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Genetics can predict and help improve outcomes after bariatric surgery

Clinicians treating severe obesity have a new genetic tool for predicting and ultimately improving bariatric surgery outcomes, according to the findings of two papers by researchers from the University at Buffalo. The papers describe that a genetic test used to predict an individual’s risk level for various addictions also has significant value in determining how bariatric surgery patients will fare after the procedure.

The findings were produced by an ongoing, longitudinal study on how best to optimise outcomes after bariatric surgery. While surgery is successful in treating most patients with severe obesity, a minority of patients regain the weight and may have negative outcomes.

Panayotis Thanos

“There is a percentage of patients who have a negative outcome after bariatric surgery,” explained Dr Panayotis K Thanos, corresponding author on the papers, senior research scientist in the Department of Pharmacology and Toxicology and the Clinical and Research Institute on Addictions in the Jacobs School of Medicine and Biomedical Sciences at UB. “Some patients regain weight, and some develop addictions that they didn’t have before, such as alcohol abuse or smoking,” adding that knowing ahead of time who is at risk for negative outcomes would be extremely helpful to clinicians and patients. In some instances, patients may develop new addictive behaviours that may or may not involve alcohol or substance use.

The idea originated at a brainstorming session in 2019 organized by Dr Teresa Quattrin, UB Distinguished Professor in the Department of Pediatrics and an endocrinologist with UBMD Pediatrics, who is also co-corresponding author on both papers. The session was comprised of UB researchers who study obesity from different disciplines. They decided to take a team science approach to the question, leveraging the expertise of a neuropharmacologist (Thanos) and endocrinologists, as well as bariatric surgeons.

“We wanted to find out, can we learn about genetic and psychosocial factors that will help predict outcomes after bariatric surgery?” added Thanos. “What predicts who will do well and who will not do so well?”

To find out, a total of 34 bariatric surgery patients at Kaleida Health’s Comprehensive Weight Loss and Bariatric Surgery Center at Buffalo General Medical Center were enrolled and underwent genetic and psychosocial testing both before and after surgery.

The Genetic Addiction Risk Severity (GARS) test invented by co-author, Dr Kenneth Blum, measures important gene variants linked to the net release of the molecule dopamine, which plays an important role in the brain’s reward signalling as well as other key brain molecules. The paper, ‘Genetic Correlates as a Predictor of Bariatric Surgery Outcomes after 1 Year’, published in the journal Biomedicines found that 76%of 34 patients in the study who had undergone bariatric surgery had a genetic risk for addictive behaviours as measured by the GARS test.

In addition, the findings also suggest that those with a specific genetic variant known as the DRD2 polymorphism were actually more responsive to weight loss treatment.

Thanos said this finding corresponds with earlier studies showing significantly better compliance in dopaminergic agonist therapy and days completed in treatment compared to non-carriers of the DRD2 A1 variant.

The researchers found that some data from psychological questionnaire screening was also helpful and associated with both body mass index and body weight six months after surgery.

“The way I’d describe it is that certain genetic variants predict greater compliance following surgery and may help us understand which patients will do better and which might need additional adjunct therapies,” he explained.

Teresa Quattrin

The findings demonstrate that precision medicine has a key role to play in optimizing bariatric surgery outcomes.

“These important longitudinal data can help patients undergoing bariatric surgery reduce potential future addictive behavioural transfer, such as alcohol abuse or gambling,” said Quattrin.

Future studies will track the same data in patients farther out from their surgeries with close monitoring of the development of any new addictive behaviours.

“You hear a lot about precision medicine, but how do you translate that to the patient? With this study, precision medicine ties in very well. We obtain psychosocial and genetic information from individual patients and then use it as a precision approach to optimizing outcomes,” concluded Thanos. “The idea is that as we collect more data, we will be able to provide more information for clinicians so they can say, ‘OK, here are some things that predict success or that we may need to customise in order to overcome some obstacle.’”


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