title: The association of lumbar intervertebral disc degeneration on magnetic resonance imaging with body mass index in overweight and obese adults: a population-based study.
abstract: OBJECTIVE
  To investigate the association of being overweight or obese with the presence, extent, and severity of lumbar disc degeneration on magnetic resonance imaging (MRI) in adults.
  
  
  METHODS
  A population-based cross-sectional study of 2,599 southern Chinese volunteers was conducted. Subjects underwent radiographic and clinical assessment, and weight and height were measured. Sagittal T2-weighted MRIs of the lumbar spine were obtained. The presence, extent, and severity of disc degeneration and additional radiographic and clinical parameters were assessed. Asian-modified body mass index (BMI) (kg/m(2) ) categories were used. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated.
  
  
  RESULTS
  The study included 1,040 men and 1,559 women (mean age 41.9 years). Disc degeneration was noted in 1,890 subjects (72.7%). BMI was significantly higher in subjects with disc degeneration (mean 23.3 kg/m(2) ) than in subjects without degeneration (mean 21.7 kg/m(2) ) (P < 0.001). A significant increase in the number of degenerated levels (P < 0.001), global severity of disc degeneration (P < 0.001), and end-stage disc degeneration with disc space narrowing (P < 0.001) was noted with elevated BMI, in particular in overweight and obese subjects. In the adjusted multivariate logistic regression model, there was a positive linear trend (r(2)  = 0.99) between BMI and the overall presence of disc degeneration in overweight (OR 1.30 [95% CI 1.03-1.62]) and obese (OR 1.79 [95% CI 1.17-2.74]) subjects. End-stage disc degeneration with disc space narrowing was significantly more pronounced in obese subjects (adjusted OR 1.72 [95% CI 1.23-2.41] [reference normal weight]).
  
  
  CONCLUSIONS
  Our findings, in one of the largest studies to systematically assess lumbar disc degeneration on MRI, indicated a significant association between the presence, extent, and global severity of disc degeneration with weight in overweight and obese adults.
authors.affiliation: University of Hong Kong, Pokfulam, Hong Kong, China. dsamartzis@msn.com
authors.forename: Dino
authors.initials: D
authors.lastname: Samartzis
authors.forename: Jaro
authors.initials: J
authors.lastname: Karppinen
authors.forename: Danny
authors.initials: D
authors.lastname: Chan
authors.forename: Keith D K
authors.initials: KD
authors.lastname: Luk
authors.forename: Kenneth M C
authors.initials: KM
authors.lastname: Cheung
mesh_terms: D000328:Adult; D015992:Body Mass Index; D015897:Comorbidity; D005260:Female; D006723:Hong Kong / Q000453:epidemiology; D006801:Humans; D055959:Intervertebral Disc Degeneration / Q000453:epidemiology* / Q000473:pathology; D008159:Lumbar Vertebrae / Q000473:pathology; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000453:epidemiology* / Q000473:pathology; D050177:Overweight / Q000453:epidemiology* / Q000473:pathology; D011159:Population Surveillance; D055815:Young Adult