title: A nomogram to estimate the HbA1c response to different DPP-4 inhibitors in type 2 diabetes: a systematic review and meta-analysis of 98 trials with 24 163 patients.
abstract: OBJECTIVE
  To develop a nomogram for estimating the glycated haemoglobin (HbA1c) response to different dipeptidyl peptidase-4 (DPP-4) inhibitors in type 2 diabetes.
  
  
  METHODS
  A systematic review and meta-analysis of randomised controlled trials (RCTs) of DPP-4 inhibitors (vildagliptin, sitagliptin, saxagliptin, linagliptin and alogliptin) on HbA1c were conducted. Electronic searches were carried out up to December 2013. Trials were included if they were carried out on participants with type 2 diabetes, lasted at least 12 weeks, included at least 30 participants and had a final assessment of HbA1c. A random effect model was used to pool data. A nomogram was used to represent results of the metaregression model.
  
  
  METHODS
  Adults with type 2 diabetes.
  
  
  METHODS
  Any DPP-4 inhibitor (vildagliptin, sitagliptin, saxagliptin, linagliptin or alogliptin).
  
  
  METHODS
  The HbA1c response to each DPP-4 inhibitor within 1 year of therapy.
  
  
  RESULTS
  We screened 928 citations and reviewed 98 articles reporting 98 RCTs with 100 arms in 24 163 participants. There were 26 arms with vildagliptin, 37 with sitagliptin, 13 with saxagliptin, 13 with linagliptin and 11 with alogliptin. For all 100 arms, the mean baseline HbA1c value was 8.05% (64 mmol/mol); the decrease of HbA1c from baseline was -0.77% (95% CI -0.82 to -0.72%), with high heterogeneity (I(2)=96%). Multivariable metaregression model that included baseline HbA1c, type of DPP-4 inhibitor and fasting glucose explained 58% of variance between studies, with no significant interaction between them. Other factors, including age, previous diabetes drugs and duration of treatment added low predictive power (<1%). The nomogram estimates the absolute HbA1c reduction from baseline using the type of DPP-4 inhibitor, baseline values of HbA1c and fasting glucose.
  
  
  CONCLUSIONS
  Baseline HbA1c level and fasting glucose explain most of the variance in HbA1c change in response to DPP-4 inhibitors: each increase of 1.0% units HbA1c provides a 0.4-0.5% units greater fall.
authors: Diabetes Unit, Department of Clinical and Experimental Medicine, Second University of Naples, Naples, Italy.
authors: Katherine
authors: K
authors: Esposito
authors: Department of Mental and Physical Health, Second University of Naples, Naples, Italy.
authors: Paolo
authors: P
authors: Chiodini
authors: Diabetes Unit, Department of Clinical and Experimental Medicine, Second University of Naples, Naples, Italy.
authors: Maria Ida
authors: MI
authors: Maiorino
authors: Department of Experimental Medicine, Second University of Naples, Naples, Italy.
authors: Annalisa
authors: A
authors: Capuano
authors: Division of Internal Medicine, Department of Clinical and Experimental Medicine, Second University of Naples, Naples, Italy.
authors: Domenico
authors: D
authors: Cozzolino
authors: Diabetes Unit, Department of Clinical and Experimental Medicine, Second University of Naples, Naples, Italy.
authors: Michela
authors: M
authors: Petrizzo
authors: Division of Endocrinology and Metabolic Diseases, Department of Medical, Surgical, Neurological, Metabolic Sciences and Aging, Second University of Naples, Naples, Italy.
authors: Giuseppe
authors: G
authors: Bellastella
authors: Division of Endocrinology and Metabolic Diseases, Department of Medical, Surgical, Neurological, Metabolic Sciences and Aging, Second University of Naples, Naples, Italy.
authors: Dario
authors: D
authors: Giugliano
mesh_terms: D000465:Algorithms; D001786:Blood Glucose / Q000378:metabolism*; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000188:drug therapy; D054873:Dipeptidyl-Peptidase IV Inhibitors / Q000494:pharmacology* / Q000627:therapeutic use; D006442:Glycated Hemoglobin / Q000378:metabolism*; D006801:Humans; D007004:Hypoglycemic Agents / Q000494:pharmacology* / Q000627:therapeutic use; D049451:Nomograms
chemical_list: D001786:Blood Glucose; D054873:Dipeptidyl-Peptidase IV Inhibitors; D006442:Glycated Hemoglobin; D007004:Hypoglycemic Agents
keywords: THERAPEUTICS