Randomised multicentre study of a low-protein diet on the progression of chronic renal failure in children. European Study Group of Nutritional Treatment of Chronic Renal Failure in Childhood.

BACKGROUND: Some studies have suggested that a low-protein diet slows the deterioration of renal function in patients with chronic renal failure (CRF). The effects of a low-protein diet on renal function and growth, have not been assessed in a large, prospective randomised trial in children with CRF. METHODS: A 2-year prospective, stratified, and randomised multicentre study recruited 191 patients aged 2-18 years. After a run-in period of at least 6 months, patients were stratified into either a progressive or non-progressive category based on the change in creatinine clearance in this period. The patients were also stratified into three renal-disease categories and then randomly assigned to a control or diet group. In the diet group, the protein intake was the lowest, safe WHO recommendation--i.e., 0.8-1.1 g/kg daily adjusted for age. All patients were advised to have a calorie intake of at least 70% of the WHO recommendations. Glomerular filtration rate (GFR) was measured every 2 months by creatinine clearance; dietary compliance was checked by urinary urea-nitrogen excretion and dietary diaries (weighing method). 112 patients completed an optional third year of the study. FINDINGS: The low-protein diet did not affect growth. However, there was no effect of diet on the mean decline in creatinine clearance over 2 years (diet vs control: progressive group -9.7 [SD 8.0] vs -10.7 [11.8] mL/min per 1.73 m2; non-progressive group -2.5 [7.5] vs -4.3 [10.0] mL/min per 1.73 m2). Patients classified as having progressive disease were older and had a lower creatinine clearance and a higher blood pressure at randomisation, and had a greater decrease in creatinine clearance than non-progressive patients. On multivariate regression analysis proteinuria (partial R2 = 0.259) and systolic blood pressure (partial R2 = 0.087) were independent predictors of the change in GFR. Similar results were found after the study was extended for a third year. INTERPRETATION: A low-protein diet for 3 years did not affect the decrease in renal function in children with CRF. Proteinuria and blood pressure explain a large part of the variability of, and may be causally related to the decline in the GFR.

Evaluation of protein intake by dietary diaries and urea-N excretion in children with chronic renal failure. European Study Group for Nutritional Treatment of Chronic Renal Failure in Childhood.

In 1988 a European multicentre, randomized trial was started in order to analyse the influence of protein intake on the progression of chronic renal failure in children. Compliance to the dietary prescriptions, i.e. protein intake, was checked by written dietary diaries and in addition by urinary urea-N excretion. This provided a unique chance to compare both methods in non-hospitalized children. Of a total of 200 patients 123 were selected, in whom at least 4 consecutive dietary diaries plus 4 completely collected 24-hour urine samples were available. Whereas urea-N excretion and simultaneously recorded protein intake did not correlate well, mean urinary urea-N excretion and mean protein intake of at least 4 observations in each patient correlated highly (r = 0.803, p = 0.0001). The difference between protein-N intake and urea-N excretion was not a constant amount of 0.031 g/kg/day as proposed by Maroni et al. [1985] but figured at 0.085 +/- 0.061 g/kg/day and was highly correlated to protein intake (r = 0.839, p = 0.0001). The correlation of protein intake and urea-N excretion was best described by the formula: protein-intake (g/kg/day) = (urea-N excretion [g/kg/day]x 15.39) -0.8 or protein intake (g/kg/day) = urea-N excretion (g/kg/day) x 9.5. Maroni's formula underestimated the high protein intake of young children. In only a few patients dietary diaries severely underestimated protein intake as compared to calculation by urea-N excretion.(ABSTRACT TRUNCATED AT 250 WORDS)

Energy and nutrient intake of patients with mild-to-moderate chronic renal failure compared with healthy children: an Italian multicentre study.

Nutritional counselling is important in the management of children with chronic renal failure (CRF). In 1988, a controlled European multicentre study was started to evaluate the effects of a low-protein diet on the progression of CRF in children. To assess the energy, macro- and micronutrient intake, 4-day weighed dietary records were obtained from 50 children with low to moderate CRF (creatinine clearance 65 to 15 ml/min per 1.73 m2) and from 93 healthy children. The mean energy intake was 90%-93% of the recommended dietary allowance for Italian children in controls and 76%-88% in CRF patients. The mean protein intake was 2.1-3.1 g/kg per day in controls and 1.6-2.7 g/kg per day in CRF patients. Overall, the energy intake was 10% and the protein intake 33% lower in CRF patients than in healthy children. Children with CRF consumed less cholesterol, calcium and phosphorus than healthy children. The lower spontaneous intake of energy, protein and other nutrients should be taken into account when planning the nutrition of children with CRF.

Multicentre randomized study on the effect of a low-protein diet on the progression of renal failure in childhood: one-year results. European Study Group for Nutritional Treatment of Chronic Renal Failure in Childhood.

After an adaptation period of 6 months, 200 children (mean age 10.3 years; 138 boys and 62 girls) were stratified according to their renal diseases and the progression of renal failure during the adaptation period and randomized for low protein intake amounting to the WHO safe levels for age (0.8-1.1 g/kg/day) or free protein intake. Energy intake of both groups should be near the WHO recommendations. Compliance was controlled by written dietary diaries and urea-N excretion. 101 children had been randomized for the diet group and 99 for the control group. 165 of these patients finished their first year after randomization. Mean protein intake was 126% of the recommendations in the diet group vs. 187% in the control group while energy intake was similar in both groups (85 vs. 90%). SDS for height at start and 1 year later did not change (diet: -0.9 vs. -1.1; control: -0.9 vs. -0.9). Weight gain was not different. Only the stratification for two groups according to the progression of renal failure ('nonprogressive' and 'progressive' diseases) was used in the analyses. Progression of renal disease during the adaptation period proved to be a significant prognostic factor. Mean loss of GFR/year was similar in patients with 'nonprogressive' diseases in the control group (-1.1 ml) and the diet group (-1.3 ml). In patients with 'progressive' diseases mean loss of GFR was significantly higher in the diet group (-6.5 ml) than in the control group (-4.0 ml).(ABSTRACT TRUNCATED AT 250 WORDS)

Low-protein diet in children with chronic renal failure--1-year results. European Study Group for Nutritional Treatment of Chronic Renal Failure in Childhood.

In 1988 the European Study for Nutritional Treatment of Children with Chronic Renal Failure started its multicentre randomized trial to investigate the influence of protein intake on the progression of renal failure. A total of 284 children had been registered. Of these 221 were accepted for the study. The data from 105 patients after 1 year of study are available for preliminary analysis. Fifty children were randomized for the diet group and 55 for the control group. Both groups were comparable concerning age, glomuerlar filtration rate (GFR) and height standard deviation score for chronological age at the start of the study period and the distribution of primary renal diseases and sex. Limits for protein and energy intake were set according to the safe levels and recommendations given by the World Health Organization. The compliance with dietary prescriptions as calculated from dietary diaries was good. A low-protein diet did not do any harm to the children with respect to length gain and weight gain. The progression of renal failure was minimal in the diet group (mean loss of GFR 3.6 ml/min per 1.73 m2 per year) as well as in the control group (2.3 ml/min per 1.73 m2 per year). The differences between the diet group and the control group were statistically not significant when either all patients or only subgroups of various primary renal diseases were analysed. When only patients with a good compliance were considered (documented by dietary diaries or by urea nitrogen excretion) the same results were obtained. In summary, reduction of protein intake was accepted by the majority of patients.(ABSTRACT TRUNCATED AT 250 WORDS)