The total urine protein-to-creatinine ratio can predict the presence of microalbuminuria

PLoS One. 2014 Mar 10;9(3):e91067. doi: 10.1371/journal.pone.0091067. eCollection 2014.

Abstract

Background: The Kidney Disease: Improving Global Outcomes chronic kidney disease (CKD) guidelines recommend that CKD be classified based on the etiology, glomerular filtration rate (GFR) and degree of albuminuria. The present study aimed to establish a method that predicts the presence of microalbuminuria by measuring the total urine protein-to-creatinine ratio (TPCR) in patients with cardiovascular disease (CVD) risk factors.

Methods and results: We obtained urine samples from 1,033 patients who visited the cardiovascular clinic at St. Luke's International Hospital from February 2012 to August 2012. We measured the TPCR and the urine albumin-to-creatinine ratio (ACR) from random spot urine samples. We performed correlation, receiver operating characteristic (ROC) curve, sensitivity, and subgroup analyses. There was a strong positive correlation between the TPCR and ACR (R2 = 0.861, p<0.001). A ROC curve analysis for the TPCR revealed a sensitivity of 94.4%, a specificity of 86.1%, and an area under the curve of 0.903 for detecting microalbuminuria for a TPCR cut-off value of 84 mg/g of creatinine. The subgroup analysis indicated that the cut-off value could be used for patients with CVD risk factors.

Conclusions: These results suggest that the TPCR with an appropriate cut-off value could be used to screen for the presence of microalbuminuria in patients with CVD risk factors. This simple, inexpensive measurement has broader applications, leading to earlier intervention and public benefit.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Albuminuria / diagnosis*
  • Albuminuria / urine*
  • Cardiovascular Diseases / diagnosis
  • Cardiovascular Diseases / urine
  • Creatinine / urine*
  • Diabetes Mellitus / urine
  • Female
  • Humans
  • Male
  • Proteins / metabolism*
  • ROC Curve
  • Sensitivity and Specificity

Substances

  • Proteins
  • Creatinine

Grants and funding

This study was supported, in part, by a grant from St. Luke's Life Science Institute. No additional external funding received for this study. http://sllsi.luke.or.jp/. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.