title: Hormone replacement therapy and glucose tolerance in EPIC-Norfolk: a population-based study.
abstract: BACKGROUND
  Hormone replacement therapy (HRT) can affect glucose homeostasis in postmenopausal women but it is unclear whether long-term use is associated with changes in glucose tolerance. The objective was to examine the relationship of glycated haemoglobin (HbA(1C)) concentration with HRT use in non-diabetic postmenopausal women.
  
  
  METHODS
  A cross-sectional analysis of baseline data on 2753 postmenopausal women, aged 45-74 years who were recruited to the EPIC-Norfolk study between 1995 and 1998 was performed. Women completed a health and lifestyle questionnaire from which information on HRT use was obtained and gave blood for HbA(1C) assay.
  
  
  RESULTS
  Of the women, 23% were current HRT users and 14% were former users. Mean HbA(1C) was significantly lower in current users compared to former and never users. This difference was independent of age, body mass index (BMI), waist-to-hip ratio (WHR), family history of diabetes, educational status, employment status, smoking history, history of alcohol consumption, parity, known illness and hysterectomy status. Compared to never users of HRT, the unadjusted odds ratio (OR) for being in the highest quintile of HbA(1C) distribution as opposed to the lowest was 0.28 (95% CI 0.20-0.39) for current users and 0.41 (0.32-0.53) for ever users. After adjustment for confounders, the OR were 0.52 (0.34-0.79) and 0.72 (0. 51-1.03) for current and ever users, respectively.
  
  
  CONCLUSIONS
  Women currently using HRT have lower HbA(1C) levels not explained by known confounders though we cannot completely exclude a healthy user effect. Nevertheless, this population study suggest that current use of HRT was not associated with impairment of glucose tolerance in postmenopausal women.
authors.affiliation: Department of Community Medicine, University of Cambridge, Institute of Public Health, Robinson Way, Cambridge CB2 2SR, UK. lincoln.sargeant@srl.cam.ac.uk
authors.forename: L A
authors.initials: LA
authors.lastname: Sargeant
authors.forename: N J
authors.initials: NJ
authors.lastname: Wareham
authors.forename: K T
authors.initials: KT
authors.lastname: Khaw
mesh_terms: D000368:Aged; D000704:Analysis of Variance; D001824:Body Constitution; D015992:Body Mass Index; D003430:Cross-Sectional Studies; D003920:Diabetes Mellitus / Q000453:epidemiology; D004739:England; D015914:Estrogen Replacement Therapy; D005260:Female; D006442:Glycated Hemoglobin / Q000032:analysis*; D006801:Humans; D007044:Hysterectomy; D008019:Life Style; D008487:Medical History Taking; D008875:Middle Aged; D016017:Odds Ratio; D017698:Postmenopause; D012044:Regression Analysis; D011795:Surveys and Questionnaires
chemical_list: D006442:Glycated Hemoglobin