When patients suffer from insomnia, the 5 salivary cortisol measurements on the DUTCH Plus may not be enough to assess cortisol’s potential role in the sleep disturbances. Salivary measurements typically begin when the patient wakes and rises in the morning. It would be very helpful to also provide cortisol levels in the middle of the night when the patient is struggling to sleep. Determining cortisol’s potential role will help the provider treat the patient’s insomnia with precision.
The DUTCH Plus offers an evaluation of the Cortisol Awakening Response (CAR) by measuring salivary cortisol upon waking and then again 30 and 60 minutes later (additional measurements are made around dinner and bedtime). Research has shown that this post-waking increase in cortisol (the CAR) is the best way to assess an individual’s stress response and HPA-axis function.
When we open our eyes upon waking, cortisol levels naturally begin to rise by an average of 50%. 30 minutes after waking, cortisol levels will still show this sharp increase. By 60 minutes after waking, cortisol levels have peaked and begin to decline. Measuring this rise and fall of cortisol levels at waking can be used as a “mini stress test”. Research shows that the size of this increase correlates with HPA-axis function, even if the sample measurements are all within range. A quick saturation of saliva swabs upon waking, and at 30 and 60 minutes after waking, provide what is required to assess a patient’s Cortisol Awakening Response.
This can be a result of an underactive HPA axis, excessive psychological burnout, seasonal affective disorder (SAD), sleep apnea or poor sleep in general, PTSD, chronic fatigue and/or chronic pain. A decreased CAR has also been associated with systemic hypertension, functional GI diseases, postpartum depression, and autoimmune diseases.
This can be a result of an over-reactive HPA axis, ongoing job-related stress (anticipatory stress for the day), glycemic dysregulation, pain (i.e. waking with painful joints or a migraine), and general depression (not SAD). A recent study1 showed that neither the waking nor post-waking cortisol results correlated to Major Depressive Disorder, but the CAR calculation (the change between the first two samples) did. This measurement of the response to waking has independent clinical value showing dysfunction that may be hidden by current testing options.