[HTML][HTML] The effects of dietary protein restriction and blood-pressure control on the progression of chronic renal disease

S Klahr, AS Levey, GJ Beck, AW Caggiula… - … England Journal of …, 1994 - Mass Medical Soc
S Klahr, AS Levey, GJ Beck, AW Caggiula, L Hunsicker, JW Kusek, G Striker
New England Journal of Medicine, 1994Mass Medical Soc
Background Restricting protein intake and controlling hypertension delay the progression of
renal disease in animals. We tested these interventions in 840 patients with various chronic
renal diseases. Methods In study 1, 585 patients with glomerular filtration rates of 25 to 55 ml
per minute per 1.73 m2 of body-surface area were randomly assigned to a usual-protein diet
or a low-protein diet (1.3 or 0.58 g of protein per kilogram of body weight per day) and to a
usual-or a low-blood-pressure group (mean arterial pressure, 107 or 92 mm Hg). In study 2 …
Background
Restricting protein intake and controlling hypertension delay the progression of renal disease in animals. We tested these interventions in 840 patients with various chronic renal diseases.
Methods
In study 1, 585 patients with glomerular filtration rates of 25 to 55 ml per minute per 1.73 m2 of body-surface area were randomly assigned to a usual-protein diet or a low-protein diet (1.3 or 0.58 g of protein per kilogram of body weight per day) and to a usual- or a low-blood-pressure group (mean arterial pressure, 107 or 92 mm Hg). In study 2, 255 patients with glomerular filtration rates of 13 to 24 ml per minute per 1.73 m2 were randomly assigned to the low-protein diet (0.58 g per kilogram per day) or a very-low-protein diet (0.28 g per kilogram per day) with a keto acid-amino acid supplement, and a usual- or a low-blood-pressure group (same values as those in study 1). An 18-to-45-month follow-up was planned, with monthly evaluations of the patients.
Results
The mean follow-up was 2.2 years. In study 1, the projected mean decline in the glomerular filtration rate at three years did not differ significantly between the diet groups or between the blood-pressure groups. As compared with the usual-protein group and the usual-blood-pressure group, the low-protein group and the low-blood-pressure group had a more rapid decline in the glomerular filtration rate during the first four months after randomization and a slower decline thereafter. In study 2, the very-low-protein group had a marginally slower decline in the glomerular filtration rate than did the low-protein group (P = 0.07). There was no delay in the time to the occurrence of end-stage renal disease or death. In both studies, patients in the low-blood-pressure group who had more pronounced proteinuria at base line had a significantly slower rate of decline in the glomerular filtration rate.
Conclusions
Among patients with moderate renal insufficiency, the slower decline in renal function that started four months after the introduction of a low-protein diet suggests a small benefit of this dietary intervention. Among patients with more severe renal insufficiency, a very-low-protein diet, as compared with a low-protein diet, did not significantly slow the progression of renal disease.
The New England Journal Of Medicine