Comparison of total and salivary cortisol in a low-dose ACTH (Synacthen) test: influence of three-month oral contraceptives administration to healthy women

The objective of this study was to evaluate the influence of low-dose combined oral contraception (COC) on basal and stimulated (1 microg ACTH test) levels of serum and salivary cortisol (F), cortisone and on basal serum cortisol binding globulin (CBG), adrenocorticotropic hormone (ACTH), dehydroepiadrosterone (DHEA) and calculated free cortisol in healthy young women. Three-month administration of COC resulted in 1) significant increase of basal (454.0+/-125.0 to 860.9+/-179.7 nmol/l) and ACTH-stimulated serum cortisol in 30th min (652.3+/-60.5 to 1374.1+/-240.6 nmol/l); 2) no significant change of basal (15.4+/-7.3 to 18.9+/-8.5 nmol/l) and ACTH-stimulated salivary cortisol at the 30th min (32.4+/-8.8 to 32.9+/-9.0 nmol/l); 3) no significant change of basal serum cortisone (38,8+/-7.68 to 45.2+/-24.2 nmol/l) and ACTH-stimulated cortisone at the 30th (34.8+/-10.9 to 47.0+/-35.7 nmol/l); 4) significant increase of basal ACTH (17.2+/-9.0 to 38.2+/-29.4 ng/l), CBG (991.0+/-161.0 to 2332.0+/-428.0 nmol/l), and 5) no significant change of basal DHEA (24.6+/-15.7 to 22.6+/-11.7 micromol/l) and calculated basal value for free cortisol (22.8+/-14.9 to 19.2+/-6.9 nmol/l). In conclusions, higher basal and ACTH-stimulated serum cortisol were found after three-month administration of COC, while basal and stimulated salivary cortisol were not significantly affected. Therefore, salivary cortisol can be used for assessment of adrenal function in women regularly using COC.     

Increased ratio of serum cortisol to cortisone in acute-phase response

BACKGROUND/OBJECTIVES: 11beta-Hydroxysteroid dehydrogenase (11beta-HSD) enzymes convert cortisol into inactive cortisone and vice versa. While 11beta-HSD type 2 (mainly localized in the kidney) unidirectionally inactivates cortisol to cortisone, type I isoform (mainly localized in the liver) acts bidirectionally and can thus potentially restore cortisone to active cortisol. The aim of this pilot study was to investigate whether the serum cortisol:cortisone ratio is altered during the acute-phase response, possibly due to altered modulation of 11beta-hydroxysteroid dehydrogenase isoforms. METHODS: Using liquid chromatography electrospray tandem mass spectrometry, cortisol and cortisone were measured in the serum of hospitalized patients with normal and abnormal CRP concentrations, the latter indicating acute-phase response. Fifteen unselected samples were analyzed, all with a CRP concentration within one of the following ranges to cover a wide range of CRP concentrations evenly: <5, 5-20, 21-50, 51-100, 101-200, and >200 mg/l. RESULTS: In the heterogeneous study population, increased CRP concentrations significantly correlated with an increased cortisol:cortisone ratio (p < 0.001; r = 0.65, Spearman correlation coefficient). This correlation was independent of increased serum cortisol concentrations found by multivariate regression analysis. The median ratio was 6.4 (interquartile range 5.5-7.4; n = 30) in patients with a CRP concentration < or =20 mg/l, and 11.2 (interquartile range 8.8-13.9; n = 60) in patients with CRP >20 mg/l (p < 0.01). CONCLUSION: The balance between serum cortisol and cortisone is altered during acute-phase response with a shift towards active cortisol, suggesting that 11beta-HSD isoenzymes play a role in the modulation of systemically available cortisol during acute illness.     

Urinary high performance reverse phase chromatography cortisol and cortisone analyses before and at the end of a race in elite cyclists

A functional and basic method for the quantitative analysis of urine cortisol (F) and cortisone (E) using a Solid-Phase Extraction column and HPLC with ultraviolet detection is here described and validated to analyse urine samples. Urine specimens were analysed to study F and E relation and ratio in athletes and healthy sedentary subjects. The F and E concentrations in random urine specimens were significantly higher in the post exercise versus pre exercise condition in cyclists (F: 136+/-93 nmol/l versus 67+/-50 nmol/l (p<0.001); E: 797+/-400 nmol/l versus 408+/-252 nmol/l (p<0.001)). The F/E ratio was 0.18+/-0.11 versus 0.16+/-0.07, respectively, and a significant difference was only demonstrated comparing sedentary (0.11+/-0.07) and cyclist individuals at rest (p<0.05).     

Blood levels of corticosteroid-binding globulin, total cortisol and unbound cortisol in patients undergoing coronary artery bypass grafting surgery with cardiopulmonary bypass

Previous studies have demonstrated a persistent rise in serum cortisol concentrations after cardiac surgery. To further investigate this finding and to evaluate the effect of hemodilution that occurs with the onset of cardiopulmonary bypass (CPB), concentrations of cortisol-binding globulin (CBG), total and unbound cortisol, and packed cell volume (PCV) were studied in 28 patients undergoing coronary artery bypass graft surgery. All patients received a standardized general anesthetic using a balanced technique with sufentanil, isoflurane, and midazolam. Blood was collected preoperatively, intraoperatively during CPB, and postoperatively in the evenings on the day of surgery and on the first and second postoperative day. Cortisol and CBG concentrations were measured by radioimmunoassay and were used to calculate the fraction of unbound cortisol. Serum CBG and cortisol concentrations corrected for hemodilution were significantly higher than non-corrected values. Perioperatively, CBG measurements were significantly intercorrelated. Intraoperatively, total and unbound cortisol concentrations were not significantly increased compared to preoperative values. Postoperatively up to the end of the study period serum concentrations of total and unbound cortisol were significantly increased compared to baseline values. Our results suggest that hemodilution occurs in all patients during cardiac surgery and continues up to the second postoperative day. This may lead to an underestimation of serum cortisol and CBG concentrations in patients undergoing heart surgery with CPB. Intraoperatively, concentrations of total and unbound cortisol were not significantly elevated. The postoperative rise in serum total cortisol concentration was accompanied by an increase in unbound cortisol concentration. The postoperative increase of unbound cortisol concentrations in patients undergoing cardiac surgery with CPB was largely due to an increase in cortisol secretion.     

Markers of acute stress in pigs

This study explores the biological validation of markers of acute stress in pigs subjected to transportation for slaughter. The stress markers selected for monitoring were neopterin and cortisol. Their levels in pig serum were measured for two porcine stress syndrome genotypes, NN and Nn, after a 30-min transport to a slaughterhouse. Blood samples were withdrawn before transport (control group) and immediately after the animals' arrival (experimental group). The values of neopterin and cortisol measured before the transport were 5.60+/-1.65 nmol/l and 273.54+/-66.17 nmol/l respectively. After the transfer, the concentration of cortisol rose significantly compared to the control (355.69+/-85.13 nmol/l, p<0.01). Neopterin concentrations in the serum (8.25+/-1.60 nmol/l) were also significantly higher (p<0.01) after transportation. The elevated concentrations of both analytes were found to be independent of the genotype. These results document the stimulation of the endocrine system and the immune system that develops in animals undergoing transportation for slaughter.     

Validation and application of a highly specific and sensitive ELISA for the estimation of cortisone in saliva, urine and in vitro cell-culture media by using a novel antibody

It is generally acknowledged that local tissue concentrations of cortisol and cortisone are modulated by site-specific actions of 11β-hydroxysteroid dehydrogenase (11β-HSD) isoenzymes 1 and 2. Cortisone, the inactive metabolite of cortisol is produced by 11βHSD type 2. To assess 11β-HSD types 1 and 2 activities, the cortisol/cortisone ratio has to be accurately determined. Immunoassays to measure cortisone levels are not widely available and tend to lack specificity. The aim of this project was to develop a highly specific and sensitive ELISA method for the estimation of free cortisone levels in urine, saliva and in vitro media samples without chromatographic separation. Antibodies against cortisone were raised in rabbits using cortisone-3-CMO-KLH as immunogen. HRP-goat anti-rabbit IgG conjugate was used as enzyme tracer. Cross-reactivities of the untreated cortisone antiserum with major interfering steroids were minimal except for cortisol (3.15%). However, following an immune-affinity purification of the antibodies using CNBr-activated sepharose-cortisol-3-CMO-BSA, cross-reactivity of the purified cortisone antibody with cortisol was reduced to 0.27%. The minimum detection limit of cortisone ELISA was 28 pg/mL (77.7 pM). The validity of the cortisone ELISA was confirmed by the excellent correlation obtained before and after an HPLC fractionation step (Y=1.09X-0.21, R2=0.98). Intra-assay and inter-assay imprecision were 5.5-11.7% and 8.7-12.8% CV, respectively. Using this assay, salivary cortisone levels showed a circadian rhythm in men and women (11.2±7.3 nM at 08.00 h and 5.1±3.6 nM at 18.00 h), and the levels were reduced following liquorice ingestion. In media of adrenocortical H295 cell line incubations, basal cortisone levels were 4.24±0.22 nM that increased to 8.6±1.2 nM post forskolin treatment. Urinary free cortisone excretion levels in healthy subjects were 56.66±36.9 nmol/day. In human volunteers following ingestion of green coffee bean extract for 2 weeks, urinary free cortisol excretion reduced significantly from 66.67±22.3 to 42.66±17.5 nmol/day (p=0.02) and the cortisol/cortisone ratio from 2.04±1.33 to 1.49±1.13, p=0.05. In conclusion, a simple and highly specific and sensitive ELISA has been developed and applied to estimate cortisone levels in biological fluids and culture media.     

Salivary cortisol in low dose (1 microg) ACTH test in healthy women: comparison with serum cortisol

To date, a single report has appeared on the use of salivary cortisol for adrenal function testing with a low dose ACTH, although 1 microg has become preferred as a more physiological stimulus than the commonly used 250 microg ACTH test. Our present study was aimed to obtain physiological data on changes of free salivary cortisol after 1 microg ACTH stimulation. This approach was compared with the common method based on the changes of total serum cortisol. Intravenous, low-dose ACTH test was performed in 15 healthy women (aged 22-40 years) with normal body weight, not using hormonal contraceptives, in the follicular phase of the menstrual cycle. Blood and saliva for determination of cortisol were collected before ACTH administration and 30 and 60 min after ACTH administration. Basal concentration of salivary cortisol (mean +/- S.E.M., 15.9+/-1.96 nmol/l) increased after 1 microg ACTH to 29.1+/-2.01 nmol/l after 30 min, and to 27.4+/-2.15 nmol/l after 60 min. The differences between basal and stimulated values were highly significant (p<0.0001). The values of salivary cortisol displayed very little interindividual variability (p<0.04) in contrast to total serum cortisol values (p<0.0001) A comparison of areas under the curve (AUC) related to initial values indicated significantly higher AUC values for salivary cortisol than for total serum cortisol (1.89+/-0.88 vs. 1.22+/-0.19, p<0.01). Correlation analysis of serum and salivary cortisol levels showed a borderline relationship between basal levels (r=0.5183, p=0.0525); correlations after stimulation were not significant. Low-dose ACTH administration appeared as a sufficient stimulus for increasing salivary cortisol to a range considered as a normal adrenal functional reserve.     

The potential role of hypocortisolism in the pathophysiology of PTSD and psoriasis

Different physical, chemical and psychological stressors can provoke a unique but different endocrine response involving activation of the hypothalamo-pituitary-adrenal (HPA) axis. Inability of adequate compensatory reaction can lead to many disorders. The aim of our study was comparison of cortisol values in diseases provoked by various stressors. Our investigation included 34 posttraumatic stress disorder (PTSD) patients, as an example of disorder caused by extremely strong, acute stressful stimulus, 19 psoriatic patients, as an example of chronic stress stimulus and 17 healthy volunteers. In each patient we determined 24-hour urinary cortisol, serum cortisol at 8 a.m. and 5 p.m., and cortisol in dexamethasone suppression test by the standard radioimmunoassay (RIA) method. PTSD patients showed lower urinary 24-hour cortisol values, (361 +/- 28 nmol/24 h), "stronger" circadian rhythm of serum cortisol (595 +/- 57 nmol/l at 8 a.m. and 242 +/- 23 nmol/l at 5 p.m.) and attenuated suppression of cortisol in dexamethasone suppression test (197 +/- 45 nmol/l) in comparison to healthy volunteers (590 +/- 87 nmol/24 h urine, 590 +/- 32 nmol/l at 8 a.m., 402 +/- 31 nmol/l, and < 86 nmol/l in dexa test). Psoriatic patients showed markedly lower 24-hour cortisol values (150 +/- 98 nmol/24 h), even in comparison to PTSD patients, then serum cortisol values (404 +/- 138 nmol/l at 8 a.m., 187 +/- 80 nmol/l at 5 p.m.) and enhanced suppression of cortisol (23 +/- 5 nmol/l). The model of attenuated feedback inhibition in PTSD patients shows that they are unusually reactive to stress and represents an alternative model of acute stress reaction to extremely strong stressful stimulus. Unusually low cortisol values in psoriatic patients correlate to our hypothesis that in chronic stress-related disease, as psoriasis is, exists, by still undefined mechanism, altered HPA axis function, which is obviously incompetent to realise its immunoregulatory function, so consequentially, clinical signs of psoriasis persist.     

Hormonal indices of the normal dolphin Turpsiops truncatus and in the dynamics of experimental stress

Radioimmune assay has been made of the content of cortisol, insulin, triiodothyronine (T3) and thyroxine (T4) in the blood serum of the dolphin under normal conditions and during 3- ad 6-hour stress. Normal levels of these hormones were found to be equal to 90.34 +/- 6.86 nmol/l, for cortisol, 64.1 +/- 11.1 pmol/l for insulin, 1.27 +/- 0.04 nmol/l for T3 and 138.3 +/- 8.9 nmol/l for T4. Seasonal changes in cortisol level were observed, hormonal concentration being significantly higher during winter and spring as compared to that during summer and autumn. On the whole, the dynamics of hormonal shifts during stress reaction in the dolphin is similar to that in the terrestrial animals reflecting the development of general adaptive syndrome.     

Changes of several adrenal delta 4-steroids measured by HPLC-UV spectrometry in neonatal patients with congenital adrenal hyperplasia due to 21-hydroxylase deficiency

We have developed an easy and rapid method of reverse-phase high-performance liquid chromatography (HPLC)-UV spectrometry for measuring adrenal delta 4-steroids. Three female neonates with adrenal 21-hydroxylase deficiency (2 salt-losers and 1 simple virilizer), two of whom were recalled by neonatal mass-screening for congenital adrenal hyperplasia (CAH), were diagnosed using this method. Changes of several adrenal steroids were examined in these patients before and after treatment with hydrocortisone. Before treatment, the cortisone and cortisol peaks were very low and those of 17 alpha-hydroxyprogesterone (17-OHP) and 21-deoxycortisol (21-DOF) were high in all 3 patients (17-OHP: 79.9-997 nmol/l, 21-DOF: 83.7-324 nmol/l). The androstenedione peak was also high in 2 of them. A peak produced by 21-deoxycortisone, which is a product of oxidation of 21-DOF at the C-11 position, was also detected in all cases (14.5-297 nmol/l). After treatment, all of these abnormally elevated delta 4-steroids decreased or disappeared. This new method is thought to be valuable for the rapid diagnosis of CAH, and especially for use in neonatal mass-screening for CAH.     

Variable sensitivity to the glucocorticoid activity of cortisol in patients with primary adrenal insufficiency: assessment with ACTH profiles

Our aim was to investigate the usefulness of circulating levels of adrenocorticotropic hormone (ACTH) and also salivary cortisol to monitor cortisone substitution in patients with Addison's disease. 13 patients with primary adrenal insufficiency (8 women and 5 men, age 44 ± 11 years) received 12.5 mg cortisone acetate orally at 16:00 h and 25 mg at 07:00 h. Blood samples for cortisol and ACTH analysis were drawn every hour for 24 h, and also every half hour between 07:00 and 12:00 h. Samples for salivary cortisol were collected in parallel. Total ACTH levels showed large inter-individual variations and a diurnal rhythm with a nadir in the early evening at 19:00 (median 19 ng/l, range 2-434 ng/l) and high levels in the early morning, with a peak around 07:30 (median 844 ng/l, range 45-2,249 ng/l). Plasma cortisol concentrations showed 2 peaks distinct in time, but variable in height, 1-2 h after intake of cortisone. Plasma cortisol correlated significantly with ln(ACTH) at 17:00 h (r=-0.56), at 10:00 h (r=-0.51), and at 10.30 h (r=-0.57). When tested at different time points, ln(ACTH) at 10:00 to 12:00 h was negatively correlated with plasma cortisol between 08:30 and 12:00 h. Plasma cortisol was highly correlated to ln(salivary cortisol) most of the time points measured, but 30-60 min after intake of cortisone acetate the correlation disappeared. In conclusion, the large interindividual variation in ACTH levels most likely indicates varying sensitivity to cortisol with a need for individualized dosing schemes. Furthermore ACTH-determinations may be useful for dose titration of cortisol.     

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.     

Dynamics of endogenous glucocorticoid secretion and its metabolism in Kawasaki disease

Objective

Kawasaki disease (KD) is a severe inflammatory disease that occurs in childhood. Recently, the initial corticosteroid therapy for KD has been reconsidered because its efficacy is controversial. The aim of this study was to evaluate the dynamic change in endogenous glucocorticoid levels and their relation with 11beta-hydroxysteroid dehydrogenase (11β-HSD) activity in the acute phase of KD.

Study design

Sixteen KD patients were investigated. Cortisol and cortisone levels, the cortisol/cortisone ratio and C-reactive protein (CRP) levels were measured on admission, before the first intravenous immunoglobulin (IVIG) therapy and convalescence.

Results

The 16 patients were divided into two groups. Group A included patients who received the first IVIG on admission and blood samples were collected before the first IVIG and convalescence. Group B included patients whose blood samples were collected at three different time points (on admission, before the first IVIG, and convalescence). CRP and cortisol levels and the cortisol/cortisol ratio were markedly higher before the first IVIG than those of convalescence in all patients except in one patient. In Group B patients, both serum cortisol levels and the cortisol/cortisone ratio on admission were significantly increased compared with those before the first IVIG (cortisol: p < 0.005, cortisol/cortisone: p < 0.001).

Conclusions

Decreases in cortisol levels and the cortisol/cortisone ratio before the first IVIG may be explained by a reduction in adrenal secretion and/or local glucocorticoid action through 11β-HSD activity. These findings suggest that exogenous glucocorticoid treatment in combination with the first IVIG at the acute stage may play a synergetic role in KD.     

Plasma levels of adrenocorticotropic hormone and cortisol in people living in an environment below sea level (Jordan Valley) during fasting in the month of Ramadan

OBJECTIVES: To investigate the effects of Ramadan fasting on plasma levels of ACTH and cortisol in athletic students living in the Jordan Valley (JV) and compare them to those living at above sea level in Ramtha City (RC). METHODS: Sample collection and measurements were done in November 1998 from non-fasting and in December 1998 from fasting people. RESULTS: ACTH levels in non-fasting subjects in the JV were 36 +/- 4 IU/ml compared to 43 +/- 3 IU/ml for those in RC. Cortisol levels were 483 +/- 76 (JV) and 539 +/- 89 nmol/l (RC). Fasting led to an increase in ACTH (49 +/- 6 (JV) and 58 +/- 5 IU/ml (RC)) and cortisol levels (637 +/- 101 (JV) and 805 +/- 72 nmol/l (RC)). CONCLUSION: Fasting increases ACTH and cortisol levels in an altitude-independent fashion.     

Adrenal cortical response in clinically normal dogs before and after adaptation to a housing environment

58 dogs (29 males and 29 females) selected as healthy on clinical and biochemical evaluations were subjected to an ACTH adrenal function test 2 days after their admission to a veterinary hospital (t + 0). Basal female serum cortisol concentrations were significantly higher than concentrations in males (77 nmol/l versus 43 nmol/l; P less than 0.01). Concentrations post stimulation were not statistically different (P greater than 0.05) between males and females: 306 (+/- 69) nmol/l versus 291 (+/- 73) nmol/l, respectively. Twelve dogs (6 males and 6 females), randomly selected from the 58, were subjected to the same test 5 weeks later (t + 5) and 12 weeks later (t + 12). Basal cortisol concentrations were lower at t + 5 or at t + 12 than at t + 0. Post stimulation mean cortisol concentrations were lower in males than in females at t + 5 (162 versus 232 nmol/l; P less than 0.05) but not at t + 0 (262 versus 320 nmol/l; P greater than 0.05) and t + 12 (188 versus 233 nmol/l; P greater than 0.05). These findings are indicating an increased susceptibility of bitches to environmental stress.     

Diet and serum sex hormones in healthy men

The possible effect of dietary fat content and the ratio of polyunsaturated to saturated fatty acids (P/S-ratio) on serum sex hormones was studied in 30 healthy male volunteers. The customary diet of the subjects, which supplied 40% of energy as fat (mainly from animal sources, P/S-ratio 0.15) was replaced for a 6 weeks period by a practically isocaloric experimental diet containing significantly less fat (25% of energy) with a higher P/S-ratio (1.22) and other environmental factors were stabilized. Serum testosterone and 4-androstenedione decreased from 22.7 +/- 1.1 nmol/l to 19.3 +/- 1.2 nmol/l, (SEM, P less than 0.001) and from 4.6 +/- 0.2 nmol/l to 4.3 +/- 0.2 nmol/l (SEM, P less than 0.01), respectively. These changes were paralleled by a reduction in serum free (non-protein bound) testosterone (P less than 0.01) suggesting a possible change in biological activity. During the low fat period a significant negative correlation between serum prolactin and androgens was observed. All the changes in androgen levels were reversible. With the exception of a small but non-significant decrease in serum estradiol-17 beta, the other hormone parameters were practically unaffected by the dietary manipulation. Our results indicate that in men a decrease in dietary fat content and an increase in the degree of unsaturation of fatty acids reduces the serum concentrations of androstenedione, testosterone and free testosterone. The mechanism and importance of this phenomenon is discussed in the light of epidemiological and experimental data.     

Changes in the levels of growth hormones, insulin, cortisol, thyroxine and somatomedin-C/IGF-1, with increasing gestational age in the fetal pig, and the effect of thyroidectomy in utero

1. Blood samples were taken from 30 chronically catheterized pig fetuses in utero. Levels of growth hormone, insulin, cortisol, thyroxine and somatomedin-C/IGF-1 were measured in the plasma of intact fetuses and the plasma of thyroidectomized fetuses at various gestational ages during the latter part of pregnancy. 2. Growth hormone levels were high (mean +/- SEM: 83 +/- 9 ng/ml and remained constant throughout this period. 3. Insulin levels were also constant and ranged between 4 and 14 mU/l. 4. Cortisol levels showed a general increase from 400 nmol/l at 97 days to 1200 nmol/l at term and this increase was not affected by thyroidectomy. 5. IGF-1 levels were lower than in the sows (48.0 +/- 3.0 ng/ml) and did not change throughout this period. 6. Thyroxine levels were also unchanged at about 92 +/- 4 nmol/l. 7. Thyroidectomy resulted in lower (P less than 0.001) thyroxine levels (28 +/- 3 nmol/l) but had no effect on the levels of any other hormone.     

Effect of glucocorticoid excess on the cortisol/cortisone ratio

OBJECTIVE: The conversion of cortisol, which binds avidly to the mineralocorticoid receptor, to cortisone, which no longer has mineralocorticoid function, is predominantly catalyzed by the 11beta-hydroxysteroid dehydrogenase type 2 (11beta-HSD 2). It was the objective of the present study to examine the impact of different forms of glucocorticoid excess on the cortisol/cortisone ratio and to differentiate their role in the genesis of hypertension. DESIGN AND METHODS: Plasma cortisol and cortisone levels were determined in 12 adults with Cushing's disease, 12 adults with hypercortisolism due to an adrenal tumor, and 20 healthy volunteers before and after an intravenous ACTH test, using specific radioimmunoassays after automated Sephadex LH 20 chromatography. RESULTS: The cortisol/cortisone ratios were significantly higher in patients with Cushing's disease (13.9 +/- 1.1), adrenal tumors (11.5 +/- 2.3), and in healthy volunteers after ACTH stimulation (14.1 +/- 2.0) than in untreated controls (6.0 +/- 0.5) (P < 0.001, P < 0.05, and P < 0.001, respectively). Similar differences were seen for cortisol plasma concentrations, whereas cortisone concentrations did not differ among the groups. CONCLUSIONS: Our data suggest that the excessive mineralocorticoid effects in patients with hypercortisolism are inflicted by elevated cortisol/cortisone ratios possibly due to an insufficient conversion of cortisol to cortisone by 11beta-HSD 2. This may provide a possible explanation for the occurrence of hypertension. This effect seems to be independent of the role of ACTH in the mechanism of hypercortisolism.     

The discriminatory value of the low-dose dexamethasone suppression test in the investigation of paediatric Cushing's syndrome

BACKGROUND: Low- and high-dose dexamethasone suppression tests (LDDST, HDDST) are used in the investigation of Cushing's syndrome (CS). In adults with Cushing's disease (CD), cortisol suppression during LDDST predicts suppression during the HDDST. METHODS: We reviewed the results of the LDDST (0.5 mg 6 hourly x 48 h), HDDST (2.0 mg 6 hourly x 48 h) and corticotrophin-releasing hormone (CRH) test in 32 paediatric patients with CS: 24 had CD, 1 ectopic ACTH syndrome, 5 nodular adrenal hyperplasia and 2 adrenocortical tumours. Results: In CD, LDDST suppressed cortisol from 590.7 +/- 168.8 (mean +/- SD) to 333.7 +/- 104.0 nmol/l after 48 h (0 vs. 48 h, p < 0.05; mean suppression, 45.1%; CI (30.8, 59.4%); 16/24 (66%) suppressed >30%; mean suppression 68.1%, CI (58.1, 77.9%)). The HDDST suppressed cortisol from 596.3 +/- 174.5 to 47.1 +/- 94.8 nmol/l after 48 h (0 vs. 48 h, p < 0.05; mean suppression, 93.5%; CI (88.2, 98.8%) with 17/24 (71%) suppressing to <50 nmol/l and 100% to <50% of baseline). In the LDDST, suppression correlated with that during the HDDST (r = +0.45, p < 0.05) with >30% suppression predicting that in the HDDST and hence CD. CRH increased cortisol by +100.3% (CI 62, 138.5%), 22/24 (91.7%) showing a >20% increase. In the other CS pathologies (n = 8) the LDDST induced no significant decrease in cortisol. CONCLUSION: The LDDST was of diagnostic value by discriminating between CD and other CS aetiologies. In our view the HDDST is redundant in the investigation of paediatric CS.     

Effect of reduced uterine blood flow on fetal and maternal cortisol

We have measured the changes in fetal and maternal plasma concentrations of cortisol in relation to blood gases and percent oxygen saturation during 2- and 4-h episodes of reversibly reduced uterine blood flow in sheep between 120 days gestation and term. During that period of reduced uterine blood flow there was a significant decrease in fetal arterial percent oxygen saturation (SaO2), PO2 and pH. Fetal SaO2 decreased from 59.5 +/- 3.2% to 31.8% +/- 2.8% by 15 min, 32.9 +/- 2.9% by 60 min, and 33.5 +/- 2.9% by 120 min. Fetal PO2 decreased from 3.2 +/- 0.1 KPa to 2.0 +/- 0.2 KPa by 15 min, 2.2 +/- 0.2 KPa by 60 min and 2.3 +/- 0.1 KPa by 120 min. Fetal pH decreased from 7.36 +/- 0.01 to 7.30 +/- 0.03 by 15 min, 7.27 +/- 0.02 by 60 min and 7.25 +/- 0.03 by 120 min. During the period of reduced uterine blood flow, fetal plasma concentrations of cortisol increased from 37.1 +/- 10.8 nmol/l to 53.3 +/- 9.2 nmol/l by 15 min, 49.2 +/- 11.4 nmol/l by 60 min and 43.3 +/- 9.0 nmol/l by 120 min. The greatest percentage increase in fetal plasma concentrations of cortisol occurred in fetuses of 126-139 days gestation. There was no significant change in maternal blood gases, SaO2 or plasma concentrations of cortisol. These experiments demonstrate that there is a significant increase in fetal plasma concentrations of cortisol in response to reductions in uterine blood flow from as early as 120 days gestation.