its disorders in chronic kidney diseases in children]

Ninety children with varying renal diseases were under observation. The investigations conducted have shown that disorders in phosphoric-calcium metabolism depend on the type, activity of chronic glomerulonephritis (CGN) and etiology of chronic renal insufficiency (CRI). Significant disorders in phosphoric-calcium metabolism were detected in patients with nephrotic and mixed types of CGN. Most manifest clinical and x-ray changes of the osseous system were observed in patients with CRI that developed as a result of the tubulointerstitial pathologic process. Low-phosphate diets with preset amounts of Ca and P were developed, composed of products with relatively low content of P, and of new dietetic products rich in Ca. The diets were used for correction of hyperphosphatemia in children with CGN and in those with CRI, simultaneously with drug therapy, to prevent or diminish disorders in phosphoric-calcium metabolism, and to reduce the risk of invalidism among children with chronic renal diseases.

Conservative long-term treatment of chronic renal failure with keto acid and amino acid supplementation

In a group of 119 patients with advanced chronic renal failure (serum creatinine level 733 +/- 186 mumol/l) the effect of a low-protein diet supplemented with essential amino acids (EAA) or their keto analogues (KA) on uremic metabolism and rehabilitation status was investigated. The protein intake amounted to 0.4 g/kg B.W./day, the phosphorus intake 0.4-0.6 g/day and the energy supply 120-150 kJ/kg B. W./day. In 51 patients there was a substitution with EAA and in 68 patients with their KA. The mean duration of dietary treatment in this study was 19 months (6-64 months). During this time, the serum creatinine increased from 733 +/- 186 to 1,220 +/- 256 mumol/l, whereas the urea nitrogen values remained relatively constant at between 26 and 30 mmol/l. There were no signs of protein malnutrition (nitrogen balance, serum transferrin and serum protein were normal). The hemoglobin concentration remained at greater than 5 mmol/l with creatinine levels of 1,220 +/- 256 mumol/l. During the substitution with KA, there was a significantly greater decrease in serum phosphate (p less than 0.05) and parathyroid hormone (PTH) (p less than 0.01) as compared with the uremics given EAA. In addition, we found a significant increase in testosterone (p less than 0.01) in patients supplemented with KA. Despite advanced chronic renal failure there was a good degree of rehabilitation (full-time work: 21%; part-time work: 66.4%). It can be concluded that a low-protein diet supplemented with EAA or KA can improve the uremic metabolism, rehabilitation status and safely postpone the start of maintenance dialysis.

Influence of diet and underlying renal disease on the rate of progression of chronic renal failure

The data presented demonstrate that the underlying renal disease and the type of diet used are considerably influencing the rate of progression of chronic renal failure. In relative terms the course of the renal disease is mostly changed in patients suffering from glomerulonephritis, while in absolute terms patients suffering from polycystic kidney disease exhibit the slowest rate of progression. The comparison suggests that a low-protein diet purely based on vegetarian food might considerably slow down the overall rate of progression of chronic renal failure. This finding is supported by results obtained in animal experiments.

Effect of different levels of protein intake on renal deterioration and nutritional state in experimental renal disease

We examined the effects of various levels of dietary protein on the course of adriamycin-induced nephropathy in rats fed with high (30%), intermediately low (10%) or strictly low (5%) protein diets for 24 weeks. In the rats fed on the 30% protein diets, there were massive proteinuria, progressive increases in serum creatinine and focal glomerular sclerosis associated with severe tubulo-interstitial changes. With the 5% dietary protein, proteinuria was decreased, the levels of serum creatinine were preserved within normal ranges and renal histological changes diminished. Weight loss and hypoproteinaemia were more marked. With intermediate protein restriction (10% protein), renal function and plasma protein were preserved but body weight did not increase normally. Aggregated human immunoglobulin G, which had been intravenously injected at weeks 12 and 24, accumulated in the glomeruli more densely in rats fed on the 30% protein diet than in those fed on the 10% or 5% protein diets. We tentatively conclude that functional and histological deterioration of focal glomerular sclerosis can be prevented by appropriate restriction of dietary protein; however, severe protein restriction does aggravate nutritional states.

Selective effect of low protein diets in chronic renal diseases

It has recently been established that the rate of progression of chronic renal failure in man can be slowed by restricting dietary protein. Consequently, the short term and long term effects of a low protein diet on the course of different chronic nephropathies were studied in an attempt to delineate the factors that determine the response to such a diet. When a low protein diet was given for six months renal function improved significantly in nine patients with chronic tubulointerstitial nephritis (p less than 0.025); the diet had a marginally beneficial effect in 12 patients with chronic glomerulonephritis (p less than 0.05) and no effect in nine with hypertensive nephrosclerosis. The heterogeneous functional response in the patients with chronic glomerulonephritis correlated closely with the effect of the diet on these patients' proteinuria (r = 0.76, p less than 0.01). In a short term study (four weeks) of 12 patients with chronic renal failure changes in renal plasma flow were proportional to dietary protein intake. Renal vascular resistance fell during a high protein diet and increased when dietary protein was restricted. The changes in renal plasma flow during the low protein diet correlated well with the patients' long term functional response to the diet (r = 0.76, p less than 0.01). It is concluded that the response to a low protein diet in chronic renal failure is determined, firstly, by the nature of the underlying nephropathy, with maximal benefit being observed in non-glomerular disorders; secondly, by the effect of the diet on the proteinuria in chronic glomerulonephritis; and, thirdly, by the haemodynamic response to the diet, with patients with a reactive renal vascular bed improving with a low protein diet.

Amelioration of experimental glomerulonephritis by dietary protein restriction

We have examined the effects of various levels of dietary protein intake on the course of nephrotoxic serum nephritis in the rat by feeding low (4.6% casein), standard (23% casein), and high (57.5% casein) protein diets which were identical in calorie, mineral, and electrolyte content. Nephritic rats on a high protein diet manifested heavy proteinuria, hypoalbuminemia, hypercholesterolemia, azotemia, and elevated serum creatinine levels. In those subjected to dietary protein restriction, proteinuria remitted and azotemia did not develop. While mesangial widening, interstitial abnormalities, and segmental proliferation and sclerosis of glomeruli occurred regularly in nephritic rats fed high protein diets, histologic abnormalities were virtually absent in those on low protein intake. Animals on a standard protein intake manifested histologic and clinical features intermediate in severity. We conclude that the renal functional and histologic consequences of nephrotoxic serum nephritis can be averted by dietary protein restriction.

[Lipid metabolism and free-radical oxidation in children with glomerulonephitis incorporating plant fats into their diet]

A study was made of the effect of vegetable fats on lipid metabolism and free radical oxidation, phospholipase activity and antioxidant content in 43 children suffering from chronic glomerulonephritis. After intake of a vegetative fat in a dose of 2 g/kg bw for 7 days the sick children demonstrated a significant rise in the level of total lipids in red cells and in their excretion with urine. This was in a good agreement with an increase in phospholipase activity in blood and diminution of lipid peroxides in red cell membranes. The reaction of antioxidant enzymes metabolizing hydrogen peroxide was different. Catalase activity in urine was elevated, whereas urine peroxidase activity was decreased. All these changes gave rise to a decrease in the pool of peroxide radicals which correlated with the time course of hydroperoxides. The biochemical data indicate that lipids contained by vegetative fats may be regarded as treatment-and-dietetic factor in multiple modality therapy of children with renal diseases.

Progression rate of residual renal function in conservative treatment and early dialysis

A retrospective comparative study was carried out in patients with chronic renal failure on conservative treatment (26 cases) and early dialysis (23 cases). The two groups were well matched for age, sex, etiology of renal disease and residual Ccr. In contrast with other papers, patients on dialysis showed a gentler deterioration rate of residual renal function than those on conventional low protein diet regimen. Between the two groups statistically significant differences concerned the control of blood pressure, serum phosphate and uric acid.

Dietary enrichment with the polyunsaturated fatty acid eicosapentaenoic acid prevents proteinuria and prolongs survival in NZB x NZW F1 mice

Prostaglandins and related compounds are active mediators of inflammation, but data concerning their role in the pathogenesis of the glomerulonephritis of New Zealand Black x New Zealand White (NZB x NZW) F1 mice are conflicting. Dietary eicosapentaenoic acid (EPA, C20:5), a fatty acid analogue of arachidonic acid (C20:4), has been shown to impair platelet aggregation in humans, apparently through inhibition of the synthesis of prostaglandins and thromboxanes from arachidonic acid. We report here the effects of a diet high in EPA on the development of renal disease and survival in female NZB x NZW F1 mice. Animals from 4--5 wk of age were fed diets containing 25% lipid, supplied either as beef tallow or menhaden oil, with fatty acid analysis of less than 0.05 and 14.4% EPA, respectively. In the first experiment, by 13.5 mo of age, mice on the beef tallow diet had all (9/9) developed proteinuria and the majority (6/9) had died, with renal histologic examination revealing severe glomerulonephritis. In contrast, none of 10 menhaden oil-fed animals had developed proteinuria, and all were alive at this time (P less than 0.005 for both proteinuria and survival). In a second experiment using 50 mice in each dietary group, 56% of the beef tallow group vs. none of the menhaden oil group had developed proteinuria at 9 mo of age (P less than 0.005). Native DNA binding at 6 mo of age was 23.9 +/- 14.7 vs. 10.1 +/- 9.7% in the beef and menhaden oil groups, respectively (P less than 0.01). Weights were similar in all groups, and there was no evidence of essential fatty acid deficiency in any group. These results demonstrate that a diet high in EPA protects NZB x NZW F1 mice from the development of glomerulonephritis.

Modulated nitrogen intake for patients on low-protein diets

In order to overcome malnutrition and poor palatability associated with long lasting low-protein intakes, a diet was devised based on modulated nitrogen intake and energy supply of at least 155 KJ/kg a day. Each patient underwent three different regimens (A, B, C) of protein intake. In period A, the protein intake was 0.33 g/kg a day. In period B, the patients were given 0.33 g/kg a day during day 1, 2, 3, 5, 6 and 1.00 g/kg a day during day 4 and day 7 of the week. In period C the daily protein intake was the mean of the weekly value from day 1 to 7 of period B. Data obtained show that in period A the urea appearance rate was equal to that in period B and lower than that in period C.

Preservation of renal function in experimental glomerulonephritis

To evaluate the protective effect of dietary phosphorus restriction in an immunologic model of experimental renal disease, we randomized 24 Sprague-Dawley rats with established nephrotoxic serum nephritis into two groups. Group A animals (N = 13) were fed a diet with a normal phosphorus content (0.5% phosphorus), and group B animals (N = 11) received an identical diet low in phosphorus (0.04% phosphorus). Over the ensuing 133 days, group A rats developed progressive renal failure and had a mean serum creatinine concentration of 3.0 +/- 0.5 mg/dl at the time of death or completion of the study. In contrast, group B animals maintained near normal renal function and had a final mean serum creatinine concentration of 0.93 + 0.2 mg/dl (P < 0.001). Survival was markedly improved in group B animals (P < 0.001). Histologic damage was diminished greatly in group B animals by both light and electron microscopy; immunofluorescence was positive in all animals. Group A animals had increased kidney calcium concentration (30 +/- 6 mmoles/kg) when compared to group B animals (18 +/- 1 mmoles/kg) and animals with normal kidneys (13 +/- 1 nmoles/kg, P< 0.001). Conclusion. Dietary restriction of phosphorus retards functional deterioration and reduces histologic damage in experimental immunologic renal disease. The mechanism for this protective effect has not been elucidated.

[Changes in lipid metabolic indices in children with chronic kidney diseases under the influence of diet therapy]

Variations in lipid metabolism were studied in 20 children with chronic glomerulonephritis (CGN) associated with the nephrotic syndrome and 14 children with chronic renal insufficiency given protein deficient therapeutic diets. Suggestive abnormalities of lipid metabolism involved hyperlipidemia, hypercholesterinemia and hypertriglyceridemia (more sharply pronounced in patients with CGN associated with the nephrotic syndrome) as well as hyperlipoproteidemia, chiefly of types IY and IIB. Disproportions in lipoproteid spectra of the plasma towards increase in atherogenous beta- and pre-beta-lipoproteids are characteristic for patients of both groups but sharply pronounced in CRI. These patients also show a reduced metabolization efficacy coefficient (MEC) of essential fatty acids of food to the lipid structures of erythrocyte membranes. As a results of the treatment the lipid metabolism returned to normal in most patients with CGN and in part of the patients with CRI. In order to raise the efficacy of therapeutic diets during normalization of lipid metabolism in CRI it is recommended that the fat and carbohydrate components of the diet may be changed qualitatively with due regard for the types of hyperlipoproteidemia.