Antiobesity Medications May Support Long-term 10% Weight Loss, Suggests New Study

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Persons with overweight and obesity maintained an average weight loss of 10.6% over 3 to 5 years following a program of lifestyle change in combination with antiobesity medications, according to research presented Sunday, June 12, 2022, at ENDO 2022, the Endocrine Society’s annual meeting in Atlanta, GA.

The number is significant, the study authors note, as weight loss of 10% is associated with improvements in both morbidity and mortality related to the disease of obesity. The findings may also support wider adoption of antiobesity medications, which to date, according to investigators are “an underutilized treatment option for obesity” and can prevent related chronic diseases including diabetes and cardiovascular disease. The authors say real-world data are lacking on the role for these agents in maintaining weight loss.

"Data on the effectiveness of antiobesity medications for long-term weight loss maintenance in the real world has been limited to 1 to 2 years," said lead researcher Michael A. Weintraub, MD, of Weill Cornell Medicine in New York, NY, in an Endocrine Society statement. "Our study is unique because we analyzed weight loss maintenance over 3-5 years in more than 400 adults…who were taking weight-loss medications."

Weintraub led the retrospective observational study that evaluated data from adults aged 18 to 75 years who were treated for overweight or obesity at a tertiary weight management center and had an initial visit between April 1, 2014, and April 1, 2016.

Patients with follow-up of less than 2.5 years or a gap in follow-up of more than 2 years were excluded as were those who had undergone bariatric surgery, had a condition predisposing them to weight loss during the study period, or who were pregnant.

All patients received counseling focused on a low-glycemic diet and exercise with an obesity medicine specialist at each office visit and were offered additional counseling with a registered dietitian. Medical therapy included FDA-approved and off-label weight-loss medications.

From data for each clinic visit over a mean follow-up period of 4.4 years, Weintraub et al recorded demographic details, medical history, and weight. To calculate total exposure to each weight loss medication used, the investigators used chart review to determine when patients initiated and stopped an antiobesity medication, paying particular attention to patient self-reporting of medication adherence.

The outcome of interest, weight loss maintenance, was defined as ≤3% of the nadir weight.

There were 428 patients included in the final analysis. The group had a mean age of 50.9 years, 73% were women, and median initial body mass index (BMI) was 34.3 kg/m2.

Patients fell into the following weight categories:

• Overweight 19%
• Class 1 obesity 35%
• Class 2 obesity 25%
• Class 3 obesity 20%

Diabetes was identified in 16% of the cohort and prediabetes in 36%.

Findings

Weintraub and colleagues report the median nadir BMI was 25.6 and maximum weight loss reached 14.7% of baseline bodyweight. The median time to reaching nadir weight was 1.9 years. They calculated the average change in weight from initial to final clinic visit as -10.6% (-10.9 kg) and median BMI at the final visit was 27.4.

The proportion of patients reaching progressive levels of total weight loss were:

• >5% 70.8%
• >10% 48.1%
• >15% 30.1%
• >20% 16.8%

Patients tried a mean of 4.2 antiobesity medications throughout the study, according to the abstract, and were taking an average of 2.5 medications at the final study visit. At that final visit, authors write, the most common medications being taken either alone or in combination were metformin (76.2% of patients), phentermine (31.1%), topiramate (30.8%), bupropion (29.9%), and semaglutide (24.5%).

In the Endocrine Society statement Weintraub notes that rates of obesity are approaching 40% in the United States. "This research supports the utility of anti-obesity medications in achieving long-term weight loss maintenance."

Reference: Andre C, Aronne L, D’Angelo D, et al. Long-term weight loss maintenance with obesity pharmacotherapy: a 5-year retrospective study. Abstract presented at ENDO 2022; June 11-14, 2022; Atlanta, GA