Sialochemistry and cortisol levels in patients with Sjogren’s syndrome
OBJECTIVES: (i) To determine whether salivary cortisol and electrolyte levels differ between patients with Sjogren’s syndrome (SjS) and healthy individuals. (ii) To assess correlations between whole-saliva cortisol and some clinical manifestations in patients with SjS.
METHODS: A total of 24 healthy women (mean age 49.3 ± 9.8) served as controls (C) vis-a-vis 17 patients with SjS (mean age 55.5 ± 15.7). Salivary cortisol concentration was determined, and sialochemistry analysis was performed. RESULTS: Significantly lower saliva flow rates and higher salivary chloride (Cl)), potassium (K+), and Ca2+ levels were found in the SjS group. No significant differences or correlations were found in other parameters, including sodium (Na+), magnesium (Mg2+), phosphate (PO3/4), urea (U), and salivary cortisol levels.
CONCLUSION: Increased whole-salivary output of Cl- and K+ in SjS may reflect release from apoptotic rests of acinar cells after secondary necrosis. Normal levels of salivary Na+, Mg2+, and PO3/4 – argue against concentration effect, deranged tubular function or cortisol (mineralocorticosteroid) effect as the cause for these findings. Increased salivary Ca2+ levels probably reflect leakage of plasma Ca2+ through the injured oral mucosa in SjS. In spite of disease-associated stress, salivary cortisol, a stress biomarker, was not increased, suggesting insufficient hypothalamus–pituitary–adrenal (HPA) axis response and/or local consumption of cortisol by lymphocyte infiltrates.