High BMI at MS diagnosis tied to faster disability progression: Study
Weight loss before or early in the disease course may have potential benefits
Having a higher body mass index (BMI), a measure of body fat based on a person’s height and weight, at diagnosis is tied to faster disability progression in people with multiple sclerosis (MS), according to a recent study in Sweden.
This effect was particularly pronounced when excess weight was present since early adulthood.
Notably, participants with high BMI in early adulthood who achieved a normal weight before diagnosis did not show increased risk of disability progression, “suggesting potential benefits of weight loss before or early in the disease course,” researchers wrote.
The study, “Early-life and adult body mass index in relation to MS disability progression,” was published in the Journal of Neurology.
Obesity a significant risk factor for developing MS
Obesity is a significant risk factor for developing MS and also influences prognosis, likely because it causes chronic inflammation in the body, metabolic dysfunction, and altered immune regulation.
However, research has indicated that losing weight after diagnosis does not slow disease progression. This suggests that the consequences of obesity may be established earlier in life and that weight loss in adulthood may not be sufficient to modify the disease course.
In this study, a team of researchers in Sweden set out to assess if early-life obesity exerts a lasting influence on disease outcomes, and whether losing weight in early life, before an MS diagnosis, could attenuate the impact of obesity on disease progression.
The researchers examined data from 2,940 individuals with relapsing forms of MS who had available follow-up disability data in the Swedish MS registry. All participants also had available data on BMI both at age 20 and at diagnosis.
This observation suggests that early-life adiposity [excess of body fat] may influence not only disease severity at onset but also the timing of clinical manifestation.
A high BMI was defined as being 28 or above. For context, someone with a BMI between 25 and 29.9 is generally considered overweight, and obese people have a BMI of 30 or higher.
The majority of patients (54%) had a BMI below 28, meaning they had a healthy weight or were slightly overweight. The rest had persistently elevated BMI (5.4%), elevated BMI only at diagnosis (14.3%), or elevated BMI only at age 20 (2%).
The researchers noted that patients with an elevated BMI at age 20 not only had higher disability levels at diagnosis but were also diagnosed at younger ages than those with lower early-life BMI.
“This observation suggests that early-life adiposity [excess of body fat] may influence not only disease severity at onset but also the timing of clinical manifestation,” they wrote.
Patients with persistently elevated BMI had higher risk of disability progression
Looking at disease outcomes, the team found that patients with persistently elevated BMI had a higher risk of disability progression. Compared with people with a BMI below 28, these patients had a 28% higher risk of confirmed disability worsening, which is defined as an increase in Expanded Disability Status Scale (EDSS) scores that is sustained for at least six months.
Patients also had a 64% higher risk of reaching an EDSS score of 3, indicating moderate disability, and a 51% higher risk of reaching an EDSS of 4, which corresponds to significant disability.
These risks were also increased among those with high BMI only at diagnosis, though less pronounced.
Similar results were seen in patient-reported measures of physical and psychological well-being, with those with persistently elevated BMI or elevated BMI at diagnosis having a higher risk of worsening in those measures.
A major finding, however, was that participants with elevated BMI at age 20, but not at diagnosis, were not more likely to experience worse outcomes than those with persistently low BMI.
The data may suggest “that current rather than past adiposity is more strongly associated with MS progression,” the researchers wrote, adding that “these findings underscore the potential benefits of early weight management in MS.”
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