Associations between smoking and walking, fatigue, depression, and health-related quality of life in persons with multiple sclerosis

Smoking is associated with increased multiple sclerosis (MS) risk. In addition, some studies have reported that smoking is associated with anxiety and depression. However, the associations between smoking, walking, and fatigue are needed to be investigated. The objective was to investigate the associations between cigarette smoking and walking, fatigue, depression symptom severity, and health-related quality of life in persons with MS. Two hundred seventy-nine persons with MS were evaluated in this cross-sectional study. Study outcomes were neurological disability level, walking speed, walking endurance, perceived walking impact of MS, fatigue, depression symptom severity, and health-related quality of life. There were 95 (34.1%) current smokers who had significantly higher fatigue (p = 0.003, pη² = 0.031) and depression (p = 0.044, pη² = 0.015), and lower health-related quality of life (p = 0.003, pη² = 0.031) after adjusting for age, gender, neurological disability level, and disease duration compared to non-smokers (n = 184). There was no significant difference between smokers and non-smokers in walking measures (p > 0.05). Smoking intensity was significantly correlated with age (r = 0.487), neurological disability level (r = 0.227), disease duration (r = 0.30), walking speed (r = 0.574), walking endurance (r =  − 0.461), perceived walking impact of MS (r = 0.684), fatigue (r = 0.370), health-related quality of life (r =  − 0.259), and depression (r = 0.269) in current smokers. Cigarette smokers with MS had significantly more fatigue and depression symptom severity and less health-related quality of life compared to non-smokers. Increased pack-years of cigarette smoking was associated with worse walking ability and health-related quality of life, and greater depression symptom severity and fatigue.