Dr Ruth Ann Marrie on Comorbidities Affecting MS Treatment Decisions

November 17, 2020

Ruth Ann Marrie, MD, PhD, director of the Multiple Sclerosis Clinic at the University of Manitoba, discusses how comorbidities affect treatment and options for patients with multiple sclerosis (MS).


How does the presence of comorbidities affect treatments and outcomes for MS?

Well, in terms of outcomes, the effects of comorbidities really affect the entire trajectory of multiple sclerosis. So if we go back to when people first have symptoms of MS, and they're working through that diagnostic process, people who already have another health condition at the time their symptoms start have a longer time to diagnosis. So greater diagnostic delay. People with multiple comorbid conditions at the time of diagnosis tend to have more severe disability at the time of diagnosis, and then disability progression appears to be faster over the course of the illness if you have conditions such as depression, or cardiovascular comorbidities like hypertension, diabetes, hyperlipidemia. Relapse rates appear to be higher if you have multiple comorbidities, so at least 3 or more, or if you have hyperlipidemia, or anxiety disorders. And then things that are more patient centered in terms of their mental health related quality of life are produced in the presence of comorbid conditions. And of the ones that we've talked about so far depression and anxiety disorder seem to have the most adverse impact on quality of life. We need to recognize that many of the medications that we're using as disease-modifying therapies now, for example, may have contraindications in the presence of some comorbid conditions or medications used to treat those conditions. Fingolimod is an example, or siponimod; if you have ischemic heart disease, you're taking beta blockers, calcium channel blockers—contraindications. So we need to think about those kinds of things in the choice of medications. But we also need to recognize that people may have a harder time staying on their disease-modifying therapies, if they have multiple other conditions that they're already dealing with for reasons we haven't fully explored, but it's a big burden to taking multiple medications and side effects from one medication may affect you know, other conditions. And so it is important for us to think about all those issues when talking to the individual with MS about what medication is going to be best suited for them.