Table 2

Associations of weight-related measures with LBP and physician-diagnosed low back disorders

LBP, preceding 30 days (n=1363)Chronic LBP syndrome (n=1350)Radiating LBP, preceding 30 days (n=1363)Sciatica, assessed by physician (n=1350)
PR/OR95% CI*PR/OR95% CI*PR/OR95% CI*PR/OR95% CI*
Longitudinal associations between BMI at baseline and outcomes at follow-up
 BMI at baseline†1.070.96 to 1.191.180.96 to 1.441.261.08 to 1.461.150.89 to 1.50
 Life course BMI (Z score)‡0.990.86 to 1.141.090.87 to 1.361.231.03 to 1.481.100.83 to 1.46
Cross-sectional associations between weight-related factors, and outcomes at follow-up
 BMI (continuous)§0.950.84 to 1.071.090.90 to 1.331.160.99 to 1.351.100.86 to 1.41
 BMI (categorical), kg/m2
  <251.001.001.001.00
  25–29.91.030.80 to 1.340.950.60 to 1.511.420.97 to 2.080.840.47 to 1.51
  ≥300.880.61 to 1.251.130.63 to 2.001.641.02 to 2.651.040.50 to 2.15
 Waist circumference (continuous)¶1.000.88 to 1.121.130.92 to 1.381.150.98 to 1.351.180.92 to 1.52
 Waist circumference (categorical), cm
  <941.001.001.001.00
  94–101.91.110.83 to 1.471.040.63 to 1.731.030.69 to 1.530.910.47 to 1.75
  ≥1021.030.77 to 1.391.240.75 to 2.031.310.88 to 1.961.190.64 to 2.23
 Waist-to-height ratio
  Normal (≤0.5)1.001.001.001.00
  Critical (>0.5)0.960.76 to 1.221.330.75 to 1.721.441.02 to 2.040.880.52 to 1.49
  • Significant associations have been marked with bold.

  • *PRs (for the longitudinal analyses) and ORs (for cross-sectional analyses) and their 95% CIs are adjusted for age, smoking and education.

  • †Continuous variable, one SD increase, corresponding to 3.0 kg/m2 for baseline BMI.

  • ‡One unit increment in Z score, corresponding to 2.92 units of BMI during follow-up.

  • §Continuous variable, one SD increase, corresponding to 4.0 kg/m2 for follow-up BMI.

  • ¶Continuous variable, one SD increase, corresponding to 11 cm for waist circumference at follow-up.

  • BMI, body mass index; LBP, low back pain; PR, prevalence ratio.