The effect of dietary protein restriction on the progression of diabetic nephropathy. A 12-month follow-up.

Eight patients with insulin-dependent diabetes mellitus and progressive renal dysfunction as determined by serial serum creatinine values were placed on a diet containing 40 g of high-biologic-value protein. Selected factors of renal function were determined over a 12-month interval. After the first 12 months of the protein-limited diet, creatinine clearance was not significantly changed. The rate of decline in renal function during the dietary protein restriction slowed from the rate over the prior 12 months in seven patients. Five of these seven demonstrated improvement in renal function. Daily urinary protein excretion decreased significantly, from 2105 +/- 1355 to 142 +/- 164 mg/d (2.11 +/- 1.36 to 0.14 +/- 0.16 g/d). Body weight did not change significantly, whereas serum albumin level increased significantly from a mean of 3.5 +/- 0.6 to 4.3 +/- 0.3 g/dL (35 +/- 6 to 43 +/- 3 g/L). These findings suggest that dietary protein restriction has a beneficial role in treating patients with diabetic nephropathy.