title: Risk factors for inguinal hernia in middle-aged and elderly men: results from the Rotterdam Study.
abstract: BACKGROUND
  Prospective data on risk factors and the incidence of inguinal hernia are sparse, especially in an elderly population. The aim of this study was to determine the incidence of and risk factors for inguinal hernia.
  
  
  METHODS
  We analyzed data from the Rotterdam Study, a prospective cohort study that observed the general population aged ≥45 years of Ommoord, a district in Rotterdam, from baseline (1990) over a period of >20 years. Diagnoses of inguinal hernia were obtained from hospital discharge records and records from general practitioners. Multivariate regression analysis was performed to determine risk factors for inguinal hernia development.
  
  
  RESULTS
  Among 5,780 men, with a total of 50,802 person-years, who did not have a hernia at baseline, 416 cases of inguinal hernia (7.2%) occurred. The 20-year cumulative incidence was 14%. Age-adjusted hazard ratio (HR) for inguinal hernia for men relative to women was 12.4 (95% CI, 9.5-16.3; P < .001). On multivariate analysis, the risk of inguinal hernia increased with advancing age (HR per 1-year increase in age, 1.03; 95% CI, 1.02-1.04; P < .001). Participants with a body mass index (BMI) of 25-30 kg/m2 had an HR of 0.72 (95% CI, 0.58-0.89; P = .003) compared with a BMI of <25; a BMI of >30 had an associated HR of 0.63 (95% CI, 0.42-0.94; P = .025).
  
  
  CONCLUSIONS
  Inguinal hernia is common in the middle-aged and elderly male population and its incidence increases with advancing age. Overweight or obese patients have a lesser risk of developing an inguinal hernia.
authors.affiliation: Department of Surgery, Erasmus Medical Center, University Medical Center Rotterdam, Rotterdam, The Netherlands; Department of Surgery, VU Medical Center, University Medical Center Rotterdam, Rotterdam, The Netherlands. Electronic address: b.degoede@erasmusmc.nl.
authors.forename: Barry
authors.initials: B
authors.lastname: de Goede
authors.affiliation: Department of Surgery, Erasmus Medical Center, University Medical Center Rotterdam, Rotterdam, The Netherlands.
authors.forename: Lucas
authors.initials: L
authors.lastname: Timmermans
authors.affiliation: Department of Epidemiology and Radiology, Erasmus Medical Center, University Medical Center Rotterdam, Rotterdam, The Netherlands.
authors.forename: Bob J H
authors.initials: BJ
authors.lastname: van Kempen
authors.affiliation: Department of Epidemiology and Radiology, Erasmus Medical Center, University Medical Center Rotterdam, Rotterdam, The Netherlands.
authors.forename: Frank J A
authors.initials: FJ
authors.lastname: van Rooij
authors.affiliation: Department of Surgery, VU Medical Center, University Medical Center Rotterdam, Rotterdam, The Netherlands.
authors.forename: Geert
authors.initials: G
authors.lastname: Kazemier
authors.affiliation: Department of Surgery, Erasmus Medical Center, University Medical Center Rotterdam, Rotterdam, The Netherlands.
authors.forename: Johan F
authors.initials: JF
authors.lastname: Lange
authors.affiliation: Department of Epidemiology and Radiology, Erasmus Medical Center, University Medical Center Rotterdam, Rotterdam, The Netherlands.
authors.forename: Albert
authors.initials: A
authors.lastname: Hofman
authors.affiliation: Department of Neuroscience, Erasmus Medical Center, University Medical Center Rotterdam, Rotterdam, The Netherlands.
authors.forename: Johannes
authors.initials: J
authors.lastname: Jeekel
mesh_terms: D000368:Aged; D015992:Body Mass Index; D015331:Cohort Studies; D006552:Hernia, Inguinal / Q000453:epidemiology / Q000209:etiology*; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors