Serum Free Cortisol Research Articles

Salivary Cortisone Is a Potential Biomarker for Serum Free Cortisol

Salivary cortisol measurement is used as a practical surrogate for serum free cortisol. However, parotid tissue harbors 11β-hydroxysteroid dehydrogenase (11β-HSD2) activity converting cortisol to cortisone. This study was designed to assess the impact of parotid 11β-HSD2 activity on the measurement of salivary cortisol. PATIENTS, DESIGN, AND OUTCOME MEASURES: Study participants with changes in circulating corticosteroid-binding globulin (CBG) (±oral contraceptive, functionally CBG null) and controls were studied during adrenal stimulation by ACTH and postoral and iv hydrocortisone administration. Simultaneous serum and saliva samples were collected for the measurement of total serum cortisol (SerF) by immunoassay, and unbound cortisol and cortisone in serum (FreeF and FreeE) and saliva (SalF and SalE) by liquid chromatography-tandem mass spectrometry. ACTH stimulation increased SerF, FreeF, SalF, SalE, but not FreeE in all individuals. SerF significantly decreased after stopping oral contraceptive administration, but FreeF, SalF and SalE remained unchanged. In the hydrocortisone administration study, individual FreeF and SalE curves were nearly identical and SalE closely reflected FreeF in all participants, irrespective of CBG changes. The highest correlation in all (n = 537) matched serum-saliva samples was between SalE and FreeF (r = 0.95, P < 0.0001), and there was no evidence of 11β-HSD2 saturation. Salivary cortisol is a useful surrogate for circulating free cortisol, but its concentration is determined both by serum free cortisol and parotid metabolism to cortisone. We have shown that salivary cortisone closely reflects free serum cortisol after adrenal stimulation and hydrocortisone administration and is unaffected by CBG changes. Salivary cortisone has potential as a useful surrogate for serum free cortisol in research and clinical assessment, and further research in states of chronic glucocorticoid excess is now needed.

Novel Corticosteroid-Binding Globulin Variant That Lacks Steroid Binding Activity

Abstract Background: Corticosteroid-binding globulin (CBG) is the principal carrier for glucocorticoids in the circulation and a regulator of their bioavailability. Inherited CBG deficiencies are rarely reported, and only three causative mutations in four families have been described. Patients, Methods, and Results: In a 26-yr-old female with hypotension, fatigue, and undetectable serum cortisol at presentation, we have identified a novel homozygous c.776g&amp;gt;t transversion in exon 3 of the CBG (SERPINA6) gene. This results in a p.Gly237Val substitution that is predicted to influence the positioning of two β-sheets that constitute part of the CBG steroid-binding site. Two siblings were also homozygous for the variant, whereas her mother and an unaffected sibling were heterozygous. No other symptomatic family members were identified apart from the proband. Individuals homozygous for the variant had serum CBG levels below the reference range when measured by RIA, but CBG was unmeasurable in cortisol-binding capacity assays. In the same individuals, we observed very low baseline and stimulated serum cortisol levels but normal free serum and salivary cortisol and plasma ACTH. In a study of ultradian cortisol pulsatility, increased pulse frequency was only observed in the proband. Conclusion: We describe a novel CBG variant that lacks steroid binding. All mutant homozygotes have very low serum cortisol, but normal free cortisol levels. The only biochemical feature to distinguish the symptomatic subject was increased cortisol pulsatility, and we suggest that this may influence glucocorticoid signaling and contribute to symptoms previously associated with CBG deficiency.

Primary Empty Sella with Partial Hypopituitarism and Autoimmune Thyroiditis

Laboratory Work-up : LH and FSH were low with estradio l at pre-puber ta l leve l , suggest ing hypogonadotropic hypogonadism. Prolactin was slightly elevated. Twenty four-hour urinary free cortisol and 8AM serum cortisol were low with low normal plasma ACTH, indicating secondary adrenal insufficiency. TSH was elevated with depressed FT4 and elevated antithyroglobulin, suggesting autoimmune thyroiditis. The following tests were normal: growth hormone, FBS and 2-hour OGTT. Patient had delayed bone age by the Greulich-Pyle method. Bone densitometry revealed osteoporosis. Patient had 46XX karyotype. Pelvic ultrasound revealed infantile uterus. Sellar MRI showed empty sella.

Novel Corticosteroid-Binding Globulin Variant That Lacks Steroid Binding Activity

Corticosteroid-binding globulin (CBG) is the principal carrier for glucocorticoids in the circulation and a regulator of their bioavailability. Inherited CBG deficiencies are rarely reported, and only three causative mutations in four families have been described. In a 26-yr-old female with hypotension, fatigue, and undetectable total serum cortisol at presentation, we have identified a novel homozygous c.776g>t transversion in exon 3 of the CBG (SERPINA6) gene. This results in a p.Gly237Val substitution that is predicted to influence the positioning of two β-sheets that constitute part of the CBG steroid-binding site. Two siblings were also homozygous for the variant, whereas her mother and an unaffected sibling were heterozygous. No other symptomatic family members were identified apart from the proband. Individuals homozygous for the variant had serum CBG levels below the reference range when measured by RIA, but CBG was unmeasurable in cortisol-binding capacity assays. In the same individuals, we observed very low baseline and stimulated total serum cortisol levels but normal free serum and salivary cortisol and plasma ACTH. In a study of ultradian cortisol pulsatility, increased pulse frequency was only observed in the proband. We describe a novel CBG variant that lacks steroid binding activity. All mutant homozygotes have very low total serum cortisol, but normal free serum cortisol levels. The only biochemical feature to distinguish the symptomatic subject was increased cortisol pulsatility, and we suggest that this may influence glucocorticoid signaling and contribute to symptoms previously associated with CBG deficiency.

Salivary and Free Serum Cortisol Evaluation

Physiologic free serum cortisol may more accurately reflect adrenal function than total cortisol levels. Salivary cortisol estimates free serum cortisol. We researched the clinical viability of salivary cortisol in hospitalized patients. Free serum cortisol, and salivary cortisol were measured via ELISA in hospitalized and outpatient patients. We obtained 37/71 satisfactory saliva samples from intensive care unit (ICU) patients. The correlation between free serum, and salivary cortisol over all collected samples was 0.914 (p < 0.001). We identified disparate interpretations for adrenal insufficiency (AI) utilizing total versus free serum cortisol. Salivary cortisol is an acceptable surrogate for free serum cortisol when satisfactory salivary volumes are procured. Due to inadequate sample volumes, and contamination, it should not be generally adopted in the ICU. We identified discordance between free and total cortisol in interpreting AI, suggesting reinterpretation of seminal trials investigating physiologic corticosteroid replacement on the basis of total cortisol levels. The analysis of both free serum cortisol via ultrafiltration and salivary cortisol involved two steps: sample centrifugation followed by ELISA, suggesting consideration of widespread adoption of free serum cortisol in future investigations.

An evaluation of measured and calculated serum free cortisol in a group of patients with known adrenal suppression

Since more than 90% of cortisol is bound to protein, serum free cortisol (SFC) may be a more appropriate marker of adrenal status than total cortisol. However, measurement of SFC is technically difficult and calculated SFC may offer a more practical alternative. SFC, measured by equilibrium dialysis coupled with immunoassay, and calculated using Coolens' equation from total cortisol and corticosteroid binding globulin (CBG) concentrations, was compared in short Synacthen test (SST) serum from 42 patients, of whom 20 demonstrated a suppressed adrenal response. Considering the patient group as a whole, calculated SFC was found to be significantly lower than measured SFC, pre- and post-Synacthen (P < 0.05 and <0.001, respectively). Upon classifying the patients as pass or fail based on total cortisol response to Synacthen, the difference in calculated and measured SFC only reached statistical significance for post-Synacthen concentrations in the pass group (P < 0.01), suggesting a greater discrepancy at higher cortisol concentrations. There was no difference in CBG levels between the pass and fail groups and both measured and calculated SFC gave a diminished 30 min response in subjects deemed to have failed the SST. Coolens' equation was found to underestimate measured SFC in this cohort of outpatients, as has been previously demonstrated, particularly in patients with a pronounced acute phase response. Although calculated SFC gave a diminished response in individuals deemed to have failed the SST, the concentration-dependent nature of the discrepancy may limit the usefulness of this method for assessing adrenal status.

Effect of mutations of the human serpin protein corticosteroid-binding globulin on cortisol-binding, thermal and protease sensitivity

Corticosteroid-binding globulin (CBG, transcortin) belongs to the serpin family of serine protease inhibitors (SERPINA6) and is mainly secreted by the liver. The negative acute phase protein CBG regulates free cortisol levels in the blood and distributes cortisol to its target tissues. So far no CBG serpin partner protease has been identified. However, its cleavage by human neutrophil elastase destroys ligand binding capacity and supposedly liberates cortisol at sites of inflammation. Here we report on the recombinant expression and secretion of human wild-type CBG and several novel mutants by human 293-EBNA cells. Functional characterization of wild-type and mutant CBG revealed distinct differences in ligand binding sensitivity to heat or elastase. Certain mutants are almost devoid of cortisol binding activity (Q232R and CBG Lyon), some display higher sensitivity for heat inactivation (G335V, Q232R and CBG Lyon) or for elastase cleavage (G335V). CBG mutant T342A is more resistant to elastase cleavage. Our data support the validity of the serpin structural concept. The expression system used provides functionally active human recombinant transcortin for further functional characterization of wild-type and human CBG mutant variants, which have been associated with altered serum free cortisol levels or pathophysiological constellations such as increased body weight, fatigue or hypotension.

Assessment of serum‐free cortisol levels in patients with adrenocortical carcinoma treated with mitotane: a pilot study

Mitotane treatment in adrenocortical carcinoma (ACC) results in unreliable measurement of serum total cortisol (TC) levels because of an elevation in corticosteroid-binding globulin (CBG). The use of a newly-developed serum-free cortisol (FC) assay was assessed to investigate the characteristics of a more valid measure of cortisol status. Sixty-two serum samples from patients with ACC treated with mitotane were studied. Different subgroups were studied according to mitotane levels (<14, 14-20 and >20 mg/dl), hydrocortisone replacement treatment, presence of Cushing's syndrome (CS) and adrenocorticotrophin (ACTH) levels. Serum FC was measured using a newly-developed assay, TC, CBG and plasma ACTH using conventional laboratory kits; TC-to-CBG (Free cortisol index, FCI, nmol/mg) and TC-to-FC (TFR) ratios were calculated. CBG levels were elevated and positively correlated to mitotane levels. FC was positively related to TC and FCI in nearly all subgroups studied. Plasma ACTH was negatively related to parameters of cortisol levels in the total samples studied. In the 'target' subgroup with normal ACTH levels and mitotane levels 14-20 mg/dl, no correlation of plasma ACTH with any parameter studied was seen, and FC suggested over-replacement with hydrocortisone treatment in the subgroup with CS. FC measurement may offer additional information in the follow-up of patients on mitotane, especially when there is a history of CS which invalidates the use of acute changes in plasma ACTH as a parameter of hydrocortisone replacement. These preliminary data suggest that it may prove useful as a biochemical marker when TC or FCI are invalidated by mitotane treatment or plasma ACTH is suppressed by hypercortisolaemia. Larger studies are needed to substantiate the clinical utility of FC measurement in specific groups of patients.

Cortisol Dynamics in the Acute Phase of Aneurysmal Subarachnoid Hemorrhage: Associations with Disease Severity and Outcome

The purpose of this study was to assess cortisol dynamics in the acute phase after aneurysmal subarachnoid hemorrhage (SAH) and to set the parameters of cortisol release in relation to the severity of illness and outcome. In 22 consecutive patients with aneurysmal SAH, cortisol, corticosteroid binding globulin, interleukin-6, and adrenocorticotrophic hormone were measured immediately after hospital admission (t(0)), 7 days (t(1)) later, and at least 14 days later (t(2)). Additionally, diurnal profiles of cortisol secretion were assessed at t(1) and t(2), and area under the curve (AUC) was computed for calculated free serum cortisol (CFSC). In this study, normal diurnal CFSC profiles were associated with a significantly shorter ICU-stay, less complications, and a more favorable outcome than abnormal diurnal profiles. AUC and 8 a.m. cortisol were not related to clinical course or outcome. It is concluded that cortisol secretion patterns are associated with the severity and outcome of SAH. For an appraisal of the hypothalamo-pituitary-adrenal axis in SAH patients, single cortisol measurements are insufficient.

Determining relevant cortisol concentrations in critically ill patients

The importance of adrenal function to survival in critically ill patients has been established; however, identifying the best method to diagnose adrenal insufficiency has been problematic. Multiple methods of determining adrenal function have been developed, each with its advantages and disadvantages. Serum-free cortisol levels are probably the most accurate, although obtaining this result is technically demanding. Cohen and colleagues investigated the feasibility of measuring tissue cortisol levels in burn patients and whether tissue cortisol levels could be used as a surrogate for plasma-free cortisol levels.

Simultaneous measurement of cortisol and cortisone in human saliva using liquid chromatography–tandem mass spectrometry: Application in basal and stimulated conditions

Immunoassays used for the measurement of salivary cortisol are limited by variable interference from cortisone. Salivary cortisone is a consequence of the salivary glands expressing 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD2) which converts cortisol to cortisone. We report a combined salivary cortisol and cortisone (SalF and SalE respectively) liquid chromatography–tandem mass spectrometry (LC–MS/MS) assay to address the cortisone cross-reactivity in cortisol immunoassays and as a tool to study 11β-HSD2 activity. The method was linear up to 400 nmol/L for SalF and 200 nmol/L for SalE and the lower limits of quantitation were 0.39 nmol/L (SalF) and 0.78 nmol/L (SalE). No evidence of ion suppression was found and precision, accuracy and recovery were within internationally accepted limits. No interference was identified from 13 structurally related steroids. SalF, SalE and SalF/SalE were significantly greater in the morning than at bed-time and following stimulation of the adrenal glands. As serum cortisol increased, an exponential rise was observed in SalF and a linear increase in SalE which reached a plateau at higher SalF concentrations. We have developed a novel, robust LC–MS/MS assay for the combined measurement of SalF and SalE. Our results confirm the 11β-HSD2 activity of the salivary glands resulting in high SalE concentrations and the enzyme saturation at high substrate concentrations. This method can be used as a simple, non-invasive and highly specific tool to assess the value of salivary cortisol as a surrogate for free serum cortisol and as a potential novel way to assess 11β-HSD2 activity.

Serum total cortisol and free cortisol index give different information regarding the hypothalamus–pituitary–adrenal axis reserve in patients with liver impairment

The short synacthen test (SST) is used to investigate patients with suspected hypothalamus-pituitary-adrenal (HPA) axis pathology. A rise of serum total cortisol (total cortisol) above 550 nmol/L is accepted as sufficient adrenal reserve. In total, 80% of cortisol is bound to cortisol-binding globulin (CBG) and 10% to albumin. In the acute phase responses CBG concentrations decrease and can influence the interpretation of SST. The free cortisol index (FCI) is a surrogate marker for free cortisol and is defined as total cortisol (nmol/L)/CBG (mg/L) with an FCI > 12 representing sufficient adrenal reserve. The aim of this study was to compare total cortisol and FCI in the interpretation of SST in patients with liver impairment. SST was done on 26 patients with liver impairment. Total cortisol was measured on Advia Centaur; serum CBG by radioimmunoassay and FCI calculated. Eleven (42%) patients had a total cortisol >550 nmol/L (range 555-2070) and FCI > 12 (12.0-68.9) suggesting sufficient cortisol reserve. Three patients (13%) had total cortisol <550 nmol/L (268-413) and FCI < 12 (3.5-11.6) consistent with cortisol deficiency. Twelve patients (46%) had a total cortisol <550 nmol/L (144-529), but an FCI > 12 (12.0-52.9). None of the patients had a total cortisol >550 nmol/L and FCI < 12. When total cortisol alone is used to interpret SST in patients with liver impairment, 46% may have been classified as having adrenal insufficiency because of low CBG. FCI may be better for the evaluation of HPA axis insufficiency in patients with liver impairment.

Salivary Cortisol as an alternative for serum Cortisol in the low-dose adrenocorticotropic hormone stimulation test?

Salivary cortisol is unaffected by cortisol binding globulin and reflects free serum cortisol as compared to total serum cortisol. The aim of the present study was to compare the salivary cortisol response with the serum cortisol response in a low-dose (1-microg) ACTH test in a clinical setting and to determine the optimal cut-off value of salivary cortisol as an alternative to serum cortisol. We measured serum and salivary cortisol responses to iv administration of 1-microg ACTH in 51 patients (17 males) referred to the Department of Clinical Chemistry for ACTH-testing. Serum cortisol was assessed before, 20, and 30 min after ACTH-administration, and salivary cortisol was assessed before and 30 min after ACTH administration. Mean cortisol at baseline, 20, and 30 min were 0.44 micromol/l (SD: 0.22), 0.64 micromol/l (SD: 0.24), and 0.70 micromol/l (SD: 0.25), respectively. Median basal salivary cortisol was 8.4 nmol/l [interquartile range (IQR): 3.8-14.2]. Salivary cortisol at 30 min equaled 35.9 nmol/l (IQR: 21.1-46.2). Basal salivary cortisol was significantly correlated with salivary cortisol at 30 min (r=0.53; p<0.001). Salivary cortisol at 30 min of 23.5 nmol/l had a sensitivity and specificity of 78.1% and 70.0%, respectively as compared to the serum cortisol cut-off values of >0.50 micromol/l. The salivary low-dose ACTH-test yields more dynamic responses than serum cortisol. However, the sensitivity and specificity of salivary cortisol are too low to be adequate as an alternative to the serum cortisol measurements. In women on estrogen therapy, however, the use of salivary cortisol might be superior to serum cortisol.

The Dexamethasone Suppression Test and Long-Term Contraceptive Treatment: Measurement of ACTH or Salivary Cortisol Does Not Improve the Reliability of the Test

Under the influence of high estrogen levels, the suppression of total serum cortisol in the dexamethasone test has often been found to be incomplete. Its measurement for the purpose of excluding Cushing's disease or adrenal tumors in women taking oral contraceptives is, therefore, considered unreliable. This study was designed to compare the reliability of measurements of total cortisol, unbound cortisol and ACTH suppression during chronic hyperestrogenaemia. An overnight suppression test with 2 mg of dexamethasone was performed in 19 women receiving long-term contraceptive treatment (group A) and in 12 controls (group C). Baseline and post-dexamethasone morning levels of ACTH, total serum cortisol and unbound salivary cortisol were determined by RIA. In addition, unbound serum cortisol was measured by equilibrium dialysis. Mean baseline levels of all four parameters were significantly higher in group A. This result points towards the possibility of a direct stimulatory effect of estrogens upon the corticotroph axis which is independent from CBG-mediated increase of total cortisol. Post-dexamethasone values of total and unbound cortisol showed no statistically significant differences, while ACTH suppression in group A was even slightly better than in group C. From these data it is concluded that there is no need for post-dexa routine measurement of ACTH or unbound cortisol under contraceptive treatment since neither one of these parameters provides any additional information in comparison to total cortisol.

Thyroid Hormone Therapy is Not Indicated in the Majority of Patients with the Sick Euthyroid Syndrome

The sick euthyroid syndrome is a general term used to describe alterations in thyroid hormone concentrations during a variety of acute and chronic illnesses in patients with no previously diagnosed intrinsic thyroid disease (1-3). These effects are nonspecific and relate to the severity of the illness. Changes in thyroid hormone variables are rarely isolated and often are associated with alterations in other endocrine systems, such as reductions in serumgonadotropin and sex hormone concentrations (4) and increases in serum adrenocorticotropic hormone (corticotropin) and free cortisol levels (5).

Cosyntropin-stimulated salivary cortisol in hospitalized patients with hypoproteinemia

Analysis of adrenocortical function in acutely ill, hospitalized patients can be challenging due to changes in plasma binding proteins. This study used dynamic testing of salivary cortisol levels to evaluate adrenal function in hospitalized patients with low/low-normal plasma protein concentration in whom adrenal insufficiency was suspected. Twenty-eight patients with low serum albumin and proteins hospitalized for acute illness were evaluated for decreased adrenocortical function because of clinical presentations suspicious for adrenal insufficiency. Baseline and post cosyntropin-stimulated levels of serum total and salivary cortisol levels were assessed. Data were gathered by a retrospective analysis of medical records. Eight patients had normal peak serum total and salivary cortisol responses, consistent with intact adrenocortical function. Five patients had abnormal peak serum total and salivary cortisol responses indicating decreased adrenocortical function. Fifteen patients had subnormal peak serum total cortisol, but normal peak salivary cortisol responses indicating normal adrenal function. Salivary cortisol testing can identify hospitalized patients with apparently intact adrenal function in whom low serum protein confounded interpretation of serum total cortisol measurements. Salivary cortisol is a clinically useful surrogate for serum free cortisol in dynamic testing of adrenocortical function.

The relationship between cortisol, muscle mass and muscle strength in older persons and the role of genetic variations in the glucocorticoid receptor

Cortisol levels increase with age and hypercortisolism is associated with muscle weakness. This study examines the relationship between cortisol, muscle mass and muscle strength in community-dwelling older persons and the role of genetic variations in the glucocorticoid receptor (GR). The study was conducted within the Longitudinal Ageing Study Amsterdam (LASA, 1992-ongoing), a cohort study in a population-based sample of older persons in the Netherlands. Data were used from 1196 and 1046 participants in the second (1995-1996) and fourth (2001-2002) cycle, respectively. Total serum cortisol and free cortisol were measured in the mornings of the second cycle while salivary cortisol sampled early in the morning and late at night were measured in the fourth cycle. The GR gene polymorphisms (ER22/23EK, N363SS, 9beta and BclI) were genotyped by Taqman. Appendicular skeletal muscle mass (ASMM) was measured using DXA in the second cycle and 3 years later (third cycle). Grip strength was assessed using a handgrip dynamometer in the second, third, fourth and fifth cycle. A relationship was found between both morning and evening salivary cortisol, and loss of grip strength: participants in the highest quartile of cortisol concentration had a twofold higher risk of loss of grip strength than participants in the lowest quartile (P < 0.05). No relationships were found between serum cortisol (loss of) ASMM, and (loss of) grip strength. The ER22/23EK and N363S-polymorphisms modified the relationships between serum cortisol, ASMM and grip strength, respectively. Due to limited power, these relationships were not significant after stratification for the polymorphisms. High salivary cortisol is associated with a higher risk of loss of grip strength in older persons. GR genotypes modify the relationship between muscle mass and muscle strength.

Free Cortisol in Sepsis and Septic Shock

Severe sepsis activates the hypothalamopituitary axis, increasing cortisol production. In some studies, hydrocortisone substitution based on an adrenocorticotropic hormone-stimulation test or baseline cortisol measurement has improved outcome. Because only the free fraction of cortisol is active, measurement of free cortisol may be more important than total cortisol in critically ill patients. We measured total and free cortisol in patients with severe sepsis and related the concentrations to outcome. In a prospective study, severe sepsis was defined according the American College of Chest Physicians/Society of Critical Care Medicine criteria. Blood samples were drawn within 24 h of study entry. Serum cortisol was analyzed by electrochemiluminescence immunoassay. The Coolens method was used for calculating serum free cortisol concentrations. Blood samples were collected from 125 patients, of whom 62 had severe sepsis and 63 septic shock. Hospital mortality was 21%. Calculated free serum cortisol correlated well with serum total cortisol (r = 0.90, P < 0.001). There was no difference in the total cortisol concentrations in patients with sepsis and septic shock (728 +/- 386 nmol/L vs 793 +/- 439 nmol/L, P = 0.44). Nonsurvivors had higher calculated serum free (209 +/- 151 nmol/L) and total (980 +/- 458 nmol/L) cortisol concentrations than survivors (119 +/- 111 nmol/L, P = 0.002, and 704 +/- 383 nmol/L, P = 0.002). Depending on the definition, the incidence of adrenal insufficiency varied from 8% to 54%. Clinically, calculation of free cortisol does not provide essential information for identification of patients who would benefit from corticoid treatment in severe sepsis and septic shock.

The evaluation of endothelial function with flow-mediated dilatation and carotid intima media thickness in young nonobese polycystic ovary syndrom patients; existence of insulin resistance alone may not represent an adequate condition for deterioration of endothelial function

To evaluate endothelial function with flow-mediated dilatation (FMD) and carotid intima media thickness (IMT) in young nonobese polycystic ovary syndrome (PCOS) patients. Prospective case-control study. Healthy volunteers and nonobese young PCOS patients in clinical research. Thirty-nine PCOS patients with mean age of 22.82 +/- 5.53 years and 30 body mass index- and age-matched healthy controls were evaluated. Insulin resistance was calculated with area under the curve, quantitative insulin sensitivity check, and the Matsuda index. Endothelial function was assessed with FMD and carotid IMT by ultrasonography. Antropometric, hormonal, biochemical (insulin and glucose, tumor necrosis factor-alpha, hs-c-reactive protein, and homocysteine levels, and so forth), FMD, and IMT were measured. There was a significant insulin resistance in PCOS patients. Serum FSH, total and free testosterone, cortisol, androstenedione, and DHEA-S levels of PCOS patients were also higher than control subjects, but we could not find any significant difference in terms of endothelial function determined with FMD. Existence of insulin resistance alone may not be an adequate factor for deterioration of endothelial function and carotid IMT in young, nonobese patients with PCOS. Other factors such as duration of insulin resistance, older age, presence of obesity, and inflammatory markers may play an important role in this process.

Effect of a Pre-Exercise Energy Supplement on the Acute Hormonal Response to Resistance Exercise

The effect of a pre-exercise energy sport drink on the acute hormonal response to resistance exercise was examined in eight experienced resistance trained men. Subjects were randomly provided either a placebo (P: maltodextrin) or the supplement (S: combination of branched chain amino acids, creatine, taurine, caffeine, and glucuronolactone). Subjects performed 6 sets of no more than 10 repetitions of the squat exercise at 75% of their 1 repetition maximum (1RM) with 2 minutes of rest between sets. Blood draws occurred at baseline pre-exercise, immediately post- (IP), 15 minutes post- (15P), and 30-minutes post (30P) exercise for measurement of serum growth hormone, total and free testosterone, cortisol, and insulin concentrations. Although significant differences were seen only at set 5, the total number of repetitions and training volume tended (p = 0.08) to be higher with S compared to P. Serum growth hormone and insulin concentrations were significantly higher at 15P and IP, respectively, in S compared to P. Results suggest that a pre-exercise energy S consumed 10 minutes before resistance exercise can enhance acute exercise performance by increasing the number of repetitions performed and the total volume of exercise. The enhanced exercise performance resulted in a significantly greater increase in both growth hormone and insulin concentrations, indicating an augmented anabolic hormone response to this pre-exercise S.