title: Time-dependent risk factors associated with the decline of estimated GFR in CKD patients.
abstract: BACKGROUND
  Targeting the modifiable risk factors may help halt the progression of CKD, thus risk factor analysis is better performed using the parameters in the follow-up. This study aimed to examine the time-dependent risk factors for CKD progression using time-averaged values and to investigate the characteristics of rapid progression group.
  
  
  METHODS
  This is a retrospective cohort study enrolling 770 patients of CKD stage 3-4. Time-dependent parameters were calculated as time-averaged values by a trapezoidal rule. % decline of estimated GFR (eGFR) per year from entry was divided to three groups: <10% (stable), 10-25% (moderate progression), and ≥25% (rapid progression). Multivariate regression analyses were employed for the baseline and the time-averaged datasets.
  
  
  RESULTS
  eGFR decline was 2.83 ± 4.04 mL/min/1.73 m(2)/year (8.8 ± 12.9 %) in male and 1.66 ± 3.23 mL/min/1.73 m(2)/year (5.4 ± 11.0%) in female (p < 0.001). % decline of eGFR was associated with male, proteinuria, phosphorus, and systolic blood pressure as risk factors and with age, albumin, and hemoglobin as protective factors using either dataset. Baseline eGFR and diabetic nephropathy appeared in the baseline dataset, while uric acid appeared in the time-averaged dataset. The rapid progression group was associated with proteinuria, phosphorus, albumin, and hemoglobin in the follow-up.
  
  
  CONCLUSIONS
  These results suggest that time-averaged values provide insightful clinical guide in targeting the risk factors. Rapid decline of eGFR is strongly associated with hyperphosphatemia, proteinuria, and anemia indicating that these risk factors should be intervened in the follow-up of CKD.
authors.affiliation: Department of Internal Medicine, Teikyo University School of Medicine, 2-11-1 Kaga, Itabashi, Tokyo, 173-8605, Japan.|Department of Nephrology, Tianjin First Central Hospital, No. 24 Fukang Road, Nankai District, Tianjin, China.
authors.forename: Wen-xiu
authors.initials: WX
authors.lastname: Chang
authors.affiliation: Department of Internal Medicine, Teikyo University School of Medicine, 2-11-1 Kaga, Itabashi, Tokyo, 173-8605, Japan.
authors.forename: Shigeyuki
authors.initials: S
authors.lastname: Arai
authors.affiliation: Department of Internal Medicine, Teikyo University School of Medicine, 2-11-1 Kaga, Itabashi, Tokyo, 173-8605, Japan.
authors.forename: Yoshifuru
authors.initials: Y
authors.lastname: Tamura
authors.affiliation: Support for Community Medicine Endowed Chair, Teikyo University School of Medicine, 2-11-1 Kaga, Itabashi, Tokyo, 173-8605, Japan.
authors.forename: Takanori
authors.initials: T
authors.lastname: Kumagai
authors.affiliation: Department of Internal Medicine, Teikyo University School of Medicine, 2-11-1 Kaga, Itabashi, Tokyo, 173-8605, Japan.
authors.forename: Tatsuru
authors.initials: T
authors.lastname: Ota
authors.affiliation: Department of Internal Medicine, Teikyo University School of Medicine, 2-11-1 Kaga, Itabashi, Tokyo, 173-8605, Japan.
authors.forename: Shigeru
authors.initials: S
authors.lastname: Shibata
authors.affiliation: Department of Internal Medicine, Teikyo University School of Medicine, 2-11-1 Kaga, Itabashi, Tokyo, 173-8605, Japan.
authors.forename: Yoshihide
authors.initials: Y
authors.lastname: Fujigaki
authors.affiliation: Department of Organ Transplantation, Tianjin First Central Hospital, No. 24 Fukang Road, Nankai District, Tianjin, China.
authors.forename: Zhong-yang
authors.initials: ZY
authors.lastname: Shen
authors.affiliation: Department of Internal Medicine, Teikyo University School of Medicine, 2-11-1 Kaga, Itabashi, Tokyo, 173-8605, Japan. s_uchida@netjoy.ne.jp.
authors.forename: Shunya
authors.initials: S
authors.lastname: Uchida
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000740:Anemia / Q000453:epidemiology; D016009:Chi-Square Distribution; D015897:Comorbidity; D018450:Disease Progression; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D054559:Hyperphosphatemia / Q000453:epidemiology; D007564:Japan / Q000453:epidemiology; D007668:Kidney / Q000503:physiopathology*; D016014:Linear Models; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D015995:Prevalence; D011507:Proteinuria / Q000453:epidemiology; D051436:Renal Insufficiency, Chronic / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology* / Q000628:therapy; D012189:Retrospective Studies; D012307:Risk Factors; D012737:Sex Factors; D013997:Time Factors; D055815:Young Adult
keywords: Estimated glomerular filtration rate; Multivariate linear regression analysis: multivariate logistic regression analysis; Rapid progression; Time-averaged value; Time-dependent parameter