title: The association of diabetes mellitus and high-grade prostate cancer in a multiethnic biopsy series.
abstract: OBJECTIVE
  To analyze the association of diabetes mellitus (DM) with risk of prostate cancer and cancer grade among men undergoing prostate biopsy and to analyze how obesity and race modify these associations.
  
  
  METHODS
  Retrospective analysis of 998 men from the Durham VA undergoing first prostate biopsy between 2001 and 2009 with complete data available. History of DM was determined by chart review. Patients' characteristics at biopsy were analyzed with chi-square and ranksum. Multivariable analyses of DM and risk of cancer and cancer grade were done using logistic regression adjusting for PSA, body mass index, race, age, year, and digital rectal exam.
  
  
  RESULTS
  At biopsy, 284 (28%) men had DM. DM was associated with African American (AAM; p = 0.010) and higher BMI (p < 0.001). DM was not associated with prostate cancer risk on either bivariate (p = 0.600) or multivariate analysis (p = 0.485). Similar results were found after stratification by race and obesity. In multivariable analysis, DM was associated with greater risk of high-grade disease (RR = 2.13, p = 0.024). The association was stronger among obese men (RR = 3.84, p = 0.020) and null in non-obese subjects (RR = 1.39, p = 0.460). After further stratification by race, DM was associated with high-grade disease only in obese Caucasian men (CM; RR = 5.81, p = 0.025) but not in obese AAM. DM was not associated with risk of low-grade disease in all men together or after stratification by obesity or race.
  
  
  CONCLUSIONS
  History of DM was associated with greater risk of high-grade disease. The association was strongest among obese CM suggesting the effect of DM on high-grade prostate cancer is modified by race and obesity.
authors.affiliation: Division of Urologic Surgery, Department of Surgery and Duke Prostate Center, Duke University School of Medicine, Durham, NC, USA. daniel.moreira@duke.edu
authors.forename: Daniel M
authors.initials: DM
authors.lastname: Moreira
authors.forename: Tiffany
authors.initials: T
authors.lastname: Anderson
authors.forename: Leah
authors.initials: L
authors.lastname: Gerber
authors.forename: Jean-Alfred
authors.initials: JA
authors.lastname: Thomas
authors.forename: Lionel L
authors.initials: LL
authors.lastname: Bañez
authors.forename: Madeline G
authors.initials: MG
authors.lastname: McKeever
authors.forename: Cathrine
authors.initials: C
authors.lastname: Hoyo
authors.forename: Delores
authors.initials: D
authors.lastname: Grant
authors.forename: Jayakrishnan
authors.initials: J
authors.lastname: Jayachandran
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Freedland
mesh_terms: D000368:Aged; D001706:Biopsy; D015992:Body Mass Index; D002277:Carcinoma / Q000150:complications / Q000453:epidemiology* / Q000208:ethnology / Q000473:pathology; D048909:Diabetes Complications / Q000453:epidemiology / Q000208:ethnology; D003920:Diabetes Mellitus / Q000453:epidemiology* / Q000208:ethnology; D005006:Ethnicity / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications / Q000453:epidemiology / Q000208:ethnology; D011471:Prostatic Neoplasms / Q000150:complications / Q000453:epidemiology* / Q000208:ethnology / Q000473:pathology; D012189:Retrospective Studies