Vascular Comorbidities Linked to Progression of MS

March 30, 2010—In Neurology, Ruth Ann Marrie, MD, et al have published a study on the impact of vascular comorbidities on the disease severity of multiple sclerosis (MS) (2010;74:1041–1047). The investigators noted that vascular comorbidity adversely influences health outcomes in several chronic conditions, and these conditions are common in MS patients; therefore, they may contribute to the poorly understood heterogeneity in MS disease severity. The study's hypothesis is that treating vascular comorbidities may represent an avenue for treating MS.

In the study, 8,983 patients with MS enrolled in the North American Research Committee on MS registry participated in this cohort study. The investigators compared time from symptom onset or diagnosis until ambulatory disability for patients with or without vascular comorbidities to determine their impact on MS severity. Multivariable proportional hazards models were adjusted for sex, race, age at symptom onset, year of symptom onset, socioeconomic status, and region of residence.

The investigators found that participants reporting one or more vascular comorbidity at diagnosis had an increased risk of ambulatory disability, and risk increased with the number of vascular conditions reported (hazard ratio [HR]/condition for early gait disability, 1.51; 95% confidence interval [CI], 1.41–1.61). Vascular comorbidity at any time during the disease course also increased the risk of ambulatory disability (adjusted HR for unilateral walking assistance, 1.54; 95% CI, 1.44–1.65). The median time between diagnosis and need for ambulatory assistance was 18.8 years in patients without and 12.8 years in patients with vascular comorbidities.

The findings show that whether present at symptom onset, diagnosis, or later in the disease course, vascular comorbidity is associated with a substantially increased risk of disability progression in multiple sclerosis. The impact of treating vascular comorbidities on disease progression deserves investigation, the investigators concluded.