Saliva and serum cortisol dynamics following intravenous dexamethasone in normal volunteers

In order to further explore the utility of saliva cortisol as an accurate measure of adrenal steroid production, dexamethasone (DEX) and saline were administered intravenously at 0800h to eight normal male volunteers in a randomized design, and the effects on serum and saliva cortisol concentrations were measured at hourly intervals from 0800h-2300h. Saliva cortisol values were highly correlated to serum cortisol levels within-subjects under both conditions (r = 0.78, p less than 0.025), however correlations were reduced in the DEX day sample pairs. Across-subject correlations at each time point were considerably more variable, reflecting interindividual differences in the saliva to serum cortisol ratios. No consistent time lag of saliva cortisol values in response to serum cortisol fluctuations was observed. These data suggest that saliva cortisol is an excellent index of changes in adrenal production of cortisol over time within individuals; however, it also suggests that salivary cortisol measures have less usefulness in comparing values across groups of individuals.     

Dissociation of plasma cortisol and ACTH responses to dexamethasone in healthy subjects

We examined the plasma cortisol and ACTH concentrations after graded doses of dexamethasone in a group of young, healthy adults. The decrease in cortisol was uniform in all subjects, and in 8 subjects there was a high degree of correspondence with the plasma ACTH concentration. The remaining 5 subjects had no change in plasma ACTH concentration during dexamethasone administration. All subjects had an expected diurnal change in cortisol on 2 pretreatment days and there was a corresponding diurnal change in ACTH for those subjects who had associated ACTH and cortisol responses after dexamethasone, while those with dissociated ACTH and cortisol after dexamethasone had no diurnal ACTH pattern. These findings were consistent with the 24-hour pattern of ACTH and cortisol before and after 1.0 mg of dexamethasone in 2 of the same subjects. These results are further evidence for ACTH independent regulation of adrenal function and indicate that pituitary-adrenal regulation in man is more complex than the traditional model of ACTH-cortisol feedback would predict.     

Glucocorticoid response to exercise as measured by serum and salivary cortisol

Serum and salivary cortisol concentrations were studied in 78 elite athletes engaged in different sports, by subjecting them to high-intensity laboratory exercise. The mean difference in the pre-exercise cortisol concentrations in the seven groups studied were more marked in serum (from 311 to 768 nmol.l-1) than in saliva (from 17.9 to 22.7 nmol.l-1, only one group reaching 40 nmol.l-1). Judging from the correlation coefficients based on total variances, the post-/pre-exercise differences in cortisol concentrations in serum depended chiefly on pre-exercise values, while those in saliva tended to depend more on the postexercise concentrations. The coefficients of correlation between that difference and either the pre- or postexercise values were -0.71 and 0.47, respectively, for serum, and -0.51 and 0.58, respectively, for saliva. This would suggest that salivary cortisol concentration might be a more suitable variable for assessing glucocorticoid activity in exercise than serum cortisol concentration, probably being less sensitive to pre-exercise emotional state.     

Serum cortisol concentrations during low dose dexamethasone suppression test to screen for Cushing's syndrome.

Forty four subjects (23 obese controls, 11 patients with possible Cushing''s syndrome, and 10 patients with definite Cushing''s syndrome) underwent low dose (0 X 5 mg every six hours for two days) dexamethasone suppression tests during which serum cortisol concentration at 0800 and excretion of urinary free cortisol over 24 hours were measured. Serum cortisol concentration fell to below 60 nmol/1 (2 X 2 micrograms/100 ml) in 31 subjects and remained above 250 nmol/1 (9 X 1 micrograms/100 ml) in the 13 others. Excretion of urinary free cortisol showed a similar response, falling to below 110 nmol (40 micrograms)/24 h in 31 and remaining above 180 nmol (65 micrograms)/24 h in the 13 others. There was complete concordance between the two variables in terms of the pattern of response. Serum cortisol concentration fell to below 60 nmol/1 (2 X 2 micrograms/100 ml) in at least 97% (31 of a possible 32) of subjects without Cushing''s syndrome. On the other hand, a serum cortisol concentration of above 250 nmol/1 (9 X 1 micrograms/100 ml) after low dose dexamethasone gave a false positive diagnosis of Cushing''s syndrome in at most only one of 13 patients (7 X 7%). Measurement of serum cortisol concentration during the low dose dexamethasone test is simpler than, and as accurate and reliable as, measurements of urinary steroids.     

The short-term effect of cortisol, dexamethasone and ACTH administration on the serum levels of hexuronic acids and monosaccharides in man

The levels of serum monosaccharides (SMO) and hexuronic acids (SHA) were measured in subjects without any metabolic or endocrine disease after a short-time administration of cortisol, dexamethasone and ACTH. The effects of the three hormones were evaluated in regard to the urinary excretion of free cortisol and cortisone at basal conditions. In thirteen subjects a significant increase of SMO during cortisol treatment was registered after 24 hours. A distinct difference in the response of SMO to cortisol treatment was observed in patients with normal or increased cortisol excretion, respectively. In the subjects with high urinary free corticoids a peak of SMO occurred soon after 4 hours after cortisol administration, in the next 48 hours no tendency of return towards basal levels was observed. In the subjects with normal urinary free cortisol excretion only a slight increment was seen after 24 hours. Soon after 4 hours in eight subjects dexamethasone administration resulted in an increase of SMO without regard to the excretion of urinary free corticoids. The highest values were obtained after 28 hours of dexamethasone treatment. Ten hours after cessation of dexamethasone the levels of SMO reached the basal values. In the study in which ACTH was administered, an increment of SMO was registered only in the first four hours. In the group of subjects treated with ACTH a slight difference between subjects with normal and increased corticoid excretion was seen. The levels of SHA successively increased after the administration of all three hormones, without regard to the basal excretion of urinary free corticoids. This increase persisted also 10 hours after cessation of cortisol and dexamethasone, and 40 hours after the last dosis of ACTH, respectively. The possibility of an altered metabolism of glucose through the glucuronate pathway under conditions of glucocorticoid excess is discussed.     

Serum and saliva adrenocortical hormones in obese diabetic men during submaximal exercise

The aim of this study was to evaluate serum and saliva adrenocortical hormones and their relationships at rest and during submaximal exercise and recovery in 9 obese diabetic middle-aged men (BMI: 35.2 ± 1.6 kg/m (2)). Blood and saliva samples were taken at rest, every 10 min of a 30-min cycling exercise at 70% of maximal heart rate, and after 10 min of recovery in order to analyze cortisol, dehydroepiandrosterone sulfate (DHEA-S) and dehydroepiandrosterone (DHEA). Serum and saliva cortisol increased significantly during recovery (p<0.05), but no significant difference was observed between the rest, exercise, and recovery DHEA-S and DHEA concentrations. A strong correlation was found at rest between both serum and saliva cortisol (r=0.72, p<0.001) and DHEA-S and DHEA (r=0.93, p<0.001). Serum DHEA-S and saliva DHEA remained strongly correlated during and after the submaximal exercise (r=0.81, p<0.001), whereas a weaker but still significant relationship was observed between serum and saliva cortisol during and after the exercise (r=0.52, p<0.001). In conclusion, these results suggest that saliva adrenocortical hormones, and especially saliva DHEA, may offer a practical surrogate for serum concentrations during both rest and exercise in obese diabetic men.     

Plasma acth and cortisol levels in depressed patients: Relation to dexamethasone suppression test

Blood samples collected from normal subjects and newly hospitalized depressed patients at 8 AM on the day before and at 8 AM and 4 PM the day after receiving dexamethasone, 1 mg orally at 11 PM, were analyzed for ACTH and cortisol. The mean plasma ACTH values of these two groups were not significantly different at any of the times, while the cortisol levels of the depressed patients were significantly higher than those of the normal subjects at 8 AM pre-dexamethasone (P<0.001). There was no correlation between plasma ACTH and cortisol values in either group. The cortisol responses to dexamethasone in depressed patients revealed two subgroups. In one subgroup, the cortisol was suppressed as much as in normal subjects, but in the other, cortisol levels were not suppressed. The post-dexamethasone ACTH rebounded at 4 PM in the latter subgroup to higher values than in the subgroup with suppressed cortisol levels and in the normal subjects. After dexamethasone, the ACTH values were negatively correlated with plasma cortisol only in the normal subjects (P<0.01), not in the depressed patients. These results indicate that ACTH levels do not account for the elevated cortisol and the failure of dexamethasone to suppress cortisol levels in some depressed patients.     

Serum concentrations of deoxycorticosterone in women during the luteal phase of the ovarian cycle are not suppressed by dexamethasone treatment

We determined the serum levels of deoxycorticosterone (DOC) in plasma of six healthy, apparently ovulatory women during the mid-follicular and mid-luteal phases of their ovarian cycles; and we evaluated the effect of dexamethasone (1 mg by mouth) on the concentrations of DOC and cortisol in serum at times when plasma progesterone levels were high or low. The serum levels of DOC, unlike those of cortisol, did not vary significantly in single blood samples obtained in the morning (8-10 a.m.) and afternoon (3-5 p.m.); and serum DOC levels in women were significantly higher (P less than 0.05) during the mid-luteal phase than during the mid-follicular phase of the cycle. There were unmistakable diurnal variations in serum levels of cortisol, and cortisol concentrations were reduced to less than 20% of pretreatment levels after the ingestion of 1 mg dexamethasone during the mid-follicular or mid-luteal phase. The serum concentrations of DOC were reduced only to approx 70% of pretreatment levels after dexamethasone ingestion during the follicular phase. The serum levels of DOC did not decline significantly after administration of dexamethasone during the mid-luteal phase, when progesterone levels in serum are high (14-16 ng/ml). Blood samples also were obtained at hourly intervals during the 24 h before and after dexamethasone administration in one woman during the follicular phase and in another woman the during the early luteal phase (progesterone levels = 1-3 ng/ml) of the ovarian cycle. DOC levels (pre-dexamethasone) fluctuated in synchrony with those of cortisol in the woman studied during the follicular phase but not in the woman studied during the early luteal phase of the cycle. In the post-dexamethasone period, plasma cortisol levels were suppressed for at least 24 h in both women whereas DOC levels were decreased only partially. We conclude that plasma DOC is derived from both adrenal secretion and from extraadrenal 21-hydroxylation of progesterone--the latter source of DOC is not affected by dexamethasone suppression of ACTH secretion.     

Activated hypothalamic pituitary adrenal axis in patients with metabolic syndrome

Metabolic syndrome (MetS) is correlated with the activity of hypothalamic-pituitary-adrenal axis (HPA), but the underlying mechanism still remains elusive. The aim of this study was to investigate the HPA axis function in patients with MetS. This case-control study included 159 people. They were divided into 2 groups. The first group included 73 healthy volunteers (control group: 19 males, 54 females, mean±SD: 49.9±7.5 years old, with BMI: 27.9±4.42?kg/m2) and the second group included 86 patients with MetS (case group: 48 males, 38 females, mean±SD: 52.2±7.6 years old, with BMI: 30.5±5.35?kg/m2). An oral glucose tolerance test (OGTT) was performed for all subjects after a 12-h overnight fast, and blood samples were obtained for determination of ACTH, cortisol, insulin, C-peptide, and glucose levels. Serum cortisol after an overnight dexamethasone suppression test was determined in both groups. Patients with MetS had serum cortisol levels after an overnight dexamethasone suppression test significantly higher than controls. During OGTT plasma ACTH levels were higher at all time points in patients with MetS compared to controls, whereas serum cortisol levels were comparable between the 2 groups. Plasma ACTH during OGTT was also correlated with most of the components of MetS. The HPA axis in patients with MetS seems to be more active as evidenced by the higher cortisol levels after the overnight dexamethasone suppression test and by the higher ACTH levels during OGTT. This functional hypercortisolism might be involved in the pathogenesis of the metabolic syndrome.     

Overnight Dexamethasone Suppression Test: A Reliable Screen for Cushing's Syndrome in the Obese

Objective: Reevaluation of the validity of the 1-mg overnight dexamethasone suppression test (ODST) as a screening test for Cushing's syndrome in obese patients. Research Methods and Procedures: Eighty-six obese patients (body mass index, 30 to 53 kg/m²) that were referred to a general endocrine outpatient clinic for evaluation of simple obesity, diabetes mellitus, hypertension, polycystic ovary disease, or pituitary tumor. One milligram dexamethasone was administered orally at 11:00 pm , and serum cortisol levels were measured the following morning between 8:00 am and 9:00 am . Suppression of serum cortisol to <80 nM (3 μg/dL) was chosen as the cut-off point for normal suppression. Patients with serum cortisol levels ≥80 nM were evaluated for Cushing's syndrome. Results: Suppression of morning cortisol levels to <80 nM occurred in 79 of the 86 obese patients. Seven patients had serum cortisol levels higher than 80 nM; five were eventually diagnosed with Cushing's syndrome and two were considered false positive results in view of normal 24-hour free urinary cortisol and normal suppression on a low dose dexamethasone suppression test (0.5 mg of dexamethasone every 6 hours for 2 days). We found a false positive rate of 2.3% for the ODST using a cut-off serum cortisol of 80 nM. Discussion: The ODST is a valid screening test for Cushing's syndrome in the obese population. The false positive rate was 2.3%, even when using a strict cut-off serum cortisol of 80 nM. Abnormal cortisol suppression in obese patients should be investigated and not be considered false positive results.     

Overnight dexamethasone suppression test: normal responses and the diagnosis of Cushing's syndrome

Serum cortisol levels were measured the morning after the administration of 1 mg of dexamethasone. Only 5 of 190 subjects had serum cortisol levels greater than 2 micrograms/dL. Thus, the normal value after dexamethasone suppression is less than 2 micrograms/dL rather than less than 5 micrograms/dL as has generally been accepted. The distinction is important because some individuals with Cushing's syndrome partially suppress their cortisol levels to less than 5 but more than 2 micrograms/dL during the test procedure. Thus, the use of 5 micrograms/dL as the normal value may lead to an unnecessary delay in diagnosis.     

Evaluation of hepatic 11 beta-hydroxysteroid dehydrogenase activity by cortisone acetate test in young adults with diabetes mellitus type 1

Cortisone acetate test was performed in twelve young adult patients with diabetes mellitus type 1, after dexamethasone administration to suppress endogenous cortisol production. Previous screening revealed that all of the subjects had peak cortisol responses in the range from subnormal to normal, as determined by a low-dose Synacthen test. The aim was to find out whether these patients would exhibit different conversion of cortisone to cortisol by 11beta-hydroxysteroid dehydrogenase. Using multifactorial ANOVA the following significant relationships were obtained between cortisol or cortisol/cortisone ratio measured during the test and other parameters examined a) before dexamethasone suppression and b) during the test: a) Cortisol at 120(th) minute negatively correlated with daily insulin dose and positively with basal aldosterone. Cortisol/cortisone ratio at 60(th), 120(th), 180(th), and 240(th) minute negatively correlated with basal aldosterone/plasma renin activity ratio, urinary free cortisol/24 hours and positively with basal dehydroepindrosterone sulphate. b) Cortisol at 120(th) minute negatively correlated with suppressed basal serum glycemia; cortisol/cortisone ratio during the whole test negatively correlated with supressed basal ACTH. The examination of peripheral metabolism of cortisol using cortisone acetate test in patients with diabetes mellitus type 1 showed adaptive changes of 11beta-hydroxysteroid dehydrogenace activity associated with altered cortisol tissue supply.     

Diagnostic value of salivary cortisol in children with abnormal adrenal cortex functions

AIMS: It has been shown that the free cortisol level in saliva may reflect plasma free cortisol. The measurement of cortisol in saliva is a simple method, and as such it is important in the pediatric age group. In this research, the diagnostic value of measurement of salivary cortisol (SC) measurement was examined in adrenal insufficiency (AI). METHODS: Fifty-one patients, mean age 10.8 +/- 4.29, who were investigated for possible AI, were included. Basal cortisol levels were below 18 microg/dl. Adrenal function was determined by low-dose ACTH test. During the test, samples for SC were obtained simultaneously with serum samples (at 0-10-20-30-40 min). RESULTS: Mean basal serum cortisol level was 8.21 +/- 4.10 microg/dl (mean +/- SD). Basal SC was correlated to basal serum cortisol (r = 0.64, p < 0.001). A cut-off of 0.94 microg/dl for SC differentiated adrenal insufficient subjects from normals with a sensitivity and specificity of 80 and 77%, respectively. A peak SC less than 0.62 microg/dl defined AI with a specificity of 100%; however, sensitivity was 44%. CONCLUSION: Measurement of SC may be used in the evaluation of AI. It is well-correlated to serum cortisol. Peak SC in low-dose ACTH test can be used to differentiate patients with AI in the initial evaluation of individuals with suspected AI.     

Adrenocorticotropic Hormone Stimulation Test During High-Dose Glucocorticoid Therapy

ObjectiveTo define the effective time frame of adequate serum cortisol response to the short standard 250-μg adrenocorticotropic hormone stimulation test (ACTH-ST) after initiation of high-dose glucocorticoid therapy in order to assist in the diagnosis of adrenal insufficiency.MethodsWe performed an ACTH-ST at 4 different times in hospitalized patients, who had a documented intact hypothalamic-pituitary-adrenal axis and were receiving high-dose dexamethasone therapy for nonendocrine diseases, to determine the time until the serum cortisol response is compromised. The ACTH-ST was performed at the following time intervals after initiation of dexamethasone therapy—24, 48, 72, and 96 hours. The outcome measures were cortisol levels measured at 0, 30, and 60 minutes after administration of 250 μg of cosyntropin.ResultsOf the overall group of 11 study patients, all those (n = 8) tested within the first 72 hours after initiation of dexamethasone therapy had an adequate response (serum cortisol level at 60 minutes, ≥ 18 μg/dL). Two of the 3 patients tested at 96 hours after initiation of dexamethasone therapy had a suppressed cortisol response at 60 minutes. At 30 minutes, all cortisol levels except 1 were inadequate (< 18 μg/dL).ConclusionThis study suggests indirectly that the ACTH-ST may be used for the diagnosis of suspected adrenal insufficiency within the first 3 days after initiation of empiric glucocorticoid therapy. An inadequate response of serum cortisol at 60 minutes to the ACTH-ST may be indicative of adrenal insufficiency in this setting. Additional studies with more patients in each therapy time point are needed to confirm these initial results. (Endocr Pract. 2009;15:122-127)     

Serum total prostate-specific antigen assay in women with Cushing's disease or alcohol-dependent pseudo-Cushing's State

BACKGROUND: The distinction between Cushing's disease (Cushing's syndrome dependent on adrenocorticotropic hormone (ACTH)-secreting tumors of pituitary origin) and pseudo-Cushing's states (Cushingoid features and hypercortisolism sometimes present in alcoholic, depressed or obese subjects) can present a diagnostic challenge in clinical endocrinology. Recently, the availability of a highly sensitive immunofluorometric assay for the measurement of total prostate-specific antigen (PSA) provided the possibility to measure serum PSA levels in women. Interestingly, PSA gene expression and protein production has been found to be upregulated by steroid hormones, such as androgens, glucocorticoids, mineral corticoids and progestins. In fact, serum total PSA concentrations appear to be higher in female patients with Cushing's disease than in normal women. We wondered whether a similar phenomenon also occurs in pseudo-Cushing's state. METHODS: In order to answer this question, we compared the serum total PSA levels measured in 10 female subjects with alcohol-dependent pseudo-Cushing's state with those observed in 8 female patients with Cushing's disease and in 15 age-matched healthy women. Serum testosterone, ACTH and cortisol, and 24-hour urinary cortisol levels were measured; cortisol suppression after dexamethasone was also tested in all subjects. RESULTS: The basal serum levels of ACTH and cortisol were significantly lower in normal subjects than in patients with Cushing's disease or pseudo-Cushing's state; these latter groups showed similar basal hormonal values. Dexamethasone administration was unable to suppress serum cortisol levels in 5 subjects with Cushing's disease and 6 subjects with pseudo-Cushing's state. Serum testosterone values in the group with Cushing's disease were higher than in the other groups. No differences were observed between pseudo-Cushing's and normal subjects. Serum total PSA levels were significantly higher in women with Cushing's disease than in subjects with pseudo-Cushing's state and normal controls; these latter groups showed similar PSA values. When serum total PSA and testosterone levels were considered together, a significant positive correlation was observed in the group with Cushing's disease, but not in the other groups. CONCLUSIONS: These data indicate that the steroid milieu responsible for the elevation in serum PSA in women with Cushing's disease is not present in subjects with alcohol-dependent pseudo-Cushing's state, suggesting the possible use of PSA as a marker of differentiation between these pathological conditions in women.     

Alterations of irisin concentrations in saliva and serum of obese and normal-weight subjects,before and after 45 min of a Turkish bath or running

The purpose of this study was to ascertain (1) whether human saliva contains irisin and whether its level correlates with serum irisin concentration, (2) whether salivary glands, eccrine glands and sebaceous glands in human skin produce irisin, (3) how the changes in saliva and serum irisin concentrations after the Turkish bath at 47 ± 3 °C compare with the changes caused by moderate exercise in obese and normal weight subjects. Seven obese male subjects and seven normal weight subjects were enrolled for Turkish bath. Seven obese male subjects and seven normal weight subjects were also enrolled for moderate outdoor exercise, and thirteen male normal weight subjects neither exercised nor showered at the Turkish bath. From each participant, 1.5 ml of saliva and 5 ml blood were collected simultaneously before and after the moderate exercise and Turkish bath. Salivary glands and eccrine and sebaceous glands in the skin were screened immunohistochemically for irisin while serum and saliva irisin were measured with an ELISA. Submandibular glands, eccrine glands and sebaceous glands in the human skin showed strong irisin immunoreactivity. Human saliva contained irisin and its level was significantly higher than the serum levels in both obese and normal weight subjects. However, irisin concentrations were more markedly increased in both saliva and serum samples from subjects who had showered at a Turkish bath than in obese subjects who had exercised or in normal weight subjects. Human submandibular glands, eccrine sweat glands and sebaceous glands synthesize irisin.     

Radioimmunoassay of cortisol in saliva.

A direct (without extraction) radioimmunoassay of cortisol in saliva has been developed. The samples of saliva were subjected to four freezing-thawing cycles in order to decrease viscosity which may interfere with the determination. The method is simple, has good specificity and reproducibility. The determination in saliva has also the merit of noninvasiveness, and besides, the level of cortisol in saliva reflects the free, biologically active fraction of the hormone in blood serum. The volume of saliva required does not exceed 25 microliters per tube and the range of concentrations is between 0.6 and 15 nanograms per milliliter (1.5-40 nmol/l).     

Enzyme immunoassay for serum dexamethasone using 4-(carboxymethylthio)dexamethasone as a new hapten.

A sensitive and simple enzyme immunoassay for direct quantitation of serum dexamethasone was established. An antiserum with high specificity was produced by the immunization of rabbits with a newly synthesized 4-(carboxymethylthio)dexamethasone-bovine serum albumin conjugate. Alkaline phosphatase was used as a labeling enzyme. The minimum amount of dexamethasone detected was 2 pg per tube on the basis of B/Bo 100 - 2 SD (%) of standard curve. However, taking into account the cross-reaction with steroids such as cortisol in dexamethasone-free serum, the measurable range was from approximately 0.13 to 10 micrograms/dl. Intra- and interassay coefficients of variation were 1.5 - 5.4% and 0.6 - 6.5%, respectively. Serum levels of dexamethasone and cortisol in four normal subjects after an oral administration of 1 mg of dexamethasone are also reported.     

Plasma and salivary 6beta-hydroxycortisol measurements for assessing adrenocortical activity in patients with adrenocortical adenomas.

The aim of this study was to examine and compare the potential usefulness of plasma and salivary 6beta-hydroxycortisol measurements for assessing adrenocortical activity in patients with adrenocortical adenomas. Plasma and salivary cortisol as well as 6beta-hydroxycortisol determinations were performed by radioimmunoassay after extraction with ethyl acetate followed by chromatographic separation using a modified paper chromatographic system. Samples were obtained from 36 control subjects and 37 patients with non-hyperfunctioning adrenocortical adenomas in the morning at 8 a.m. after a low-dose of dexamethasone and after stimulation with synthetic depot ACTH. Basal and post-dexamethasone hormone levels were also measured in plasma and salivary samples of 4 patients with Cushing's syndrome from adrenal adenomas. In the baseline state, patients with non-hyperfunctioning adrenocortical adenomas had significantly higher plasma and salivary 6beta-hydroxycortisol levels (mean+/-SE, 79.0+/-7 and 17.1+/-2.2 ng/dl, respectively) compared to those measured in controls (62.0+/-4 and 7.7+/-0.6 ng/dl, respectively), whereas baseline plasma and salivary cortisol levels (9.6+/-0.5 microg/dl and 342+/-39 ng/dl, respectively) were similar to those measured in the control group (9.9+/-0.4 microg/dl and 366+/-24 ng/dl, respectively). In all groups, the changes in plasma and salivary 6beta-hydroxycortisol concentrations after dexamethasone suppression and ACTH stimulation were similar to the changes in plasma and salivary cortisol levels, although the differing ratios of 6betaOHF to cortisol indicated potentially important variations in the induction of 6beta-hydroxylase activity between the three groups. In patients with Cushing's syndrome, baseline plasma and salivary 6beta-hydroxycortisol concentrations (754+/-444 and 104+/-88 ng/dl, respectively) were more markedly increased than plasma and salivary cortisol levels (24.8+/-6.7 microg/dl and 1100+/-184 ng/dl, respectively), and all remained non-suppressible after dexamethasone administration. These results suggests that plasma and salivary 6beta-hydroxycortisol determinations may precisely detect not only overt increases of cortisol secretion in patients with Cushing's syndrome but also mild glucocorticoid overproduction presumably present in patients with non-hyperfunctioning adrenocortical tumors.     

Changes in aldosterone and cortisol secretion and serum thyroxine levels in patients with active urolithiasis

The changes in calcemia and calciuria levels following low calcium diet have been studied in 35 patients with active urolithiasis and in 20 healthy subjects. Blood serum concentrations of thyroxine, cortisol and aldosterone in basal conditions as well as cortisol and aldosterone following stimulation with synacten were determined in addition. The levels of calcemia and calciuria (2.56 +/- 0.015 mmol/l and 4.70 +/- 0.41 mmol/10 mmoles of creatinine, respectively) were found to be significantly higher in patients with active urolithiasis than in healthy subjects. In addition, in patients with urolithiasis the basal blood serum concentrations of thyroxine and aldosterone were significantly higher than in healthy subjects, while the reactivity of cortisol and aldosterone secretion to synacten stimulation was normal. The results obtained suggest the participation of the described hormonal aberrations in the pathogenesis of active urolithiasis.