Controlled low protein diets in chronic renal insufficiency: meta-analysis.

Abstract

unique criterion for all studies. Meta-analysis is partiIntervention-Difference in protein intake cularly suitable for studies of rare events in, for between control and treated groups of at least 0*2 g example, ponderous or longlasting trials that do not protein/kg/day. include many patients.9 The quality and impact of a Main outcome measure-Number of renal deaths meta-analysis depends on the selection process for the (the necessity to start dialysis or death of patient criterion, which must be well defined at the beginning during study).of the meta-analysis, and easily collected by nonResults-156 renal deaths were recorded, 61 in the specialist observers. low protein diet group and 95 in the control group, Definition ofa common event-We defined renal death leading to an odds ratio of low protein to control of as either the necessity to begin dialysis or the death of 0-54 with a 95% confidence interval of 0 37 to 0 79. patients during the study. Patients receiving grafts Conclusions-This result, obtained on a large before starting dialysis were counted as having had population of patients suffering from chronic renal renal death. Patients who were lost to follow up or who insufficiency, strongly supports the effectiveness of stopped taking the diet were not counted as having had low protein diets in delaying the onset of end stage renal death. These criteria were applied independently renal disease.of the randomised treatment by the authors on the basis of published data or complementary data kindly provided by the investigators. IntroductionCollection of data and study selection-To avoid During the past 10 years a lot of experimental data omission of results from less well known studies we have suggested that dietary protein restriction may scanned research reports with a computer search of retard or even halt the development of non-specific Medline files and abstract books from the International glomerular lesions and hence the

Low‐protein diet for conservative management of chronic kidney disease: a systematic review and meta‐analysis of controlled trials

“…Even though the latter is of immense clinical importance, many clinicians often encounter patients in very late stages of CKD, for example, estimated GFR < 25 mL/min/1.73m 2 , who wish to avoid or defer dialysis therapy by any means possible. Several individual trials17, 18, 22, 23, 24, 25, 26, 27, 28, 29, 30, 34 as well as meta‐analysis studies12, 35, 36, 37 have shown the benefits of protein restriction for such conservative management of CKD patients 38…”

Protein restriction, glomerular filtration rate and albuminuria in patients with type 2 diabetes mellitus: a randomized trial

“…Best-case analyses were then applied. Patients in the experimental group were included only if they had had, on average during the intervention period, a protein intake that was at least 0.20 g=kg=day lower than at baseline (Fouque et al, 1992); patients in the control group were included if their average protein intake during the study was not lower than at baseline. It was also assessed, finally, whether a dose-response relationship was present between the mean level of protein intake during the intervention period, and the rates of change in GFR (Levey et al, 1996b) and AER (Dullaart et al, 1993).…”

“…The best-case analysis implied confinement of the analysis to patients in the experimental group with at least 0.20 g=kg=day decrease in protein intake (Fouque et al, 1992), and those inthe control group with no decrease. This analysis on small numbers of patients did not indicate a slower rate of decline in GFR in the experimental than in the control group either; in the experimental group (n ¼ 14) the decline was even estimated to be 2.5 AE 5.8 ml=min= 1.73 m 2 =y faster than in the control group (n ¼ 30; P ¼ 0.7).…”

“…Several meta-analyses concerning non-diabetic (Fouque et al, 1992;Pedrini et al, 1996;Waugh & Robertson, 1997;Kasiske et al, 1998) and type 1 diabetic patient (Pedrini et al, 1996;Waugh & Robertson, 1997;Kasiske et al, 1998) have addressed the effect of protein restriction on macroalbuminuria, on the rate of decline in GFR, and on the course of end-stage renal disease. The most recent meta-analysis of randomized trials among type 1 diabetic patients, with 2 y of follow-up, suggested that the rate of decline in GFR was slowed down by 5.8 ml=min=y (Kasiske et al, 1998).…”

“…Type 2 diabetes is said to be the major single cause of end-stage renal disease (US Renal Data System, 1994;Humphrey et al, 1989;Pugh et al, 1995). Evidence of the beneficial effects of protein restriction on non-diabetic and type 1 diabetic renal disorders is ample and consistent (Fouque et al, 1992;Pedrini et al, 1996;Waugh & Robertson, 1997;Kasiske et al, 1998). The most recent meta-analysis suggests that the effect of protein restriction on renal function is greater in type 1 diabetic patients than in nondiabetic patients (Kasiske et al, 1998).…”