Salivary Cortisol: A Better Measure of Adrenal Cortical Function than Serum Cortisol

Abstract

SUMMARY Salivary cortisol concentration was found to be directly proportional to the serum unbound cortisol concentration both in normal men and women and in women with elevated cortisolbinding globulin (CBG). The correlation was excellent in dynamic tests of adrenal function (dexamethasone suppression, ACTH stimulation), in normals and patients with adrenal insufficiency, in tests of circadian variation and randomly collected samples. Women in the third trimester of normal pregnancy exhibited elevated salivary cortisol throughout the day. The relationship between salivary and serum total cortisol concentration was markedly non-linear with a more rapid increase in salivary concentration once the serum CBG was saturated. The rate of equilibrium of cortisol between blood and saliva was very fast, being much less than 5 minutes. These data, combined with a simple, stress-free, non-invasive collection procedure, lead us to suggest that salivary cortisol is a more appropriate measure for the clinical assessment of adrenocortical function than is serum cortisol. Materials and methods SUBJECTSCircadian variation The circadian rhythm of salivary cortisol was examined in seven female and seven male healthy adults (age range 24-32 years). Each subject collected a saliva sample every hour for one day throughout their normal waking hours. On another day the same groups provided matched serum and saliva samples at 0900 and 1700. The circadian rhythm of salivary cortisol in the third trimester of normal pregnancy was examined in 13 sets of samples from 10 women (age range 22-35 years) with uncomplicated pregnancies who delivered healthy single babies at 38-42 weeks' gestation. dexamethasone suppression, adrenocorticotrophin (ACTH) stimulation, and circadian variation; (3) examined the circadian variation of salivary cortisol in women in the third trimester of normal pregnancy; and (4) examined the rate of appearance of cortisol in saliva.

Health and immune traits of Basque and Large White pigs housed in a conventional or enriched environment

“…The discrepancy between salivary and plasma results may be explained by diurnal-related variations. Indeed, the influence of housing on salivary cortisol was observed at 0700 h but not at 1100 h, whereas blood samples were drawn between 0830 and 0930 h. Moreover, salivary cortisol is more tightly linked to the free fraction of circulating cortisol than to the total concentration of cortisol that was measured in this study (Vining et al, 1983;Perogamvros et al, 2010).…”

Evaluation of Plasma, Salivary, and Urinary Cortisol Levels for Diagnosis of Cushing’s Syndrome

“…In our study, late-night plasma and salivary cortisol levels showed a positive correlation. In fact, salivary cortisol concentrations are directly proportional to serum unbound cortisol concentration [18]. our data, combined with a simple, stress-free, and non-invasive collection procedure, suggest that the salivary cortisol level is a more appropriate measure for the clinical assessment of adrenocortical function than the plasma cortisol level.…”

Salivary Cortisol Can Replace Free Serum Cortisol Measurements in Patients With Septic Shock

“…11 The rate of appearance of cortisol in the saliva following an increase in the blood level is very rapid, , 5 min. 12 Studies in healthy volunteers and for the evaluation of patients with hypothalamus-pituitary-adrenal axis disease have showed an excellent correlation between free or unbound serum and salivary cortisol levels, although the relationship is nonlinear and correlation is more closely related at lower levels (when total serum concentration is , 16.3 m g/dL). [13][14][15] We evaluated the correlation between salivary cortisol and total serum cortisol with free serum cortisol levels in adult medical intensive care patients with septic shock.…”

“…In our study the mean salivary cortisol was higher than the mean free serum cortisol, without reaching statistical signifi cance. 12,19 Prior salivary cortisol studies were performed in healthy volunteers and not ICU patients with septic shock in whom normal adrenal function and cortisol concentrations are still unknown. It has been postulated that salivary cortisol determination is more useful, especially after ACTH stimulation test, since it refl ects immediate changes in the unbound serum cortisol without being affected by the CBG or albumin concentration.…”