People who are obese and those who take birth control pills are at a higher risk of multiple sclerosis, a new study finds.
Researchers from Raúl Carrera Institute for Neurological Research conducted two separate studies to examine the role of the "obesity hormone" leptin and hormones used for birth control in the development of multiple sclerosis (MS).
For the obesity study, researchers examined the health data of 210 people with MS and 210 people without MS. They were all of the same age group (15 to 20 years) and sex. Researchers found that the participants who were obese at the age of 20 years were twice as likely to later develop MS than the participants who were not obese. People with higher BMI had higher levels of leptin, which is made by fat tissue that regulates weight, appetite and immune response.
"Leptin promotes inflammatory responses in the body, which could potentially explain the link between obesity and MS," said study author Jorge Correale, MD, of the Raúl Carrera Institute for Neurological Research in Buenos Aires, Argentina, in a press statement.
For the other study, researchers examined the health data of 305 women with MS and had been members of Kaiser Permanente Southern California for at least three years before the MS symptoms began. They compared this data to that of 3,050 women who did not have MS. A total of 29 percent of the women with MS and 24 percent of those without MS had used hormonal contraceptives for at least three months in the three years before symptoms began.
Researchers found women who had used hormonal contraceptives were 35 percent more likely to develop MS than those who did not use them. Those who had used the contraceptives but had stopped at least one month before symptoms started were 50 percent more likely to develop MS.
"These findings suggest that using hormonal contraceptives may be contributing at least in part to the rise in the rate of MS among women," said study lead author Kerstin Hellwig, MD, from Bochum Germany, post-doctoral research fellow, Kaiser Permanente Southern California.
The obesity study was supported by the Raúl Carrera Institute for Neurological Research; the birth control study was supported by Kaiser Permanente Direct Community Benefit Funds, the National Institutes of Health and the German Research Foundation.
Findings of the new study will be presented at the American Academy of Neurology's 66th Annual Meeting in Philadelphia, April 26 to May 3, 2014.
