title: The total urine protein-to-creatinine ratio can predict the presence of microalbuminuria.
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.
  
  
  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.
authors.affiliation: Department of Laboratory Medicine and Clinical Science, Tohoku University Graduate School of Medicine, Sendai, Japan; Division of Nephrology, Department of Internal Medicine, St. Luke's International Hospital, Tokyo, Japan.
authors.forename: Kyoko
authors.initials: K
authors.lastname: Yamamoto
authors.affiliation: Division of Nephrology, Department of Internal Medicine, St. Luke's International Hospital, Tokyo, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Yamamoto
authors.affiliation: Healthy Medical Center, Tohoku Kosai Hospital, Sendai, Japan.
authors.forename: Katsumi
authors.initials: K
authors.lastname: Yoshida
authors.affiliation: Department of Cardiology, Cardiovascular Center, St. Luke's International Hospital, Tokyo, Japan.
authors.forename: Koichiro
authors.initials: K
authors.lastname: Niwa
authors.affiliation: Department of Cardiology, Cardiovascular Center, St. Luke's International Hospital, Tokyo, Japan.
authors.forename: Yutaro
authors.initials: Y
authors.lastname: Nishi
authors.affiliation: Department of Cardiology, Cardiovascular Center, St. Luke's International Hospital, Tokyo, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Mizuno
authors.affiliation: Department of Cardiology, Cardiovascular Center, St. Luke's International Hospital, Tokyo, Japan.
authors.forename: Masanari
authors.initials: M
authors.lastname: Kuwabara
authors.affiliation: Department of Cardiology, Cardiovascular Center, St. Luke's International Hospital, Tokyo, Japan.
authors.forename: Taku
authors.initials: T
authors.lastname: Asano
authors.affiliation: Department of Cardiology, Cardiovascular Center, St. Luke's International Hospital, Tokyo, Japan.
authors.forename: Kunihiro
authors.initials: K
authors.lastname: Sakoda
authors.affiliation: Department of Cardiology, Cardiovascular Center, St. Luke's International Hospital, Tokyo, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Niinuma
authors.affiliation: Clinical Laboratory Department, St. Luke's International Hospital, Tokyo, Japan.
authors.forename: Fumiko
authors.initials: F
authors.lastname: Nakahara
authors.affiliation: Clinical Laboratory Department, St. Luke's International Hospital, Tokyo, Japan.
authors.forename: Kyoko
authors.initials: K
authors.lastname: Takeda
authors.affiliation: Department of Laboratory Medicine and Clinical Science, Tohoku University Graduate School of Medicine, Sendai, Japan.
authors.forename: Chiyohiko
authors.initials: C
authors.lastname: Shindoh
authors.affiliation: Division of Nephrology, Department of Internal Medicine, St. Luke's International Hospital, Tokyo, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Komatsu
mesh_terms: D000368:Aged; D000419:Albuminuria / Q000175:diagnosis* / Q000652:urine*; D002318:Cardiovascular Diseases / Q000175:diagnosis / Q000652:urine; D003404:Creatinine / Q000652:urine*; D003920:Diabetes Mellitus / Q000652:urine; D005260:Female; D006801:Humans; D008297:Male; D011506:Proteins / Q000378:metabolism*; D012372:ROC Curve; D012680:Sensitivity and Specificity
chemical_list: D011506:Proteins; D003404:Creatinine