title: Body mass index and comorbidity are associated with postoperative renal function after nephrectomy.
abstract: OBJECTIVE
  To explore the association of body mass index (BMI) and comorbidity with renal function after nephrectomy.
  
  
  METHODS
  We retrospectively analyzed 263 patients submitted to partial or radical nephrectomy from 2000-2013. Variables assessed included BMI, Charlson Comorbidity Index (CCI), race, tobacco use, tumor histology, surgical approach, Fuhrman nuclear grade, and tumor (T) classification. Glomerular filtration rate (GFR) was estimated using the Cockroft-Gault equation, adjusted for gender. Logistic regression was performed and included all interaction terms.
  
  
  RESULTS
  Median follow-up was 19.6 months (IQR 5.2, 53.7). Median preoperative GFR was 86.2 mL/min/1.73 m2 and median postoperative GFR was 68.4 mL/min/1.73 m2. BMI (OR 1.07, 95%CI 1.02-1.11), CCI (OR 1.19, 95%CI 1.04-1.37), and radical nephrectomy (OR 3.09, 95%CI 1.51-6.33) were significantly associated with a decline in renal function of ≥ 25%.
  
  
  CONCLUSIONS
  BMI and CCI are associated with postoperative decline in renal function after nephrectomy. Additionally, radical nephrectomy is significantly associated with decreasing renal function compared to partial nephrectomy. These findings highlight the importance of assessing patient comorbidity in the decision making process for patients presenting with a renal mass.
authors.affiliation: Department of Surgery, Section of Urology, Medical College of Georgia-Georgia Regents University, Augusta, GA.
authors.forename: Lael
authors.initials: L
authors.lastname: Reinstatler
authors.affiliation: Department of Surgery, Section of Urology, Medical College of Georgia-Georgia Regents University, Augusta, GA.
authors.forename: Zachary
authors.initials: Z
authors.lastname: Klaassen
authors.affiliation: Department of Surgery, Section of Urology, Medical College of Georgia-Georgia Regents University, Augusta, GA.
authors.forename: Brittani
authors.initials: B
authors.lastname: Barrett
authors.affiliation: Department of Surgery, Section of Urology, Medical College of Georgia-Georgia Regents University, Augusta, GA.
authors.forename: Martha K
authors.initials: MK
authors.lastname: Terris
authors.affiliation: Department of Surgery, Section of Urology, Medical College of Georgia-Georgia Regents University, Augusta, GA.
authors.forename: Kelvin A
authors.initials: KA
authors.lastname: Moses
mesh_terms: D000368:Aged; D015992:Body Mass Index; D002292:Carcinoma, Renal Cell / Q000473:pathology / Q000601:surgery*; D015897:Comorbidity; D005260:Female; D005919:Glomerular Filtration Rate / Q000502:physiology; D006801:Humans; D007680:Kidney Neoplasms / Q000473:pathology / Q000601:surgery*; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009392:Nephrectomy / Q000379:methods / Q000534:rehabilitation*; D011184:Postoperative Period; D020127:Recovery of Function / Q000502:physiology*; D012189:Retrospective Studies; D012307:Risk Factors; D016896:Treatment Outcome