Is chronic low back pain and radicular neuropathic pain associated with smoking and a higher nicotine dependence? A cross-sectional study using the DN4 and the Fagerström Test for Nicotine Dependence.

Objective - To evaluate if a current smoking status and a higher nicotine dependence were associated with chronic low back pain and/or radicular neuropathic pain. Materials and methods- A cross-sectional study was conducted on the first eligible consecutive 120 patients. Demographic data, pain intensity, worst pain location, most distal pain radiation, the DN4 questionnaire, STarT back tool, and the Fagerström Test were collected during the initial examination. An age- and gender-matched control group (n=50), free from chronic low back pain was recruited. Results- In the chronic pain group, there was a significant difference between smokers and lifetime non-smokers in the average pain intensity (p=0.037), total DN4 score (p=0.002), STarT Back tool (p=0.006), worst pain location (p=0.023) and the most distal pain radiation (p=0.049). The mean total DN4 score increased with a corresponding increase in the number of cigarettes smoked daily (p=0.002). Current smokers had an OR of 3.071 (p=0.013) (95% CI 1.268-7.438) for developing chronic low back pain and lumbar related leg pain and an OR of 6.484 (p<0.001) (95% CI 2.323-18.099) for developing chronic radicular neuropathic leg pain. For every one-unit increase in the Fagerström test score, the likelihood for chronic low back pain and lumbar related leg pain increased by 40.71% (p=0.008) (95% CI 1.095-1.809) and for chronic radicular neuropathic leg pain increased by 71.3% (p<0.001) (95% CI 1.292-2.272). Conclusion- A current smoking status and a higher nicotine dependence were both independently associated with an increased risk for chronic low back pain and/or chronic radicular neuropathic pain.