title: Cystatin C is Better than Serum Creatinine for Estimating Glomerular Filtration Rate to Detect Osteopenia in Chronic Kidney Disease Patients.
abstract: OBJECTIVE
  Recent studies have reported that loss of bone mass is associated with renal function decline and increased fracture risks in chronic kidney disease (CKD) patients. The aim of this study was to investigate the best estimated glomerular filtration rate (eGFR) equation to detect osteopenia in CKD patients.
  
  
  METHODS
  This was a cross-sectional study, and 780 patients aged 50 years or above were classified into normal bone mass or osteopenia groups according to the -1.0 of T-scores at total hip and femur neck. Comparisons of area under the receiver operating characteristic (ROC) curves (AUC) were performed to investigate significant differences among three eGFR formulas: Modification of Diet in Renal Disease, CKD-Epidemiology Collaboration (EPI) creatinine, and CKD-EPI cystatin C (CKD-EPI-Cys).
  
  
  RESULTS
  The mean age was 61 years old and the proportion of females was 37.3%. The total hip osteopenia group showed lower CKD-EPI-Cys eGFR levels (osteopenia group, 33.3±19.0 mL/min/1.73 m²; normal group, 48.1±26.2 mL/min/1.73 m², p<0.001). In multiple logistic regression analysis, CKD-EPI-Cys eGFR was independently associated with osteopenia at the total hip (per 1 mL/min/1.73 m² increase, odds ratio 0.98, 95% confidence interval 0.97-0.99, p=0.004) after adjusting for confounding variables. ROC curve analyses indicated that CKD-EPI-Cys shows the largest AUC for osteopenia at the total hip (AUC=0.678, all p<0.01) and the femur neck (AUC=0.665, all p<0.05).
  
  
  CONCLUSIONS
  Decreased renal function assessed by CKD-EPI-Cys equation correlates with osteopenia better than creatinine-based methods in CKD patients, and the CKD-EPI-Cys formula might be a useful tool to assess skeletal-related event risks.
authors.affiliation: Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Young Eun
authors.initials: YE
authors.lastname: Kwon
authors.affiliation: Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Mi Jung
authors.initials: MJ
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Kyoung Sook
authors.initials: KS
authors.lastname: Park
authors.affiliation: Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Seung Hyeok
authors.initials: SH
authors.lastname: Han
authors.affiliation: Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Tae Hyun
authors.initials: TH
authors.lastname: Yoo
authors.affiliation: Department of Internal Medicine, Seoul National University, Seoul, Korea.
authors.forename: Kook Hwan
authors.initials: KH
authors.lastname: Oh
authors.affiliation: Medical Research Collaborating Center, Seoul National University Hospital, Seoul, Korea.
authors.forename: Joongyub
authors.initials: J
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, Kangbuck Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Kyu Beck
authors.initials: KB
authors.lastname: Lee
authors.affiliation: Division of Nephrology, Department of Internal Medicine, Gachon University Gil Medical Center, Incheon, Korea.
authors.forename: Wookyung
authors.initials: W
authors.lastname: Chung
authors.affiliation: Department of Nephrology, College of Medicine, Inje University, Busan, Korea.
authors.forename: Yeong Hoon
authors.initials: YH
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Seoul National University, Seoul, Korea.
authors.forename: Curie
authors.initials: C
authors.lastname: Ahn
authors.affiliation: Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea. khchoi6@yuhs.ac.
authors.forename: Kyu Hun
authors.initials: KH
authors.lastname: Choi
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D001851:Bone Diseases, Metabolic / Q000097:blood / Q000175:diagnosis* / Q000503:physiopathology; D012080:Chronic Kidney Disease-Mineral and Bone Disorder / Q000097:blood / Q000175:diagnosis* / Q000503:physiopathology; D003404:Creatinine / Q000097:blood*; D003430:Cross-Sectional Studies; D055316:Cystatin C / Q000097:blood*; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D012372:ROC Curve; D051436:Renal Insufficiency, Chronic / Q000097:blood / Q000150:complications* / Q000503:physiopathology
chemical_list: D015415:Biomarkers; D055316:Cystatin C; D003404:Creatinine
keywords: Renal insufficiency; bone diseases; chronic; glomerular filtration rate; metabolic