A preliminary study of association of cigarette smoking with risk of neuromyelitis optica spectrum disorder

Various studies have revealed an association between cigarette smoking and increased risk for multiple sclerosis (MS). However, its role in neuromyelitis optica spectrum disorder (NMOSD) remains elusive. Therefore, in the present case-control study, we aimed to assess the association of active and passive cigarette smoking with the risk of MS and NMOSD. Thirty-six patients with NMOSD, 46 patients with MS, and 122 healthy individuals were included in this study. Standardized questionnaires and telephone interviews were used to collect information regarding the active and passive cigarette smoking behaviors of the patients and normal controls. The risk of MS was significantly higher among smokers than among nonsmokers (odds ratio = 2.166, 95% confidence interval: 1.109-4.170; P = .027). Further analysis of the risk between active and passive smokers, male smokers and nonsmokers showed no statistical difference. However, neither smokers nor active smokers had a greater or lower risk of NMOSD than their nonsmoking counterparts. Our preliminary study showed no significant association between cigarette smoking and the risk of NMOSD, strongly suggesting that, unlike MS, cigarette smoking might not confer NMOSD susceptibility, at least in the Northern Han Chinese population.