Assessment of Pfirrmann lumbar disc degeneration with body mass index using 3T magnetic resonance imaging: A cross-sectional study

Objectives: The objective is to determine disc degeneration in the lumbar spine using the quantitative Pfirrmann scale in magnetic resonance imaging (MRI) and to correlate the Pfirrmann scale with body mass index (BMI). Methods: Fifty-eight participants with low back pain (LBP) referred for MRI were included in the study. Before the scan, patient details such as height, weight, age, and BMI were collected. To evaluate quantitative Pfirrmann disc degeneration, a region of interest was placed at the nucleus pulposus (NP) of all the disc levels (L1–L5) on the T2-weighted image, and for fat only at the degenerated level. Pfirrmann grading was performed at all disc levels (L1–L2 to L5–S1). Grades III, IV, and V are associated with BMI at the L4–L5 and L5–S1 levels. The data were collected and analyzed. Results: Of 58 participants, 37 were male and 21 were female. A significant difference was observed in fat content between males and females, with females exhibiting higher fat content in L4 and L5 compared to males. There was a significant correlation across all fat levels (L1–L5) as well as the NP of adjacent lumbar levels. In addition, no statistically significant difference was found between BMI and lumbar disc degeneration. Conclusion: Even though disc degeneration was evident across several BMI groups, the results showed there was no significant association between disc degeneration and BMI. Thus, the study concludes that other factors, such as age and body composition, also play an essential role in triggering disc degeneration, in addition to BMI.