title: Glycaemic durability with dipeptidyl peptidase-4 inhibitors in type 2 diabetes: a systematic review and meta-analysis of long-term randomised controlled trials.
abstract: OBJECTIVE
  To evaluate glycaemic durability with dipeptidyl peptidase-4 (DPP-4) inhibitors in type 2 diabetes.
  
  
  METHODS
  A systematic review and meta-analysis of long-term randomised trials of DPP-4 inhibitors on haemoglobin A1c (HbA1c) was conducted. Electronic searches were carried out on the following databases: MEDLINE, EMBASE, Scopus and Web of Knowledge to December 2013. Searches were supplemented by a review of trial registries and references from identified trials. Trials were included if they lasted at least 76 weeks, and had intermediate and final assessments of HbA1c. Citations and full-text articles were screened by two reviewers. A random effect model was used to pool data.
  
  
  METHODS
  Adults with type 2 diabetes.
  
  
  METHODS
  Any DPP-4 inhibitor (sitagliptin, vildagliptin, saxagliptin, linagliptin and alogliptin).
  
  
  METHODS
  The difference between final and intermediate HbA1c assessment was the primary outcome.
  
  
  RESULTS
  We screened 461 citations and reviewed 12 articles reporting 12 trials in 14 829 participants. All trials were of 76 weeks duration at least. The difference in HbA1c changes between final and intermediate points averaged 0.22% (95% CI 0.15% to 0.29%), with high heterogeneity (I(2)=91%, p<0.0001). Estimates of differences were not affected by the analysis of six extension trials (0.24%, 0.02 to 0.46), or five trials in which a DPP-4 inhibitor was added to metformin (0.24%, 0.16 to 0.32).
  
  
  CONCLUSIONS
  There is evidence that the effect of DPP-4 inhibitors on HbA1c in type 2 diabetes significantly declines during the second year of treatment. Future research should focus on the characteristics of patients that benefit most from DPP-4 inhibitors in terms of glycaemic durability.
authors.affiliation: Department of Experimental and Clinical Medicine, Second University of Naples, Naples, Italy.
authors.forename: Katherine
authors.initials: K
authors.lastname: Esposito
authors.affiliation: Department of Mental and Physical Health and Preventive Medicine, Second University of Naples, Naples, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Chiodini
authors.affiliation: Department of Medical, Surgical, Neurological, Metabolic and Geriatric Sciences, Second University of Naples, Naples, Italy.
authors.forename: Maria Ida
authors.initials: MI
authors.lastname: Maiorino
authors.affiliation: Department of Medical, Surgical, Neurological, Metabolic and Geriatric Sciences, Second University of Naples, Naples, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Bellastella
authors.affiliation: Department of Experimental Medicine, Second University of Naples, Naples, Italy.
authors.forename: Annalisa
authors.initials: A
authors.lastname: Capuano
authors.affiliation: Department of Medical, Surgical, Neurological, Metabolic and Geriatric Sciences, Second University of Naples, Naples, Italy.
authors.forename: Dario
authors.initials: D
authors.lastname: Giugliano
mesh_terms: D000328:Adult; D001786:Blood Glucose / Q000032:analysis*; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000188:drug therapy*; D054873:Dipeptidyl-Peptidase IV Inhibitors / Q000494:pharmacology / Q000627:therapeutic use*; D006442:Glycated Hemoglobin / Q000032:analysis* / Q000187:drug effects*; D006801:Humans; D007004:Hypoglycemic Agents / Q000494:pharmacology / Q000627:therapeutic use*; D016032:Randomized Controlled Trials as Topic; D013997:Time Factors
chemical_list: D001786:Blood Glucose; D054873:Dipeptidyl-Peptidase IV Inhibitors; D006442:Glycated Hemoglobin; D007004:Hypoglycemic Agents
keywords: DIABETES & ENDOCRINOLOGY; DPP-4 inhibitors; Meta-analysis