There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.
Abstract
The Modification of Diet in Renal Disease (MDRD) Study examined the effects of dietary
protein restriction and strict blood pressure control on the decline in glomerular
filtration rate (GFR) in 840 patients with diverse renal diseases. We describe a systematic
analysis to determine baseline factors that predict the decline in GFR, or which alter
the efficacy of the diet or blood pressure interventions. Univariate analysis identified
18 of 41 investigated baseline factors as significant (P < 0.05) predictors of GFR
decline. In multivariate analysis, six factors--greater urine protein excretion, diagnosis
of polycystic kidney disease (PKD), lower serum transferrin, higher mean arterial
pressure, black race, and lower serum HDL cholesterol--independently predicted a faster
decline in GFR. Together with the study interventions, these six factors accounted
for 34.5% and 33.9% of the variance between patients in GFR slopes in Studies A and
B, respectively, with proteinuria and PKD playing the predominant role. The mean rate
of GFR decline was not significantly related to baseline GFR, suggesting an approximately
linear mean GFR decline as renal disease progresses. The 41 baseline predictors were
also assessed for their interactions with the diet and blood pressure interventions.
A greater benefit of the low blood pressure intervention was found in patients with
higher baseline urine protein. None of the 41 baseline factors were shown to predict
a greater or lesser effect of dietary protein restriction.