title: Comparison of GLP-1 analogues versus sitagliptin in the management of type 2 diabetes: systematic review and meta-analysis of head-to-head studies.
abstract: BACKGROUND
  Incretin-based therapies which include glucagon-like peptide-1 (GLP-1) receptor agonists and dipeptidyl peptidase-4 (DPP-4) inhibitors are recommended by several practice guidelines as second-line agents for add-on therapy to metformin in patients with type 2 diabetes (T2DM) who do not achieve glycemic control with metformin plus lifestyle interventions alone. The purpose of this study is to perform a systematic review with meta-analysis of existing head to head studies to compare the efficacy and safety of GLP-1 analogues with DPP-4 inhibitors.
  
  
  METHODS
  We performed a systematic review and meta-analysis of head-to-head studies to compare GLP-1 analogues with DPP-4 inhibitors in the management of type 2 diabetes. A random effects model was selected to perform the meta-analyses, results were expressed as weighted mean differences for continuous outcomes and relative risks for dichotomous outcomes, both with 95% confidence intervals, and with I2 values and P values as markers of heterogeneity.
  
  
  RESULTS
  Four head-to-head randomized controlled studies with 1755 patients were included. Compared to sitagliptin, GLP-1 analogues are more effective in reducing HbA1C (weight mean difference -0.41%, 95% CI -0.51 to -0.31) and body weight (weight mean difference -1.55 kg, 95% CI -1.98 to -1.12). Conversely, GLP-1 analogues are associated with a higher incidence of gastrointestinal adverse events compared to sitagliptin: nausea (relative risk 3.14, 95% CI 2.15 to 4.59), vomiting (relative risk 2.60, 95% CI 1.48 to 4.56), diarrhea (relative risk 1.82, 95% CI 1.24 to 2.69), and constipation (relative risk 2.50, 95% CI 1.33 to 4.70).
  
  
  CONCLUSIONS
  The result of this meta-analysis demonstrates that compared to sitagliptin, GLP-1 analogues are more effective for glycemic control and weight loss, but have similar efficacy in reducing blood pressure and lipid parameters, however, GLP-1 analogues are associated with a higher incidence of gastrointestinal adverse events and a similar incidence of hypoglycemia compared to sitagliptin.
authors.affiliation: Department of Pharmacy Administration and Clinical Pharmacy, Peking University Health Science Center, Beijing, China; Department of Pharmacy, Peking University Third Hospital, Beijing, China.
authors.forename: Tiansheng
authors.initials: T
authors.lastname: Wang
authors.affiliation: Department of Pharmacy, First Affiliated Hospital of Harbin Medical University, Harbin, China.
authors.forename: Zhuoyue
authors.initials: Z
authors.lastname: Gou
authors.affiliation: Department of Pharmacy Practice, School of Pharmacy, University of Connecticut, Storrs, Connecticut, United States of America.
authors.forename: Fei
authors.initials: F
authors.lastname: Wang
authors.affiliation: Department of Pharmacy, First Affiliated Hospital of Harbin Medical University, Harbin, China.
authors.forename: Manling
authors.initials: M
authors.lastname: Ma
authors.affiliation: Department of Pharmacy, Peking University Third Hospital, Beijing, China.
authors.forename: Suo-di
authors.initials: SD
authors.lastname: Zhai
mesh_terms: D001786:Blood Glucose / Q000378:metabolism; D001794:Blood Pressure / Q000187:drug effects; D001835:Body Weight / Q000187:drug effects; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000188:drug therapy* / Q000503:physiopathology; D005215:Fasting / Q000097:blood; D052216:Glucagon-Like Peptide 1 / Q000009:adverse effects / Q000031:analogs & derivatives / Q000627:therapeutic use*; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D008055:Lipids; D011719:Pyrazines / Q000009:adverse effects / Q000627:therapeutic use*; D016032:Randomized Controlled Trials as Topic; D000068900:Sitagliptin Phosphate; D016896:Treatment Outcome; D014230:Triazoles / Q000009:adverse effects / Q000627:therapeutic use*
chemical_list: D001786:Blood Glucose; D052216:Glucagon-Like Peptide 1; D006442:Glycated Hemoglobin; D008055:Lipids; D011719:Pyrazines; D000068900:Sitagliptin Phosphate; D014230:Triazoles
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