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Association of genetically determined chronotype with circulating testosterone: a Mendelian randomization study
Tomohiro Ichikawa1, Takuro Kobayashi1, Tsuyoshi Hachiya2
1Department of Urology, Juntendo University, Graduate School of Medicine, Tokyo, Japan.
Frontiers in Endocrinology
|May 13, 2024
Summary
Men with a morning chronotype have higher testosterone levels. This Mendelian randomization study suggests a causal link between chronotype and testosterone, impacting men's health.
Area of Science:
- Endocrinology
- Genetics
- Men's Health
Background:
- Low testosterone levels are associated with reduced physical and mental function in men.
- Previous studies suggest a link between testosterone and sleep traits, but causality is unclear.
Purpose of the Study:
- To investigate the potential causal relationship between genetically determined sleep traits and testosterone levels in men.
- To explore the influence of chronotype and sleep duration on sex steroid hormones using Mendelian randomization.
Main Methods:
- Utilized Mendelian randomization (MR) analysis on UK Biobank data.
- Exposures included genetic variants for chronotype and sleep duration.
- Outcomes comprised total testosterone (TT), bioavailable testosterone (BAT), and sex hormone-binding globulin (SHBG).
Main Results:
- A genetically predicted morning chronotype was significantly associated with increased TT and BAT levels.
- No significant association was found between chronotype and SHBG.
- Sleep duration showed no significant causal association with TT, BAT, or SHBG.
Conclusions:
- Findings support a causal association between chronotype and circulating testosterone levels in men.
- A morning preference correlates with higher testosterone levels, highlighting the impact of lifestyle on hormone health.
- Lifestyle adjustments may be important for maintaining testosterone levels in men.
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