Intramuscular Adipose Tissue in the Lumbar Paraspinal Muscles Does Not Correlate With Low Back Pain in Medical Students

Abstract

Objective: The objective of the study is to identify any intergroup differences or statistically significant correlations between paraspinal intramuscular adipose tissue (IntraMAT) deposition and variables such as low back pain, gender, self-reported activity level, body mass index (BMI), age, and academic class-year, as measured by sonographic intensity analysis. This study is specific to a cohort of first- and second-year medical students. Materials and Methods: The right lumbar paraspinal muscles, at the level of the fifth lumbar vertebrae, were investigated with sonography among a cohort of medical students. Image pixels, within the selected region of interest, were segregated by pixel intensity and analyzed for IntraMAT content. Participants reported on additional study variables by responding to a survey. The cohort responses were analyzed to seek correlations between those variables and IntraMAT. Results: The female participants were found to have more IntraMAT ( P < .001). Most participants reported low back pain. There were no significant correlations between IntraMAT and reported low back pain, academic class year, or BMI. Moderate exercise increased IntraMAT deposition, and each year of increasing age decreased IntraMAT ( P < .05). Second-year students experienced more self-reported low back pain than first-year students. Conclusion: A cohort of medical students who were reportedly sedentary had more low back pain than their peers. Back pain was more prevalent in second-year students, irrespective of age, suggesting that ill effects of a sedentary lifestyle may be cumulative. The validity of the sonographic pixel intensity analysis performed was supported by the highly significant increase in IntraMAT observed in female participants. The relationship between low back pain, exercise, BMI, and IntraMAT was uncertain based on available evidence and the results of this study.