***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Ar and omized , controlled study of 12 patients with mild chronic renal failure was design ed to assess the metabolic effects of a low-protein diet supplemented ( n = 6 ) or not ( n = 6 ) with ketoanalogs of amino acids . The protein intake was prescribed so that both groups were isonitrogenous . The dietary survey each month included a 3-d food record and a 24-h urine collection for urea measurement . After a 4- to 6-wk equilibrium period ( st and ard occidental diet , 1.11 g of protein and 32 kcal/kg per d ) , patients reduced their protein intake to reach 0.71 g of protein/kg per d during the third month . Energy intake was kept constant ( 31 kcal/kg per d ) during the 3-mo period . Compliance to the diet was achieved after 2 mo of training . Leucine turnover measurement was performed before and at the end of the 3-mo low-protein period . There was no clinical change , whereas total body flux decreased by 8 % ( P < 0.05 ) and leucine oxidation by 18 % ( P < 0.05 ) . No difference could be attributed to the ketoanalogs themselves . Thus , under sufficient energy intake , a low-protein diet is nutritionally and metabolically safe during chronic renal failure . The nitrogen-sparing effect of a low-protein diet is still present during mild chronic renal insufficiency In 15 ambulatory patients with renal insufficiency ( creatinine clearance , 9.9 + /- 3.0 ml/min ) the effect of oral supplementation with alpha-ketoacids has been compared with that of placebo . The protein intake amounted to 0.55 g protein per kilogram body weight of high biological value , as estimated by dietary recordings . After a control period of 3 months the patients received , in a double-blind study , 1.05 g alpha-ketoacids/10 kg body weight per day or a placebo for 6 weeks with a subsequent cross-over . Fasting blood sample s were analyzed at 3-week intervals for routine laboratory parameters and 17 proteins . Anthropometric and clinical data have been recorded every 3 weeks . While therapy with alpha-ketoacids diminished PO4 levels ( P less than 0.05 ) , no other significant effect could be demonstrated . No signs of protein deficiency existed either before or during alpha-ketoacid therapy . Therefore , supplementation with alpha-ketoacids appears to be superfluous in patients with renal insufficiency maintained on a 40-g protein diet 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 ( 0.35 g/kg/day ) , low protein diet ( LPD , 0.60 g/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+/-0.21 g/kg/day , respectively ; P<0.0001 ) . BP diminished only in VLPD , from 143+/-19/84+/-10 to 128+/-16/78+/-7 mm 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+/-36 mEq/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 BACKGROUND AND OBJECTIVES High levels of fibroblast growth factor 23 are associated with mortality , CKD progression , and calcification in CKD patients . The aim of this pilot study is to assess whether a very-low-protein diet ( 0.3 g/kg per day ) with a consequent low intake of phosphorus would reduce fibroblast growth factor 23 compared with a low-protein diet ( 0.6 g/kg per day ) in CKD patients not yet on dialysis . DESIGN , SETTING , PARTICIPANTS , & MEASUREMENTS A prospect i ve , r and omized , controlled crossover study was performed in which 32 patients were r and omized into two groups . Group A ( 16 patients ) received a very-low-protein diet ( 0.3 g/kg body wt per day ) supplemented with ketoanalogues during the first week and a low-protein diet during the second week , and group B ( 16 patients ) received a low-protein diet during the first week and a very-low-protein diet during the second week .  Fibroblast growth factor 23 , seric , and urinary phosphate levels were measured at baseline and the end of each study period . RESULTS After only 1 week of the very-low-protein diet , reductions in fibroblast growth factor 23 levels ( 33.5 % ) , serum phosphate ( 12 % ) , and urinary phosphate ( 34 % ) with the very-low-protein diet compared with the low-protein diet were observed . Serum and urinary phosphate levels and protein intake were significant determinants of fibroblast growth factor 23 ( 95 % confidence interval=1.04 - 1.19 , 1.12 - 1.37 , and 1.51 - 2.23 , respectively ) . CONCLUSIONS A very-low-protein diet supplemented with ketoanalogues reduced fibroblast growth factor 23 levels in CKD patients not yet on dialysis OBJECTIVE To compare a severe protein restriction diet supplemented with ketoanalogues to a moderate protein restriction diet in order to limit glomerular filtration rate ( GFR ) decrease in an advanced renal insufficiency stage . DESIGN Prospect i ve r and omised study conducted to compare a severe protein restriction diet ( 0.30 g/kg/day ) supplemented with a preparation of ketoanalogues , hydroxyanalogues of aminoacids and aminoacids ( Group A ) to a moderate protein restriction diet ( 0.65 g/kg/day ) ( Group B ) . PATIENTS 50 uremic patients included ( 25 in each group ) with GFR is < 20 mL/min/1.73m2 . RESULTS There were no statistically significant differences between the two dietary regimens for the renal survival . But uremia decreased significantly in Group A ( 22.7+/-5.2 to 18.5+/-6.7 mmol/L ) and increased in Group B ( 26.8+/-9.0 to 34.9+/-9.9 mmol/L ) . Calcemia increased in Group A from 2.28+/-0.18 to 2.42+/-0.17 mmol/L , p<0.01 with a stable phosphoremia while calcemia decreased in Group B ( 2.33+/-0.18 to 2.25+/-0.17 mmol/L , p<0.05 ) . At the end of the study , Group A was different from Group B for calcemia ( 2.42+/-0.17 vs. 2.25+/-0.17 mmol/L , p<0.01 ) , phosphoremia ( 1.39+/-0.30 vs. 1.80+/-0.65 mmol/L , p<0.02 ) , alkaline phosphatase ( 61.42+/-22.93 vs. 78.8+/-27.0 , p<0.05 ) and parathormone plasma levels ( 2.71+/-1.55 vs. 5.91+/-1.41 ng/mL , p<0.001 ) . COMMENTS Compared to a moderate protein restriction ( 0.65 g/kg/day ) , a severe protein restriction ( 0.3 g/kg/day ) supplemented by ketoanologues does not limit GFR decrease when GFR is below 20 mL/min/1.73m2 , but improves phosphocalcic plasma parameters The  therapeutical effect of keto acids on bone histology was investigated in a prospect i ve r and omized controlled study of 40 patients . A marked improvement in osteofibrotic as well as in osteomalacic changes was found in bone biopsies after 12 months of treatment with keto acids OBJECTIVE To investigate if a-keto/amino acid supplemented low protein diet can slow down the progression of diabetic nephrophathy in comparison with non-supplemented diabetes diet . METHODS A prospect i ve , r and omized , controlled clinical study was conducted . Twenty three cases of type 2 diabetic nephropathy in IV stage were r and omly divided into alpha-keto/amino acid supplemented diet group ( trial group ) and conventional diabetes diet group ( control group ) , The treatment duration was 52 weeks . 24 h urine protein was measured at 0 , 12 , 20 , 36 and 52 weeks . Before and after the 52 weeks treatment , all the patients received the measurement of glomerular filtration rate ( GFR ) , blood glucose , blood lipids , inflammatory markers , as well as nutritional status . RESULTS After the treatment for 20 , 36 , 52 weeks , mean 24 h urine protein decreased significantly in trial groups ( P < 0.05 ) , and 24 h urine protein in trial group were significantly decreased ( P < 0.05 ) compared with control group in 20 weeks after treatment . Either in trial group or in control group , GFR remained relatively stable during the observation period . Nutrition status , inflammatory markers , and serum calcium , phosphorus levels between the two groups were no significantly difference . The adverse events experienced by the patients in trial group were similar and consistent with the patients underlying renal diseases . CONCLUSION Alpha-keto/amino acid can reduce proteinuria more effectively , while improve renal function and nutritional status in diabetic nephropathy patients with well-toleration Objective : To evaluate the effects on the nutritional and metabolic parameters of a very-low-protein diet supplemented with ketoacids ( VLPD+KA ) in comparison with a conventional low-protein diet ( LPD ) in chronic kidney disease ( CKD ) patients . Design : Prospect i ve , r and omized , controlled clinical study . Setting : Outpatient Clinic of the Nephrology Division of Federal University of São Paulo , Brazil . Subjects : The study involved 24 patients with advanced CKD ( creatinine clearance < 25 ml/min ) that were r and omly assigned to either a VLPD+KA ( VLPD+KA group , 12 patients ) or to a conventional LPD with 0.6 g/kg/day ( LPD group , 12 patients ) . The patients were followed for 4 months . Results : Nutritional status was adequately maintained with both diets for the studied period . Protein intake and serum urea nitrogen decreased significantly only in the VLPD+KA group ( from 0.68±0.17 to 0.43±0.12 g/kg/day , P<0.05 ; from 61.4±12.8 to 43.6±14.9 mg/dl , P<0.001 ; respectively ) . Ionized calcium did not change in the VLPD+KA group but tended to decrease in the LPD group . Serum phosphorus tended to decrease in the VLPD+KA group probably as a result of a significant reduction in dietary phosphorus ( 529±109 to 373±125 mg/day , P<0.05 ) associated to the phosphorus-binding effect of the ketoacids . No change in these parameters was found in the LPD group . Serum parathormone increased significantly only in the LPD group ( from 241±138 to 494±390 pg/ml , P<0.01 ) . The change in PTH concentration was negatively correlated with changes in ionized calcium concentration ( r=−0.75 , P=0.02 ) and positively correlated with changes in serum phosphorus ( r=0.71 , P=0.03 ) only in the LPD group . Con 
    Output:
    
Conclusion Restricted protein diet supplemented with keto analogues ( s(v)LPD ) could delay the progression of CKD effectively without causing malnutrition