Does stress response axis activation differ between patients with autoimmune disease and healthy people?

Many studies have shown that patients with autoimmune disease present a hypoactive hypothalamic-pituitary-adrenal (HPA) axis, but the results are controversial. Our objective was to study differences in stress response axis activity between patients with autoimmune disease and healthy people. The study sample consisted of 97 women divided into four groups: 37 healthy women (HW), 21 with systemic lupus erythematosus (SLE), 21 with Sjögren's syndrome (SS), and 18 with systemic sclerosis (SSc). After being exposed to a stress task, participants' skin conductance and salivary cortisol levels were measured in order to assess their response to psychological stress. Diurnal cortisol concentrations were assessed by measuring salivary cortisol in samples collected five times over one day. In addition, self-administered questionnaires were used to assess psychological variables. A time × group interaction effect was found (p = 0.003) in salivary cortisol secretion in response to stressful challenge. The healthy group presented normal activation, the SS and SLE groups showed no activation, and the SSc group presented a similar activation pattern to the HW group, except at the time of recovery. Total cortisol production (AUCg) was higher in the SSc group than in the HW group (p = 0.001). Differences were also observed in the cortisol AUCg collected over one day between healthy women and patients with SLE (p = 0.004) as well as with SSc (p = 0.001): women with SLE and SSc presented higher total hormone production than healthy women. Patients with autoimmune disease present a different HPA axis response, which may contribute to the harmful effects of stress in these diseases.