The fetuses of obese mother rats are programmed in utero to develop adulthood obesity, according to new research from the University of Buffalo.
For the first time, the researchers have shown that the metabolic programming occurs in the fetal hypothalamus, the part of the brain that maintains a stable body weight throughout life. The new findings were published in the October 2008 issue of the American Journal of Physiology, Endocrinology and Metabolism.
"Our earlier studies looked at newborn rats of the obese mothers in the post-weaning period, so we didn't know how early this programming occurred," said Mulchand Patel, University of Buffalo distinguished professor of biochemistry and senior author on the study. "Now we know it occurs in utero and specifically in the hypothalamus.
"While these studies were done with rats, there is good reason to think the mechanism would be similar in humans," he said. "The fact that more than one-third of women of child-bearing age in the United States are expected to be overweight or obese during pregnancy, based on a 2003 study, does not portend well for good health of their offspring."
The phenomenon of metabolic programming, also known as dietary patterning, was known to researchers. "Epidemiologic studies of malnourished mothers showed that their babies often were underweight and at increased risk for several chronic diseases as adults," Patel said. "Animal studies on maternal protein malnourishment or caloric restriction have shown that pre- and immediate postnatal nutritional modifications have long-term consequences on adult-onset diseases."
Unlike many animal models that are investigating the role of maternal obesity on children's lives, the mother rats used in this study consumed normal laboratory chow during pregnancy, Patel noted. He also added that it remained vital for mothers to keep themselves fit and healthy during pregnancy.
"Our findings that malprogramming effects induced during fetal development in the altered intrauterine environment in obese mother rats predispose the offspring for adult-onset obesity underscore the importance of women maintaining optimal conditions during their pregnancies."