Sweat: a potential marker of clinical activity in panic disorder.

OBJECTIVE: Panic disorder (PD) is a paroxysmal neuropsychiatric disorder with unclear etiology and obscure pathophysiology. Despite the frequency of its occurrence, PD still has no reliable laboratory markers. The sweat is a neglected human secrete reacting immediately to various neurovegetative challenges including psychic imupulses. We hypothesized a possible dysfunction of sweat homeosthasis in PD.

SUBJECTS AND METHODS: 10 patients with active PD, 9 patients with PD in remission and 11 age-matched controls participated in this study. All subjects underwent a single 8-min session in the dry-heat sauna. Sweat and venous blood have been collected immediately after the end of this session. Concentrations of lactate, glucose, creatinine, natrium, potassium, chlorine, calcium and magnesium have been quantitatively estimated in both liquids and compared statistically among three groups.

RESULTS: We did not find any significant difference in blood parameters of the three above groups. However, the patients with active PD had significantly higher sweat levels of lactate, glucose, creatinine and magnesium than both the other groups which did not differ. Moreover, sweat concentrations of natrium, potassium and chlorine were significantly higher in active PD comparing to the group of PD patients in remission.

CONCLUSIONS: The sweat of patients with active PD in comparison to PD in its clinical remission exhibits surprisingly distinctive changes of selected parameters after dry-heat sauna exposure. Increased concentrations of lactate, glucose and magnesium in the sweat are not contradictory with presupposed neurotransmitter-metabolic firing mechanisms in PD. These findings appear to be perspective biochemical markers in PD and its course.