查看文章

Cystatin C is being considered as a replacement for serum creatinine in the estimation of the glomerular filtration rate (GFR); however, its plasma levels might be affected by factors other than the GFR, such as protein intake. We performed a post hoc analysis of the data in the Modification of Diet in Renal Disease study, in which we compared serum creatinine and cystatin C levels in 741 patients with available estimates of protein intake at baseline prior to their randomization to diets containing various amounts of protein, and at 2 years of follow-up in 426 of these patients in whom a cystatin C measurement was available. The 503 patients in study A (GFR 25–55 ml/min per 1.73 m²) had been assigned a low (0.58 g/kg per day) or a usual (1.3 g/kg per day) protein intake, and the 238 participants in study B (GFR 13–24 ml/min per 1.73 m²) were assigned a very low (0.28 g/kg per day) or the low protein intake …