title: Effects of body mass index or dosage on gastrointestinal disorders associated with extended-release metformin in type 2 diabetes: Sub-analysis of a Phase IV open-label trial in Chinese patients.
abstract: OBJECTIVE
  To determine whether gastrointestinal (GI) tolerability of metformin monotherapy varies according to baseline BMI or at doses >1500mg/day in patients newly diagnosed with type 2 diabetes.
  
  
  METHODS
  We performed a sub-analysis of the safety population from a prospective, multicenter, Phase IV open-label study in which 371 Chinese patients with type 2 diabetes received extended-release metformin monotherapy for 16 weeks. The incidence, severity and duration of GI adverse events (AEs) were compared between normal-weight (BMI<25kg/m(2), n=155) and overweight/obese (BMI≥25kg/m(2), n=216) patients. The primary objective was to determine whether baseline BMI affect the incidence, severity and duration of GI AEs, using Fisher's exact test and Student's t-test. Secondary objectives were to compare these factors according to final metformin dose (≤1500mg/day versus 2000mg/day).
  
  
  RESULTS
  The proportion of patients who reported ≥1 GI AE did not differ significantly between BMI groups (25.2% of the normal-weight group versus 21.3% of the overweight/obese group; p=0.3840). Patients who reported GI AEs in the two BMI groups experienced similar GI AE severity (p=0.5410), mean duration (p=0.3572) and duration distribution (p=0.1347). There was no significant difference in GI AE severity and duration between metformin dosage groups (≤1500mg/day versus 2000mg/day).
  
  
  CONCLUSIONS
  Newly-diagnosed Chinese type 2 diabetes patients of normal weight are no more likely than overweight/obese patients to suffer from increased incidence rates, severity or duration of GI AEs when treated with first-line extended-release metformin monotherapy. Doses of 2000mg/day did not increase the severity or duration of GI AEs.
authors.affiliation: Department of Endocrinology, Beijing Hospital of the Ministry of Health, Beijing, China.
authors.forename: Lixin
authors.initials: L
authors.lastname: Guo
authors.affiliation: Department of Endocrinology, Peking University First Hospital, Beijing, China.
authors.forename: Xiaohui
authors.initials: X
authors.lastname: Guo
authors.affiliation: Department of Endocrinology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Endocrinology, Beijing Friendship Hospital, Capital Medical University, Beijing, China.
authors.forename: Xu
authors.initials: X
authors.lastname: Hong
authors.affiliation: Department of Endocrinology, Shanghai Pudong New Area People's Hospital, Shanghai, China.
authors.forename: Xiaozhen
authors.initials: X
authors.lastname: Jiang
authors.affiliation: Department of Endocrinology, Xin Hua Hospital Affiliate to Shanghai Jiao Tong University School of Medicine, Shanghai, China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Su
authors.affiliation: Department of Endocrinology, The Luhe Teaching Hospital of the Capital Medical University, Beijing, China.
authors.forename: Dong
authors.initials: D
authors.lastname: Zhao
authors.affiliation: Department of Biostatistics, PPD Pharmaceutical Development (Beijing) Co, Ltd, Beijing, China.
authors.forename: Xiaojing
authors.initials: X
authors.lastname: Wu
authors.affiliation: Department of Endocrinology and Metabolism, Peking University People's Hospital, No 11, Xizhimen South Street, Beijing, 100044, China. Electronic address: jilinong@gmail.com.
authors.forename: Linong
authors.initials: L
authors.lastname: Ji
mesh_terms: D000328:Adult; D000368:Aged; D015992:Body Mass Index; D003924:Diabetes Mellitus, Type 2 / Q000150:complications / Q000188:drug therapy*; D005260:Female; D005767:Gastrointestinal Diseases / Q000139:chemically induced* / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D008297:Male; D008687:Metformin / Q000008:administration & dosage / Q000009:adverse effects* / Q000633:toxicity; D008875:Middle Aged; D019055:No-Observed-Adverse-Effect Level; D009765:Obesity / Q000150:complications; D050177:Overweight / Q000150:complications
chemical_list: D008687:Metformin
keywords: Adverse drug event; Chinese; Diabetes mellitus; Gastrointestinal; Glucophage; type 2