Steroid hormone levels in healthy adults are influenced by oral contraceptives and smoking, as well as other lifestyle choices and factors such as biological sex and age, according to new research published in Science Advances.¹

The objective of the research was to expand knowledge and understanding of steroid hormone levels, including corticoids and sex hormones, in healthy women and men over a broad age range. This is the first study to analyse such a large number of hormones in nearly 1,000 healthy people, filling a major gap in the knowledge of molecules that are important for our day-to-day well-being.

The work was conducted by members of the Milieu Interieur consortium and led by Dr Darragh Duffy (Institut Pasteur) and Dr Molly Ingersoll (Institut Pasteur and Institut Cochin (Inserm U1016, CNRS, Université Paris Cité). Dr Jamie Sugrue, a Trinity College Dublin graduate, now a Marie Curie-funded postdoctoral researcher at the Institut Pasteur, is the co-first author. Dr Sugrue also worked with Trinity’s Professor Cliona O’Farrelly to secure a Research Ireland Ulysses grant, which kickstarted the ongoing collaboration between Trinity researchers and the Pasteur and Milieu Interieur consortium teams.

The team involved in this current study found that hormone levels vary according to an individual’s age and sex, but that they are also associated with many other factors, such as genetics and common behaviours. 

Notably, many steroid hormone levels, beyond sex hormones, are influenced by oral contraceptive use in women, while in men, smoking was associated with altered levels of nearly every steroid hormone measured.

Additionally, measurement of hormones in the same donors 10 years after the original visit showed that decreases in specific androgens were associated with diverse diseases in aging men, implying that these hormones – which are associated with physical characteristics, and supporting strong bones and red blood cell production – play a role in disease development.

The results in this paper were first presented to an international audience at the Sex Differences in Immune Health conference recently hosted by Trinity College Dublin.