Abstract: Objective To explore retrospectively the influence of different protein intake on renal prognosis in patients with stage 3 chronic kidney disease(CKD). Methods Follow up data was successfully obtained in the 221 patients with stage 3 CKD who followed more than 24 months from January 2013 to May 2015, the clinical data and laboratory tests were collected, including primary disease, body mass index, diet reviews, daily protein intake(DPI) and laboratory tests. A simplified modification of diet in renal disease(MDRD) formula was adopted to calculate the level of estimated glomemlar filtration rate(eGFR). The patients were divided into 3 groups according to the level of DPI: very low protein diet(VLPD) as DPI ≤ 0.6 g·kg^-1·d^-1(n=61), low protein diet(LPD) as DPI from 0.6 to 0.8 g·kg^-1·d^-1(n=118) and normal protein diet(NPD) as DPI > 0.8 g·kg^-1·d^-1(n=42). Results There were no significant difference between 3 groups in eGFR level at the baseline(P > 0.05). However, the eGFR of VLPD and NPD group tend to decrease progressively in a similar rate with the prolonging of time, both were merely missed the statistically significance compared with each baseline level at the end of the observation(P=0.050, P=0.054), and no decrease was observed in NPD group. Compared with LPD group, the eGFR level of VLPD group significantly decreased on month 24(P=0.024). Conclusion The low-protein diet(DPI between 0.6-0.8 g·kg^-1·d^-1) may contribute to delaying the deterioration of renal function, but the very low protein diet(DPI ≤ 0.6 g·kg^-1·d^-1) may increase the risk of the progress of CKD.

Key words: chronic kidney disease, renal insufficiency, daily protein intake, low protein diet