Association of smoking with risk of multiple sclerosis and neuromyelitis optica spectrum disorders

Abstract

Background Previous studies showed that smoking is associated with increased multiple sclerosis (MS) susceptibility, while investigation of relation between smoking and risk of neuromyelitis optica spectrum disorders (NMOSDs) is rarely reported. Hence, this study aims to explore the association of smoking with MS and NMOSDs susceptibility and ascertain whether smoking can increase the risk of these two diseases.  Methods Fifty-three MS patients, 62 NMOSDs patients and 85 healthy individuals were enrolled in this study. Standardized questionnaire or follow-up by telephone call were adopted to collect information regarding whether patients, healthy controls and their relatives have smoking behavior, and to learn circumstances of active smoking and passive smoking in these subjects. Results There were 156 subjects who finished effective questionnaires and telephone follow-up, including 39 MS patients, 43 NMOSDs patients and 74 controls. Compared with passive smoking and non-smoking subjects, the susceptibility of both MS (OR = 10.800, 95%CI: 2.202-52.975; P = 0.001) and NMOSDs (OR = 5.838, 95%CI: 1.123-30.357; P = 0.050) was significantly increased in active smoking subjects. Compared with non-smoking subjects, the susceptibility of both MS (OR = 3.444, 95% CI: 1.491-7.953; P = 0.003) and NMOSDs (OR = 2.370, 95%CI: 1.039-5.407; P = 0.038) was significantly increased in active and passive smoking subjects. In comparison with non-smoking males, smoking males were susceptible to MS (OR = 15.000, 95%CI: 2.239-100.483; P = 0.005).  Conclusions Smoking is definitely the risk factor for MS, whereas it is not clear whether it is a risk factor for NMOSDs.

DOI: 10.3969/j.issn.1672-6731.2016.09.009