title: Albuminuria, proteinuria, and urinary albumin to protein ratio in chronic kidney disease.
abstract: BACKGROUND
  Both albuminuria and proteinuria are important disease markers of chronic kidney disease (CKD). Their relationship and the ratio between urinary albumin and protein in patients with CKD have not been investigated. Whether clinical features can affect these measurements is not clear.
  
  
  METHODS
  We conducted a cross-sectional study in 602 CKD patients. Demographic data, including age, gender, and co-morbidity such as diabetes, hypertension, hyperuricemia, and hyperlipidemia, were reviewed and recorded. Their urinary albumin, total protein, and creatinine were determined and urinary albumin to creatinine ratio (UACR), total protein to creatinine ratio (UPCR), and albumin to total protein ratio (UAPR) were calculated. Their estimated glomerular filtration rate (eGFR) was calculated according to serum creatinine. The correlation between UACR and UPCR was thus analyzed. We also investigated factors associated with these urinary measurements.
  
  
  RESULTS
  UACR and UPCR increased progressively as renal function deteriorated, while UAPR increased to a plateau in CKD stage 4. There was direct relationship between UACR and UPCR. UAPR rose exponentially with the increase of both UACR and UPCR when UACR <500 mg/g or UPCR <1,000 mg/g. Multivariate regression analysis revealed diabetes and hyperuricemia were associated with increased UACR and UPCR, while both urinary parameters were inversely related to male gender and eGFR. Diabetes and hyperuricemia were associated with increased UAPR and UAPR was negatively correlated with age and eGFR.
  
  
  CONCLUSIONS
  There was a significant association between UACR and UPCR in patients with CKD. Characteristics of patients, renal function, and co-morbidities all affected UACR, UPCR, and UAPR.
authors.affiliation: Division of Nephrology, Department of Internal Medicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan.
authors.forename: Men-Tai
authors.initials: MT
authors.lastname: Wu
authors.forename: King-Kwan
authors.initials: KK
authors.lastname: Lam
authors.forename: Wen-Chin
authors.initials: WC
authors.lastname: Lee
authors.forename: Kao-Tai
authors.initials: KT
authors.lastname: Hsu
authors.forename: Chien-Hsing
authors.initials: CH
authors.lastname: Wu
authors.forename: Ben-Chung
authors.initials: BC
authors.lastname: Cheng
authors.forename: Hwee-Yeong
authors.initials: HY
authors.lastname: Ng
authors.forename: Po-Jui
authors.initials: PJ
authors.lastname: Chi
authors.forename: Yueh-Ting
authors.initials: YT
authors.lastname: Lee
authors.forename: Chien-Te
authors.initials: CT
authors.lastname: Lee
mesh_terms: D000418:Albumins / Q000378:metabolism*; D000419:Albuminuria / Q000150:complications* / Q000652:urine*; D003404:Creatinine / Q000652:urine; D003710:Demography; D048909:Diabetes Complications / Q000652:urine; D005260:Female; D006801:Humans; D007676:Kidney Failure, Chronic / Q000150:complications* / Q000652:urine*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis
chemical_list: D000418:Albumins; D003404:Creatinine