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, bl ack race, diagnosis of polycystic kidney disease, serum transferin lev els, and serum high density lipoprotein (HDL) cholesterol. Hypertensio n as a factor in progressive renal disease has been documented in both animal and human studies. Patients in the MDRD study were randomly as signed to two levels of blood pressure control: usual (mean arterial p ressure of 107 mmHg) or low (mean arterial pressure of 92 mmHg). Patie nts 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 t he 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 blo od pressure of 125/75 mmHg) should be the target. Several studies have suggested that dietary protein restriction benefits patients with chr onic renal disease. The MDRD study found that dietary protein restrict ion slowed disease progression in patients with more advanced renal di sease (GFR 13-24 ml/min) at the onset of the trial. In summary, curren t evidence indicates that a decrease in proteinuria, lowering of syste mic blood pressure, and a decreased intake of protein ameliorate the r ate of progression (loss of GFR) in patients with chronic renal diseas e.