title: Risk factors for lumbar disc degeneration: a 5-year prospective MRI study in asymptomatic individuals.
abstract: METHODS
  A longitudinal magnetic resonance imaging investigation of lumbar disc degeneration in asymptomatic individuals was conducted.
  
  
  OBJECTIVE
  To investigate risk factors for the development or deterioration of lumbar disc degeneration.
  
  
  BACKGROUND
  Numerous studies have explored the significance of certain risk factors for the development or progression of disc degeneration, but no comprehensive longitudinal magnetic resonance imaging-based study has been reported that simultaneously considers clinical, morphologic, physical, psychosocial, and occupational risk factors.
  
  
  METHODS
  In the 5-year follow-up evaluation of 41 asymptomatic individuals, the risk factors for the development of lumbar disc degeneration and its progression were investigated. All 41 individuals had a magnetic resonance imaging scan at baseline and at the minimum 5-year follow-up assessment using the same scanner and protocol. The magnetic resonance images were analyzed independently by two radiologists with regard to disc degeneration. Various predictor variables were assessed both at baseline and follow-up, with special emphasis on physical job characteristics, sports activities, and magnetic resonance image-based morphologic findings.
  
  
  RESULTS
  Of the 41 individuals, 17 (41%) exhibited a deterioration of the disc status. In 10 individuals, the progression of disc degeneration was one grade or more. Only a weak correlation existed between progressive disc degeneration and low back pain development during a 5-year follow-up period. Multiple logistic regression analysis demonstrated that the extent of disc herniation (odds ratio [OR], 12.63; confidence interval [CI], 1.24-128.49), the lack of sports activities (OR, 2.71; CI, 1.04-7.07), and night shift work (OR, 23.01; CI, 1.26-421.31) were significant predictors for disc degeneration during follow-up evaluation when control was used for the number of degenerated discs at baseline, gender, age, and body mass index.
  
  
  CONCLUSIONS
  The results indicate that the extent of disc herniation, the lack of sports activities, and night shift work are significant risk factors for the development of lumbar disc degeneration and its progression.
authors.affiliation: Department of Psychology, University of Berne, Switzerland.
authors.forename: Achim
authors.initials: A
authors.lastname: Elfering
authors.forename: Norbert
authors.initials: N
authors.lastname: Semmer
authors.forename: Daniel
authors.initials: D
authors.lastname: Birkhofer
authors.forename: Marco
authors.initials: M
authors.lastname: Zanetti
authors.forename: Juerg
authors.initials: J
authors.lastname: Hodler
authors.forename: Norbert
authors.initials: N
authors.lastname: Boos
mesh_terms: D000328:Adult; D015992:Body Mass Index; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007405:Intervertebral Disc Displacement / Q000175:diagnosis* / Q000503:physiopathology; D017116:Low Back Pain / Q000175:diagnosis / Q000503:physiopathology; D008159:Lumbar Vertebrae / Q000502:physiology / Q000503:physiopathology*; D008279:Magnetic Resonance Imaging / Q000379:methods / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D009784:Occupational Diseases / Q000175:diagnosis / Q000503:physiopathology; D010147:Pain Measurement / Q000379:methods / Q000706:statistics & numerical data; D011237:Predictive Value of Tests; D012307:Risk Factors; D011795:Surveys and Questionnaires; D016474:Weight-Bearing / Q000502:physiology