title: The association of plasma IGF-I with dietary, lifestyle, anthropometric, and early life factors in postmenopausal women.
abstract: OBJECTIVE
  Higher circulating concentrations of insulin like growth factor (IGF-I) are associated with an increased risk of breast cancer. The objective of this study was to investigate associations between circulating IGF-I concentrations and dietary factors (intakes of protein, dairy protein, and alcohol), lifestyle factors (smoking and HT use), anthropometric indices (height and adiposity) and factors in early life (birth weight, having been breastfed, body size at age 10, and at age 20) in postmenopausal women in the UK.
  
  
  METHODS
  An analysis of plasma IGF-I concentrations (measured by immunoassay) in 1883 postmenopausal women. Multivariate analysis was used to examine correlates of plasma IGF-I concentrations.
  
  
  RESULTS
  Women in the highest quintile of total protein and dairy protein intakes had, respectively, 7.6% and 5.5% higher plasma IGF-I concentrations than women in the lowest quintile (p trend <0.05 for both). Other factors significantly (p<0.05) associated with reduced IGF-I concentrations were: consuming 14 or more vs 3-7 alcoholic drinks per week (8.8% lower IGF-I); current vs non-current HT users (9.9% lower IGF-I); current use of oestrogen alone vs oestrogen+progestagen (16.9% lower IGF-I); obese vs overweight (6.8% lower IGF-I); and women who reported wearing larger vs smaller clothes sizes at age 20 (4.9% lower IGF-I).
  
  
  CONCLUSIONS
  This study in post-menopausal women identified several potentially modifiable determinants of circulating IGF-I concentrations. There is now strong evidence from this and other studies that IGF-I concentrations are associated with dietary protein intakes.
authors: Cancer Epidemiology Unit, Nuffield Department of Population Health, University of Oxford, Oxford OX3 7LF, UK. Electronic address: kathryn.bradbury@ceu.ox.ac.uk.
authors: Kathryn E
authors: KE
authors: Bradbury
authors: Cancer Epidemiology Unit, Nuffield Department of Population Health, University of Oxford, Oxford OX3 7LF, UK.
authors: Angela
authors: A
authors: Balkwill
authors: Cancer Epidemiology Unit, Nuffield Department of Population Health, University of Oxford, Oxford OX3 7LF, UK.
authors: Sarah J
authors: SJ
authors: Tipper
authors: Cancer Epidemiology Unit, Nuffield Department of Population Health, University of Oxford, Oxford OX3 7LF, UK.
authors: Francesca L
authors: FL
authors: Crowe
authors: Cancer Epidemiology Unit, Nuffield Department of Population Health, University of Oxford, Oxford OX3 7LF, UK.
authors: Gillian K
authors: GK
authors: Reeves
authors: Cancer Epidemiology Unit, Nuffield Department of Population Health, University of Oxford, Oxford OX3 7LF, UK.
authors: Jane
authors: J
authors: Green
authors: Cancer Epidemiology Unit, Nuffield Department of Population Health, University of Oxford, Oxford OX3 7LF, UK.
authors: Valerie
authors: V
authors: Beral
authors: Cancer Epidemiology Unit, Nuffield Department of Population Health, University of Oxford, Oxford OX3 7LF, UK.
authors: Timothy J
authors: TJ
authors: Key
mesh_terms: D000368:Aged; D001724:Birth Weight / Q000502:physiology; D001837:Body Weights and Measures / Q000706:statistics & numerical data; D001942:Breast Feeding / Q000706:statistics & numerical data; D015331:Cohort Studies; D004032:Diet; D005260:Female; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D008019:Life Style; D008875:Middle Aged; D017698:Postmenopause / Q000097:blood* / Q000378:metabolism; D011181:Postnatal Care / Q000706:statistics & numerical data; D012307:Risk Factors; D011795:Surveys and Questionnaires; D006113:United Kingdom / Q000453:epidemiology
chemical_list: D007334:Insulin-Like Growth Factor I
keywords: Anthropometry; Dietary protein; Early life; IGF-I; Postmenopausal women