Some people don’t lose enough weight after bariatric surgery, but a new study shows that adding a daily shot of GLP-1 drug liraglutide can help patients shed extra pounds and may reduce the need for further surgery.
Bariatric, or weight loss, surgery is highly effective for most people with moderate-to-severe obesity. Studies have shown it produces long-term weight loss and significant improvement or remission of obesity-related conditions like type 2 diabetes, high blood pressure, and sleep apnea.
For around 15% of people who undergo bariatric surgery, weight loss is less than expected, meaning that improvements to health are, too. A new Australian study has found that one of the newer injectable weight-loss drugs, the GLP-1 receptor agonist liraglutide, can help.
“We have shown that for people who regain weight or don’t have an optimal weight loss effect from bariatric surgery, adding in a weight loss drug will help them to lose weight, often at a lower dose than is needed in people who have not had surgery,” said lead author Professor Wendy Brown, MD, PhD, head of the Monash University Department of Surgery and Director of the Alfred Hospital’s Esophago-Gastric-Bariatric Unit.
“We are the first to show that the full dose of obesity management medication may not be needed in the post-bariatric surgery setting, and importantly, quality of life is not affected by introducing the obesity management medication,” Brown continued. “This raises the possibility of avoiding risky repeat surgery, which is the current main option when people need more weight loss after bariatric surgery.”
The researchers recruited 48 adults aged 20 to 65 who’d undergone one of four types of bariatric surgery (gastric banding, sleeve gastrectomy, one-anastomosis gastric bypass, or Roux-en-Y gastric bypass). However, by between 12 and 36 months post-op, these patients’ weight loss was below expected levels. Participants were randomly assigned to one of two groups. One self-injected liraglutide daily (up to 3 mg, the standard dose); the other received a placebo injection. The primary outcome was the change in body weight at 12 months. Secondary outcomes included changes in blood pressure, blood sugar, cholesterol, nutritional status, and quality of life.
The liraglutide group lost an average of 5.7 kg (12.6 lb) after 12 months. On average, the placebo group gained 1.4 kg (3.1 lb). This equals a 7.1-kg (15.6-lb) difference. Expressed as a percentage of total body weight, this was about a 4.4% reduction in the liraglutide group vs a 1.4% gain in the placebo group.
There were no significant differences between groups for blood sugar, cholesterol, or nutritional markers. In addition, those taking liraglutide had a slight rise in diastolic blood pressure (the bottom number), from 78 to 82 mmHg. In terms of quality of life, there were minor differences between the groups, but no meaningful overall changes in wellbeing, mood, or eating/swallowing comfort.
Most patients didn’t reach the full 3-mg dose – the average was around 2.4 mg – but still achieved significant weight loss. It’s noted, however, that no formal data were collected on why doses weren’t maximized. The authors suggest that either patients felt no need to increase further, or speculated that mild nausea or gastrointestinal symptoms may have discouraged dose escalation. It’s well known that common side effects associated with liraglutide include nausea, diarrhea or constipation, and vomiting. Early in the paper, the authors even noted that they excluded participants who lived more than an hour away from the hospital in case a gastric band needed immediate deflation due to nausea. Despite this, the study reported no serious adverse events, suggesting that while some side effects may have occurred, they were mild and manageable.
The researchers noted some study limitations. Namely, the small sample size and the fact that not all participants completed the study. The COVID-19 pandemic and subsequent drug shortages caused long delays and early terminations, disrupting the study timeline. Most participants were female and from one Australian medical center. Many patients didn’t reach the full liraglutide dose, so it’s unclear if higher doses might have worked even better.
Nonetheless, the findings suggest that liraglutide may help patients who plateau or regain weight after bariatric surgery, reducing the need for risky further surgeries. The study also suggests that starting GLP-1 drugs before significant weight regain could improve outcomes earlier in recovery. The broader implications of the study are that combining medication with surgery could one day form part of a new standard of care for people with obesity who respond partially to surgery.
“Our demonstration that incretin drugs [such as GLP-1s] enhance weight loss following bariatric surgery provides great hope,” said Professor John Wentworth, MD, PhD, an endocrinologist at the Royal Melbourne Hospital and the study’s co-corresponding author. “Excitingly, newer, more effective drugs have become available and should help our patients achieve even better weight and health outcomes.”
“There are no quick fixes, but we now have increasingly effective, evidence-based treatment options,” added co-author, Adjunct Associate Professor Paul Burton, MD, PhD. “These findings support a personalized, long-term strategy that pairs surgical expertise with medication, lifestyle support, and ongoing engagement to achieve durable remission rather than a cure.”
The study was published in the journal JAMA Network Open.
Source: Monash University
