Nicotine dependence and the International Association for the Study of Pain neuropathic pain grade in patients with chronic low back pain and radicular pain: is there an association?

BACKGROUND: This study investigated whether current smoking and a higher nicotine dependency were associated with chronic low back pain (LBP), lumbar related leg pain (sciatica) and/or radicular neuropathic pain. METHODS: A cross-sectional study was conducted on 150 patients (mean age, 60.1 ± 13.1 yr). Demographic data, the International Association for the Study of Pain (IASP) neuropathic pain grade, STarT Back tool, and the Fagerström test were completed. A control group (n = 50) was recruited. RESULTS: There was a significant difference between current smokers and non-smokers in the chronic LBP group in the mean pain score (P = 0.025), total STarT Back score (P = 0.015), worst pain location (P = 0.020), most distal pain radiation (P = 0.042), and in the IASP neuropathic pain grade (P = 0.026). There was a significant difference in the mean Fagerström score between the four IASP neuropathic pain grades (P = 0.005). Current smoking yielded an odds ratio (OR) of 3.071 (P = 0.011) for developing chronic LBP and sciatica, and an OR of 4.028 (P = 0.002) for obtaining an IASP “definite/probable” neuropathic pain grade, for both cohorts. The likelihood for chronic LBP and sciatica increased by 40.9% (P = 0.007), while the likelihood for an IASP neuropathic grade of “definite/probable” increased by 50.8% (P = 0.002), for both cohorts, for every one unit increase in the Fagerström score. CONCLUSIONS: A current smoking status and higher nicotine dependence increase the odds for chronic LBP, sciatica and radicular neuropathic pain.