Saliva samples - Cortisol
Cortisol Testing
What is cortisol?
Cortisol is a steroid hormone which is produced by the adrenal glands which are located on the top of each kidney. It is part of the body's normal function and helps control blood sugar levels and to fight inflammation. An increased level of cortisol is secreted as a natural response to stress. So measuring it will give us an accurate measure of stress levels.
Testing Kit
Cortisol is found in saliva, so in order to measure it we will be asking you for saliva samples. The kit is made up of two tubes, a large one and a small one. The small tube fits inside the larger tube and contains a cotton wool pad. Please ensure that the smaller tube remains inside the larger tube.
Giving a sample
- Rinse your mouth out with water and swallow
- Remove the blue stopper
- Take out the cotton wool pad and place it under your tongue (if it is too large chew the pad a little first)
- Keep the cotton wool pad under your tongue for a minute
- Place the saturated cotton wool pad back in the tube and replace the stopper firmly (ensure the small tube is inside the larger tube at this point)
- Make a note of the time on the card provided with the tubes
When to do the saliva samples
Cortisol levels follow a daily pattern. When you wake up there is a sharp increase in cortisol. Cortisol then decreases through out the day and is at its lowest in the evening. Therefore in order to capture this pattern samples need to be provided at the following times:
- When you first wake up in the morning, about 7am (tube 1)
- 30 minutes after the first sample, about 7.30am (tube 2)
- In the evening, about 9pm (tube 3)
Place the first two samples in the fridge once they are done. Please keep weekend day samples in the fridge until collection day.
A number of factors can affect the sample so please do not eat, drink or brush your teeth between the first two samples. Do not eat, drink, exercise or brush your teeth for an hour before the evening sample.
Why is a weekday and weekend day sample needed?
People tend to be more relaxed on the weekends and spend more time doing activities outdoors. To fully understand the role the environment has on stress we need to see whether there is a difference in young adults stress levels on a weekday, when at school, and on the weekend, during free time.
What happens to the samples?
Once the PEACH team have picked up the samples from you they are taken back to the University. Once there they will be spun in a centrifuge to separate the saliva from the cotton wool. At this point the cotton wool will be destroyed by the University biological waste disposal team. As for your saliva this will be frozen and stored at -20 degrees (in order to preserve the sample) until being tested.
At no point during the study will the samples be tested for anything other than cortisol. Any remaining saliva after the testing process will be destroyed.