***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 
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    Input: To assess whether moderate dietary protein restriction can delay the progression of overt diabetic nephropathy , 22 subjects with insulin-dependent diabetes mellitus were r and omly assigned to an unrestricted protein diet ( > 1.6 g.kg body wt-1.d-1 ) or a moderately protein-restricted diet ( 0.8 g.kg body wt-1.d-1 ) and followed prospect ively for six mo . Direct isotope methods were used to assess renal function . Protein intake was assessed by measurement of urinary urea nitrogen . The two groups were well-matched for age , sex , duration of diabetes , glycemic control , blood pressure , and degree of renal insufficiency . Patients consuming the unrestricted protein diet ( n = 11 ) showed a progressive decline in glomerular filtration rate of 1.3 mL.min-1.mo-1 with no change in proteinuria . Patients consuming the moderately protein-restricted diet showed a marked decrease in the degree of proteinuria ( 2.15 - 1.13 g/d , P = 0.036 ) and a stabilization of glomerular filtration rate . This occurred independently of changes in blood pressure or glycemic control . Moderate dietary protein restriction can ameliorate progression of overt diabetic nephropathy Abstract Aims /hypothesisThere is currently insufficient evidence to recommend a low-protein diet for type 2 diabetic patients with diabetic nephropathy . We assessed whether a low-protein diet could prevent the progression of diabetic nephropathy . Methods This was a multi-site parallel r and omised controlled trial for prevention of diabetic nephropathy progression among 112 Japanese type 2 diabetic patients with overt nephropathy . It was conducted in Japan from 1 December 1997 to 30 April 2006 . The participants were r and omly assigned using a central computer-generated schedule to either low-protein diet ( 0.8 g kg−1 day−1 ) and normal-protein diet ( 1.2 g kg−1 day−1 ) , and were followed for 5 years . The participants and investigators were not blinded to the assignment . The primary outcomes were the annual change in estimated GFR and creatinine clearance , the incidence of doubling of serum creatinine and the time to doubling of baseline serum creatinine . Results The study was completed by 47 ( 84 % ) of 56 participants in the  low-protein  diet group and 41 ( 73 % ) of 56 participants in the normal-diet group . During the study period , the difference in mean annual change in estimated GFR between the low-protein diet and the normal-protein diet groups was −0.3 ml min−1 1.73 m−2 ( 95 % CI −3.9 , 4.4 ; p = 0.93 ) . The difference in mean annual change in creatinine clearance between the low-protein diet and the normal-protein diet groups was −0.006 ml s−1 1.73 m−2 ( 95 % CI −0.089 , 0.112 ; p = 0.80 ) . A doubling of serum creatinine was reached in 16 patients of the low-protein group ( 34.0 % ) , compared with 15 in the normal-protein group ( 36.6 % ) , the difference between groups being −2.6 % ( 95 % CI −22.6 , 17.5 ; p = 0.80 ) . The time to doubling of serum creatinine was similar in both groups ( p = 0.66 ) . Conclusions /interpretationIt is extremely difficult to get patients to follow a long-term low-protein diet . Although in the low-protein group overall protein intake was slightly ( but not significantly ) lower , it did not confer renoprotection . Clinical trial registration : Clinical Trials.gov NCT00448526 Funding : Research grant from the Ministry of Health , Labour and Welfare of BACKGROUND A r and omized trial was conducted to assess whether protein restriction helps to delay the onset of renal disorders in type 2 diabetic patients . METHODS Included in the trial were 121 type 2 diabetic patients with microalbuminuria or at least detectable albuminuria , or diabetes of duration > or = 5 years . The experimental ( 39 male/19 female ) and control group ( 35 male/28 female ) received counselling on protein restriction and the usual dietary advice , respectively . The outcome measure was albuminuria ( mg/24 h ) . Results . After 6 months in experimental and control groups the change in protein intake was -0.05+/-0.21 and + 0.03+/-0.19 g/kg ( P = 0.02 ) , and in albuminuria -14 % and + 11 % ( P = 0.01 ) , respectively . After 12 months , the differences between the experimental and the control group with respect to both protein intake and albuminuria had decreased . At 6 and 12 months , respectively , albuminuria was 28 % ( P<0.001 ) and 18 % ( P = 0.08 ) lower in the experimental than the control group . The effect in normoalbuminuric patients did not differ from that in microalbuminuric patients . In the experimental group , blood pressure , HbA1c and body weight decreased ; in the control group , such decreases were less or absent . Dose-response analysis showed that a 0.10 g/kg change at 6 months in the intake of protein , of animal protein in particular , was related to an 11.1 % change in albuminuria ( P<0.005 ) . Combining the intakes at 6 and 12 months suggested a percentage change of 9.1 % . CONCLUSIONS Substantial protein restriction in primary care , type 2 diabetic patients with no nephropathy is barely feasible . However , even a small reduction has a substantial and potentially beneficial effect on albuminuria 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 Recent clinical investigations have demonstrated that an early restriction of dietary protein intake may reduce the rate of progression of chronic renal failure in humans . In this study the effects of a restricted-protein diet on kidney function in type I diabetic patients with clinical nephropathy were evaluated . Sixteen patients ( 9 men , 7 women ) with mean age 37.1 ± 9.8 yr , mean duration of diabetes 17.7 ± 6.6 yr , proteinuria > 0.5 g/24 h , and serum creatinine concentration of 0.7−1.9 mg/dl were studied . Patients were r and omly divided into two groups . The low-protein diet ( LPD ) group comprised seven patients who were kept for 4.5 ± 1 mo on a diet containing 0.71 ± 0.12 g × kg−1 × day−1 protein . The normal-protein diet ( NPD ) group comprised nine patients as controls maintained for 11.7 ± 7 mo on their usual diabetic diet containing 1.44 ± 0.12 g × kg−1 × day−1 protein . All patients were studied every 1–2 mo . Metabolic control was assessed by evaluation of 5–8 blood glucose determinations/day and by glycosylated hemoglobin , whereas renal function was evaluated by albumin , IgG and β2-microglobulin urinary excretion rates , serum creatinine concentration , and creatinine clearance . At each visit , serum concentrations of total protein , albumin , phosphate , calcium , and electrolytes and weight and blood pressure were also measured . A significant reduction ( 434 ± 244 to 205 ± 212 μg/min , mean ± SD ) in albumin excretion rate was found in all LPD patients after dietary protein restriction , with a significant reincrease ( 689 ± 201 μg/min ) in the same patients several months after interruption of diet . In contrast , a significant increase in albumin ( 452 ± 200 to 850 ± 288 μg/min ) and IgG ( 82 ± 63 to 129 ± 79 μg/min ) urinary excretion rates was found in NPD patients . No significant variations were noticed during the study regarding creatinine clearance , serum creatinine , urinary β2-microglobulin , arterial blood pressure , and other parameters . Mean daily insulin requirements remained unchanged in all patients . We conclude that our study supports the hypothesis that diabetic nephropathy , like other forms of chronic renal disease , might benefit from an early restriction of dietary protein intake Objective : Protein restriction delays the progression of non-diabetic and type 1 diabetic renal disorders . This study assessed whether protein restriction delays the onset or early progression of renal disorders in type 2 diabetes . Design : R and omized controlled trial . Outcomes were albuminuria ( mg/24 h ) and , as an estimate of the glomerular filtration rate , cimetidine-influenced creatinine clearance . Setting : Primary care . Subjects : Patients with type 2 diabetes and microalbuminuria or at least detectable albuminuria , or a diabetes duration > 5 y. Interventions : The experimental group received dietary counselling on protein restriction ( n=63 ) ; a control group ( n=68 ) received the usual dietary advice . The duration of intervention and follow-up was 28±7 months . Results : After 6 months , protein intake differed only by 0.08 g/kg/day between the study groups . Subsequently , this difference decreased and eventually disappeared . An initial effect of protein restriction on albuminuria in favor of the experimental group was not sustained , and the glomerular filtration rate decreased in the experimental group at a 1.6±2.2 ml/min/1.73 m2 y lower rate than in the control group ( P=0.5 ) . Comparison of patients in the experimental group with a decrease in protein intake of at least 0.20 g/kg/day , with controls with no decrease , indicated a similarly small and insignificant effect on glomerular filtration rate . Conclusions : It is concluded that , in the longer term prevention or delay of renal damage in patients with type 2 diabetes , protein restriction is neither feasible nor efficacious . Sponsorship : Financial support for this study was provided by the Dutch Organization for Scientific Research ( NWO , The Hague , grant number 904 - 58 - 051 ) and the Health Research and Development Council ( ZON , The Hague , grant number 28 - 2298 ) . Smithkline & Beecham provided cimetidine ( Tagemet ® ) Reduced function mutations in the insulin/IGF‐I signaling pathway increase maximal lifespan and health span in many species . Calorie restriction ( CR ) decreases serum IGF‐1 concentration by ~40 % , protects against cancer and slows aging in rodents . However , the long‐term effects of CR with adequate nutrition on circulating IGF‐1 levels in humans are unknown . Here we report data from two long‐term CR studies ( 1 and 6 years ) showing that severe CR without malnutrition did not change IGF‐1 and IGF‐1 : IGFBP‐3 ratio levels in humans . In contrast , total and free IGF‐1 concentrations were significantly lower in moderately protein‐restricted individuals . Reducing protein intake from an average of 1.67 g kg−1 of body weight per day to 0.95 g kg−1 of body weight per day for 3 weeks in six volunteers practicing CR result ed in a reduction in serum IGF‐1 from 194 ng mL−1 to 152 ng mL−1 . These findings demonstrate that , unlike in rodents , long‐term severe CR does not reduce serum IGF‐1 concentration and IGF‐1 : IGFBP‐3 ratio in humans . In addition , our data provide evidence that protein intake is a key determinant of circulating IGF‐1 levels in humans , and suggest that reduced protein intake may become an important component of anticancer and anti‐aging dietary intervent 
    Output:
    
Conclusion The present research showed that LPD was not significantly associated with improvement of renal function  in patients with either type 1 or 2 diabetic nephropathy .
Although these results do not completely eliminate the possibility that LPD is beneficial for patients with diabetic nephropathy , it does not seem to be significant benefit to renal function