Could Weight Loss Injections Replace Obesity Surgery?

Glucagon-like peptide 1 (GLP-1) analogs, also called “incretin mimetics” and colloquially referred to as “weight loss injections,” are highly effective for weight reduction in obesity treatment. Will semaglutide, tirzepatide, and similar medications eventually diminish the role of obesity surgery or even replace it altogether?

Dr Matthias Blüher, head of the Adult Obesity Clinic and professor of clinical obesity research at the University of Leipzig in Germany, as well as media spokesperson for the German Obesity Society, explained to Medscape Medical News which patients are more suited for obesity surgery and how incretin mimetics and surgical options currently interact.

GLP-1 analogs are effective for patients with obesity. What does this mean for obesity surgery? Is the number of gastric bypass procedures declining?

There are indications in the United States that this is the case. However, it is not yet entirely clear whether this can be attributed to the effectiveness of the medications, because these drugs have been used in the US for much longer than here. If this trend is confirmed, it would be a positive development, especially considering the risks associated with surgery.

Will this trend also develop in Germany?

That is possible. However, I believe that initially, there will be more patients opting for obesity surgery. The problem is that access to these medications is limited. In Germany, health insurance does not cover the costs. Many people cannot afford these medications, even as a preparatory step for surgical intervention. In contrast, bariatric surgery is usually covered by insurance, so I think surgery will remain the option for many patients.

The second aspect is that there are patients who do not respond well to medication or for whom weight loss from medication is insufficient. These patients will probably find it easier to choose the surgical option, reasoning that they have exhausted all medical avenues and will now proceed with surgery. Therefore, I think the number of surgeries will not decrease in the short term.

Dr Miguel A. Burch, a bariatric surgeon at Cedars-Sinai Medical Center in Los Angeles, speaks of a  “new era” regarding the potential of GLP-1 analogs. Does this mean, speaking broadly, that we will rely on medications instead of surgeries in the future?

It cannot be put so broadly because there will always be patients who will benefit more from surgical than medical therapy owing to their extremely high weight.

It also depends on the risk factors of each patient, as well as consideration of the cumulative costs of lifelong medication, compared with those of surgery. However, the treatment of obesity could include multiple approaches, not just a choice between surgery or weight loss medications.

Could GLP-1 analogs and surgical therapy be combined?

Yes. In Leipzig, for example, we treat patients with semaglutide before bariatric surgery because weight reduction before surgery can be beneficial in reducing surgical risks. We also use these medications postoperatively to minimize the risk for weight regain. Some patients regain weight after surgery, and with GLP-1 analogs, we have the option to counteract that medically.

Is greater weight loss still achieved with obesity surgery compared with GLP-1 analogs?

It is difficult to say for an individual, but on average, surgery remains the more effective method for weight loss. Data show — though there has not yet been a direct comparison between incretin mimetics and bariatric surgery — that tirzepatide, which can lead to an average weight loss of 23%, is still not as effective as surgery.

On average, sleeve gastrectomy or bypass can achieve weight loss of 30%-35%. However, when looking at weight reduction from gastric band surgery, tirzepatide or semaglutide are comparably effective. We can say that weight loss medications are already within the treatment outcome range of gastric band surgeries.

For which patients is surgical therapy more appropriate than medication?

Patients who come to us with a body mass index (BMI) over 50. There are no good data on how effective current medications are in such cases, and for patients with such a BMI, surgical treatment remains more appropriate. 

Additionally, for patients who need to lose a significant amount of weight quickly — such as those with severe heart failure requiring a heart transplant — or patients needing knee or hip replacements who should also lose weight quickly, these cases are good candidates for surgical treatment.

And what do you think is more sustainable?

Medications only work for as long as they are taken. The weight loss achieved through surgery is sustainable. With drug therapy, sustainability is achieved by continuing the medication and combining it with lifestyle interventions.

There are various ways to improve this sustainability — through long-term therapy, increasing the dosage, incorporating exercise, dietary changes, and so on. Ultimately, however, we cannot yet say over a long period of 10 or 20 years whether these medications are as sustainable as surgery, because these medications have not been available for that long.

For my patients with a BMI under 35, I would always recommend starting with diet and exercise therapy. If that is insufficient, then I would move on to medication, and obesity surgery only as a last resort. Especially for patients with 10-20 kg of excess weight, surgical therapy is not a sensible starting point.

https://www.medscape.com/viewarticle/could-weight-loss-injections-replace-obesity-surgery-2024a1000kk1