Dietary treatment of diabetic nephropathy with chronic renal failure

Thirty-two patients with diabetes mellitus (22 IDDM and 10 NIDDM, 21 males and 11 females, age 44+/-11.8 years) were followed for 5.2+/-3.8 years afte r the onset of chronic renal failure, with the aim of evaluating the effect of low protein diets on the rate of decline of the residual renal function . During the 1.8+/-1.6 year follow-up period on free or uncontrolled low pr otein diet the mean rate of decline of creatinine clearance was 0.9+/-0.6 m l/min/month, significantly greater than that observed during 3.7+/-3.1 year s on low or very low protein diets. The reduction of protein intake was fol lowed by a significant decrease in daily urinary protein loss. A better gly caemic control was obtained on the low protein diet, and the daily insulin requirement decreased. The anthropometry, as well as the serum concentratio ns of rapid turnover proteins, did not change, in spite of the low or very low protein dietary supply for a long duration. The values of mean arterial pressure were quite similar during the followup period on free or uncontro lled low protein diet and during the study period on the low protein diet. A good compliance with reduced dietary intake (as demonstrated by the measu rement of the daily urea excretion) was obtained in a large number of patie nts. In conclusion, our study confirms the protective effect on the residua l renal function of low protein diets in IDDM and NIDDM patients with chron ic renal failure due to diabetic nephropathy, in the absence of any sign of protein malnutrition.