High BMI at MS diagnosis liked to faster disability progression

Having a higher body mass index (BMI) at the time of multiple sclerosis (MS) diagnosis is linked to faster disability progression, particularly when excess weight has been present since early adulthood.

A Swedish study of 2,940 people with relapsing forms of MS found that those with persistently elevated BMI – a measure of body fat based on height and weight – had a 28 per cent higher risk of confirmed disability worsening.

Multiple sclerosis is a neurological condition in which the immune system attacks the protective covering around nerve fibres, disrupting communication between the brain and body.

Researchers examined data from the Swedish MS registry, tracking participants who had BMI measurements at both age 20 and diagnosis. A high BMI was defined as 28 or above. For reference, a BMI between 25 and 29.9 is generally classed as overweight, while 30 or higher is considered obese.

The study found that patients with persistently high BMI had a 64 per cent higher risk of developing moderate disability and a 51 per cent higher risk of reaching significant disability, measured using the Expanded Disability Status Scale (EDSS) – a standard tool used to assess MS progression.

Those with high BMI only at diagnosis also showed increased risks, though these were less pronounced.

Importantly, participants who had high BMI in early adulthood but achieved a normal weight before diagnosis did not show an increased risk of disability progression.

“This observation suggests that early-life adiposity may influence not only disease severity at onset but also the timing of clinical manifestation,” the researchers wrote.

Patients with elevated BMI at age 20 were typically diagnosed at a younger age and had higher disability scores at diagnosis compared with those with lower early-life BMI.

The researchers said the results indicate that “current rather than past adiposity is more strongly associated with MS progression,” and that “these findings underscore the potential benefits of early weight management in MS.”

Similar findings were seen in patient-reported measures of physical and psychological well-being, with those who had persistently elevated BMI or high BMI at diagnosis more likely to experience worsening in these areas.

The findings suggest that losing weight before or early in the disease course may have potential benefits for people living with or at risk of MS, although the consequences of obesity may be established earlier in life.