Semaglutide vs. liraglutide: One-year weight loss efficacy in obesity and type 2 diabetes

By Dr. Priyom Bose, Ph.D.Reviewed by Benedette Cuffari, M.Sc.Sep 17 2024

New study reveals semaglutide outperforms liraglutide in weight loss for obesity, highlighting key factors that contribute to significant weight reduction in patients.

Study: One-Year Weight Reduction With Semaglutide or Liraglutide in Clinical Practice. Image Credit: Pixel-Shot / Shutterstock.com

A recent JAMA Network Open study compares the weight loss efficacy of injectable liraglutide and semaglutide, in addition to identifying the factors associated with a weight reduction of 10% or more after one year of treatment.

Treating obesity

Obesity leads to or worsens the risk of various health disorders, some of which include cardiovascular disease, cancer, type 2 diabetes (T2D), osteoarthritis, and obstructive sleep apnea. Over the past two decades, the United States Food and Drug Administration (FDA) has approved two glucagon-like peptide-1 receptor agonists (GLP-1 RAs) for treating obesity, of which include liraglutide and semaglutide.

In randomized clinical trials, liraglutide and semaglutide have led to significant weight reductions. However, outside of clinical trials, weight loss data with liraglutide or semaglutide has been limited to a short follow-up period of six months.

About the study

In the present study, weight outcomes among obese patients who received injectable forms of semaglutide or liraglutide at one year were assessed between January 1, 2015, and July 28, 2023. Outcomes were compared by GLP-1 RA agent, dosage, indication, and persistent coverage with the medication.

The main exposure variable was injectable forms of liraglutide or semaglutide approved for T2D or obesity. Comparatively, main outcome measures were categorical weight reduction of 10% or greater and percentage weight change at one year.

Adult patients with a body mass index (BMI) of at least 30 kg/m² who completed a follow-up weight measurement at least 12 months after treatment initiation were included in the study. Patients prescribed these medications between January 1 and June 30, 2015, were excluded. Furthermore, patients with cancer diagnoses, were pregnant, and those who recently underwent bariatric surgery were excluded.

Study findings

A total of 1,718 and 1,671 patients filled an initial prescription for injectable semaglutide and liraglutide, respectively. The median BMI was 38.5 kg/m² and the average age of the study participants was 50 years.

Approximately 55% of patients were female and about 82% reported T2D as a treatment indication. Moreover, 20.3% of the study participants were Black, 7% were Hispanic, 68.5% were White, and 3.4% belonged to other races or ethnicities. Most patients were privately insured and about 28% lived in the most disadvantaged area by quartile of the area deprivation index (ADI).

At one-year, the average weight change was -3.7% in the study cohort. The average changes with semaglutide and liraglutide were -5.1% and -2.2%, respectively.

In patients receiving T2D medication, the mean change was -3.2% as compared to -5.9% of those who were being treated for obesity. Among patients with fewer than 90 medication coverage days, between 90 to 275 medication coverage days, and coverage at one year, weight changes were -1.8%, -2.8%, and -5.5%, respectively. Patients prescribed high doses exhibited an average weight change of -6.6% as compared to -3.5% for those on a low-maintenance dose.

The reduction in body weight was -12.9% for semaglutide for obesity patients with persistent coverage with their medication at one year. For the same coverage, the reduction in body weight was -5.9% with semaglutide for T2D, -3.1% with liraglutide for T2D, and -5.6% with liraglutide for obesity.

About 37% of individuals prescribed semaglutide for obesity achieved 10% or more body weight reduction as compared to 16.6% of those prescribed semaglutide for T2D, 14.5% of those prescribed liraglutide for obesity, and 9.3% of those receiving liraglutide for T2D.

Among patients receiving persistent medication at one year, 61% of patients prescribed semaglutide for obesity achieved at least 10% weight reduction as compared to 23.1% among those prescribed semaglutide for T2D, 28.6% liraglutide for obesity, and 12.3% liraglutide for T2D groups.

Achieving 10% or greater weight reduction at one year was associated with several factors such as semaglutide or liraglutide, obesity as a treatment indication as compared to T2D, female sex, persistent coverage for one year, and high or low dosage of medication.

The likelihood of achieving 10% or more weight loss at one year was 2% higher for every unit increase in baseline BMI. When medication switchers were excluded, the multivariable model results remained robust.

Conclusions

Weight reduction one year after treatment initiation was associated with the medication’s active agent, patient sex, dosage, medication coverage, and treatment indication. Importantly, additional research is needed to better understand the reasons for discontinuing treatment and interventions to enhance long-term persistent coverage.