…And we’re back! After a month in exile from the blogging world my comprehensive exams are done!… for now. Assuming that my committee finds my answers satisfactory I will move on to an oral exam sometime between now and the holiday season. The good news is that I have read a ton of papers in the past few months (probably somewhere north of 200) so I’ve found plenty of interesting things to blog about well into the new year!
Out of all of these papers , one of the most interesting was published in Pediatrics by Dr John Kral and colleagues at the State University of New York and Laval University. First, a bit of background: It is becoming relatively well established that the environment that a fetus experiences in the womb can have a dramatic impact of their health well into adulthood. So for example, when pregnant animals are overfed, their offspring are more likely to experience both obesity and metabolic dysfunction than the offspring of animals who were not overfed. Not surprisingly then, the children of obese women are more than 4x more likely to be obese themselves, compared to children of non-obese parents. Of course there are likely other mechanisms involved here as well (e.g. learned behaviours), but there does seem to be a pretty strong relationship between the prenatal environment and subsequent risk of obesity.
What Dr Kral and colleagues did that was so interesting, was to compare the obesity rates of siblings born to mothers before and after large weight loss due to bariatric surgery. Among children born before their mothers had surgery, the prevalence of obesity was 41%. In contrast, the prevalence was reduced to just 17% among children born to mothers post surgery. That is still very high, but reducing the prevalence of obesity in any group by two-thirds is pretty impressive! Even more interesting, when matching women for BMI at the time of conception, children born in the post-surgery group were still half as likely to be obese compared to those born pre-surgery. The authors suggest that these benefits were likely due to both a healthier metabolic environment post surgery, as well as small weight gain during pregnancy (which could explain why there were benefits even when matching for BMI).
My research focuses entirely on the importance of lifestyle factors (e.g. diet and exercise), so I’ve been a reluctant convert to the benefits of obesity surgery. But I’ve got to say that anything that reduces the risk of childhood obesity by 50-65% is incredibly impressive. This study also poses an interesting conundrum for those who argue against increasing access to bariatric surgery on the basis that obesity is a matter of “personal choice” – how can obesity be a matter of choice when the prenatal environment plays such an important role? I know that some people remain hesitant to embrace bariatric surgery as a treatment strategy for adult obesity, but it may be hard to ignore its value in preventing childhood obesity – a condition which is both extremely difficult to treat, and which predisposes to excess risk of death and disability well into adulthood.
I know that this is just one relatively small study, but I’m curious to hear what people think of it. And for those who are interested in the relationship between the prenatal environment and future risk of obesity, I’ll be posting an interview with a researcher whose work focuses on this area later in the week.
Have a good afternoon!
Kral, J., Biron, S., Simard, S., Hould, F., Lebel, S., Marceau, S., & Marceau, P. (2006). Large Maternal Weight Loss From Obesity Surgery Prevents Transmission of Obesity to Children Who Were Followed for 2 to 18 Years PEDIATRICS, 118 (6) DOI: 10.1542/peds.2006-1379