Alcohol intake and endogenous hormones in pre- and post-menopausal women: findings from the UK Biobank


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Sandar Tin Tin1, Timothy J Key1, Gillian K Reeves1
1University of Oxford

Abstract

Background

Alcohol intake may influence cancer risk in women through hormonal changes, but the evidence to date is inconclusive. We investigated cross-sectional associations between habitual alcohol intake and serum concentrations of testosterone, SHBG (sex hormone binding globulin), IGF-1 (insulin-like growth factor-1) and oestradiol (pre-menopausal women only) in UK Biobank.

Method

UK Biobank is a large prospective cohort study involving about 500,000 adults, including over 270,000 women, aged between 40-69 years when recruited between 2006 and 2010. At their initial assessment visit, habitual alcohol intake was assessed using a touchscreen questionnaire with reassessment in a subsample to reduce measurement error, and serum hormone concentrations were assayed. Multivariable linear regression analysis was performed, and trends in hormone concentrations and 95% confidence intervals (CIs) in relation to alcohol intake were estimated.

Results

Of the 30,557 pre-menopausal and 134,029 post-menopausal women included, 28,180 and 120,309, respectively, reported drinking alcohol. Per 10 g/day increment in alcohol intake, testosterone concentration was 4.0% (95% CI: 3.3%, 4.6%) higher in pre-menopausal women and 2.3% (95% CI: 1.9%, 2.8%) higher in post-menopausal women (pheterogeneity<0.0001); SHBG concentration was 0.7% (95% CI: 0.3%, 1.2%) higher in pre-menopausal women and 2.5% (95% CI: 2.2%, 2.7%) lower in post-menopausal women (pheterogeneity<0.0001); and IGF-1 concentration was 1.8% (95% CI: 1.6%, 2.0%) lower in pre-menopausal women and 0.7% (95% CI: 0.5%, 0.8%) lower in post-menopausal women (pheterogeneity<0.0001). There was no significant overall association with oestradiol in pre-menopausal women but a positive association was observed in the early and mid-luteal phases.

Conclusion

 This study confirms significant associations of habitual alcohol intake with concentrations of hormones and SHBG, with evidence of heterogeneity by menopausal status.

Impact statement

These findings add substantially to our knowledge of the effects of alcohol consumption on serum hormone concentrations. Given the complex nature of the observed associations, further work is necessary to fully understand the hormonal mechanisms linking alcohol and cancer risks.