Although a rare condition, multiple sclerosis (MS) appears to be more common among overweight and obese girls, to the point where extremely obese girls have nearly four times the risk of developing the neurological disease, or its precursor clinically isolated syndrome (CIS). This was the finding of a new study whose authors urge parents to consult a doctor should their obese children develop symptoms like numbness and tingling.
Multiple sclerosis is a central nervous system disease that damages the nerve fibers in the brain and spinal cord, making it difficult for various signals, such as for muscle control, touch and vision, to travel. MS has varying, unpredictable symptoms, and they affect each person differently. Common symptoms include blurring of vision, numbness and tingling, muscle weakness and tightness, and problems with balance and mobility.
Clinically isolated syndrome (CIS) is a term that describes a first clinical episode (lasting at least 24 hours) with features suggestive of MS. Although patients usually recover, it is often the first sign of MS.
While there is currently no cure for MS, many researchers believe it is just a matter of time before one is found, especially as we find out more and more about the disease and the underlying biological mechanisms.
For instance, a study published in November 2012, describes how scientists working on lab mice found an early trigger for MS. It appears that a clotting protein that leaks across the blood-brain barrier, triggers an immune response and causes a toxic environment that damages nerve cells.
According to the US Centers for Disease Control and Prevention (CDC), childhood obesity in the US has more than doubled in children and tripled in adolescents in the past 30 years, to the point where more than one in three American children and adolescents is overweight or obese.
Annette Langer-Gould who is with the Kaiser Permanente Southern California Department of Research & Evaluation in Pasadena and first author of the study, says in a statement from the American Academy of Neurology, of which she is a member:
“In our study, the risk of pediatric MS was highest among moderately and extremely obese teenage girls, suggesting that the rate of pediatric MS cases is likely to increase as the childhood obesity epidemic continues.”
For their analysis, Langer-Gould and colleagues used data from a large children’s health study in Southern California that included nearly a million children. They identified 75 children and adolescents diagnosed with pediatric MS/CSI between the ages of 2 and 18. The children’s Body Mass Index (BMI) had been measured before the disease symptoms appeared.
The researchers compared the children with MS/CSI with over 913,000 children who did not have the disease.
They grouped the data according to four weight categories: normal weight, overweight, moderate obesity and extreme obesity.
Nearly 51% of the children with MS/CSI were overweight or obese, compared to under 37% who did not have MS/CSI.
When they analyzed the results, the researchers found that compared to girls of normal weight, the risk of developing MS/CSI was more than 1.5 times higher for overweight girls and nearly 1.8 times higher for moderately obese girls.
For extremely obese girls the risk of developing MS/CSI was nearly 4 times higher.
No such associations were found for boys, note the researchers.
The authors suggest their findings show the childhood obesity epidemic is likely to lead to more cases of MS and CIS in children, and adolescent girls in particular.
Langer-Gould says:
“Even though pediatric MS remains rare, our study suggests that parents or caregivers of obese teenagers should pay attention to symptoms such as tingling and numbness or limb weakness, and bring them to a doctor’s attention.”
Funds from the National Institute of Diabetes and Digestive and Kidney Disorders, and Kaiser Permanente Direct Community Benefit Funds helped pay for the study.
Written by Catharine Paddock PhD