Correlation between lumbar intervertebral disc degeneration, abdominal MRI imaging parameters, and body mass index

English Keywords:Lumbar disc degeneration  Paravertebral muscle fat infiltration  Abdominal fat  Vertebral bone quality score  Body mass index

English Abstract:

  【Abstract】 Objectives: To investigate the correlation between lumbar intervertebral disc degeneration and paraspinal muscle fat infiltration, abdominal fat, vertebral bone quality(VBQ) score as well as body mass index(BMI). Methods: A retrospective analysis was conducted on 280 patients who underwent lumbar MRI examination at the affiliated Su Bei People′s Hospital of Yangzhou University from August 2022 to March 2023. The patients included 159 males and 121 females, with ages ranging from 24 to 87 years(51.4±15.1 years). The L4/5 and L5/S1 intervertebral discs were classified according to the Pfirrmann grading system: grade Ⅱ was included in the normal group, and grades Ⅲ-Ⅴ were included in the degeneration group (no grade Ⅰ patients). The degree of paraspinal muscle fat infiltration was evaluated based on the modified Goutallier grading system using MRI T2-weighted images. Abdominal fat indicators were measured, including abdominal diameter(AD), sagittal diameter(SAD), ventral subcutaneous thickness(VST), dorsal subcutaneous thickness(DST) at the level of the posterior margin of the L5/S1 disc, and visceral fat ratio(VFR). VBQ score was assessed using MRI T1-weighted images (the average signal intensity of L1-L4 vertebrae divided by the signal intensity of cerebrospinal fluid at L3 level). Chi-square tests and independent sample t-tests were used to compare the differences in paraspinal muscle fat infiltration, abdominal fat, VBQ scores, and BMI between the two groups. Pearson and Spearman correlation analyses were performed to examine the correlations between lumbar intervertebral disc degeneration and paraspinal muscle fat infiltration, abdominal fat, VBQ scores, and BMI. Logistic regression analysis was conducted to determine the odds ratios(OR) and 95% confidence intervals(CI) for factors related to lumbar disc degeneration. Receiver operating characteristic(ROC) curves were further used to analyze the correlation between lumbar disc degeneration and paraspinal muscle fat infiltration, abdominal fat, and VBQ scores. Results: For the L4/5 intervertebral disc, 107 cases were classified as grade Ⅱ(normal group) and 173 cases as grades Ⅲ-Ⅴ(degeneration group) according to the Pfirrmann classification; For the L5/S1 intervertebral disc, 101 cases were grade Ⅱ(normal group) and 179 cases were grades Ⅲ-Ⅴ(degeneration group). There were statistically significant differences between L4/5 intervertebral disc degeneration and the degree of paravertebral muscle fat infiltration, AD, SAD, VFR, and VBQ scores(P<0.05). L4/5 intervertebral disc degeneration was positively correlated with the degree of paravertebral muscle fat infiltration, AD, SAD, VFR, and VBQ scores(r=0.412, r=0.244, r=0.234, r=0.244, r=0.254). L4/5 intervertebral disc degeneration was negatively correlated with DST(r=-0.139, P<0.05), and there was no correlation between L4/5 intervertebral disc degeneration and BMI(P>0.05). There were statistically significant differences between L5/S1 intervertebral disc degeneration and the degree of paravertebral muscle fat infiltration, AD, SAD, VFR, and VBQ scores(P<0.05). L5/S1 intervertebral disc degeneration was positively correlated with the degree of paravertebral muscle fat infiltration, AD, SAD, VFR, and VBQ scores(r=0.424, r=0.201, r=0.150, r=0.201, r=0.205). L5/S1 intervertebral disc degeneration was negatively correlated with DST(r=-0.175, P<0.05), and there was no correlation between L5/S1 intervertebral disc degeneration and BMI(P>0.05). Logistic regression analysis showed that L4/5 disc degeneration was closely related to SAD(OR=1.065), DST(OR=0.904), VBQ score(OR=2.143), and paraspinal muscle fat infiltration(OR=5.110). L5/S1 disc degeneration was closely related to DST(OR=0.889) and paraspinal muscle fat infiltration(OR=4.739). Conclusions: Lumbar disc degeneration is significantly correlated with paraspinal muscle fat infiltration, abdominal fat, and VBQ score.