title: Reproductive factors and risk of type 2 diabetes in an occupational cohort of Chinese women.
abstract: Hormonal milieu has long been known to play an important role in the development of type 2 diabetes (T2D). The aims of this study are to investigate the roles of menstrual and reproductive factors in relation to T2D risk in an occupational cohort of Chinese women; and to explore the role of endogenous estrogen in T2D development.
  
  
  
  We conducted a cross-sectional analysis of baseline data from 16114 women (11051 premenopausal and 5063 postmenopausal) aged ≥20years who participated in the ongoing prospective occupational cohort study. Multivariable logistic regressions were modeled to evaluate the associations of reproductive factors with T2D risk.
  
  
  
  Early menarche at age (≤12 versus 15-16 years) was associated with increased T2D risk (odds ratio [OR]: 1.60, 95% confidence interval [CI]: 1.16-2.22). After multiple adjustment including age, BMI and occupation, postmenopausal status was positively associated with T2D risk (OR: 1.54, 95% CI: 1.10-2.14). Reproductive life span was significantly associated with T2D risk (P=0.02), albeit displaying a U-shape relationship. Similarly, age at menopause was also associated with T2D risk in the same U-shaped as with reproductive life span (P=0.03). Further, years since menopause (P=0.003), but not history of cycle regularity and hormone use, was associated with increased T2D risk.
  
  
  
  Reproductive factors were associated with T2D supporting the notion that either a short or prolonged exposure to endogenous estrogen affects T2D risk in Chinese women. Reproductive factors should be added to risk stratification when counseling women about their risk of developing diabetes.
authors.affiliation: Department of Epidemiology and Statistics, School of Public Health, Lanzhou University, Lanzhou, Gansu 730000, China; Department of Epidemiology, School of Public Health, Brown University, Providence, RI 02912, USA.
authors.forename: Aimin
authors.initials: A
authors.lastname: Yang
authors.affiliation: Department of Epidemiology, School of Public Health, Brown University, Providence, RI 02912, USA; Department of Medicine (Endocrinology), Rhode Island Hospital and the Alpert Medical School, Brown University, Providence, RI 02901, USA.
authors.forename: Simin
authors.initials: S
authors.lastname: Liu
authors.affiliation: Center of Medical Laboratory, Lanzhou University, Lanzhou, Gansu 730000, China.
authors.forename: Ning
authors.initials: N
authors.lastname: Cheng
authors.affiliation: Workers' Hospital of Jinchuan Group Co., Ltd., Jinchang, Gansu 737103, China.
authors.forename: Hongquan
authors.initials: H
authors.lastname: Pu
authors.affiliation: Cancer Hospital, Chinese Academy of Medical Sciences, Beijing 100021, China.
authors.forename: Min
authors.initials: M
authors.lastname: Dai
authors.affiliation: Workers' Hospital of Jinchuan Group Co., Ltd., Jinchang, Gansu 737103, China.
authors.forename: Jiao
authors.initials: J
authors.lastname: Ding
authors.affiliation: Department of Epidemiology and Statistics, School of Public Health, Lanzhou University, Lanzhou, Gansu 730000, China.
authors.forename: Juansheng
authors.initials: J
authors.lastname: Li
authors.affiliation: Workers' Hospital of Jinchuan Group Co., Ltd., Jinchang, Gansu 737103, China.
authors.forename: Haiyan
authors.initials: H
authors.lastname: Li
authors.affiliation: Department of Epidemiology and Statistics, School of Public Health, Lanzhou University, Lanzhou, Gansu 730000, China.
authors.forename: Xiaobin
authors.initials: X
authors.lastname: Hu
authors.affiliation: Department of Epidemiology and Statistics, School of Public Health, Lanzhou University, Lanzhou, Gansu 730000, China.
authors.forename: Xiaowei
authors.initials: X
authors.lastname: Ren
authors.affiliation: Cancer Hospital, Chinese Academy of Medical Sciences, Beijing 100021, China.
authors.forename: Jie
authors.initials: J
authors.lastname: He
authors.affiliation: Department of Epidemiology, School of Public Health, Brown University, Providence, RI 02912, USA. Electronic address: tongzhang_zheng@brown.edu.
authors.forename: Tongzhang
authors.initials: T
authors.lastname: Zheng
authors.affiliation: Department of Epidemiology and Statistics, School of Public Health, Lanzhou University, Lanzhou, Gansu 730000, China. Electronic address: baiyana@lzu.edu.cn.
authors.forename: Yana
authors.initials: Y
authors.lastname: Bai
mesh_terms: D000328:Adult; D044466:Asian People; D002681:China / Q000453:epidemiology; D003430:Cross-Sectional Studies; D003924:Diabetes Mellitus, Type 2 / Q000208:ethnology*; D005260:Female; D006801:Humans; D008572:Menarche; D008875:Middle Aged; D017698:Postmenopause; D017697:Premenopause; D011446:Prospective Studies; D012307:Risk Factors
keywords: Menarche; Menopause; Reproduction; Risk factors; Type 2 diabetes