The association between cigarette smoking and intervertebral disc degeneration of the lumbar spine

Abstract

INTRODUCTION: Although some studies have noted cigarette smoking to be associated with low back pain, the role of smoking and its association with intervertebral disc degeneration of the lumbar spine in adults remains questionable. As such, we addressed such concerns as part of the largest population‐based radiographic study of the lumbar spine in Southern Chinese. METHODS: Sagittal T2‐weighted MRIs of the lumbar spine were obtained of 2,542 subjects (range: 21‐81 years). Radiographic assessment entailed the presence, extent, and severity of disc degeneration, and the presence of Schmorl’s nodes and vertebral body marrow changes. Subject demographics (e.g. body mass index, age, workload, exercise) were also obtained. The presence, duration (years), and amount (cigarettes per day) of smoking was evaluated. RESULTS: The study entailed 60.6% females and 39.4% males. The mean age was 41.7 years. Of all subjects, 72.8% had disc degeneration and 11.9% were smokers. Based on logistic regression modeling, the presence and duration of smoking was not found to be significantly associated with the overall presence of disc degeneration (p>0.05). The amount of smoking was significantly associated with disc degeneration involving the mid‐lumbar region (adjusted OR: 1.05; 95% CI: 1.02‐1.09; p=0.003). Based on linear regression modeling, an increase in the amount of smoking was significantly associated with an increase in the number of levels with disc degeneration (p<0.001). Overall disc degeneration severity was not significantly associated with any smoking parameter (p>0.05). CONCLUSIONS: Based on our study, the amount of cigarette smoking may have a minor influence on lumbar disc degeneration, being primarily associated with disc degeneration of the mid‐lumbar region (i.e. L2‐L4).