Effect of a Low- Versus Moderate-Protein Diet on Progression of CKD: Follow-up of a Randomized Controlled Trial

Patient flow diagram shows selection and discontinuation according to groups. The 1st period (January 1999-June 2004) corresponds to the duration of the randomized controlled trial, and the 2nd period (July 2004-December 2006) corresponds to long-term follow-up.

Comparison of protein intake and laboratory values in the low-protein diet (LPD; solid line) and moderate-protein diet (MPD; dashed line) groups during follow-up; time (T) in months. (A) Protein intake (g/kg/d), (B) serum urea nitrogen level (mg/dL), (C) glomerular filtration rate (GFR; mL/min/1.73 m²), and (D) urinary protein excretion (g/d) during the entire follow-up period. Numbers adjacent to each line show participants in that group who were followed up at the time. **P < 0.01 for the effect of the LPD on the protein intake trend. *P < 0.05 for the effect of the LPD on the SUN level trend. Conversion factors for units: serum urea nitrogen in mg/dL to mmol/L, ×0.357; GFR in mL/min/1.73 m² to mL/s/1.73 m², ×0.01667.

Kaplan-Meier survival curves for (A) all-cause mortality, (B) dialysis therapy, and (C) the composite outcome (death + dialysis therapy). The low- (LPD) and moderate-protein diets (MPD) refer to 0.55 and 0.80 g/kg/d prescribed protein intake.