General health issues in multiple sclerosis: comorbidities, secondary conditions, and health behaviors

Comorbid conditions, secondary conditions, and health behaviors are increasingly recognized to be important factors influencing a range of outcomes in multiple sclerosis (MS). This review discusses the most common comorbidities experienced in MS, their impact on clinical outcomes, and the impact of health behaviors. Osteoporosis is a common secondary condition in MS that will be discussed along with vitamin D insufficiency.

Mental comorbidity is common in MS; depression has a lifetime prevalence of 50%, while anxiety has a lifetime prevalence of 36%. Physical comorbidity is also common, with the most frequently reported conditions including hyperlipidemia, hypertension, arthritis, irritable bowel syndrome, and chronic lung disease. Fracture risk is increased among patients with MS because of an increased risk of osteoporosis and propensity for falls. Vitamin D insufficiency is common and may contribute to increased fracture risk and increased disease activity. Comorbidities and smoking are associated with diagnostic delays, increased disability progression, lower health-related quality of life, and lower adherence to treatment.

Physical and mental comorbidity and adverse health behaviors are common in patients with MS. Comorbidities and health behaviors are associated with adverse outcomes in MS and should be considered in the assessment and management of patients with MS.