A study presented Monday explored the relationship between gut hormones and weight changes following bariatric embolization, a promising endovascular procedure used for treating obesity.
Latif
Weiss
“Bariatric embolization has been found to be a feasible and well-tolerated treatment in patients suffering with obesity and has the potential to produce substantial weight loss,” said presenter Muhammad Aamir Latif, MD, a research fellow from Johns Hopkins University School of Medicine, Baltimore.
According to Clifford Weiss, MD, one of two principal investigators on the study, bariatric embolization decreases blood supply to the gastric fundus, the main production site for ghrelin, a hormone produced by endocrine cells in the gastrointestinal tract that is often referred to as the “hunger hormone.”
Dr. Weiss and his fellow researchers sought to evaluate the association between gut hormones and weight changes.
“Preliminary results of bariatric embolization suggest that bariatric embolization-induced changes in gut hormones contribute to postprocedural weight loss by influencing satiety, hunger and energy stability,” Dr. Weiss said.
The researchers focused on the population of 20 participants who enrolled in the Bariatric Embolization of Arteries for the Treatment of Obesity (BEAT Obesity) trial, which was co-led by Dr. Weiss and Aravind Arepally, MD. The study was performed at two centers, the Johns Hopkins University School of Medicine and at the Icahn School of Medicine at Mount Sinai in New York City. The clinical results of this trial were published in Radiology in 2017 and 2019.
The current study examined post-bariatric embolization changes in the levels of three critical appetite related hormones: 1) ghrelin, 2) peptide YY 3-36 (PYY3-36) which is released in endocrine cells in the small intestine after a meal and provides eating inhibition, and 3) glucagon-like peptide 1 (GLP-1), an intestinal hormone, released after ingestion, that causes reduced appetite and insulin release.
Patients were evaluated at one- and two-weeks and three-, six- and 12-months post bariatric embolization. They were instructed to fast after dinner before their appointments and were fed a mixed meal test, a liquid meal consisting of fats, protein and carbohydrates. At each follow-up appointment, blood work was collected after 0, 15, 30, 60, 120, 180 and 240 minutes to measure ghrelin, PYY3-36 and GLP-1 levels.
Patients who were consistently in the top third of measured weight loss at each visit throughout the yearlong study, were identified as “responders.” Those who were consistently in the bottom third were identified as “non-responders.” To facilitate longitudinal data analysis, data from the group of responders was compared with data from the group of non-responders.
Reducing the Impulse to Eat
According to Dr. Latif, subjects in the study who showed consistent weight loss throughout follow-up showed decreased levels of ghrelin compared to non-responders. Responders showed statistically significant decreased serum ghrelin compared to non-responders at months six and 12, corresponding with greater weight loss in these patients over this time.
The researchers saw no difference in the levels of PYY3-36 and GLP-1 between the two groups. Dr. Latif noted that unlike traditional bariatric surgery, bariatric embolization does not affect the distal small intestine, which may explain the similarity in levels of PYY3-36 and GLP-1 levels between responders and non-responders.
In patients who suffer from obesity, eating often fails to suppress ghrelin levels, which may prevent feeling full after a meal and may contribute to overeating.
“The finding of this study supports ghrelin-suppression as a probable mechanism behind bariatric embolization-induced weight loss,” Dr. Latif said. “This is similar to gastric sleeve surgery or gastric bypass surgery which removes the portion of the stomach that produces ghrelin from the flow of food and alters the hormonal balance within days of surgery,”.
Access the poster, “The Association Between Gut Hormones and Weight Changes After Bariatric Arterial Embolization During the Beat Obesity Trial,” (IR02-A) in the Learning Center or at Meeting.RSNA.org.
