Effects of low-protein diet on patients with early chronic renal failure

Objective:To evaluate the clinical efficacy of low protein diet (LPD) with low-protein flour as staple food in the treatment of early chronic renal failure. Methodology:Sixty non-diabetic patients with early chronic renal failure (serum creatinine level of 1.3~3.0 mg/dl) were divided into two groups. They were group 1, treatment group (n=30), treated with low-protein flour (protein 0.9,344 Kcal/100g) as staple food, and group 2, control group (n=30), with common rice or flour as staple food. All of patients were observed for 6 months, the suggested diet protein intake (DPI) was 0.6 g/(kg·d),energy intake was 30~35 Kcal/(kg·d) (according to optimal body weight). Somatometric index and serum chemistry was measured. 24 hour urine was collected for the calculation of DPI. GFR was calculated with simplified MDRD equation. Results: (1) Compliance of patients: there were 5 cases withdrawal from treatment group, and also 5 cases withdrawal from control group. There were 25 patients completed the observation in each group, the calculated DPI was (0.63±0.04) g/(kg·d) in control and (0.61±0.02) g/(kg·d) in treatment group. (2)Body weight, body mass index (BMI), arm middle circumference (AMC) and arm circumference (AC) were not significantly changed in both groups. (3)The levels of serum total protein, albumin and prealbumin were slightly decreased in control group (P0.05), while those nutritional makers maintained stable in treatment group. (4)BUN was not significantly changed in control group but markedly decreased in treatment group (P0.01). The level of serum creatinine (SCr) was significantly increased in control group in the 2~ nd and 4~ th month (P0.05), but decreased to baseline in the 6~ th month, while it was significantly decreased (P0.05) in treatment group. GFR was decreased in control group in the 2~ nd and 4~ th month (P0.05) but elevated to baseline in the 6~ th month, while it was significantly increased in treatment group (P0.05). The decreasing rate of GFR were -0.31 (ml/min·1.73m~2)/month in treatment group and 0.28 (ml/min·1.73m~2 )/month in control group. (5)The level of urinary protein excretion was decreased (P0.05) in treatment group but unchanged in control group, it was decreased to normal range in 7/13(53.8)cases in treatment group, 4/15(26.7)cases in control group (P0.05). Conclusion:This six-month study indicated that, LPD with low-protein flour was much better tolerated than the common LPD, and it could delay the progression of renal dysfunction and maintain the nutritional status in patients with early chronic renal failure.