NEW YORK (Reuters Health) – A new study of mothers and children in California finds that obese women’s children are more likely to be diagnosed with autism or related developmental delays than the children of slimmer moms.
The researchers were looking for effects on kids’ cognitive development from a variety of metabolic conditions in mothers, including high blood pressure and diabetes. Although they also found ties between other metabolic conditions and developmental delays, the strongest links were between obesity and autism-related disorders.
While the study cannot prove that one condition causes the other, the authors caution that even the possibility is worrisome in light of rising U.S. obesity rates.
Paula Krakowiak at the University of California, Davis, and her colleagues studied 1,004 children who were between the ages of two and five and enrolled in the Childhood Autism Risks from Genetics and the Environment (CHARGE) case-control study.
Among the 517 kids in the study with an autism spectrum disorder, 48 were born to mothers with either type 2 or gestational diabetes, 111 to mothers who were obese and 148 to moms with another metabolic condition.
And among the 172 children with a developmental delay, 20 were born to mothers with type 2 or gestational diabetes, 41 to mothers who were obese and 60 to moms with any sort of metabolic condition.
Overall, the connection between maternal diabetes and autism was not significant, but the researchers did find links between a mother being obese or having any other metabolic condition and her child having autism.
Developmental delays were associated with both obesity and diabetes, along with having any other metabolic condition.
“There is definitely an association present and it adds to the reasons for finding ways to lower obesity rates or diabetes rates and make greater efforts to change lifestyle factors,” said Krakowiak.
The new findings come on the heels of a report from the U.S. Centers for Disease Control and Prevention that estimated every one in 88 children in the U.S. has an autism spectrum disorder. That number represents about a 25% increase from the agency’s last report in 2006.
Meanwhile, Krakowiak and her colleagues note that nearly 60% of U.S. women of childbearing age (20-39 years) are overweight, one-third are obese and 16% have metabolic syndrome.
Although no one can say the nation’s rising obesity rate is to blame for the prevalence of autism, Krakowiak said the parallel increases did catch her attention.
“That was definitely one area that I took note of too. I knew obesity rates and diabetes rates were rising, and autism rates were too,” she said.
Dr. Hannah Gardener, an epidemiologist in the Department of Neurology at the University of Miami, told Reuters Health that she thinks it’s natural for people to draw a connection between the two rising rates.
“There is a lot that is unknown and studies like these really help us figure out the questions that need to be answered,” said Dr. Gardener, who has investigated risk factors for autism in the past.
But she thinks researchers are far away from understanding what might create a link between obesity and autism.
Krakowiak told Reuters Health there are a few theories, such as that vascular problems and an overabundance of inflammatory proteins in obesity, could be crucial in a baby’s brain development.