EFFECT OF MODERATE DIETARY-PROTEIN RESTRICTION ON THE PROGRESSION OF OVERT DIABETIC NEPHROPATHY - A 6-MO PROSPECTIVE-STUDY

To assess whether moderate dietary protein restriction can delay the p rogression of overt diabetic nephropathy, 22 subjects with insulin-dep endent diabetes mellitus were randomly assigned to an unrestricted pro tein diet(> 1.6 g.kg body wt(-1).d(-1)) or a moderately protein-restri cted diet (0.8 g.kg body wt(-1).d(-1)) and followed prospectively for six mo. Direct isotope methods were used to assess renal function. Pro tein intake was assessed by measurement of urinary urea nitrogen. The two groups were well-matched for age, sex, duration of diabetes, glyce mic control, blood pressure, and degree of renal insufficiency. Patien ts consuming the unrestricted protein diet (n = 11) showed a progressi ve decline in glomerular filtration rate of 1.3 mL.min(-1).mo(-1) with no change in proteinuria. Patients consuming the moderately protein-r estricted diet showed a marked decrease in the degree of proteinuria ( 2.15-1.13 g/d, P = 0.036) and a stabilization of glomerular filtration rate. This occurred independently of changes in blood pressure or gly cemic control. Moderate dietary protein restriction can ameliorate pro gression of overt diabetic nephropathy.