Abstract
Dietary protein restriction reduces proteinuria and slows the progression of renal failure in a variety of renal diseases in native kidneys. Such beneficial effects may be mediated by the multiple renal effects of dietary protein including those on glomerular capillary hemodynamics and the renin-angiotensin system. The role of dietary protein restriction in the management of chronic renal transplant rejection is, however, unclear. This study was therefore undertaken to examine the effects of dietary protein restriction in patients with chronic rejection. Fourteen patients with biopsy proven chronic rejection, who had been on a self-selected home diet of 1.0 ± 0.1 g protein/kg/day, were randomly assigned, using a crossover design to two 11-day periods, one on a low protein diet (0.55 g/kg/day) and the other on a high protein diet (2 g/kg/day). The effect of these diets on renal hemodynamics, protein-uria. plasma renin activity, and nutritional status was examined. The low protein diet was associated with a significant improvement in glomerular permselectivity in all patients as evidenced by a significant fall in the fractional clearance of albumin and IgG and reduction in 24-hour urinary excretion of total protein, albumin and IgG without any change in blood pressure, glomerular filtration rate, or renal plasma flow. Compared to the proteinuria at the beginning of each diet, a high protein diet did not increase but a low protein diet significantly decreased the proteinuria. The low protein diet was also associated with a significant reduction in plasma renin activity, suggesting that part of the beneficial effect of protein restriction was related to the suppression of the renin-angiotensin system. Protein restriction was also associated with modest but significant falls in serum proteins. In conclusion, a low protein diet reduces proteinuria and lowers plasma renin activity in patients with chronic rejection. Dietary protein restriction may improve the course of renal failure in chronic rejection partly by suppressing the renin-angiotensin system. Studies are needed to establish the safe level of dietary protein restriction in these patients and to assess the efficacy of such restriction in slowing the progression of renal failure.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 183-190 |
| Number of pages | 8 |
| Journal | Kidney international |
| Volume | 41 |
| Issue number | 1 |
| DOIs | |
| State | Published - Jan 1992 |
Bibliographical note
Funding Information:This work was supported by U.S. Public Health Service Grants AM-31437 (T.H.H.), MOl RROO400 (National Center for Research Resources) (GCRC), and P01-AM 13083; Young Investigator Grant from the National Kidney Foundation (M.E.R.); and a Fellowship Award from the American Heart Association, Minnesota Affiliate (A.K.S.). We are indebted to the nursing, dietary and technical staff of the General Clinical Center, University of Minnesota; to the surgeons and staff of the Transplant Unit, University of Minnesota for support; and to D. Chmielewski and S. Kren for technical assistance.