Cortisol Awakening Response in Myofascial Pain Patients: Evidence of Hypocortisolism in Temporomandibular Disorders

Temporomandibular disorders (TMD), fibromyalgia (FM), and chronic fatigue syndrome (CFS) fall under the category of stress-related disorders. They share similar symptoms, multifactorial etiologies, a predominance in women, and are often comorbid with each other. Stress is associated with onset and exacerbation of symptoms ofTMD, FM, and CFS. Extensive research has shown hypothalamic-pituitary-adrenal (HPA) axis dysregulation in fibromyalgia and chronic fatigue syndrome in the form of hypocortisol ism. Few studies, however, have attempted to study HPA axis dysregulation in temporomandibular disorders. The current study will examine salivary free cortisol levels over the awakening response in 20 myofascial pain patients and 20 age-matched, healthy controls. Comorbidity of the stress-related disorders will be examined as well as the possible influence of psychological variables, such as a history of physical or emotional trauma. Lower basal cortisol levels are expected for the TMD group versus the control group immediately after awakening. A blunted increase of cortisol secretion in response to awakening is also expected in the TMD group.