Do sex hormones confound or mediate the effect of chronotype on breast and prostate cancer? A Mendelian randomization study.

Morning-preference chronotype has been found to be protective against breast and prostate cancer. Sex hormones have been implicated in relation to chronotype and the development of both cancers. This study aimed to assess whether sex hormones confound or mediate the effect of chronotype on breast an...

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Main Authors: Bryony L Hayes, Timothy Robinson, Siddhartha Kar, Katherine S Ruth, Konstantinos K Tsilidis, Timothy Frayling, Anna Murray, Richard M Martin, Deborah A Lawlor, Rebecca C Richmond
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2022-01-01
Series:PLoS Genetics
Online Access:https://journals.plos.org/plosgenetics/article/file?id=10.1371/journal.pgen.1009887&type=printable
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author Bryony L Hayes
Timothy Robinson
Siddhartha Kar
Katherine S Ruth
Konstantinos K Tsilidis
Timothy Frayling
Anna Murray
Richard M Martin
Deborah A Lawlor
Rebecca C Richmond
author_facet Bryony L Hayes
Timothy Robinson
Siddhartha Kar
Katherine S Ruth
Konstantinos K Tsilidis
Timothy Frayling
Anna Murray
Richard M Martin
Deborah A Lawlor
Rebecca C Richmond
author_sort Bryony L Hayes
collection DOAJ
description Morning-preference chronotype has been found to be protective against breast and prostate cancer. Sex hormones have been implicated in relation to chronotype and the development of both cancers. This study aimed to assess whether sex hormones confound or mediate the effect of chronotype on breast and prostate cancer using a Mendelian Randomization (MR) framework. Genetic variants associated with chronotype and sex hormones (total testosterone, bioavailable testosterone, sex hormone binding globulin, and oestradiol) (p<5×10-8) were obtained from published genome-wide association studies (n≤244,207 females and n≤205,527 males). These variants were used to investigate causal relationships with breast (nCases/nControls = 133,384/113,789) and prostate (nCases/nControls = 79,148/61,106) cancer using univariable, bidirectional and multivariable MR. In females, we found evidence for: I) Reduced risk of breast cancer per category increase in morning-preference (OR = 0.93, 95% CI:0. 88, 1.00); II) Increased risk of breast cancer per SD increase in bioavailable testosterone (OR = 1.10, 95% CI: 1.01, 1.19) and total testosterone (OR = 1.15, 95% CI:1.07, 1.23); III) Bidirectional effects between morning-preference and both bioavailable and total testosterone (e.g. mean SD difference in bioavailable testosterone = -0.08, 95% CI:-0.12, -0.05 per category increase in morning-preference vs difference in morning-preference category = -0.04, 95% CI: -0.08, 0.00 per SD increase in bioavailable testosterone). In males, we found evidence for: I) Reduced risk of prostate cancer per category increase in morning-preference (OR = 0.90, 95% CI: 0.83, 0.97) and II) Increased risk of prostate cancer per SD increase in bioavailable testosterone (OR = 1.22, 95% CI: 1.08, 1.37). No bidirectional effects were found between morning-preference and testosterone in males. While testosterone levels were causally implicated with both chronotype and cancer, there was inconsistent evidence for testosterone as a mediator of the relationship. The protective effect of morning-preference on both breast and prostate cancer is clinically interesting, although it may be difficult to effectively modify chronotype. Further studies are needed to investigate other potentially modifiable intermediates.
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spelling doaj-art-4ff3ede02b694bb2918416909fec12a52025-08-20T03:15:43ZengPublic Library of Science (PLoS)PLoS Genetics1553-73901553-74042022-01-01181e100988710.1371/journal.pgen.1009887Do sex hormones confound or mediate the effect of chronotype on breast and prostate cancer? A Mendelian randomization study.Bryony L HayesTimothy RobinsonSiddhartha KarKatherine S RuthKonstantinos K TsilidisTimothy FraylingAnna MurrayRichard M MartinDeborah A LawlorRebecca C RichmondMorning-preference chronotype has been found to be protective against breast and prostate cancer. Sex hormones have been implicated in relation to chronotype and the development of both cancers. This study aimed to assess whether sex hormones confound or mediate the effect of chronotype on breast and prostate cancer using a Mendelian Randomization (MR) framework. Genetic variants associated with chronotype and sex hormones (total testosterone, bioavailable testosterone, sex hormone binding globulin, and oestradiol) (p<5×10-8) were obtained from published genome-wide association studies (n≤244,207 females and n≤205,527 males). These variants were used to investigate causal relationships with breast (nCases/nControls = 133,384/113,789) and prostate (nCases/nControls = 79,148/61,106) cancer using univariable, bidirectional and multivariable MR. In females, we found evidence for: I) Reduced risk of breast cancer per category increase in morning-preference (OR = 0.93, 95% CI:0. 88, 1.00); II) Increased risk of breast cancer per SD increase in bioavailable testosterone (OR = 1.10, 95% CI: 1.01, 1.19) and total testosterone (OR = 1.15, 95% CI:1.07, 1.23); III) Bidirectional effects between morning-preference and both bioavailable and total testosterone (e.g. mean SD difference in bioavailable testosterone = -0.08, 95% CI:-0.12, -0.05 per category increase in morning-preference vs difference in morning-preference category = -0.04, 95% CI: -0.08, 0.00 per SD increase in bioavailable testosterone). In males, we found evidence for: I) Reduced risk of prostate cancer per category increase in morning-preference (OR = 0.90, 95% CI: 0.83, 0.97) and II) Increased risk of prostate cancer per SD increase in bioavailable testosterone (OR = 1.22, 95% CI: 1.08, 1.37). No bidirectional effects were found between morning-preference and testosterone in males. While testosterone levels were causally implicated with both chronotype and cancer, there was inconsistent evidence for testosterone as a mediator of the relationship. The protective effect of morning-preference on both breast and prostate cancer is clinically interesting, although it may be difficult to effectively modify chronotype. Further studies are needed to investigate other potentially modifiable intermediates.https://journals.plos.org/plosgenetics/article/file?id=10.1371/journal.pgen.1009887&type=printable
spellingShingle Bryony L Hayes
Timothy Robinson
Siddhartha Kar
Katherine S Ruth
Konstantinos K Tsilidis
Timothy Frayling
Anna Murray
Richard M Martin
Deborah A Lawlor
Rebecca C Richmond
Do sex hormones confound or mediate the effect of chronotype on breast and prostate cancer? A Mendelian randomization study.
PLoS Genetics
title Do sex hormones confound or mediate the effect of chronotype on breast and prostate cancer? A Mendelian randomization study.
title_full Do sex hormones confound or mediate the effect of chronotype on breast and prostate cancer? A Mendelian randomization study.
title_fullStr Do sex hormones confound or mediate the effect of chronotype on breast and prostate cancer? A Mendelian randomization study.
title_full_unstemmed Do sex hormones confound or mediate the effect of chronotype on breast and prostate cancer? A Mendelian randomization study.
title_short Do sex hormones confound or mediate the effect of chronotype on breast and prostate cancer? A Mendelian randomization study.
title_sort do sex hormones confound or mediate the effect of chronotype on breast and prostate cancer a mendelian randomization study
url https://journals.plos.org/plosgenetics/article/file?id=10.1371/journal.pgen.1009887&type=printable
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