Children who are obese may be at higher risk of being diagnosed with multiple sclerosis (MS) in early adulthood, a new study suggests.
The risk of being diagnosed with MS appears to be twice as high among children with obesity compared to those without, according to the Swedish study.
Academics from the Karolinska Institutet in Stockholm analyzed data from the Swedish Childhood Obesity Treatment Register. The database, known as "Boris," is one of the world’s largest registries for the treatment of childhood obesity.
The research team looked at data on children aged 2 to 19 who joined the registry between 1995 and 2020, and compared their information to children in the general population.
Their study included data on more than 21,600 children with obesity, who started treatment for obesity when they were an average age of 11, and more than 100,000 children without obesity.
Children involved in the study, which is set to be presented to the European Congress on Obesity in Venice in May, were tracked for an average of six years.
During the follow-up period, MS was diagnosed in 28 of those with obesity – or 0.13% of the group. This compared to 58 in the group without obesity – a total of 0.06%.
The average age of MS diagnosis was comparable between groups, with patients diagnosed, on average, when they were 23 years old.
Statistical analysis revealed that those with obesity were twice as likely to be diagnosed with MS compared to those without.
"Despite the limited follow-up time, our findings highlight that obesity in childhood increases the susceptibility of early-onset MS more than twofold," the authors said.
"One of the effects of obesity in childhood is that it causes a low-grade, but chronic, inflammation, and most probably this inflammation increases the risk to develop several diseases such as MS," study authors, associate professor Emilia Hagman and professor Claude Marcus, said.
"It is also believed that chronic low-grade inflammation increases the risk for other such diseases are asthma, arthritis, type 1 diabetes and some forms of cancers. However, we know that weight loss reduces the inflammation and most likely the risk of developing such diseases."
Commenting on the study, Dr. Clare Walton, head of research at the MS Society, said: "We don’t know for sure what causes MS, but research suggests it’s likely triggered by a mix of genetic and environmental factors, such as some viral infections and lower levels of vitamin D.
"We know smoking or being medically obese may also play a part, however, none of these alone will cause someone to develop MS.
"This research adds to our understanding of the role obesity plays in MS risk, particularly its influence in childhood.
"More than 130,000 people live with MS in the U.K. today, and research like this is important to help us predict how the number of people living with MS may change in the future."