title: More effective glycaemic control by metformin in African Americans than in Whites in the prediabetic population.
abstract: OBJECTIVE
  Metformin, a first-line diabetes drug, delays the onset of type 2 diabetes in the prediabetic population; however, in prediabetic patients, differences in glycaemic response to metformin among racial groups are unknown. We aimed to compare glucose-lowering effects of metformin between Whites and African Americans (AAs).
  
  
  METHODS
  We performed a secondary analysis using data from the diabetes prevention program, a multi-center randomized clinical trial, in which all participants were prediabetic. The metformin group (582 Whites and 210 AAs) received 850 mg of metformin twice daily, and was followed for 3 years.
  
  
  RESULTS
  We found that after 6 months on metformin, Whites had a drop of 3.89 ± 0.39 (mg/dL, mean ± SEM) in the fasting plasma glucose level, significantly less than that in African Americans (6.04 ± 0.72, P=0.006); at years 1 and 2, the differences were also significant. Consistently, the linear mixed model showed that, within 1 year of metformin treatment, the rate in reduction of glucose levels was more pronounced in AAs than in Whites (P=0.025 following adjustment for age and sex).
  
  
  CONCLUSIONS
  Therefore, AAs have a better glycaemic response to metformin treatment than Whites in the prediabetic population.
authors: Division of Geriatric and Palliative Medicine, School of Medicine, University of Michigan, Ann Arbor, MI, USA.
authors: C
authors: C
authors: Zhang
authors: Center for Molecular Medicine and Genetics, and the Cardiovascular Research Institute, School of Medicine, Wayne State University, Detroit, MI, USA. Electronic address: rzhang@med.wayne.edu.
authors: R
authors: R
authors: Zhang
mesh_terms: D000328:Adult; D001741:Black or African American; D001786:Blood Glucose / Q000187:drug effects*; D003924:Diabetes Mellitus, Type 2 / Q000517:prevention & control*; D005260:Female; D006801:Humans; D007004:Hypoglycemic Agents / Q000627:therapeutic use*; D008297:Male; D008687:Metformin / Q000627:therapeutic use*; D008875:Middle Aged; D011236:Prediabetic State / Q000188:drug therapy*; D044465:White People
chemical_list: D001786:Blood Glucose; D007004:Hypoglycemic Agents; D008687:Metformin
keywords: Diabetes prevention program; Metformin; Prediabetes