Obesity May Be Associated With More Disabling MS

Obesity in newly diagnosed patients with multiple sclerosis (MS) is associated with higher disease severity and poorer outcomes, according to new research.

Jan Lünemann

A high body-mass index (BMI) during childhood and adolescence has been linked to an increased risk for MS disease development, wrote corresponding author Jan Lünemann, M.D., MBA, a professor in the Department of Neurology at University Hospital Münster and the University of Münsterin Germany in a Journal of Neurology Neurosurgery & Psychiatry article.

Whether obesity is associated with higher MS disease activity and severity after disease onset is not completely understood. Lünemann and colleagues evaluated whether BMI, obesity and obesity-related comorbidities are related to disease severity and progression.

The researchers utilized the German National MS cohort, a multicenter prospective longitudinal observational study evaluating detailed assessment of patients with first diagnosis of MS or clinically isolated syndrome, according to the 2005 McDonald criteria.

The researchers assessed the patients every two years for a total of six years, using the Expanded Disability Status Scale (EDSS), across 22 centers in Germany. They calculated BMI in the 1,066 participating patients, along with

relapse rates, disease-modifying therapies (DMTs) and comorbidities.

At the time of MS diagnosis, 15% of patients were obese with a BMI of at least 30. Conditions associated with obesity (type 2 diabetes and high blood pressure) were reported in nearly 6.5% of patients.

While obesity at diagnosis was not associated with a higher annual relapse rate or greater build-up of nerve damage over six years, levels of disability were higher at the time of diagnosis and at each of the subsequent three times the researchers measured, after factoring in age, sex, and smoking.

In addition, the average time it took obese patients to accumulate greater levels of disability was shorter. They reached EDSS 3 at just under 12 months, on average, compared with nearly 18 months for those who weren’t obese.

Obese patients were also more than twice as likely to reach EDSS 3 within six years, regardless of what type of drug treatment they were getting.

“Our finding that obesity, but not overweight, in MS patients is associated with a poorer outcome suggests a threshold effect of body mass on disability accumulation in MS,” Lünemann wrote.

Obesity is a modifiable risk factor, Lünemann added. “In line with the aforementioned studies indicating an association of obesity with gray matter decline, obese patients undergoing bariatric surgery are reported to build up grey and white matter volume as they regain healthy weight. These data suggest that dedicated management of obesity should be explored for its potential merit in improving long-term clinical outcomes of patients diagnosed with MS,” Lünemann wrote.

The shortcomings of the study include the fact that BMI was assessed only once at the start of the study, while co-existing conditions were limited to type 2 diabetes and high blood pressure, with the number of those affected were small, Lünemann acknowledged.