Prevention of progression of nephropathy

Several factors have been implicated in progressive nephropathy. In a recent clinical trial, the Modification of Diet in Renal Disease (MDRD) study, six factors out of 41 examined were found to be predictors of progression of renal disease: proteinuria, mean arterial pressure, black race, diagnosis of polycystic kidney disease, serum transferin levels, and serum high density lipoprotein (HDL) cholesterol. Hypertension as a factor in progressive renal disease has been documented in both animal and human studies. Patients in the MDRD study were randomly assigned to two levels of blood pressure control: usual (mean arterial pressure of 107 mmHg) or low (mean arterial pressure of 92 mmHg). Patients with proteinuria > 1 g/day assigned to the low blood pressure goal had a slower mean decline in GFR as compared to patients assigned to the usual blood pressure goal. Recommendations derived from the results of the MDRD study specify that in patients with proteinuria > 1 g/day, a mean arterial pressure goal of 92 mmHg or less (equivalent to a blood pressure of 125/75 mmHg) should be the target. Several studies have suggested that dietary protein restriction benefits patients with chronic renal disease. The MDRD study found that dietary protein restriction slowed disease progression in patients with more advanced renal disease (GFR 13-24 ml/min) at the onset of the trial. In summary, current evidence indicates that a decrease in proteinuria, lowering of systemic blood pressure, and a decreased intake of protein ameliorate the rate of progression (loss of GFR) in patients with chronic renal disease.