title: Impact of baseline BMI on glycemic control and weight change with metformin monotherapy in Chinese type 2 diabetes patients: phase IV open-label trial.
abstract: BACKGROUND
  Differences exist between treatment recommendations regarding the choice of metformin as first-line therapy for type 2 diabetes patients according to body mass index (BMI). This study compared the efficacy of metformin monotherapy among normal-weight, overweight, and obese patients with newly diagnosed type 2 diabetes.
  
  
  METHODS
  In this prospective, multicenter, open-label study in China, patients aged 23-77 years were enrolled 1∶1:1 according to baseline BMI: normal-weight (BMI 18.5-23.9 kg/m(2); n = 125); overweight (BMI 24.0-27.9 kg/m(2); n = 122) or obese (BMI ≥28 kg/m(2); n = 124). Extended-release metformin was administered for 16 weeks (500 mg/day, up-titrated weekly to a maximum 2,000 mg/day). The primary efficacy endpoint was the effect of baseline BMI on glycemic control with metformin monotherapy, measured as the change from baseline in glycosylated hemoglobin (HbA1c) at week 16 compared among BMI groups using ANCOVA. Other endpoints included comparisons of metformin's effects on fasting plasma glucose (FPG), lipid levels and body weight.
  
  
  RESULTS
  Mean HbA1c decreases at week 16, adjusted for baseline values, were -1.84%, -1.78% and -1.78% in normal-weight, overweight and obese patients, (P = 0.664); body weight decreased by 2.4%, 3.9% and 3.5%, respectively. FPG levels decreased similarly over time in all BMI groups (P = 0.461) and changes from baseline in high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) did not differ significantly among BMI groups at week 16 (P = 0.143 and 0.451, respectively).
  
  
  CONCLUSIONS
  Baseline BMI had no impact on glycemic control, weight change or other efficacy measures with metformin monotherapy. These data suggest that normal-weight type 2 diabetes patients would derive the same benefits from first-line treatment with metformin as overweight and obese patients, and are not at increased risk of excess weight loss.
  
  
  BACKGROUND
  ClinicalTrials.gov NCT00778622.
authors.affiliation: Department of Endocrinology and Metabolism, Peking University People's Hospital, Beijing, China. jiln@bjmu.edu.cn
authors.forename: Linong
authors.initials: L
authors.lastname: Ji
authors.forename: Hongmei
authors.initials: H
authors.lastname: Li
authors.forename: Xiaohui
authors.initials: X
authors.lastname: Guo
authors.forename: Yan
authors.initials: Y
authors.lastname: Li
authors.forename: Renming
authors.initials: R
authors.lastname: Hu
authors.forename: Zhengying
authors.initials: Z
authors.lastname: Zhu
mesh_terms: D000328:Adult; D001786:Blood Glucose / Q000032:analysis*; D015992:Body Mass Index; D001835:Body Weight; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000188:drug therapy* / Q000503:physiopathology; D005260:Female; D006442:Glycated Hemoglobin / Q000032:analysis; D006801:Humans; D007004:Hypoglycemic Agents / Q000009:adverse effects / Q000627:therapeutic use*; D008297:Male; D008687:Metformin / Q000009:adverse effects / Q000627:therapeutic use*; D008875:Middle Aged; D010349:Patient Compliance
chemical_list: D001786:Blood Glucose; D006442:Glycated Hemoglobin; D007004:Hypoglycemic Agents; D008687:Metformin; C517652:hemoglobin A1c protein, human