The burden of Sjögren's syndrome, dryness and fatigue

Abstract

Dryness and fatigue are prevalent and debilitating symptoms in Sjögren’s syndrome. In this thesis, consequences of dryness for patients’ well-being and daily life functioning, and possible targets for treatment were described. In the first part of this thesis, an encompassing overview of the consequences of dryness from the perspective of the patients was revealed. The hierarchical overview comprised generic psychosocial consequences and disease-specific consequences including primary symptoms of eyes and mouth and hindered participation in social activities, intimacy problems, and somatic (systemic) symptoms. Second, the consequences of dryness with respect to crying problems were studied. Compared with demographically matched control participants, patients with Sjögren’s syndrome reported lower crying sensibility and capability to cry with tears, a higher presence of bodily symptoms after crying, and a higher severity of suffering from a reduced capability to cry. The crying dimensions generally showed significant but weak associations with ocular dryness and mental well-being in patients. Third, consequences for emotional well-being of the hampered ability to cry are described. It was found that processing and regulating emotions generally did not deviate from normal with one exception: a relatively large number of patients, 22%, were alexithymic (i.e., had difficulty identifying and describing feelings and focusing on external events rather than inner experiences). Processing emotions more intensely or more deficiently and regulating emotions by more suppression was associated with worse mental well-being; virtually alike in patients and control participants. The second part of this thesis describes possible targets for treatment of fatigue in Sjögren’s syndrome. Physical activity and physical activity cognitions were found to be independently associated with fatigue. Moreover, the combination of low physical activity and high activity avoidance was associated with both fatigue. These results suggest that fatigue in patients with Sjögren’s syndrome might be reduced by targeting both physical activity and physical activity cognitions. In another study, we examined whether there were different psychological profiles (subgroups) in patients with Sjögren’s syndrome, and how these profiles were related to fatigue. Four psychological profiles were identified using cluster analyses, a functional profile (in which 39% of the patients were grouped), an alexithymic profile (27%), a self-reliant profile (23%), and a dysfunctional profile (11%). Irrespective of the psychological profile of patients, the level of fatigue was substantially higher than in the general population. Patients with a dysfunctional or an alexithymic profile reported more fatigue than those with a self-reliant profile. Since cognitive behavioural therapy and graded exercise therapy are promising treatments in reducing fatigue, this thesis describes the development and feasibility of such an intervention for patients with Sjögren’s syndrome. This intervention seemed convenient for people to follow and the participants in the first intervention group noted that it had changed their way of coping with fatigue. The next, ongoing, step is to conduct a randomised controlled trial examining whether a combination of cognitive behavioural group therapy and exercise therapy are effective in reducing fatigue in Sjögren’s syndrome. Using information about psychological profiles of patients, treatment might be customized to make it effective and suitable for a large group of patients. This could improve the quality of life of patients with Sjögren’s syndrome.