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

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.

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.

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.

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.