Serum cortisol/cortisone ratio after Synacthen stimulation

OBJECTIVES: 11beta-Hydroxysteroid dehydrogenase (11beta-HSD) enzymes interconvert active cortisol and inactive cortisone. There is growing evidence that local tissue concentrations of cortisol are generally modulated by site specific different 11beta-HSD actions. While 11beta-HSD type 2 unidirectionally inactivates cortisol, type 1 isoform acts bidirectionally. 11beta-HSD type 1 is mainly localized in the liver and may thus restore circulating biologically inactive cortisone to active cortisol thereby modulating systemic glucocorticoid action; such a mechanism might be of importance in stressful situations. To study this hypothesis we investigated the influence of exogenous ACTH on serum cortisol/cortisone ratio. DESIGN AND METHODS: Paired serum samples that were submitted for routine analysis of cortisol before and 1 h after stimulation with 250 microg ACTH (1-24) (Synacthen) were collected prospectively if the routine tests indicated normal adrenal function; 40 patients were included in the study, 29 patients were female, 11 male, median age was 31 yr (range 14-70). Serum cortisol and cortisone were determined using LC-ESI/MS/MS with an online sample extraction system and tri-deuterated cortisol as the internal standard. RESULTS: While mean serum cortisol increased by 109% (mean basal concentration 373 nmol/L (SD 151 nmol/L), stimulated 781 nmol/L (SD 194 nmol/L)), mean serum cortisone significantly decreased after ACTH administration by 31% (p < 0.001, paired t-test for differences). Mean serum cortisone was 70 nmol/L (SD 16 nmol/L) before and 48 nmol (SD 16 nmol/L) after ACTH administration; decrease in serum cortisone was observed in 34 (85%) of the patients. The ratio of serum cortisol/cortisone increased in all subjects (mean 5.4 (SD 1.9) before ACTH, and 16.2 (SD 6.2) after ACTH; p < 0.001). CONCLUSIONS: The data of our observational study suggest a modulation of peripheral metabolism of cortisol by ACTH with a stimulation of systemic 11beta-HSD type 1 activity, leading to restoration of inactive cortisone to biologically active cortisol.     

Corticosteroid-binding globulin and free cortisol in the early postoperative period after cardiac surgery.

OBJECTIVES: To characterize concentrations of corticosteroid-binding globulin (CBG), total and free serum cortisol, and free urinary cortisol in patients during the postoperative period of cardiac surgery. DESIGN AND METHODS: In 24 patients serum was sampled on the first and second postoperative day after cardiac surgery (21 procedures with thoracotomy, 3 thoracoscopic procedures); urine was collected for two 10-h periods (8 P.M. until 6 A.M.) on the respective postoperative days. Total serum cortisol and free urinary cortisol were measured with an automated chemiluminescence assay (analysis of urine after extraction with dichloromethane), and CBG using a coated-tube RIA. Free serum cortisol was calculated from the concentrations of total serum cortisol and CBG as described previously. Thirty healthy volunteers were studied as controls. RESULTS: CBG was reduced to about one-half of the normal concentration on both postoperative days. Whereas total cortisol was about two-fold increased on the first postoperative day compared to controls extremely high concentrations of free serum cortisol were calculated from CBG and total cortisol [median 136 nmol/L (interquartile range 100-185); controls 21.8 nmol/L (interquartile range 16.9-29.8)]. On the second postoperative day, median total serum cortisol was within the interquartile range of the controls, free serum cortisol in contrast was still two-fold increased. Free serum cortisol and free urinary cortisol were significantly correlated (r = 0.60). CONCLUSIONS: Extremely high concentrations of free serum cortisol are typically found in the postoperative period of cardiac surgery; under these conditions the mere consideration of total cortisol does not appropriately display the activation of the adrenal cortex.     

Free serum cortisol during the postoperative acute phase response determined by equilibrium dialysis liquid chromatography-tandem mass spectrometry.

In severely ill patients low concentrations of the corticosteroid binding globulin are typically found; the aim of this study was to quantify directly free bioactive cortisol concentrations in the sera of postoperative cardiosurgical patients. Serum samples of 12 consecutive patients undergoing aortocoronary bypass surgery taken preoperatively and on the postoperative days 1 to 4 were analyzed. Total serum cortisol was quantified using liquid chromatography-tandem mass spectrometry with an on-line sample extraction system and tri-deuterated cortisol as the internal standard, and free serum cortisol was measured after over-night equilibrium dialysis. Whereas on the first postoperative day, the median total serum cortisol concentration was approximately two-fold increased compared to preoperative samples (preoperatively, 245 nmol/l (interquartile range (IQR) 203-293 nmol/l); first postoperative day, 512 nmol/l (IQR 410-611 nmol/l)), median dialyzable free cortisol concentration was almost seven-fold increased (preoperatively, 14.2 nmol/l (IOR 10.9-20.7 nmol/l); first postoperative day, 98.3 nmol/l (IQR 81.3-134 nmol/l)). On the fourth postoperative day, median free cortisol was still significantly increased compared to baseline sampling (p < 0.05), whereas median total cortisol was not. A median of 5.7% (IQR 5.4-7.0%) of total cortisol was found as free cortisol on the preoperative day, 21.2% (IQR 18.9-23.5%) on the first postoperative day and 10.5% (IQR 9.8-14.0%) on the fourth postoperative day. It is concluded that during the postoperative period the free-to-bound ratio of cortisol is highly variable and that during the acute phase response direct quantification of free bioactive cortisol concentrations seems to be biologically more appropriate than the measurement of total cortisol concentrations.     

The hypothalamic-pituitary-adrenal axis of patients with severe sepsis: altered response to corticotropin-releasing hormone

OBJECTIVE: To investigate the functional integrity of the hypothalamic-pituitary-adrenal (HPA) axis in patients with severe sepsis by stimulating with corticotropin-releasing hormone (CRH). DESIGN: Prospective observational study in consecutive intensive care unit patients with severe sepsis. SETTING: Surgical intensive care unit and outpatient department of endocrinology in a university hospital. PATIENTS: The study included 20 patients with the diagnosis of severe sepsis; six critically ill, nonseptic patients after major surgery; ten patients with primary adrenal insufficiency; ten patients with anterior pituitary insufficiency; and ten individuals without clinical signs of HPA axis disturbance. INTERVENTIONS: CRH tests were performed with an intravenous bolus injection of 100 microg of human CRH. MEASUREMENTS AND MAIN RESULTS: We studied the functional integrity of the HPA axis in patients with severe sepsis by performing the CRH test. In addition, during the period of severe sepsis, we repeatedly measured basal plasma concentrations of adrenocorticotropin hormone (ACTH) and cortisol. The mean basal plasma cortisol concentration was decreased significantly in nonsurvivors with severe sepsis (288.8 +/- 29.1 [sem] nmol/L) compared with survivors (468.1+/- 18.6 nmol/L; p <.01). By calculating the ACTH/cortisol indices, we found no evidence for adrenal insufficiency in patients with severe sepsis. The mean ACTH/cortisol indices of nonsurvivors with severe sepsis (0.02 +/- 0.008) and survivors (0.01 +/- 0.002) were significantly lower compared with the index of patients with primary adrenal insufficiency (6.8 +/- 1.0; p <.001). In contrast, in nonsurvivors with severe sepsis, the plasma cortisol response to CRH stimulation was impaired compared with survivors: The mean basal cortisol concentration within the CRH test was 269.4 +/- 39.8 nmol/L in nonsurvivors compared with 470.8 +/- 48.4 nmol/L in survivors and increased to a peak value of 421.6 +/- 72.6 nmol/L in nonsurvivors and 680.7 +/- 43.8 nmol/L in survivors (p <.02). However, the change in plasma cortisol, expressed as mean +/- sem and calculated by subtracting the basal cortisol from the peak cortisol after CRH stimulation, was not significantly different in survivors with severe sepsis (243.5 +/- 36.1, range 111.0-524.0 nmol/L, n = 15) compared with nonsurvivors (161.0 +/- 38.9, range 42.0-245.0 nmol/L, n = 5; p >.05). CONCLUSIONS: We found lower basal plasma cortisol concentrations in nonsurvivors compared with survivors of severe sepsis. In addition, the plasma cortisol response to a single CRH stimulation was impaired in nonsurvivors compared with survivors. Reduced responses to CRH stimulation may reflect a state of endocrinologic organ dysfunction in severe sepsis.     

Defining adrenal status with salivary cortisol by gold-standard insulin hypoglycemia

Background

Insulin-induced hypoglycemia (IHT) is considered the gold standard test for evaluating the HPA axis. Serum free cortisol or its surrogate, salivary cortisol as opposed to total cortisol concentrations, offers a better reflection of the activation of HPA axis. Our study aimed to derive reference ranges for the normal salivary cortisol levels in healthy patients and patients with adrenal insufficiency.

Design and methods

Serum cortisol concentrations, using the gold standard of IHT, and salivary cortisol were obtained. 36 patients referred to our outpatient endocrine testing unit for evaluation of adrenal function were included in the study. Most subjects had a history of suspected hypothalamic/pituitary disease causing adrenal insufficiency.

Results

We found a strong linear correlation between the serum and salivary cortisol concentrations in simultaneously collected samples (r = 0.81, 95% CI 0.74–0.86, p < 0.0001). The corresponding salivary cortisol equivalent to a serum cortisol of 500 nmol/L, using a linear-regression equation, was 16.7 nmol/L (95% CI 13.3–20.1 nmol/L, p = 0.0001). A salivary cortisol of 13.3 nmol/L has a specificity of 89.3% to detect abnormal HPA function. Using the upper 95% CI result of salivary cortisol 20.1 yields a sensitivity of 87.5%.

Conclusion

With the present assay, adrenal insufficiency may be diagnosed with reasonable confidence if a random salivary cortisol is lower than 13.3 nmol/L and excluded if a random salivary cortisol is higher than 20.1 nmol/L. Future studies should correlate these thresholds with clinical outcomes.     

The pituitary-adrenal axis is activated more in non-survivors than in survivors of cardiac arrest, irrespective of therapeutic hypothermia

OBJECTIVE: To investigate the effect of therapeutic hypothermia in the prognostic value of the pituitary-adrenal axis in comatose patients after cardiac arrest. DESIGN: Prospective observational study in intensive care units (ICU) of a university and an affiliated regional hospital. PATIENTS: Twenty-nine consecutive patients, in coma after cardiac arrest, admitted to the ICU and treated by hypothermia. MEASUREMENTS: On ICU-admission (T=1), at reaching the target of 32-33 degrees C during therapeutic hypothermia (T=2), at the end of hypothermia (T=3) and 48h later (T=4), plasma adrenocorticotrophic hormone (ACTH), serum cortisol, albumin and corticosteroid-binding globulin (CBG) were measured. A short 250mug ACTH test was performed at each time-point, except at T=1. The free cortisol index (FCI) and free cortisol calculated by Coolens method were also evaluated. RESULTS: The ICU mortality was 59%, including withdrawal of life-sustaining treatment in 45% because of negative somatosensory evoked potentials. ACTH and (free) cortisol levels (mean 13.1pmol/L vs. 6.0pmol/L and 1250nmol/L vs. 596nmol/L, respectively) were higher in non-survivors than in survivors. Levels decreased in time, but the relative difference between outcome groups was maintained until T=4. The cortisol response to ACTH was lower in non-survivors at T=3 (P=0.047) only. CONCLUSIONS: In comatose patients resuscitated from cardiac arrest, the pituitary-adrenal axis is activated particularly in those dying in the ICU, irrespective of therapeutic hypothermia. Hence, activation of the axis may be a marker of fatal cerebral damage. There is no firm evidence for relative adrenal insufficiency associated with death and a transiently blunted cortisol response to ACTH in non-survivors may be attributed to higher baseline values.     

Cortisol dynamics following acute severe brain injury

Objective To study the diurnal rhythm of plasma cortisol and corticosteroid binding-globulin (CBG) in brain-injured patients managed in an intensive care unit (ICU).Design Observational clinical study.Setting Twelve-bed medical/surgical critical care facility.Patients and participants Fifteen acute brain-injured (coma-inducing) patients: nine following trauma and six with subarachnoid haemorrhage (SAH).Interventions One morning and one evening blood sample were obtained from each patient via an existing arterial line at times which coincided with clinically indicated blood tests.Measurements and results The total cortisol measurements in this sample of brain-injured patients is similar to the normal reference range. Only two patients had morning total cortisol measurements greater than the reference range, 140–690 nmol/l, and five patients had evening measurements greater than the 80–330 nmol/l reference range. Eight patients demonstrated diurnal variation of plasma cortisol. Plasma CBG was significantly decreased in all 15 brain-injured patients. All patients had a free cortisol percentage greater than the quoted reference of 5% and five patients had measurements between 12–23%. No diurnal variation in CBG was detected. There was no association between age or mode of injury and cortisol secretion.Conclusion Following acute severe brain injury, total serum cortisol is not elevated. This may indicate relative hypocortisolaemia in relation to the clinically assessed stress. However, because of the decline in plasma CBG, plasma free cortisol is increased after acute severe brain injury.     

The effect of oral contraceptives on plasma-free and salivary cortisol and cortisone

The effect of a low estrogen oral contraceptive (OC) on glucocorticoid levels in plasma and saliva as well as glucocorticoid binding was studied in 23 healthy women using 30 micrograms ethinyl estradiol (EE2) + 150 micrograms desogestrel (Marvelon) (II). Fifteen healthy females with normal menses served as controls (I). Blood and salivary samples were taken between 9.00 and 9.30 a.m. on the 18th day of menstrual or pill cycle. Assay accuracy had been optimised by applying extraction and chromatographic purification before radioimmunoassay (RIA) of cortisol and cortisone in both plasma and salivary samples. Free steroid assays were performed by applying the same procedure to equilibrium dialysates obtained after dialysing plasma against an equal volume of buffer, instead of measuring tracer distribution. Corticosteroid Binding Globulin (CBG) was measured by a commercial RIA. As expected, CBG as well as plasma total cortisol were elevated in the pill group. Interestingly both plasma free and salivary cortisol were higher than in controls (free cortisol I: 18.0 +/- 7.95 nmol/l; II: 32.3 +/- 9.03 nmol/l; salivary cortisol I: 9.2 +/- 3.88 nmol/l; II: 18.8 +/- 6.92 nmol/l. Salivary cortisol closely parallelled plasma free cortisol both within and between the groups, though at a much lower level (about 50%). Free cortisone was slightly lower in the pill group (I: 10.8 +/- 2.55 nmol/l; II 8.5 +/- 1.86 nmol/l) whereas salivary cortisone was 2.3 (I) and 4.4 (II) times higher than plasma free cortisone and tended to follow the plasma free and salivary cortisol pattern, both within and between the study groups.(ABSTRACT TRUNCATED AT 250 WORDS)     

Plasma free cortisol fraction reflects levels of functioning corticosteroid-binding globulin

BACKGROUND: In normal plasma free cortisol accounts for less than 6% of the total with 80-90% bound to corticosteroid-binding globulin (CBG) and the remainder associated albumin. However little is known about the distribution of free cortisol in plasma where CBG is inactivated or in congenital CBG deficiency. METHODS AND RESULTS: Here we describe ligand binding experiments revealing that while free cortisol in unstressed individuals is less than 6% of total cortisol this rises markedly to 25% when CBG is totally inactivated by heat. Similar elevations of the free cortisol fraction were noted in a patient with a rare genetically determined complete lack of CBG (mean 32% on frequent circadian sampling). Following heat inactivation of CBG or in the congenital absence of CBG, there is a shift in cortisol binding from CBG to albumin. That this shift occurs is further supported by experiments adding [3H]-cortisol to physiological human serum albumin solutions, where 25% of cortisol remained in the free fraction. CONCLUSION: Taken together the data provide strong evidence that when CBG is inactivated or congenitally absent then more than 25% of the total cortisol appears in the free fraction with the remainder associated with albumin. The proportion of free cortisol measured in plasma thus reflects a simple measure of functional corticosteroid-binding globulin.     

Relationship between cortisol increment and basal cortisol: implications for the low-dose short adrenocorticotropic hormone stimulation test

BACKGROUND: We analyzed the low-dose (1 microg) rapid adrenocorticotropic hormone test (LDST) in 17 patients with a normal hypothalamic-pituitary-adrenal axis to determine reference intervals for the LDST on the basis of poststimulation cortisol increments. METHODS: We analyzed test results for 17 patients (14 females and 3 males; age range, 18-46 years) who had received a 2-mL aliquot of low-dose (1 microg) adrenocorticotropic hormone prepared from one 250-microg vial of Synacthen diluted in 500 mL of sterile normal saline solution. Sampling took place at 0, 20, 30, and 60 min post stimulation. The cortisol increment was plotted against basal cortisol. RESULTS: We observed a marked interdependence of the basal cortisol concentration with the increase in cortisol concentration. The relationship was inverse and linear with the best fit observed at 30 min post stimulation. The lower 95% prediction limit for basal cortisol at the zero increment was 400 nmol/L with a mean concentration of 600 nmol/L. CONCLUSIONS: We propose that a peak cortisol concentration <400 nmol/L is a sufficient single criterion for abnormal adrenal function as assessed by the LDST. Concentrations of 400-600 nmol/L are in the gray area, and those >600 nmol/L confirm normal adrenal function. Repeat analyses with larger sample sizes are warranted to confirm these observations.     

Relative adrenal insufficiency as a predictor of disease severity, mortality, and beneficial effects of corticosteroid treatment in septic shock

OBJECTIVE: To evaluate the concept of relative adrenal insufficiency necessitating corticosteroid therapy in septic shock. DESIGN: Retrospective study. SETTING: Medical-surgical intensive care unit of a university hospital. PATIENTS: We studied 218 consecutive patients with septic shock in a 3-yr period who underwent a short 250-microg adrenocorticotropic hormone test because of >6 hrs of hypotension requiring repeated fluid challenges and/or vasopressor/inotropic treatment. INTERVENTIONS: The test was performed by intravenously injecting 250 mug of synthetic adrenocorticotropic hormone and measuring cortisol immediately before and 30 and 60 mins postinjection. MEASUREMENTS AND MAIN RESULTS: Intensive care unit mortality until day 28 was 22%. Nonsurvivors had greater disease severity, as exemplified by higher Simplified Acute Physiology Score II and Sequential Organ Failure Assessment score, on the day of adrenocorticotropic hormone testing. Cortisol levels directly correlated with albumin levels. Simplified Acute Physiology Score II and Sequential Organ Failure Assessment score increased with higher strata of baseline cortisol/albumin or lower cortisol increases/albumin ratios as measures of free cortisol. Baseline cortisol, cortisol increases, and albumin levels did not independently contribute to mortality prediction by disease severity and absence of corticosteroid (hydrocortisone) treatment in a Cox proportional hazard model, although adrenocorticotropic hormone-induced cortisol increase <100 nmol/L (n = 53) predicted mortality (p = .007). Posttest treatment by corticosteroids (n = 161, 74%) was associated with higher survival in patients with cortisol increase <100 nmol/L (p = .0296). CONCLUSIONS: In intensive care unit patients with septic shock, the cortisol response to adrenocorticotropic hormone inversely relates to disease severity, independent of blood cortisol binding. An adrenocorticotropic hormone-induced cortisol increase <100 nmol/L predicts mortality and beneficial effects of corticosteroid treatment. The data favor relative adrenal insufficiency.     

The use of free cortisol index for laboratory assessment of pituitary-adrenal function.

We developed a time-resolved-fluoro-immunoassay to measure cortisol binding globulin (CBG) in serum. It is a microtitre plate, solid phase, reagent excess, sandwich assay in which the same polyclonal antiserum is used as a source of capture and labeled antibodies. The results of this assay were shown to be reliable and were fully comparable with those obtained by a commercially available kit. As a reflection of the free cortisol concentration we measured cortisol and CBG concentrations in serum and calculated the Free Cortisol Index (FCI) = [cortisol]serum/[CBG]serum.100. The clinical use of this parameter, as a screening test for disturbances of the pituitary-adrenal axis, was investigated in different groups of subjects: healthy men and women, women using oral contraceptives, pregnant women at term, patients with thyroidal illnesses, patients using anti-epileptic drugs and patients suffering from adrenal diseases. In a number of groups we compared the FCI results with measurements of cortisol in saliva, another parameter used as an estimate of the concentration of free cortisol in blood. Our conclusion is that the FCI, in contrast to a total cortisol measurement alone, can prevent unnecessary further testing.     

An enzyme-linked immunosorbent assay for corticosteroid-binding globulin using monoclonal and polyclonal antibodies: decline in CBG following synthetic ACTH

BACKGROUND: Adrenal function is commonly assessed by measuring plasma cortisol following synthetic ACTH (synacthen) challenge. Generally little regard is given to plasma levels of corticosteroid-binding globulin (CBG). We have developed and validated an enzyme-linked immunosorbent assay (ELISA) for CBG and together with plasma cortisol calculated the "free cortisol index" as an additional parameter for assessing adrenal function. METHODS: A monoclonal antibody was raised against CBG. The antibody was characterized by Western blotting and used with a polyclonal antibody to develop a direct ELISA for CBG. Together with total plasma cortisol, the free cortisol index was derived and correlated with an "in-house" ligand binding method for assessing free cortisol. The free cortisol index was also used as an adduct to total plasma cortisol in assessing adrenal function. RESULTS: The ELISA has acceptable performance and the free cortisol index correlates well with free cortisol determined by ligand binding. In addition, we show that CBG levels following synthetic ACTH (synacthen) show a modest but significant decline. CONCLUSION: We conclude that the measurement of both plasma CBG and total cortisol to derive the free cortisol index may provide an additional parameter in the interpretation of the short synacthen test and that there is a decline in plasma CBG over this test.     

Persistence of vitamin B12 insufficiency among elderly women after folic acid food fortification

OBJECTIVE: To estimate the associated risk of folate and vitamin B12 (B12) insufficiency, as well as vitamin repletion, following folic acid food fortification. DESIGN: Retrospective cross-sectional study over a 5-year period. SETTING: Two large laboratory databases in the provinces of Ontario and British Columbia, Canada. PARTICIPANTS: Canadian women aged 65 years and over who underwent concomitant clinical testing of serum folate and B12 during the pre-fortification period of January 1996 to December 1997 in Ontario (n = 733) and British Columbia (n = 3839), and in the near-complete post-fortification period of January 1998 to December 2000 in Ontario (n = 4415) and British Columbia (n = 6677). MEASUREMENTS: Geometric mean concentrations of serum folate and B12 before and after folate fortification. Prevalence ratios (PR) were used to separately compare the post- and pre-fortification period rates of folate deficiency (below 6.0 nmol/L); B12 insufficiency (below 150 pmol/L); and B12 insufficiency in combination with supraphysiological concentrations of serum folate (above 45 nmol/L). RESULTS: The mean baseline folate and B12 concentrations were similar between provinces. Using the combined provincial data, the mean serum folate concentration increased by 64% after fortification, from 14.8 to 24.2 nmol/L (p < 0.001). The average B12 concentration increased from 280 to 300 pmol/L, which was more pronounced in BC (p < 0.001) than in Ontario (p = 0.16). The prevalence of folate deficiency declined from 6.3% to 0.88% after fortification (PR 0.14, 95% confidence interval [CI] 0.11-0.18), while the decline in B12 deficiency was less pronounced (PR 0.78, 95% CI 0.71-0.86). CONCLUSIONS: The prevalence of combined B12 insufficiency with supraphysiological concentrations of serum folate increased from 0.09% pre-fortification to 0.61% post (PR 7.0, 95% CI 2.6-19.2).The introduction of folic acid food fortification was associated with a substantial improvement in the folate status of Canadian women aged 65 years and older, paralleled by a large decline in the rate of folate deficiency. Improvement in the B12 status of these women was far less pronounced. Because the prevalence of combined B12 insufficiency and supraphysiological concentrations of serum folate may have increased with folic acid food fortification, consideration should be given to confirming this finding, and possibly, to the addition of B12 to folate fortified foods.     

Adrenal Dysfunction in Hemodynamically Unstable Patients in the Emergency Department

OBJECTIVE: Adrenal failure, a treatable condition, can have catastrophic consequences if unrecognized in critically ill ED patients. The authors' objective was to prospectively study adrenal function in a case series of hemodynamically unstable (high-risk) patients from a large, urban ED over a 12-month period. METHODS: In a prospective manner, critically ill adult patients presenting to the ED were enrolled when presenting with a mean arterial blood pressure < or =60 mm Hg requiring vasopressor therapy for more than one hour after receiving fluid resuscitation (central venous pressure of 12-15 mm Hg or a minimum of 40 mL/kg of crystalloid). Patients were excluded if presenting with hemorrhage, trauma, or AIDS, or if steroids were used within the previous six months. An adrenocorticotropic hormone (ACTH) stimulation test was performed and serum cortisol was measured. Treatment for adrenal insufficiency was not instituted. RESULTS: A total of 57 consecutive patients were studied. Of these, eight (14%) had baseline serum cortisol concentrations of <20 microg/dL (<552 nmol/L), which was considered adrenal insufficiency (AI). Three additional patients (5%) had subnormal 60-minute post-ACTH-stimulation cortisol responses (<30 microg/dL) and a delta cortisol < or =9 microg/dL, which is the difference between the baseline and 60-minute levels. This is functional hypoadrenalism (FH). There were no laboratory abnormalities that distinguished patients with AI or FH from those with preserved adrenal function (PAF). Rates of survival to discharge did not differ between the AI group (7 of 8) and PAF patients (21 of 46; p = 0.052). CONCLUSIONS: Adrenal dysfunction is common in high-risk ED patients. Overall, it has a frequency of 19% among a homogeneous population of hemodynamically unstable vasopressor-dependent patients. The effect of physiologic glucocorticoid replacement in this setting remains to be determined.     

Growth hormone and cortisol secretion in patients with burn injury.

A prospective study of growth hormone, insulin-like growth factor (IGF-1), and cortisol secretion was undertaken in six adults with burn injury. Serum concentrations of growth hormone and IGF-1 were low in all patients during the first 2 weeks of hospitalization. The mean growth hormone level was 4.35 +/- 0.83 micrograms/L on day 1 and 1.70 +/- 0.50 micrograms/L on day 13. The mean serum concentration of IGF-1, which reflects overall growth hormone secretion, was 0.43 +/- 0.09 U/ml on day 1 and 0.61 +/- 0.11 U/ml on day 13; these values are distinctly low. After 3 to 4 weeks, IGF-1 concentrations increased to the mid-normal range, whereas growth hormone values did not change. Morning plasma cortisol concentrations were modestly elevated; however, urine free cortisol concentrations, which reflect total cortisol secretion, were elevated 2 to 28 times above normal values at the time of admission (mean, 443.5 +/- 323.7 nmol/L). Urinary free cortisol concentrations remained elevated after 2 weeks (mean, 230.5 +/- 94.5 nmol/L). Patients with burn injury have inappropriately low growth hormone secretion and IGF-1 production in spite of the stress of the injury and more than adequate nutritional therapy.     

Steroids in adult men with type 1 diabetes: a tendency to hypogonadism

OBJECTIVE: To compare steroids and their associations in men with type 1 diabetes and healthy control subjects. RESEARCH DESIGN AND METHODS: We studied 52 adult men with type 1 diabetes without microvascular complications, compared with 53 control subjects matched for age and BMI. Steroids and their binding globulins were assessed in a single venous blood sample and a 24-h urine sample. RESULTS: In adult men with type 1 diabetes, total testosterone did not differ from healthy control subjects, but sex hormone-binding globulin (SHBG) (42 [14-83] vs. 26 [9-117] nmol/l, P < 0.001), cortisol-binding globulin (CBG; 0.87 +/- 0.17 vs. 0.73 +/- 0.10 nmol/l, P < 0.001), and cortisol levels (0.46 +/- 0.16 vs. 0.39 +/- 0.14 nmol/l, P < 0.01) were higher. The free testosterone index was lower (60 [17-139] vs. 82 [24-200], P < 0.001), and the calculated free testosterone was slightly lower (497 [115] vs. 542 [130], P < 0.064), but the pituitary-gonadal axis was not obviously affected in type 1 diabetes. The calculated free serum cortisol was not different, and 24-h urinary free cortisol excretion was lower in type 1 diabetes (121 [42-365] vs. 161 [55-284] nmol/24 h, P < 0.009). Testosterone was mainly associated with SHBG. Estimated portal insulin was a contributor to SHBG in control subjects but not in type 1 diabetes. Cortisol was associated with CBG. HbA(1c) contributed to CBG in men with diabetes but not in control subjects, whereas estimated portal insulin did not contribute. CONCLUSIONS: Adult men with fairly controlled type 1 diabetes without complications who are treated with subcutaneous insulin have a tendency to hypogonadism, as reflected by lower free testosterone levels in the presence of similar total testosterone levels and higher SHBG levels.     

Declines in serum free and bound choline concentrations in humans after three different types of major surgery.

We examined the changes in circulating choline status in humans in response to major surgery by measuring serum free and phospholipid-bound choline concentrations before, during and 1-72 h after total abdominal hysterectomy, off-pump coronary artery graft surgery or brain tumor surgery. Preoperatively, the mean serum free and phospholipid-bound choline concentrations in patients scheduled for abdominal hysterectomy (n = 26), off-pump coronary artery grafting surgery (n = 34) or brain tumor surgery (n = 24) were 12.3 +/- 0.5, 12.1 +/- 0.4 and 11.4 +/- 0.4 micromol/l, and 2495 +/- 75, 2590 +/- 115 and 2625 +/- 80 micromol/l, respectively. Serum free choline and phospholipid-bound choline concentrations decreased from these baseline values to 8.8 +/- 0.7 (p < 0.001), 8.8 +/- 0.5 (p < 0.001) and 8.2 +/- 0.4 micromol/l (p < 0.001), and 2050 +/- 108 (p < 0.001), 2166 +/- 59 (p < 0.001) and 1884 +/- 104 micromol/l (p < 0.001) at 1 h after hysterectomy, off-pump bypass graft surgery or brain tumor surgery, respectively. They remained at these low levels for 24 h and then gradually increased towards the preoperative values at 48-72 h postoperatively. Serum cortisol increased postoperatively in all surgical patients for 24 h and its levels were inversely correlated with serum free and bound choline concentrations. These results show that circulating free and bound choline concentrations decrease for 72 h after total abdominal hysterectomy, off-pump coronary artery graft surgery or brain tumor surgery in humans.     

Validation of a high-throughput liquid chromatography-tandem mass spectrometry method for urinary cortisol and cortisone

BACKGROUND: Urinary free cortisol and cortisone measurements are useful in evaluation of Cushing syndrome, apparent mineralocorticoid excess, congenital adrenal hyperplasia, and adrenal insufficiency. To reduce analytical interference, improve accuracy, and shorten the analysis time, we developed a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for urinary cortisol and cortisone. METHODS: We added 190 pmol (70 ng) of stable isotope cortisol-9,11,12,12-d(4) to 0.5 mL of urine as an internal standard before extraction. The urine was extracted with 4.5 mL of methylene chloride, washed, and dried, and 10 microL of the reconstituted extract was injected onto a reversed-phase C(18) column and analyzed using a tandem mass spectrometer operating in the positive mode. RESULTS: Multiple calibration curves for urinary cortisol and cortisone exhibited consistent linearity and reproducibility in the range 7-828 nmol/L (0.25-30 microg/dL). Interassay CVs were 7.3-16% for mean concentrations of 6-726 nmol/L (0.2-26.3 microg/dL) for cortisol and cortisone. The detection limit was 6 nmol/L (0.2 microg/dL). Recovery of cortisol and cortisone added to urine was 97-123%. The regression equation for the LC-MS/MS (y) and HPLC (x) method for cortisol was: y = 1.11x + 0.03 microg cortisol/24 h (r(2) = 0.992; n = 99). The regression equation for the LC-MS/MS (y) and immunoassay (x) methods for cortisol was: y = 0.66x - 12.1 microg cortisol/24 h (r(2) = 0.67; n = 99). CONCLUSION: The sensitivity and specificity of the LC-MS/MS method for urinary free cortisol and cortisone offer advantages over routine immunoassays or chromatographic methods because of elimination of drug interferences, high throughput, and short chromatographic run time.