Salivary cortisol measurement in normal-weight, obese and anorexic women: comparison with plasma cortisol

OBJECTIVE: To compare salivary, plasma and urinary free cortisol (UFC) measurements in patients with anorexia nervosa, in whom an overdrive of the hypothalamic-pituitary-adrenal (HPA) axis is well established but information on salivary cortisol is lacking, in viscerally obese patients in whom subtle abnormalities of cortisol secretion and metabolism are postulated, and in normal-weight healthy women. PARTICIPANTS AND EXPERIMENTAL DESIGN: Measurement of salivary cortisol offers a convenient way to assess the concentrations of free, biologically active cortisol in plasma in different physiopathological settings. Forty-seven drug-free, newly diagnosed women with active restrictive anorexia nervosa, 30 restrictive anorexic women undergoing chronic psychopharmacological treatment, 47 women with mild-to-moderate visceral obesity, 103 women with severe central obesity and 63 normal-weight healthy women entered the study. Salivary and blood samples were collected at 0800 h, 1700 h and 2400 h, together with three consecutive 24-h urine specimens for UFC determination. In controls and patients with anorexia nervosa (n=83), salivary and plasma cortisol were also measured after a 1-mg overnight dexamethasone suppression test (DST). In patients with anorexia nervosa, mood was rated by the Hamilton scale for anxiety and depression. RESULTS: Untreated patients with anorexia nervosa showed increased plasma and salivary cortisol and UFC concentrations (all P