Physical Comorbidities Associated With Disability Progression in Multiple Sclerosis

Diabetes, hypertension, heart disease, lung disease, and hyperlipidemia are each associated with an increase in the short- and long-term progression of multiple sclerosis (MS) disability, according to study findings published in Neurology.

In this retrospective study, investigators analyzed clinical and health administrative database data for adult patients with incident MS (n=3166). Comorbidities including diabetes mellitus, hyperlipidemia, heart disease, chronic lung disease, hypertension, and epilepsy were identified and measured 1 year prior to study enrollment and then throughout the 20-year study period. The association between patient comorbidities and MS disability progression was subsequently assessed using the Expanded Disability Status Scale (EDSS), which was recorded for each patient at each clinic visit.

At baseline, a total of 454 (14.3%) patients had 1 comorbidity and 92 (2.9%) patients had ≥2 comorbidities. For each additional comorbidity, patients had an average 0.18-point increase in EDSS score (95% CI, 0.09-0.28). In a multivariable model, epilepsy (0.68; 95% CI, 0.11-1.26) and ischemic heart disease (0.31; 95% CI, 0.01-0.61) were associated with significantly higher EDSS scores compared with other comorbidities.

Patients with a higher vs lower socioeconomic status had lower EDSS scores (−0.39; 95% CI, −0.57 to −0.20). No association was found between the use of a disease-modifying drug and EDSS score (0.04; 95% CI, −0.28 to 0.35).

The investigators suggest that some comorbidities may not have been captured adequately, primarily because of the low sensitivity of comorbidity algorithms. Additionally, the study participants included in this analysis were young and possibly healthier than older patients with MS, limiting generalizability.

“On average, as the number of current comorbidities increased, EDSS scores were higher, suggesting an apparent increase in disability progression and that clinicians should pay particular attention to individuals with a high burden of comorbidity,” the authors concluded.

Reference

Zhang T, Tremlett H, Zhu F, et al; for the CIHR Team in the Epidemiology and Impact of Comorbidity on Multiple Sclerosis. Effects of physical comorbidities on disability progression in multiple sclerosis. Neurology. 2018;90(5):e419-e427.