title: High body mass index after age 20 and diabetes mellitus are independent risk factors for ossification of the posterior longitudinal ligament of the spine in Japanese subjects: a case-control study in multiple hospitals.
abstract: METHODS
  A sex- and age-matched case-control study was carried out.
  
  
  OBJECTIVE
  To facilitate early prediction, prevention, and treatment of ossification of the posterior longitudinal ligament of the spine, the authors analyzed histories of past illness, past body mass indexes, and body pliableness by nature, adjusted for other factors considered to be risk factors.
  
  
  BACKGROUND
  The cause of ossification of the posterior longitudinal ligament of the spine has not yet been elucidated in detail, although many possible causative factors have been suggested, including gender, diabetes mellitus, trauma, hormonal imbalance, and dietary habits.
  
  
  METHODS
  A self-administered questionnaire was obtained from 69 patients with ossification of the posterior longitudinal ligament of the spine and 138 sex- and age-matched control participants who were free of spinal disease, randomly selected from participants in a health checkup in a town. After univariate analysis, a stepwise method was applied to select significant factors in multivariate analysis.
  
  
  RESULTS
  A multivariate analysis revealed that the following three indicators were independent potent risk factors for ossification of the posterior longitudinal ligament of the spine: history of diabetes mellitus, history of lumbago, and maximum body mass index before manifestation > or =25, after adjustment for other possible lifestyle risk factors.
  
  
  CONCLUSIONS
  Excessive weight gain between 20 and 40 years of age, diabetes mellitus, and lumbago were found to be independent risk factors for ossification of the posterior longitudinal ligament of the spine. Follow-up studies, including the addition of hospital-based control participants and analysis of genetic polymorphisms, will be needed in the future.
authors.affiliation: Department of Health for Senior Citizens, Hokkaido University Graduate School of Medicine, Sapporo, Japan. genkoba@med.hokudai.ac.jp
authors.forename: Gen
authors.initials: G
authors.lastname: Kobashi
authors.forename: Masakazu
authors.initials: M
authors.lastname: Washio
authors.forename: Kazushi
authors.initials: K
authors.lastname: Okamoto
authors.forename: Satoshi
authors.initials: S
authors.lastname: Sasaki
authors.forename: Tetsuji
authors.initials: T
authors.lastname: Yokoyama
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Miyake
authors.forename: Naomasa
authors.initials: N
authors.lastname: Sakamoto
authors.forename: Kaori
authors.initials: K
authors.lastname: Ohta
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Inaba
authors.forename: Heizo
authors.initials: H
authors.lastname: Tanaka
mesh_terms: D000328:Adult; D015992:Body Mass Index; D016022:Case-Control Studies; D015897:Comorbidity; D003920:Diabetes Mellitus / Q000453:epidemiology*; D005260:Female; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016017:Odds Ratio; D017887:Ossification of Posterior Longitudinal Ligament / Q000453:epidemiology* / Q000235:genetics; D018570:Risk Assessment; D012307:Risk Factors