Do Genes Predict Weight Loss After Metabolic Surgery?Wednesday, August 25, 2021
Body weight is a highly heritable trait and a host of genes have now been identified as playing a role in its regulation. Furthermore, there is evidence that changes in body weight in response to caloric restriction may also be in part determined by genetic factors.
This naturally leads to the question whether or not weight loss after metabolic surgery may be predicted by genetic screening.
This is the topic of a recent systematic review by Sapana Gupta and colleagues, published in Obesity Surgery.
In their analyses of fifty-seven studies that looked at single genes or genetic risk scores in relationship to weight loss after metabolic surgery, they found some (albeit weak) evidence that certain genetic variants (e.g. UCP, FTO, MC4-R) may predict greater or lesser weight loss. However, results were inconsistent and, where stated, of rather modest magnitude (1.5-4.5 kg).
Given the host of factors that can potentially influence post-surgical weight loss, this should not be surprising. It is indeed extremely unlikely that a genetic score is likely to reliably predict weight loss in a given individual with sufficient sensitivity and specificity to meaningfully guide clinical decision making.
For this, one would need to not only link genetic markers to weight loss but also to the overall potential clinical benefit including prediction of hard outcomes.
Thus, the clinical utility of a genetic score that predicts a higher probability of a given patient perhaps achieving a 2 kg less weight loss than the average, is rather limited.
At this time, I do not see any value of adding genetic screening to assessing patients’ suitability for metabolic surgery.