Fat infiltration of paraspinal muscles is associated with low back pain, disability, and structural abnormalities in community-based adults

Spine J. 2015 Jul 1;15(7):1593-601. doi: 10.1016/j.spinee.2015.03.039. Epub 2015 Mar 28.

Abstract

Background context: Low back pain and disability are major public health problems and may be related to paraspinal muscle abnormalities, such as a reduction in muscle size and muscle fat content.

Purpose: The aim of this study was to examine the associations between paraspinal muscle size and fat content with lumbar spine symptoms and structure.

Study design/setting: This was a community-based magnetic resonance imaging (MRI) cohort study.

Patient sample: A total of 72 adults not selected on the basis of low back pain were included in the study.

Outcome measures: The outcomes measured were lumbar modic change and intervertebral disc height. Pain intensity and disability were measured from the Chronic Pain Grade Questionnaire at the time of MRI.

Methods: The cross-sectional area (CSA) and amount of fat in multifidus and erector spinae (high percentage defined by >50% of muscle) were measured, and their association with outcome was assessed.

Results: Muscle CSA was not associated with low back pain/disability or structure. High percentage of fat in multifidus was associated with an increased risk of high-intensity pain/disability (odds ratio [OR], 12.6; 95% confidence interval [CI], 2.0-78.3; p=.007) and modic change (OR, 4.3; 95% CI, 1.1-17.3; p=.04). High fat replacement of erector spinae was associated with reduced intervertebral disc height (β=-0.9 mm; 95% CI, -1.4 to -0.3; p=.002) and modic change (OR, 4.9; 95% CI, 1.1-21.9; p=.04).

Conclusions: Paraspinal fat infiltration, but not muscle CSA, was associated with high-intensity pain/disability and structural abnormalities in the lumbar spine. Although cause and effect cannot be determined from this cross-sectional study, longitudinal data will help to determine whether disabling low back pain and structural abnormalities of the spine are a cause or result of fat replacement of paraspinal muscles.

Keywords: Disability; Fat; Intervertebral disc; Low back pain; Lumbar; Modic; Muscle.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adipose Tissue / pathology*
  • Adult
  • Chronic Pain / etiology
  • Chronic Pain / pathology*
  • Cross-Sectional Studies
  • Disability Evaluation
  • Female
  • Humans
  • Intervertebral Disc / pathology
  • Low Back Pain / etiology
  • Low Back Pain / pathology*
  • Lumbar Vertebrae / pathology
  • Magnetic Resonance Imaging / methods
  • Male
  • Middle Aged
  • Paraspinal Muscles / pathology*