MONDAY, Oct. 29, 2012 (HealthDay News) -- Children born to mothers who have had weight-loss surgery and lost a large amount of weight may have better heart health than their brothers or sisters who were born before their mothers lost the excess weight, a new study suggests.
This is likely because the weight loss and metabolic changes experienced by women after weight-loss surgery have a positive effect on inflammatory-disease-related genes in their children, said researchers from Laval University in Quebec City, Canada.
The researchers analyzed DNA in blood samples from 50 children born to 20 mothers; half the children were born before the mothers had weight-loss surgery and half were born after. The children ranged in age from 2 to 24 years when the blood samples were taken.
The mothers' average body-mass index (a measure of body fat based on height and weight) was 45 before weight-loss surgery and 27 after the surgery. A BMI of 30 or higher is considered obese.
The DNA analysis revealed that the mother's weight at the time of birth influences whether certain genes are switched on or off in their children, which affects the children's future risk of obesity and cardiovascular disease.
The study was scheduled to be presented Monday at the Canadian Cardiovascular Congress, which is co-hosted by the Canadian Cardiovascular Society and the Heart and Stroke Foundation of Canada.
"We know our genetic makeup influences our children's risks -- but so can our environment," foundation spokeswoman Dr. Beth Abramson said in a news release.
"For example, if a disease runs in a family, we know to watch out for it in the children as they age," Abramson said. "This study shows that external factors also influence our risk for heart disease -- and that of our offspring -- by switching genes on or off in our DNA, providing a glimpse as to why this occurs. This is why lifestyle behaviors are so important."
The findings are another reminder about whey people need to manage and control their weight at all stages of life, she added.
Because this study was presented at a medical meeting, the data and conclusions should be viewed as preliminary until published in a peer-reviewed journal. And although the study showed an association between a mother's weight and her children's heart health, it did not prove a cause-and-effect relationship.
The March of Dimes outlines the potential pregnancy complications associated with being overweight or obese.