The device, called U-RHYTHM, can track adrenal steroids like cortisol during typical daily activities allowing researchers to identify signs of health conditions linked to cortisol and other stress hormones.
Stress hormones, such as cortisol, impact several systems in the body, including the cardiovascular, gastrointestinal, and immune systems. An imbalance of these hormones due to high levels of stress, certain health disorders, and lifestyle factors has been linked to conditions like diabetes, heart disease, and depression.
However, testing for these hormones at a single point in the day only gives a snapshot of hormone levels and fails to show the normal hormonal rhythms throughout the day and night. Capturing these rhythms could help healthcare providers identify signs of adrenal dysfunction leading to timely diagnosis and treatment of stress hormone-related health conditions.
Typically, this type of 24-hour stress hormone testing is limited to the hospital setting, where a clinician draws a person's blood several times during the day and while they sleep.
However, a team of researchers from the University of Bristol, the University of Birmingham, and the University of Bergen have developed a wearable device called U-RHYTHM that has the potential to redefine how stress hormone-related diseases are diagnosed and treated.
The U-RHYTHM wearable is worn in a band around the hips with a microdialysis membrane placed on the skin's surface. The device painlessly takes samples from underneath the skin every 20 minutes. It can draw samples for up to 72 hours in one session and captures stress hormone levels during daily activities and while the person sleeps.
In a study published in Science Translational Medicine on June 21, the research team tested U-RHYTHM for 24 hours in 214 healthy volunteers.
The team measured cortisol levels and identified daily and ultradian variations of free cortisone, corticosterone, 18-hydroxycortisol, aldosterone, tetrahydrocortisol, and allo-tetrahydrocortisol. They were also able to detect the presence of dehydroepiandrosterone sulfate.
The scientists also compared the U-RHYTHM measurements to plasma measurements in another seven healthy volunteers to validate the results.
Using mathematical and computational methods, the team developed "dynamic markers" of normal stress hormone rhythms in healthy individuals categorized by age, sex, and body mass index (BMI). This allowed the team to understand better what a healthy hormonal profile might look like.
"Our results provide insight into the dynamics of adrenal steroids in tissue in real-world settings and may serve as a normative reference for biomarkers of endocrine disorders," the authors wrote.
In addition, the collection of samples via U-RHYTHM was safe, well tolerated, and allowed most normal activities to continue, the authors note.
In a press release, the study's lead endocrinologist, Thomas Upton, Clinical Research Fellow in Automated Sampling at the University of Bristol, says, "Our results represent a paradigm shift in the understanding of how the stress hormone system works in healthy people. The information we have gathered forms an entirely new reference range which has the potential to revolutionize how diseases of the stress hormone system are diagnosed and treated."
- Science Translational Medicine. High-resolution daily profiles of tissue adrenal steroids by portable automated collection.
- University of Bristol. Wearable monitor detects stress hormone levels across a full 24-hour day.