Sex differences in the hypothalamic–pituitary–adrenal axis in patients with burning mouth syndrome

Objective: To investigate the sex differences in clinical features, including salivary flow rate, psychological distress and hypothalamic–pituitary–adrenal axis response and their inter-relationships in patients with burning mouth syndrome. Subjects and Methods: Eighteen men and 37 postmenopausal women with burning mouth syndrome underwent a comprehensive questionnaire evaluation, psychological evaluation and salivary flow rate measurement. Laboratory tests were performed to investigate the function and integrity of the hypothalamic–pituitary–adrenal axis. Results: Both unstimulated and stimulated salivary flow rates were higher in men than in women (unstimulated: 0.58 ± 0.32 vs. 0.37 ± 0.15 ml/min, p <.01; stimulated: 1.83 ± 0.63 vs. 1.22 ± 0.31, p <.001). Symptom severity scored on a visual analogue scale negatively correlated with anti-diuretic hormone levels in both sexes. The visual analogue scale scores negatively correlated with unstimulated (r = −.652, p <.01) and stimulated (r = −.376, p <.05) salivary flow rates in men and women, respectively. Unstimulated salivary flow rates positively correlated with anti-diuretic hormone (r =.453, p <.05) and progesterone (r =.402, p <.05) levels only in women. Conclusions: Our results suggest that clinicians should consider hypothalamic–pituitary–adrenal axis response, as well as sex and salivary flow rates, when identifying the aetiology of patients with burning mouth syndrome, as it may enable more accurate and effective treatment.