Obesity increases the odds of intervertebral disc herniation and spinal stenosis; an MRI study of 1634 low back pain patients

Purpose:
The objective of this study was to examine the relationships between BMI and intervertebral disc degeneration (DD), disc herniation (DH) and spinal stenosis (SS) using a large, prospectively recruited and heterogeneous patient population.

Methods:
Patients were recruited through the European Genodisc Study. An experienced radiologist scored MRI images for DD, DH and SS. Multivariate linear and logistic regression analyses were used to model the relationship between these variables and BMI with adjustment for patient and MRI confounders.

Results:
We analysed 1684 patients with a mean age of 51 years and BMI of 27.2 kg/m 2.
The mean DD score was 2.6 (out of 5) with greater DD severity with increasing age (R2 = 0.44). In the fully adjusted model, a 10-year increase in age and a 5 kg/m 2 increase in BMI were associated, respectively, with a 0.31-unit [95% CI 0.29,0.34] and 0.04-unit [CI 0.01,0.07] increase in degeneration. Age (OR 1.23 [CI 1.06,1.43]) and BMI (OR 2.60 [CI 2.28,2.96]) were positively associated with SS. For DH, age was a negative predictor (OR 0.70 [CI 0.64,0.76]) but for BMI (OR 1.19 [CI 1.07,1.33]), the association was positive. BMI was the strongest predictor of all three features in the upper lumbar spine.

Conclusions:
While an increase in BMI was associated with only a slight increase in DD, it was a stronger predictor for DH and SS, particularly in the upper lumbar discs, suggesting weight loss could be a useful strategy for helping prevent disorders associated with these pathologies.