Hormones are signalling molecules that are essential in regulating many different processes throughout the body. There are several types, including steroid hormones: corticosteroids (such as glucocorticoids and mineralocorticoids) and sex steroids (such as androgens, oestrogens and progestins).
Previous research has reported differences in steroid hormone levels between people with ME/CFS and healthy control subjects, but no one has yet looked at whether these differences are affected by sex or disease severity.
Dr Francisco Westermeier and colleagues from a number of centres in Austria, Chile, Poland and Portugal have addressed this question in a study recently published in the Journal of Endocrinological Investigation.
The team analysed blood samples, provided by the UK ME/CFS Biobank, from three groups of individuals: 28 people with mild or moderate ME/CFS, 30 people with severe ME/CFS, and 19 healthy control subjects. These groups included both males and females.
ME/CFS was diagnosed based on the Canadian Consensus and/or CDC-1994 diagnostic criteria, and information was also collected on disability levels, participants’ experiences of pain and fatigue, and other aspects of physical and mental wellbeing.
Ultra-high-performance liquid chromatography – tandem mass spectrometry was used to analyse levels of a range of steroid hormones in the blood samples, and these levels were compared between the different subject groups, and between males and females.
Among females, those with severe ME/CFS had higher levels of 11-deoxycortisol (a glucocorticoid) than those with mild/moderate ME/CFS and healthy controls, as well as higher levels of 17α-hydroxyprogesterone (a sex steroid) than healthy controls. Women with mild/moderate ME/CFS also had increased progesterone levels compared with controls.
Among males, levels of cortisol and corticosterone were lower in those with mild/moderate ME/CFS than in controls, while progesterone levels were increased.
The researchers emphasise that this is a relatively small study, and the results need to be confirmed in a larger sample. These differences in steroid hormone levels between people with ME/CFS and healthy controls could help advance our understanding of the pathophysiology of ME/CFS, but at present they represent indicators of potentially interesting avenues to explore further.
The findings also illustrate the importance of considering specific patient subgroups related to sex and disease severity when conducting research in humans. In particular, individuals with severe disease are underrepresented in ME/CFS research.