title: Age, body mass, usage of exogenous estrogen, and lifestyle factors in relation to circulating sex hormone-binding globulin concentrations in postmenopausal women.
abstract: BACKGROUND
  Circulating concentrations of sex hormone-binding globulin (SHBG) have been associated with cardiovascular diseases, type 2 diabetes, metabolic syndrome, and hormone-dependent cancers; however, correlates of SHBG concentrations are not well understood.
  
  
  METHODS
  We comprehensively investigated correlates of SHBG concentrations among 13 547 women who participated in the Women's Health Initiative and who had SHBG measurements. We estimated study- and ethnicity-specific associations of age, reproductive history, usage of exogenous estrogen, body mass index (BMI), and lifestyle factors such as physical activity, smoking, alcohol consumption, coffee intake, and dietary factors with SHBG concentrations. These estimates were pooled using random-effects models. We also examined potential nonlinear associations using spline analyses.
  
  
  RESULTS
  There was no significant ethnic difference in the age-adjusted mean concentrations of SHBG. Age, exogenous estrogen use, physical activity, and regular coffee intake were positively associated with SHBG concentrations, whereas BMI was inversely associated with SHBG concentrations after adjustment for potential confounding factors. Similar patterns were observed among both ever users and never users of exogenous estrogen. The spline analysis indicated nonlinear relations of regular intake of coffee, age, and BMI with SHBG concentrations. Two or more cups/day of regular coffee consumption and age of 60 years or older were associated with higher SHBG concentrations; the inverse BMI-SHBG relation was especially strong among women whose BMI was below 30.
  
  
  CONCLUSIONS
  In this large sample of postmenopausal women, age, exogenous estrogen use, physical activity, regular coffee intake, and BMI were significant correlates of SHBG concentrations, presenting potential targets for interventions.
authors.affiliation: Department of Diabetes Research, Diabetes Research Center, National Center for Global Health and Medicine, Tokyo, Japan;
authors.forename: Atsushi
authors.initials: A
authors.lastname: Goto
authors.forename: Brian H
authors.initials: BH
authors.lastname: Chen
authors.forename: Yiqing
authors.initials: Y
authors.lastname: Song
authors.forename: Jane
authors.initials: J
authors.lastname: Cauley
authors.forename: Steven R
authors.initials: SR
authors.lastname: Cummings
authors.forename: Ghada N
authors.initials: GN
authors.lastname: Farhat
authors.forename: Marc
authors.initials: M
authors.lastname: Gunter
authors.forename: Linda
authors.initials: L
authors.lastname: Van Horn
authors.forename: Barbara V
authors.initials: BV
authors.lastname: Howard
authors.forename: Rebecca
authors.initials: R
authors.lastname: Jackson
authors.forename: Jennifer
authors.initials: J
authors.lastname: Lee
authors.forename: Kathryn M
authors.initials: KM
authors.lastname: Rexrode
authors.forename: Simin
authors.initials: S
authors.lastname: Liu
mesh_terms: D000367:Age Factors; D000368:Aged; D015992:Body Mass Index; D004967:Estrogens / Q000008:administration & dosage; D005260:Female; D006801:Humans; D008019:Life Style; D008875:Middle Aged; D017698:Postmenopause; D012738:Sex Hormone-Binding Globulin / Q000032:analysis / Q000378:metabolism*
chemical_list: D004967:Estrogens; D012738:Sex Hormone-Binding Globulin
references.citation: Control Clin Trials. 1986 Sep;7(3):177-88
references.pmid: 3802833
references.citation: J Clin Endocrinol Metab. 2008 May;93(5):1796-803
references.pmid: 18334588
references.citation: Clin Endocrinol (Oxf). 1974 Jan;3(1):69-96
references.pmid: 4134992
references.citation: J Clin Endocrinol Metab. 2008 Jan;93(1):131-8
references.pmid: 17925335
references.citation: Control Clin Trials. 1998 Feb;19(1):61-109
references.pmid: 9492970
references.citation: Cancer. 2009 Jun 15;115(12):2765-74
references.pmid: 19384973
references.citation: J Clin Endocrinol Metab. 1987 Apr;64(4):825-31
references.pmid: 3029159
references.citation: J Natl Cancer Inst. 2002 Apr 17;94(8):606-16
references.pmid: 11959894
references.citation: Int J Obes. 1991 Jul;15(7):471-8
references.pmid: 1894424
references.citation: Menopause. 2010 May-Jun;17(3):622-9
references.pmid: 20215977
references.citation: J Endocrinol Invest. 2008 Jul;31(7):597-601
references.pmid: 18787375
references.citation: Br J Cancer. 1987 Nov;56(5):661-6
references.pmid: 3426933
references.citation: J Clin Endocrinol Metab. 1993 Feb;76(2):273-4
references.pmid: 8432767
references.citation: Med Sci Sports Exerc. 2009 Mar;41(3):530-8
references.pmid: 19204598
references.citation: Diabetes Care. 1996 Oct;19(10):1045-50
references.pmid: 8886548
references.citation: J Mol Endocrinol. 2009 Jul;43(1):19-27
references.pmid: 19336534
references.citation: J Clin Endocrinol Metab. 2005 Aug;90(8):4836-45
references.pmid: 15840738
references.citation: Stat Med. 2002 Jun 15;21(11):1539-58
references.pmid: 12111919
references.citation: Ann Epidemiol. 1999 Apr;9(3):178-87
references.pmid: 10192650
references.citation: J Endocrinol Invest. 1996 Sep;19(8):535-41
references.pmid: 8905477
references.citation: Arch Toxicol. 2002 Jan;75(11-12):685-94
references.pmid: 11876501
references.citation: PLoS Genet. 2012;8(7):e1002805
references.pmid: 22829776
references.citation: Hum Reprod Update. 2009 Jul-Aug;15(4):423-40
references.pmid: 19299447
references.citation: Endocr Relat Cancer. 2008 Jun;15(2):485-97
references.pmid: 18509001
references.citation: Obesity (Silver Spring). 2010 Mar;18(3):604-10
references.pmid: 19696765
references.citation: JAMA. 2006 Mar 15;295(11):1288-99
references.pmid: 16537739
references.citation: Diabetes. 2011 Jan;60(1):269-75
references.pmid: 21030499
references.citation: Cancer Res. 2004 Apr 15;64(8):2923-8
references.pmid: 15087413
references.citation: Am J Clin Nutr. 1990 May;51(5):759-67
references.pmid: 2333832
references.citation: Cancer Epidemiol Biomarkers Prev. 2007 May;16(5):900-5
references.pmid: 17507613
references.citation: Epidemiology. 1995 Jul;6(4):356-65
references.pmid: 7548341
references.citation: Clin Lab. 2005;51(11-12):625-32
references.pmid: 16329620
references.citation: Ann Epidemiol. 2003 Oct;13(9 Suppl):S5-17
references.pmid: 14575938
references.citation: J Clin Endocrinol Metab. 2000 Dec;85(12):4476-80
references.pmid: 11134096
references.citation: Menopause. 2011 Oct;18(10):1079-86
references.pmid: 21646925
references.citation: Breast Cancer Res Treat. 2008 Mar;108(2):217-31
references.pmid: 18297397
references.citation: J Clin Endocrinol Metab. 1988 Sep;67(3):460-4
references.pmid: 2842359
references.citation: Obesity (Silver Spring). 2006 Sep;14(9):1662-77
references.pmid: 17030978