Researchers report that being overweight or obese was associated with an increased risk of developing MS or clinically isolated syndrome (CIS, a first clinical episode suggestive of MS, indicating increased MS risk) in girls, in a study that compared 75 children or teens with MS or CIS with the health records of more than 900,000 healthy children or teens. This finding, if confirmed, opens up the possibility that reducing obesity could reduce some risk of MS in girls. Annette Langer-Gould, MD, PhD, and colleagues (Kaiser Permanente of Southern California, Pasadena) and others report their findings in the January 30, 2013, online issue of Neurology
Although MS occurs most commonly in adults, it is also diagnosed in children and adolescents. While the disease is not contagious or directly inherited, epidemiologists—the scientists who study patterns of disease—have identified factors in the distribution of MS around the world that may eventually help determine what causes or triggers the disease. These factors include gender, genetics, age, geography, and ethnic background.
Because the prevalence of obesity has increased dramatically in the past several decades, and obesity is associated with an increase in immune system activity, Dr. Langer-Gould’s team undertook a study to determine if there was any association between obesity and the risk for developing MS or CIS.
Investigators identified cases of MS and CIS in the database of Kaiser Permanente Southern California, a health maintenance organization with more than 900,000 members 18 years old or younger. They found 75 cases, and reviewed charts to examine body size, and compared findings with 913,172 child or teen controls without MS or CIS.
The results show that 50.6% of the children with MS or CIS were overweight or obese before their diagnosis, compared with 36.6% of the control cases. Compared to girls who were not overweight, the risk for developing MS was about one and a half times higher for overweight adolescent girls, and over three times higher for girls who were extremely obese. The increased risk with obesity was not found in boys.
The authors suggest that the increased risk in adolescent girls in particular may be associated with increases in sex hormones such as estrogen. They comment that although one strength of the study is the large number of control cases, the primary limitation is the small number of MS cases studied.
“If further research confirms these findings, excess weight could turn out to be a modifiable risk factor that influences the development of MS in children and adolescents,” says Nicholas LaRocca, PhD, Vice President of Health Care Delivery and Policy at the Society. “Finding such risk factors and addressing them is a crucial step toward ending MS.”
about pediatric MS.