Multiple sclerosis patients with additional diseases, high cholesterol levels or a history of migraine headaches are more likely to experience relapses than other patients, a Canadian study shows.
The report, “Comorbidity increases the risk of relapse in multiple sclerosis,” was published in the journal Neurology. Researchers said patients had to have at least three additional diseases to increase their risk of relapses.
Their initial objective was to see how additional diseases, or comorbidities, affected MS patients’ chance of a relapse.
The two-year study covered 885 patients with a history of relapses who were being treated at four specialized clinics. The team looked at their comorbidities at the start of the study and at Years 1 and 2. Researchers obtained relapse information at Years 1 and 2 from medical records and patient questionnaires.
Patients’ average age at the start of the study was 48. More than three-fourths were women. Seventy-eight percent of the participants had relapsing-remitting MS, 22 percent secondary progressive MS, and 0.6 percent clinically isolated syndrome, or CIS.
Researchers compared patients who had had no relapse during the two years of the study with those who had had at least one relapse.
The most common comorbidity, anxiety, affected 40 percent of patients. Depression occurred in 21 percent, high blood pressure in 18 percent, migraine headaches in 18 percent, and a high cholesterol condition known as hyperlipidemia in 12 percent.
There was a clear link between comorbidities and relapse rates. “We found an association between the presence of three or more comorbidities at baseline and an increased relapse rate over the next two years, compared to those with no comorbidity,” the researchers wrote.
Two comorbidities — migraines and hyperlipidemia — were associated with particularly high rates of relapse during the two years of the study.
Age also influenced relapse rates, with younger patients having higher rates than older ones. This, the authors wrote, “highlights the complexity of the associations being evaluated.”
Overall, the results suggested that MS patients with high cholesterol, a history of migraines, or three or more additional diseases were at higher risk of relapses.
“These findings have potential implications for understanding the pathophysiology of MS relapses, and suggest that closer monitoring of individuals with specific or multiple comorbidities may be needed,” the team wrote.
They said the results raise new questions about how to manage MS. One is whether patients with specific comorbidities — such as migraines or hyperlipidemia — need personalized or more aggressive therapies than those without the conditions.