Effect of a very low-protein diet on outcomes: long-term follow-up of the Modification of Diet in Renal Disease (MDRD) Study.

Abstract

BACKGROUND:

The long-term effect of a very low-protein diet on the progression of kidney disease is unknown. We examined the effect of a very low-protein diet on the development of kidney failure and death during long-term follow-up of the Modification of Diet in Renal Disease (MDRD) Study.

STUDY DESIGN:

Long-term follow-up of study B of the MDRD Study (1989-1993).

SETTING & PARTICIPANTS:

The MDRD Study examined the effects of dietary protein restriction and blood pressure control on progression of kidney disease. This analysis includes 255 trial participants with predominantly stage 4 nondiabetic chronic kidney disease.

INTERVENTION:

A low-protein diet (0.58 g/kg/d) versus a very low-protein diet (0.28 g/kg/d) supplemented with a mixture of essential keto acids and amino acids (0.28 g/kg/d).

OUTCOMES:

Kidney failure (initiation of dialysis therapy or transplantation) and all-cause mortality until December 31, 2000.

RESULTS:

Kidney failure developed in 227 (89%) participants, 79 (30.9%) died, and 244 (95.7%) reached the composite outcome of either kidney failure or death. Median duration of follow-up until kidney failure, death, or administrative censoring was 3.2 years, and median time to death was 10.6 years. In the low-protein group, 117 (90.7%) participants developed kidney failure, 30 (23.3%) died, and 124 (96.1%) reached the composite outcome. In the very low-protein group, 110 (87.3%) participants developed kidney failure, 49 (38.9%) died, and 120 (95.2%) reached the composite outcome. After adjustment for a priori-specified covariates, hazard ratios were 0.83 (95% confidence interval, 0.62 to 1.12) for kidney failure, 1.92 (95% confidence interval, 1.15 to 3.20) for death, and 0.89 (95% confidence interval, 0.67 to 1.18) for the composite outcome in the very low-protein diet group compared with the low-protein diet group.

LIMITATIONS:

Lack of dietary protein measurements during follow-up.

CONCLUSION:

In long-term follow-up of the MDRD Study, assignment to a very low-protein diet did not delay progression to kidney failure, but appeared to increase the risk of death.

• Authors: Vandana Menon, Joel D Kopple, Xuelei Wang, Gerald J Beck, Allan J Collins, John W Kusek, Tom Greene, Andrew S Levey, Mark J Sarnak
• Journal: American journal of kidney diseases : the official journal of the National Kidney Foundation (Am J Kidney Dis) Vol. 53 Issue 2 Pg. 208-17 (Feb 2009) ISSN: 1523-6838 [Electronic] United States
• PMID: 18950911 (Publication Type: Journal Article, Research Support, N.I.H., Extramural)

Chemical References

• Amino Acids
• Keto Acids

Topics

• Adult
• Amino Acids (administration & dosage)
• Chronic Disease
• Diet, Protein-Restricted
• Dietary Supplements
• Disease Progression
• Female
• Follow-Up Studies
• Humans
• Keto Acids (administration & dosage)
• Kidney Diseases (diet therapy)
• Male
• Randomized Controlled Trials as Topic
• Renal Insufficiency (mortality, prevention & control)
• Survival Analysis