Association of BMI with lumbar spinal canal stenosis in patients with low back pain

Open Access

Abstract

Background: Lumbar spine degenerative disease is a common cause of low back pain and disability worldwide. Increased body mass index (BMI) has been implicated as a potential risk factor for lumbar disc degeneration, yet the pattern of involvement across different lumbar levels in relation to BMI remains underexplored. Objective: To evaluate the distribution of lumbar disc degeneration across different spinal levels and examine its association with BMI in adult patients undergoing MRI. Materials & Methods: This retrospective study was conducted in the Radiology Department of BIRDEM General Hospital from January 2024 to December 2024. A total of 70 adult patients with MRI-confirmed degenerative changes in the lumbar spine were included. Exclusion criteria comprised prior spine surgery, spinal infections, malignancy, metabolic bone disease, or incomplete imaging/BMI data. Demographic data, height, weight, and clinical indications for MRI were recorded. BMI was calculated and categorized according to WHO criteria. MRI scans were reviewed by a consultant radiologist using standard lumbar spine imaging protocols to identify disc bulges, central and paracentral herniations at levels L1–L2 through L5–S1. Data were analyzed using descriptive statistics and chi-square tests to assess associations between BMI and disc pathology. Results: The mean age of participants was 43.15 ± 8.37 years, with 52.9% females. BMI distribution showed 50.0% normal weight, 35.7% overweight, 11.4% obese, and 2.9% underweight. Disc pathology was most prevalent at L4–L5 (71.4% disc bulge, 7.1% central and paracentral herniation) and L5–S1 (35.7% disc bulge, 25.7% central herniation, 7.1% paracentral herniation). Upper lumbar levels (L1–L2 and L2–L3) were largely normal. Higher BMI was associated with increased frequency of disc bulges and herniations, particularly at lower lumbar levels. Conclusion: Lumbar disc degeneration predominantly affects lower lumbar segments (L4–L5 and L5–S1), and elevated BMI is associated with increased severity and frequency of multi-level disc pathology. Weight management may play a key role in reducing the burden of degenerative lumbar spine disease.