Vascular Function and Oxidative Stress in Emergency Medical Responders

Launched by UNIVERSITY OF DELAWARE · May 14, 2025

Keywords

ClinConnect Summary

This clinical trial is looking at how working overnight shifts affects the health of emergency medical technicians (EMTs), specifically focusing on blood vessel function and oxidative stress, which is a harmful condition that can damage cells. The researchers want to find out if working these late shifts makes blood vessels work less effectively and increases oxidative stress. They will also test whether taking antioxidant supplements—substances that can help protect cells—can reduce these negative effects.

To participate in this study, you need to be an active EMT who has been working night shifts for at least a year, and your body mass index (BMI) should be between 18.5 and 35. You will attend two lab sessions after your overnight shifts to check your blood vessel function and oxidative stress levels. During your night shifts, you'll take either an antioxidant supplement or a placebo (a substance with no active ingredients) to see if it makes a difference. It’s important to note that certain health conditions, such as high blood pressure or sleep disorders, may exclude you from participating. If you’re interested and meet the criteria, this study could help improve our understanding of how night shifts affect EMTs’ health.

Gender

ALL

Eligibility criteria

• Inclusion Criteria:
• • Body mass index between 18.5 and \<35 kg/m²
• • Seated resting systolic blood pressure \< 140 mmHg, and seated resting diastolic blood pressure \< 90 mmHg
• • Participant must be an active first responder that works shift work schedules. e.g., emergency medical responders, basic life support emergency medical technicians (i.e., BLS EMT), advanced life support emergency medical technicians (A-EMT), and paramedics
• • Participant must have been working shift work for at least 1 year
• • Participant must work at least 4 night shifts per month
• Exclusion Criteria:
• • Participant is unwilling or unable to give consent
• • Participant has been diagnosed with any chronic disease (a history of high blood pressure, heart disease, diabetes, cancer, kidney disease)
• • Participant has been diagnosed with a sleep disorder (e.g., insomnia, restless leg syndrome, sleep apnea)
• • Participant is currently taking melatonin or other sleep aids (e.g., Ambien, sedatives, etc.), or any supplements/medications known to alter sleep patterns. Participants using melatonin must undergo a minimum 72-hour washout period prior to study participation to ensure baseline sleep patterns are not affected\[15, 16\]
• • Resting blood pressure \>140/90 mmHg
• • Body mass index \<18.5 or \>35 kg/m2
• • Currently pregnant or breast feeding (women only)
• • Currently use tobacco or nicotine products (≥1 cigarette, cigar, e-cigarette, vape, or any other nicotine-containing product in the last month), including smokeless tobacco (e.g., chewing tobacco, snuff, dip, snus), nicotine lozenges or gum, heated tobacco products, and any illicit drugs