Liraglutide's Effect on Weight Management in Subjects With Pre-diabetes: A Systematic Review & Meta-Analysis

Despite the growing literature, the effectiveness of liraglutide in weight management among individuals with prediabetes and in preventing the disease remains controversial. This study aims to critically evaluate the extent of liraglutide's impact on weight management in this population and assess the heterogeneity among extant studies.

A systematic literature search was conducted across MEDLINE, Embase, ClinicalTrials.gov, and the reference list of retrieved studies to identify eligible English language randomized controlled trials evaluating liraglutide's effect on weight in individuals with pre-diabetes. Non-randomized studies, studies not reporting relevant outcomes, and those conducted on patients with type 2 diabetes were excluded from this review. Outcomes included a change from baseline in absolute body weight in kg, body mass index (BMI), waist circumference, glycosylated hemoglobin (HbA1c), and low-density lipoprotein cholesterol levels. Additional safety outcomes were also reported. Data were analyzed using R statistical software version 4.3.1. A fixed-effect model was used when pooling crude numbers for study outcomes. Moreover, a sensitivity analysis using random-effect model was performed and heterogeneity was assessed using I² statistics.

Five eligible studies were included, with a total of 1604 subjects in the liraglutide arm and 859 subjects in the control arm. Participants exposed to liraglutide showed a decrease in body weight (mean difference [MD] = -4.95 kg; 95% CI -5.16, -4.73; I² = 93%), BMI (MD = -2.06 kg/m²; 95%CI -2.22, -1.89; I² = 97%), waist circumference (MD = -4.61 cm; 95% CI -4.79, -4.43; I² = 82%), HbA1c (MD = -0.33%; 95%CI -0.34, -0.31; I² = 100%), and low-density lipoprotein cholesterol levels (MD = -0.36 mmol/L; 95% CI -0.39, -0.33; I² = 99%). The overall effect size remained similar when using a random-effects model for all outcomes. In addition, the rate of adverse events was higher with liraglutide when compared to the control; however, the dropout rates were relatively lower in the former arm.

While our meta-analysis suggests that liraglutide can reduce body weight, BMI, waist circumference, and HbA1c levels in individuals with pre-diabetes, the findings should be interpreted cautiously due to limitations such as the small number of trials and their short duration, and variability in dosages. Further randomized controlled trials examining long-term outcomes are essential to validate these findings and address the high heterogeneity among the studies included in this analysis.