Association of Body Mass Index with Intervertebral Disc Degeneration and Disc Herniation in South-East Nigeria: An MRI Based Study

Abstract

Background: Intervertebral disc degeneration (IVDD) and disc herniation are major contributors to low back pain, a leading cause of disability worldwide. The role of body mass index (BMI) as a modifiable risk factor has been widely studied; however, there is limited MRI-based evidence from sub-Saharan Africa, particularly in Nigeria. Aim: This study aimed to evaluate the association between BMI and intervertebral disc degeneration as well as disc herniation using magnetic resonance imaging (MRI) in a South-East Nigerian population. Materials and Methods: This prospective cross-sectional study included 160 adult patients who underwent lumbosacral spine MRI over a defined study period.  BMI was categorized with World Health Organization criteria. MRI images were reviewed to assess disc degeneration using the Pfirrmann grading system and to identify the presence of disc herniation. Statistical analyses, including Chi-square tests were performed to determine associations between BMI categories and imaging findings, with significance set at p < 0.05. Results: The age of participants ranged from 26 to 85 years, with a mean age of 57.6 ± 13.3 years with a slight male predominance. Disc degeneration was identified in 86.3% of participants, while disc herniation was observed in 66.9% of participants. L4–L5 and L5–S1 levels were the most frequently affected. A statistically significant association was found between increasing BMI and the severity of disc degeneration (χ² = 15.149, p = 0.002). BMI did not show a statistically significant association with disc herniation (χ² = 3.800, p = 0.284) Conclusion: There is statistically significant association between elevated BMI with increased severity of intervertebral disc degeneration, while though disc herniation was significantly more common in elevated BMI, there is no statistically significant association. These findings underscore the importance of weight management as one of the preventive strategies in reducing spinal degenerative disease burden in South-East Nigeria.