title: Does the treatment of type 2 diabetes mellitus with the DPP-4 inhibitor vildagliptin reduce HbA1c to a greater extent in Japanese patients than in Caucasian patients?
abstract: BACKGROUND
  Previous work suggests that Japanese patients with type 2 diabetes mellitus (T2DM) may respond more favorably to a DPP-4 (dipeptidyl peptidase-4) inhibitor than Caucasians. We aimed to compare the efficacy of the DPP-4 inhibitor vildagliptin (50 mg twice daily [bid]) between Japanese and Caucasian populations.
  
  
  METHODS
  This analysis pooled data from 19 studies of drug-naïve patients with T2DM who were treated for 12 weeks with vildagliptin 50 mg bid as monotherapy. The pool comprised Japanese patients (n=338) who had been treated in Japan and Caucasian patients (n=1,275) who were treated elsewhere. Change from baseline (Δ) in glycated hemoglobin (HbA1c) at 12 weeks (in millimoles per mole) versus baseline HbA1c (both in percentage National Glycohemoglobin Standardization Program units [NGSP%] and millimoles per mole) for each population was reported. Universal HbA1c in millimoles per mole was calculated from either the Japanese Diabetes Society or the NGSP% HbA1c standards.
  
  
  RESULTS
  At baseline, mean values for Japanese and Caucasian patients, respectively, were as follows: age, 59 years and 56 years; % male, 69% and 57%. The average HbA1c was reduced from 7.90% to 6.96% (Japanese Diabetes Society) and from 8.57% to 7.50% (United States National Glycohemoglobin Standardization Program), while HbA1c was reduced from 63 mmol/mol to 53 mmol/mol and from 70 mmol/mol to 58 mmol/mol in Japanese and Caucasians, respectively. ΔHbA1c increased with increasing baseline in both populations. The slopes were the same (0.41, r (2)=0.36; and 0.41, r (2)=0.15), and the intercepts were 15.4 mmol/mol and 17.2 mmol/mol, respectively. In Japanese patients, mean ΔHbA1c was greater by 1.7 mmol/mol (0.2% NGSP HbA1c) at any given baseline HbA1c than in Caucasians (P=0.01).
  
  
  CONCLUSIONS
  The present pooled analysis suggests that Japanese patients respond better to vildagliptin treatment compared with Caucasians. However, when glycemic control was corrected by using the same glycemic standard, the difference in HbA1c reduction between these populations was not clinically meaningful.
authors: Novartis Pharmaceuticals Corporation, East Hanover, NJ, USA.
authors: James E
authors: JE
authors: Foley
authors: Novartis Healthcare Pvt Ltd, Hyderabad, Telangana, India.
authors: Vaishali
authors: V
authors: Bhosekar
authors: Sportology Center, Juntendo University Graduate School of Medicine, Juntendo University, Tokyo, Japan.
authors: Ryuzo
authors: R
authors: Kawamori
mesh_terms: D000218:Adamantane / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000627:therapeutic use; D000368:Aged; D044466:Asian People; D015415:Biomarkers / Q000097:blood; D001786:Blood Glucose / Q000187:drug effects / Q000378:metabolism; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000175:diagnosis / Q000188:drug therapy* / Q000201:enzymology / Q000208:ethnology; D018819:Dipeptidyl Peptidase 4 / Q000378:metabolism*; D054873:Dipeptidyl-Peptidase IV Inhibitors / Q000009:adverse effects / Q000627:therapeutic use*; D015536:Down-Regulation; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism*; D054624:Health Status Disparities; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009570:Nitriles / Q000009:adverse effects / Q000627:therapeutic use*; D011759:Pyrrolidines / Q000009:adverse effects / Q000627:therapeutic use*; D016032:Randomized Controlled Trials as Topic; D016896:Treatment Outcome; D000077597:Vildagliptin; D044465:White People
chemical_list: D000218:Adamantane; D015415:Biomarkers; D001786:Blood Glucose; D018819:Dipeptidyl Peptidase 4; D054873:Dipeptidyl-Peptidase IV Inhibitors; D006442:Glycated Hemoglobin; D009570:Nitriles; D011759:Pyrrolidines; D000077597:Vildagliptin; C517652:hemoglobin A1c protein, human; C042807:DPP4 protein, human
keywords: Caucasians; Japanese; baseline HbA1c; type 2 diabetes; vildagliptin