Effect of Liraglutide on Fat Mass Percentage Among Overweight and Obese Adults with Type 2 Diabetes: A Systematic Review

BACKGROUND: Obesity and type 2 diabetes mellitus (T2DM) are two global public health problems. Liraglutide, a glucagon-like peptide 1 analogue (GLP-1), is considered an effective option for weight loss. Hence, it is meaningful to understand the impact of GLP-1 therapy on body composition, particularly fat mass percentage (%), in determining health risks associated with obesity. The current meta-analysis and systematic review aimed to appraise and summarize available studies regarding the efficacy of liraglutide on fat mass (%), anthropometrics and glycemic control. METHODS: Three databases were searched up to March 2022 for randomized clinical trials (RCTs) and studies that evaluated the efficacy of liraglutide on T2DM patients: Cochrane Central Register of Controlled Trials, Web of Science, and PUBMED: Cochrane Central Register of Controlled Trials, Web of Science, and PUBMED. If at least two studies had the same outcome and treatment, a random effect model meta-analysis was used to report pooled mean difference (MD) and 95% confidence interval (CI). The protocol of this review was registered in PROSPERO under registration number CRD42022313002. RESULTS: From the 4031 articles identified and reviewed, only 5 studies (N = 263 patients) matched the inclusion criteria. Only two out of 3 RCTs have complete data to produce forest plots. No significant changes were observed from the pooled MD for body fat % [−0.56 (−2.63, 1.26)] and weight [−0.68 (−2.63, 1.26)]. A significant change in Hba1c with a pooled MD of −1.25 (−2.13, −0.36) (p = 0.006) was observed. I(2) tests were above the threshold of 50% for weight and Hba1c, indicating heterogeneity among the included studies. CONCLUSION: This review suggests that liraglutide is effective in glycemic control with no significant effect on weight and fat mass % among overweight patients with T2DM. It is important to note, however, that the certainty of the available evidence is weak.