Having Other Health Conditions Does Not Raise Risk of MS-related Hospitalization, Study Finds

Having other health conditions, or comorbidities, along with multiple sclerosis (MS) does not increase a person’s risk of being hospitalized due to MS-specific symptoms, although it does raise the rate of all-cause hospital admissions, a study found. 

The finding was described in “Impact of comorbidity on hospitalizations in individuals newly diagnosed with multiple sclerosis: A longitudinal population-based study,” published in the journal Multiple Sclerosis and Related Disorders.

Disease comorbidities — other health conditions present in a person at the same time as a primary condition — are common among people with MS, and can affect the disease’s progression and prognosis.

Previous studies had suggested that people with MS who also have comorbidities are at a higher risk of being hospitalized. However, not many studies have looked into this possibility in depth.

With this in mind, researchers at the University of Saskatchewan, in Canada, investigated the possible link between having MS comorbidities and being at higher risk for hospitalization.

The team used records from an administrative database of the Saskatchewan population, covering the time period between Jan. 1, 1996, and Dec. 31, 2017, to identify and follow-up people who developed MS during this time.

Included in the study were the comorbidities thought to be the most common or relevant among MS patients — namely hypertension, diabetes, hyperlipidemia (excessive blood fats), ischemic heart disease, chronic lung disease, migraines, epilepsy, and mood and anxiety disorders.

Among the nearly 1.2 million population of Saskatchewan, 2,275 people developed MS during the study period, and researchers were able to follow their history for a mean time of 8.7 years. Hospitalization records were analyzed dating back to Jan. 1, 2001.

At the time MS was first identified, 54% of people already had a comorbidity, with mood and anxiety disorders being the most common (26.6%). This was followed by hypertension (16.9%), migraine (14.6%), and chronic lung disease (13.5%).

During the study period, the researchers found that 52% of those with MS were hospitalized — with a total of 3,312 hospitalizations. However, MS-related hospitalizations showed a decreasing trend over time, with a rate of 7.2 per 100 persons hospitalized in 2001, and 3.0 per 100 persons in 2017. 

Generally, the presence of any comorbidity, either at the time of MS diagnosis or developing later on, was seen to increase the rate of hospitalization for any cause. With the exception of hyperlipidemia, all individual comorbidities analyzed raised the risk of hospitalization.

Moreover, the researchers found that the higher the number of comorbidities individuals had, the more likely they were to be hospitalized. 

In contrast, the results showed that the presence of any comorbidity did not increase the risk of MS-specific hospital admission. Indeed, having more than two comorbidities was linked to lower MS-related hospitalization rates.

The researchers suggested that this may be the result of “potential pleiotropic effects [effects other than the originally intended ones] of certain medications commonly used to treat comorbid conditions, such as statins and metformin, which have been suggested to have beneficial effects in MS.”

The results also showed that hospital admissions due to MS were more likely to occur in younger people, and that MS-related hospitalization decreased with age. A longer MS disease duration also was linked to a lower need for MS-related hospital admission.

Overall, the results suggest that “comorbidity increases the rate of all-cause hospitalizations, but appears to have little impact on MS-related hospital admissions,” the researchers said.

“We also observed increased hospitalization rates during the earlier stages of MS, when the disease is typically more active,” they added.

“These findings highlight the importance of recognizing and managing comorbidity in the MS population, especially early in the disease course, as this will likely have the biggest impact on reducing overall hospital admissions,” the team concluded.