Comorbidities affect MS relapse risk and disability progression

Nurse in hospital

For people with multiple sclerosis (MS), the presence of comorbidities—chronic conditions in addition to the primary diagnosis of MS—can affect the risk of relapse and disability progression. Two new papers involving Dr. Helen Tremlett’s team look at comorbidities from two distinct angles, providing new insight into how people living with MS are affected by additional chronic conditions.

People with MS have an elevated risk of comorbidities compared to the general population, with an increased risk of hyperlipidemia and other vascular disorders, as well as migraine and mood disorders.

The first paper, published recently in Neurology, demonstrates a higher risk of relapse for those with MS and multiple comorbidities. First author Dr. Kaarina Kowalec notes that migraine and hyperlipidemia specifically, as well as a combination of three or more comorbidities saw patients experience a higher likelihood of an MS relapse within a two-year period.

The team, which was led by Dr. Ruth Ann Marrie at the University of Manitoba, recruited 885 participants from MS clinics across Canada and asked them to report any of several physician-diagnosed conditions they might have. Relapse information was then collected at clinical follow-ups, over a two-year period.

“Comorbidities in MS are associated with a number of challenges, including delays in diagnosis, and now, higher risk of relapse,” says Dr. Kowalec. “Our findings imply that individuals with MS and specific or multiple comorbidities may require a tailored approach to management. However, we still need more research to determine what the best approach might be.”

The team looked at the impact of comorbidities in MS in two ways, designing the studies differently to capture complementary data and form a clear picture of the role of additional chronic conditions in MS.

A second paper, published this week in Neurology, looked at the effects of physical comorbidities including cardiovascular diseases and seizure disorders and their impacts on people with MS. Lead author Dr. Tingting Zhang and colleagues found that MS-related disability progresses more quickly in people with comorbidities; with each additional condition, there was an increase in overall disability risk.

“This suggests that we may need to take a more holistic approach to managing MS and related comorbidities,” says Dr. Zhang. “Effective treatment for each comorbidity may reduce disability risk. We need more research to identify the most appropriate treatment approach for each comorbidity in MS.”

Information for the disability progression study came from health administrative data across Canada, with nearly 30 years of anonymized clinical records providing detailed insight into the relationship between comorbidities present before and after MS symptom onset and disability progression over time.

“By understanding the impact of additional chronic conditions on people living with MS, we can start to devise strategies to target these issues more effectively,” says Dr. Helen Tremlett. “Relapses and disability progression are different, but complementary outcomes. Each gives a different insight into the MS disease course. Our findings suggest that if you could alter the trajectory of a comorbidity, you may be able to improve outcomes in MS.”

The study was funded by the Canadian Institutes of Health Research and the Rx&D Health Research Foundation (PI: Ruth Ann Marrie, University of Manitoba; co-PI Helen Tremlett, University of British Columbia). Dr Tremlett is the Canada Research Chair in Neuroepidemiology and Multiple Sclerosis. Dr. Marrie holds the Waugh Family Chair in Multiple Sclerosis.

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