Conventional glucocorticoid replacement overtreats adult hypopituitary patients with partial ACTH deficiency

Selective perioperative steroid supplementation protocol in patients undergoing endoscopic transsphenoidal surgery for pituitary adenomas

BACKGROUND

There is no consensus regarding the use of perioperative steroids for transsphenoidal pituitary surgery. We audited the effectiveness and safety of our selective perioperative steroid supplementation protocol in patients with pituitary adenomas.

METHODS

Two hundred ninety-seven patients underwent 306 endoscopic transsphenoidal surgeries for removal of their pituitary tumors. Steroids were given to those with an impaired hypothalamic-pituitary-adrenal (HPA) axis, age ≥ 60 years, clinical apoplexy, hyponatremia, or if the pituitary gland was not preserved at surgery. We excluded 111 patients in whom the integrity of the HPA axis could not be determined. We compared the incidence of early postoperative adrenal insufficiency and complications in 135 patients with intact HPA axes who underwent surgery without steroids (group A) with 60 patients who had compromised preoperative HPA axes and received perioperative steroids (group B). In addition, we audited the total number of protocol violations during this period.

RESULTS

Five patients (3.7%) in group A developed postoperative hypocortisolemia. There was no significant difference in the incidence of cerebrospinal fluid leak, diabetes insipidus, or hyponatremia between both groups. There were protocol deviations in 47 (15.4%) patients. Twenty one of these patients did not receive perioperative steroids in violation of the protocol, of whom 4 (19%) developed postoperative hypocortisolemia.

CONCLUSIONS

Our steroid sparing protocol was both safe and effective. The 15% incidence of protocol deviations is a reminder that the rigorous usage of checklists is mandatory for successful clinical practice.

Outcomes of the short Synacthen test: what is the role of the 60 min sample in clinical practice?

In recent years, the short Synacthen test (SS) has become the most widely used test to assess adrenal reserve. Despite its frequent use, there are still several areas related to the short Synacthen test (SST), which have no consensus including the optimum sampling times, that is, whether a 60 min post-Synacthen administration cortisol is necessary or not.

Methodology

We performed a retrospective data analysis of 492 SSTs performed on adult patients in a tertiary referral teaching hospital in Ireland. The SSTs were performed in the inpatient and outpatient setting and included patients across all medical disciplines and not exclusively to the endocrinology department.

Results

313 patients had 0, 30 and 60 min samples available for analysis. A total of 270/313 (82%) were deemed to pass the test, that is, cortisol ≥500 nmol/L at both 30 and 60 min. Of the 313 patients, 19 (6%) patients had an indeterminate response, cortisol <500 nmol/L at 30 min, but rising to ≥500 nmol/L on the 60 min sample. Of these 19 patients, only 9/19 patients had a serum cortisol level at 30 min <450 nmol/L, requiring clinical treatment with glucocorticoid replacement. All 24/313 (8%) patients who had insufficient responses at 60 min were also insufficient at 30 min sampling. No individuals passed (≥500 nmol/L) at 30 min and then failed (<500 nmol/L) at 60 min.

Conclusion

Using the 30 min cortisol sample post-Synacthen administration alone identifies clinically relevant adrenal insufficiency in the majority of cases. A small subset of patients have a suboptimal response at 30 min but have a 60 min cortisol concentration above the threshold for a pass. Data regarding the long-term outcomes and management of such patients are lacking and require further study.

Withholding Perioperative Steroids in Patients Undergoing Transsphenoidal Resection for Pituitary Disease: Randomized Prospective Clinical Trial to Assess Safety

BACKGROUND

Perioperative steroid protocols for patients undergoing transsphenoidal surgery (TSS) for pituitary pathology vary by institution.

OBJECTIVE

To assess the safety of withholding glucocorticoids in patients undergoing TSS.

METHODS

Patients with an intact hypothalamic-pituitary-adrenal (HPA) axis undergoing TSS for a pituitary tumor at the same academic institution between 2012 and 2015 were randomized to either receive 100 mg of intravenous hydrocortisone followed by 0.5 mg of intravenous dexamethasone every 6 h for 4 doses (STER, n = 23) or to undergo surgery without steroids (NOSTER, n = 20). Postoperative cortisol levels were then used to determine the need for glucocorticoids after surgery. Data regarding postoperative cortisol levels, hospital stay length, and complications were collected.

RESULTS

Mean postoperative 8 am cortisol levels were higher in the NOSTER group compared to the STER group (745 ± 359 nmol/L and 386 ± 193 nmol/L, respectively, P = .001) and more patients were discharged on glucocorticoids in the STER group (42% vs 12%, P = .07). There was no difference in the incidence of postoperative complications, including hyperglycemia, diabetes insipidus, or permanent adrenal insufficiency. Permanent adrenal insufficiency occurred in 8% of patients.

CONCLUSION

Perioperative steroids can be safely withheld in patients with an intact HPA axis undergoing TSS. Although administration of perioperative glucocorticoids does not appear to increase the risk of complications, it may interfere with assessment of the HPA axis after surgery.

Higher glucocorticoid replacement doses are associated with increased mortality in patients with pituitary adenoma

OBJECTIVE

Patients with secondary adrenal insufficiency (AI) have an excess mortality. The objective was to investigate the impact of the daily glucocorticoid replacement dose on mortality in patients with hypopituitarism due to non-functioning pituitary adenoma (NFPA).

METHODS

Patients with NFPA were followed between years 1997 and 2014 and cross-referenced with the National Swedish Death Register. Standardized mortality ratio (SMR) was calculated with the general population as reference and Cox-regression was used to analyse the mortality.

RESULTS

The analysis included 392 patients (140 women) with NFPA. Mean ± s.d. age at diagnosis was 58.7 ± 14.6 years and mean follow-up was 12.7 ± 7.2 years. AI was present in 193 patients, receiving a mean daily hydrocortisone equivalent (HCeq) dose of 20 ± 6 mg. SMR (95% confidence interval (CI)) for patients with AI was similar to that for patients without, 0.88 (0.68-1.12) and 0.87 (0.63-1.18) respectively. SMR was higher for patients with a daily HCeq dose of >20 mg (1.42 (0.88-2.17)) than that in patients with a daily HCeq dose of 20 mg (0.71 (0.49-0.99)), P = 0.017. In a Cox-regression analysis, a daily HCeq dose of >20 mg was independently associated with a higher mortality (HR: 1.88 (1.06-3.33)). Patients with daily HCeq doses of ≤20 mg had a mortality risk comparable to patients without glucocorticoid replacement and to the general population.

CONCLUSION

Patients with NFPA and AI receiving more than 20 mg HCeq per day have an increased mortality. Our data also show that mortality in patients substituted with 20 mg HCeq per day or less is not increased.

The incidence of anterior pituitary hormone deficiencies in patients with microprolactinoma and idiopathic hyperprolactinaemia

INTRODUCTION

Patients with microprolactinoma and idiopathic hyperprolactinaemia are not generally considered to be at risk of hypopituitarism and are therefore not routinely screened for this abnormality. In our clinical practice, we have observed a number of patients with nonmacroadenomatous hyperprolactinaemia to have anterior pituitary hormone deficits.

AIMS

We aimed to establish the frequency and clinical significance of anterior pituitary hormone deficiencies, comparing patients with radiologically proven microprolactinomas and patients with idiopathic hyperprolactinaemia.

STUDY DESIGN

We retrospectively examined the casenotes of 206 patients with hyperprolactinaemia from our centre. Patients who did not fit the profile of surgically naïve microprolactinoma or idiopathic hyperprolactinaemia or who had incomplete data were excluded, resulting in a study group of 56 patients.

RESULTS

A total of 35 patients with MRI evidence of microprolactinoma were identified, three (8.57%) of whom had one or more anterior pituitary hormone deficiencies. A total of 21 patients with MRI-negative idiopathic hyperprolactinaemia were identified, nine (42%) of whom had one or more anterior pituitary hormone deficiencies (P<.01). Only one patient in the MRI-positive group had deficiency that required hormone replacement, in contrast six patients in the MRI-negative group had deficiencies that were of clinical significance and which required hormone replacement.

SUMMARY

This study shows a clinically significant incidence of anterior pituitary hormone deficiency in patients with idiopathic hyperprolactinaemia. The authors recommend that dynamic pituitary assessment should be considered routinely in this patient group. A prospective study would be required to assess the underlying cause for these abnormalities, as they suggest a nontumour pan-pituitary process.

Hypopituitarism

Hypopituitarism refers to deficiency of one or more hormones produced by the anterior pituitary or released from the posterior pituitary. Hypopituitarism is associated with excess mortality, a key risk factor being cortisol deficiency due to adrenocorticotropic hormone (ACTH) deficiency. Onset can be acute or insidious, and the most common cause in adulthood is a pituitary adenoma, or treatment with pituitary surgery or radiotherapy. Hypopituitarism is diagnosed based on baseline blood sampling for thyroid stimulating hormone, gonadotropin, and prolactin deficiencies, whereas for ACTH, growth hormone, and antidiuretic hormone deficiency dynamic stimulation tests are usually needed. Repeated pituitary function assessment at regular intervals is needed for diagnosis of the predictable but slowly evolving forms of hypopituitarism. Replacement treatment exists in the form of thyroxine, hydrocortisone, sex steroids, growth hormone, and desmopressin. If onset is acute, cortisol deficiency should be replaced first. Modifications in replacement treatment are needed during the transition from paediatric to adult endocrine care, and during pregnancy.

Hormonal Replacement in Hypopituitarism in Adults: An Endocrine Society Clinical Practice Guideline

OBJECTIVE

To formulate clinical practice guidelines for hormonal replacement in hypopituitarism in adults.

PARTICIPANTS

The participants include an Endocrine Society-appointed Task Force of six experts, a methodologist, and a medical writer. The American Association for Clinical Chemistry, the Pituitary Society, and the European Society of Endocrinology co-sponsored this guideline.

EVIDENCE

The Task Force developed this evidence-based guideline using the Grading of Recommendations, Assessment, Development, and Evaluation system to describe the strength of recommendations and the quality of evidence. The Task Force commissioned two systematic reviews and used the best available evidence from other published systematic reviews and individual studies.

CONSENSUS PROCESS

One group meeting, several conference calls, and e-mail communications enabled consensus. Committees and members of the Endocrine Society, the American Association for Clinical Chemistry, the Pituitary Society, and the European Society of Endocrinology reviewed and commented on preliminary drafts of these guidelines.

CONCLUSIONS

Using an evidence-based approach, this guideline addresses important clinical issues regarding the evaluation and management of hypopituitarism in adults, including appropriate biochemical assessments, specific therapeutic decisions to decrease the risk of co-morbidities due to hormonal over-replacement or under-replacement, and managing hypopituitarism during pregnancy, pituitary surgery, and other types of surgeries.

Hypertension in children with congenital adrenal hyperplasia

OBJECTIVES

Estimates of high blood pressure (BP) incidence in children with congenital adrenal hyperplasia (CAH) vary widely; risk factors are poorly understood. We estimated incidence of hypertension by CAH subtype and sex, and assessed its association with body mass index, hydrocortisone and fludrocortisone.

DESIGN

Longitudinal.

PATIENTS

Chart review of 180 paediatric CAH patients (120 salt wasting; 60 simple virilizing; 93 females) seen from 1970 to 2013.

MEASUREMENTS

High BP was diagnosed by diastolic or systolic blood pressure measurement ≥95th percentile for age, sex and height; hypertension was diagnosed with high BP on at least three clinic visits.

RESULTS

Children with classic CAH who received fludrocortisone had a significantly higher rate of hypertension (55% vs 31%) than those who did not. Hypertension incidence was higher in salt-wasting CAH (58%) than in simple-virilizing CAH (35%). Hypertension first occurred before age 5 years in 91% of salt-wasting males and 50% of cases in salt-wasting females; most simple-virilizing cases occurred during ages 10-18 years. Rates of hypertension were higher in children who had three or more measurements with 17-OHP < 400 ng/dl (12·12 nmol/l), and this difference was significant in salt-wasting males. Children on fludrocortisone who had three or more readings of 17-OHP < 400 ng/dl (12·12 nmol/l) had a significantly higher rate of hypertension than those who did not. Hydrocortisone dose was not associated with hypertension.

CONCLUSION

Children with CAH are at higher risk for hypertension than the general paediatric population, and incidence differs by sex and CAH subtype. Hypertension was higher in children on fludrocortisone and who were oversuppressed.

The modulation of corticosteroid metabolism by hydrocortisone therapy in patients with hypopituitarism increases tissue glucocorticoid exposure

CONTEXT

Patients with hypopituitarism have increased morbidity and mortality. There is ongoing debate about the optimum glucocorticoid (GC) replacement therapy.

OBJECTIVE

To assess the effect of GC replacement in hypopituitarism on corticosteroid metabolism and its impact on body composition.

DESIGN AND PATIENTS

We assessed the urinary corticosteroid metabolite profile (using gas chromatography/mass spectrometry) and body composition (clinical parameters and full body DXA) of 53 patients (19 female, median age 46 years) with hypopituitarism (33 ACTH-deficient/20 ACTH-replete) (study A). The corticosteroid metabolite profile of ten patients with ACTH deficiency was then assessed prospectively in a cross over study using three hydrocortisone (HC) dosing regimens (20/10 mg, 10/10 mg and 10/5 mg) (study B) each for 6 weeks. 11 beta-hydroxysteroid dehydrogenase 1 (11β-HSD1) activity was assessed by urinary THF+5α-THF/THE.

SETTING

Endocrine Centres within University Teaching Hospitals in the UK and Ireland.

MAIN OUTCOME MEASURES

Urinary corticosteroid metabolite profile and body composition assessment.

RESULTS

In study A, when patients were divided into three groups - patients not receiving HC and patients receiving HC≤20 mg/day or HC>20 mg/day - patients in the group receiving the highest daily dose of HC had significantly higher waist-to-hip ratio (WHR) than the ACTH replete group. They also had significantly elevated THF+5α-THF/THE (P=0.0002) and total cortisol metabolites (P=0.015). In study B, patients on the highest HC dose had significantly elevated total cortisol metabolites and all patients on HC had elevated THF+5α-THF/THE ratios when compared to controls.

CONCLUSIONS

In ACTH-deficient patients daily HC doses of >20 mg/day have increased WHR, THF+5α-THF/THE ratios and total cortisol metabolites. GC metabolism and induction of 11β-HSD1 may play a pivitol role in the development of the metabolically adverse hypopituitary phenotype.

A comparison of low-dose ACTH, glucagon stimulation and insulin tolerance test in patients with pituitary disorders

CONTEXT

Diagnosis of secondary adrenal insufficiency and GH deficiency requires evaluation by dynamic stimulation tests in most cases. Although insulin tolerance test (ITT) is accepted as the gold-standard test for the evaluation of both hypothalamo-pituitary-adrenal (HPA) and (GH)-IGF-1 axes, the test is cumbersome. In clinical practice, low-dose adrenocorticotrophic hormone (ACTH) stimulation test is a sensitive, safe and easily applicable alternative to ITT. Although it takes more time, glucagon stimulation test (GST) is also a good alternative to ITT and can evaluate both axes.

OBJECTIVE

The primary aim of this study was to compare the ITT, low-dose ACTH and GSTs in the evaluation of HPA and GH-IGF-1 axes in patients with pituitary disorders and to evaluate the repeatability of all three tests.

DESIGN

ITT, low-dose ACTH and GSTs were performed in all 129 patients, and the tests were repeated in 66 of these patients.

SETTING

Erciyes University Medical School, Department of Endocrinology.

PATIENTS OR OTHER PARTICIPANTS

One hundred and twenty-nine adult patients (76 women, 53 men) with pituitary disorder were included in the study.

MAIN OUTCOME MEASURE(S)

The cortisol and GH responses of patients to dynamic tests.

RESULTS

Peak cortisol levels obtained during ITT were significantly lower than the values obtained during both low-dose ACTH and GSTs. Peak cortisol levels obtained during the GST were lower than those found during the low dose ACTH stimulation test. Peak GH responses were found to be higher in GST than in ITT. All three tests had good reproducibility.

CONCLUSIONS

Any of 3 tests can be used in the evaluation of the HPA axis and either GST or the ITT can be used in the evaluation of the GH-IGF-1 axis but cut-off levels for the insufficiency of HPA or GH-IGF-1 axis should be individualized for each test.

Improving outcomes in patients with adrenal insufficiency: a review of current and future treatments

INTRODUCTION

Adrenal insufficiency is a rare but life-threatening disease. Conventional therapy consists of glucocorticoid replacement using hydrocortisone administered two or three times daily. Although such therapy extends life expectancy, mortality is not normalized, and quality of life remains poor. This failure to restore normal health is thought to be due to the inability of conventional glucocorticoid replacement therapy to normalize total cortisol exposure and to respond to the increased need for glucocorticoids during illness and stress. Also, current management regimens do not restore or replicate the intrinsic circadian rhythm of cortisol secretion.

AREAS COVERED

This narrative review was based on a PubMed and Medline search of all English-language articles on the safety and efficacy of glucocorticoid replacement therapy in patients with adrenal insufficiency. Based on this search we discuss current treatment strategies in terms of the failure to maintain or normalize metabolism and quality of life in patients with adrenal insufficiency. The rationale for, and technology behind, the development of modified-release preparations of hydrocortisone are described, together with the evidence suggesting that hydrocortisone preparations that mimic the physiological circadian pattern of cortisol release are more effective than conventional glucocorticoid replacement therapies.

CONCLUSIONS

Modified-release hydrocortisone treatments for patients with adrenal insufficiency more closely mimic the physiological circadian pattern of cortisol secretion than conventional twice or thrice daily treatment. The available evidence suggests that these modified-release preparations should improve metabolic outcomes and quality of life.

Late recovery of cranial diabetes insipidus following pituitary surgery

BACKGROUND

Diabetes insipidus (DI) is common following surgery for a pituitary/sellar lesion. Postoperative DI persisting beyond a few weeks is usually regarded as permanent, requiring lifelong desmopressin therapy.

CASE PRESENTATION

A 16-year-old girl underwent pituitary decompression following a pituitary tumour apoplexy. She developed DI with thirst and hypotonic polyuria in the immediate post-operative period, which was controlled with parenteral DDAVP. Her symptoms persisted and she was discharged on oral desmopressin. Subsequently, she commenced growth hormone replacement. A water deprivation test 6 weeks postoperatively confirmed persistent DI with failure to concentrate urine after 8 hours of dehydration. She was maintained on desmopressin and reported intense thirst and polyuria every time she delayed taking the medication up until 1 year postoperatively. After 1 year, she complained of bloating and stopped taking desmopressin but her symptoms did not recur. A repeat water deprivation test confirmed very late resolution of DI with normal urinary concentration. She has remained asymptomatic ever since.

CONCLUSION

Delayed recovery of normal posterior pituitary function is exceptionally rare. We hypothesise that the underlying mechanism may be the revascularisation and regeneration of the posterior pituitary tissues or of the axons terminating in the posterior pituitary.

Subclinical hypopituitarism

The presence of subclinical or minor pituitary hormone deficiencies could be recognised in clinical practice and might represent intermediate situations among normal pituitary hormone secretion and clinical hypopituitarism. However, this entity has not been correctly identified and associated clinical impairment and even more, long-term consequences regarding to morbidity and mortality, strongly related to clinical hypopituitarism, has not been correctly settled. Furthermore, best test or methods for diagnosis and the cut off to define these intermediate situates are also unknown. With this purpose, long-term controlled studies are needed to define correctly this entity, the appropriate methods for diagnosis and the potential benefits of substitutive hormone therapy in detected cases. The present review will focus on the available evidence concerning the prevalence, clinical features and diagnosis of subclinical hypopituitarism.

Optimizing glucocorticoid replacement therapy in severely adrenocorticotropin-deficient hypopituitary male patients

BACKGROUND

The optimal replacement regimen of hydrocortisone in adults with severe ACTH deficiency remains unknown. Management strategies vary from treatment with 15-30 mg or higher in daily divided doses, reflecting the paucity of prospective data on the adequacy of different glucocorticoid regimens.

OBJECTIVE

Primarily to define the hydrocortisone regimen which results in a 24 h cortisol profile that most closely resembles that of healthy controls and secondarily to assess the impact on quality of life (QoL).

DESIGN

Ten male hypopituitary patients with severe ACTH deficiency (basal cortisol <100 nm and peak response to stimulation <400 nm) were enrolled in a prospective, randomized, crossover study of 3 hydrocortisone dose regimens. Following 6 weeks of each regimen patients underwent 24 h serum cortisol sampling and QoL assessment with the Short Form 36 (SF36) and the Nottingham Health Profile (NHP) questionnaires. Free cortisol was calculated using Coolen's equation. All results were compared to those of healthy, matched controls.

RESULTS

Corticosteroid binding globulin (CBG) was significantly lower across all dose regimens compared to controls (P < 0·05). The lower dose regimen C (10 mg mane/5 mg tarde) produced a 24 h free cortisol profile (FCP) which most closely resembled that of controls. Both regimen A(20 mg mane/10 mg tarde) and B(10 mg mane/10 mg tarde) produced supraphysiological post-absorption peaks. There was no significant difference in QoL in patients between the three regimens, however energy level was significantly lower across all dose regimens compared to controls (P < 0·001).

CONCLUSIONS

The lower dose of hydrocortisone (10 mg/5 mg) produces a more physiological cortisol profile, without compromising QoL, compared to higher doses still used in clinical practice. This may have important implications in these patients, known to have excess cardiovascular mortality.

Carotid atheromatic plaque is commonly associated with hypopituitary men

Hypopituitarism increases the risks of many cardiovascular conditions and therefore, patients with this disease are more prone to cardiovascular disease. To our knowledge, there have been few studies on carotid artery plaque in male patients with hypopituitarism in assessing cardiovascular risks. The aim of this study was to specifically compare carotid artery plaque while examining other major cardiovascular risk factors between male patients with hypopituitarism and control subjects. Forty male patients aged 30-70 years with hypopituitarism and forty age, sex- matched control subjects were recruited at the Yonsei University Severance Hospital, Seoul, Korea. Carotid intima media thickness (IMT) and atheromatous plaque, anthropometry, lipid profile, and pituitary hormones were assessed. Atheromatous plaque in the carotid arteries was observed more frequently in patients with hypopituitarism than age- and sex-matched control subjects (59.5% vs. 2.5%, P<0.01) without differences of carotid IMTs. Patients with hypopituitarism also exhibited higher waist circumference, waist to hip ratio, total cholesterol and LDL cholesterol than control subjects. In subgroup analysis in male patients with hypopituitarism including GH deficiency, lower testosterone levels were associated with higher waist circumference (r=0.446, P=0.033). In conclusion, hypopituitary males exhibit an increased incidence of carotid artery plaque without differences of carotid IMTs, central obesity and higher total cholesterol level. Lower testosterone levels were associated with central obesity- a strong component of a metabolic syndrome, and unsubstituted testosterone deficiency might be an important cardiovascular risk factor in patients with hypopituitarism.

Evaluation of pituitary function after traumatic brain injury in childhood

OBJECTIVES

Post-traumatic hypopituitarism is well described amongst adult traumatic brain injury (TBI) survivors. We aimed to determine the prevalence and clinical significance of pituitary dysfunction after head injury in childhood.

DESIGN

Retrospective exploratory study.

PATIENTS

33 survivors of accidental head injury (27 boys). Mean (range) age at study was 13·4 years (5·4-21·7 years) and median (range) interval since injury 4·3 years (1·4-7·8 years). Functional outcome at study: 15 good recovery, 16 moderate disability, two severe disability.

MEASUREMENTS

Early morning urine osmolality and basal hormone evaluation were followed by the gonadotrophin releasing hormone (GnRH) and insulin tolerance (n = 25) or glucagon tests (if previous seizures, n = 8). Subjects were not primed. Head injury details were extracted from patient records.

RESULTS

No subject had short stature (mean height SD score +0·50, range -1·57 to +3·00). Suboptimal GH responses (<5 μg/l) occurred in six peri-pubertal boys (one with slow growth on follow-up) and one postpubertal adolescent (peak GH 3·2 μg/l). Median peak cortisol responses to insulin tolerance or glucagon tests were 538 and 562 nm. Nine of twenty-five and two of eight subjects had suboptimal responses, respectively, two with high basal cortisol levels. None required routine glucocorticoid replacement. In three, steroid cover was recommended for moderate/severe illness or injury. One boy was prolactin deficient. Other basal endocrine results and GnRH-stimulated LH and FSH were appropriate for age, sex and pubertal stage. Abnormal endocrine findings were unrelated to the severity or other characteristics of TBI or functional outcome.

CONCLUSIONS

No clinically significant endocrinopathy was identified amongst survivors of accidental childhood TBI, although minor pituitary hormone abnormalities were observed.

Mortality in patients with pituitary disease

Pituitary disease is associated with increased mortality predominantly due to vascular disease. Control of cortisol secretion and GH hypersecretion (and cardiovascular risk factor reduction) is key in the reduction of mortality in patients with Cushing's disease and acromegaly, retrospectively. For patients with acromegaly, the role of IGF-I is less clear-cut. Confounding pituitary hormone deficiencies such as gonadotropins and particularly ACTH deficiency (with higher doses of hydrocortisone replacement) may have a detrimental effect on outcome in patients with pituitary disease. Pituitary radiotherapy is a further factor that has been associated with increased mortality (particularly cerebrovascular). Although standardized mortality ratios in pituitary disease are falling due to improved treatment, mortality for many conditions are still elevated above that of the general population, and therefore further measures are needed. Craniopharyngioma patients have a particularly increased risk of mortality as a result of the tumor itself and treatment to control tumor growth; this is a key area for future research in order to optimize the outcome for these patients.

Is there any relationship between imatinib mesylate medication and hypothalamic-pituitary-adrenal axis dysfunction?

BACKGROUND

Imatinib mesylate [tyrosine kinase (TK) inhibitor] is a novel medication in the treatment of chronic myelogenous leukaemia (CML). TK is also essential in hypothalamo-pituitary-adrenal (HPA) axis.

PURPOSE

The aim of this study was to evaluate HPA axis in patients treated with imatinib. Twenty-five patients were included in this study.

METHODS

Glucagon stimulation test (GST) and low-dose (1 microg) adrenocorticotropin test (LDSST) were used to assess the HPA gland axis.

RESULTS

Seventeen (68%) subjects had impaired peak response when a cortisol cut-off value is accepted as 500 nmol/L. Twelve (48%) out of 17 subjects also failed to show a response to LDSST. Therefore, 12 patients (48%) were defined as HPA deficient. Only two of these 25 patients had morning serum cortisol < 200 nmol/l (7.22 microg/dl), and failed the GST and/or LDSST, indicating that the majority had partial glucocorticoid deficiency. If the cut-off presume for LDSST is from 500 to 600 nmol/l, 16 patients (64%) would have failed both the GST and LDSST.

CONCLUSION

Our results indicate an increased prevalence of subclinical glucocorticoid deficiency in patients receiving imatinib mesylate for CML. Therefore under stressed conditions, such as intercurrent illness state, overt and untreated partial glucocorticoid deficiency in CML patients become life threatening.

A subnormal peak cortisol response to stimulation testing does not predict a subnormal cortisol production rate

INTRODUCTION

The decision to commence lifelong glucocorticoid replacement therapy is often based on a cortisol stimulation test. We investigated the relationship between the peak cortisol response to insulin-induced hypoglycemia and daily cortisol production rate (CPR) to ascertain whether provocative tests are accurate in indicating the need to initiate lifelong glucocorticoid replacement.

PATIENTS AND METHODS

Ten patients (five male; mean age, 44 +/- 13 yr) with pituitary disease and with demonstrably suboptimal peak cortisol response (350-500 nmol/liter) to insulin-induced hypoglycemia, underwent CPR measurement by isotope dilution using gas chromatography-mass spectrometry and 24-h urinary free cortisol (UFC).

RESULTS

The median baseline and peak cortisol attained with hypoglycemia were 284 (164-323) and 473.5 (366-494) nmol/liter, respectively. A strong positive correlation was seen between peak stimulated cortisol and CPR (adjusted for body surface area) (r = 0.75; P = 0.02), and in all patients CPR [4.6 (2.9-15.1) mg/d x m(2)] was within the reference range (2.1-12 mg/d x m(2)) or elevated (one patient). A wide range was found for 24-h UFC [116.5 (20.5-265.9) nmol/liter] in this group of patients, and this parameter lacked significant correlation with either serum cortisol concentration or CPR.

CONCLUSION

This is the first study to demonstrate a significant correlation between CPR and peak cortisol values during hypoglycemic challenge. An inadequate cortisol response to hypoglycemia suggests the need for glucocorticoid cover at times of stress, but these data indicate that a suboptimal peak cortisol does not equate to a low CPR and should not be an automatic indication for lifelong glucocorticoid replacement therapy. UFC bears no relation to serum cortisol or CPR and is therefore unhelpful in assessment of such patients.

Clinical insights into the safety and utility of the insulin tolerance test (ITT) in the assessment of the hypothalamo-pituitary-adrenal axis

OBJECTIVE

The insulin tolerance test (ITT) is the gold standard for assessing GH and cortisol production in pituitary disease. However, areas of uncertainty remain regarding its safety in older people, the optimal duration of the test and its performance in insulin resistant states. Whether basal cortisol concentration can reliably predict an adequate adrenal response to hypoglycaemia remains to be determined.

PATIENTS AND DESIGN

We performed a cross-sectional retrospective examination of 197 consecutive patients (mean age 41.8 +/- 16.4, range 13-76 years) with pituitary disease who underwent the ITT over 18 months. The standard intravenous insulin dose administered was 0.15 units/kg body weight. Patients with acromegaly or with type 2 diabetes received 0.2 units/kg; those with basal cortisol < 100 nmol/l received 0.1 units/kg.

RESULTS

Adequate hypoglycaemia (nadir glucose < 2.2 mmol/l) was achieved in 87% of patients, amongst whom 17% did not achieve peak cortisol until 120 min. There were no significant adverse events, even in those >or= 65 years. Of the 18 patients who had basal cortisol < 100 nmol/l, 78% achieved adequate hypoglycaemia; 29% of those had an adequate peak cortisol response >or= 500 nmol/l. A receiver operating characteristics curve identified a basal cortisol of >or= 393 nmol/l to predict a normal peak cortisol response to hypoglycaemia.

CONCLUSIONS

In specialized units, the ITT is safe even in elderly patients and those with hypocortisolaemia. The standard 90-min. cut-off for the ITT misses one in six peak cortisol responses. Some patients with basal cortisol < 100 nmol/l had a normal cortisol response to hypoglycaemia.

Peri-operative glucocorticoid replacement therapy in transsphenoidal pituitary adenoma surgery: a prospective controlled study

BACKGROUND

We set out to prospectively study the peri-operative changes of the hypothalamic-pituitary-adrenal axis (HPA), and to test the hypothesis that the peri-operative corticoid replacement regimen used at the authors' institution in patients with impaired HPA undergoing transsphenoidal pituitary adenoma surgery is adequate.

METHOD

Thirty seven patients (21 females, 16 males, mean age 50.6 years) underwent transsphenoidal pituitary adenoma surgery (mean tumour diameter 20.6 mm, 13 tumours hormone-secreting). The HPA functions of these patients were classified as impaired (group A, n = 15) or preserved (group B, n = 22) according to the results of a pre-operative corticotrophin releasing-hormone test (CRHT). Eleven patients (9 female, 2 male, mean age 53.6 years) without pituitary adenomas and with a preserved HPA (as assessed by medical history and morning serum cortisol (MSC) measurements), undergoing decompressive surgery for degenerative lumbar disc disease, were also studied (group C). On the day of surgery, the patients of group A received 100 mg hydrocortisone (HC) replacement therapy, which was thereafter gradually tapered off in a standardised fashion. The patients of groups B and C were not treated with corticoids. Pre-operative, intra-operative and post-operative variables of these three patient groups were compared.

FINDINGS

The urinary free cortisol excretion (UFC) in group A declined from 6732 +/- 7683 microg/d on the day of surgery to 305 +/- 358 microg/d on the 10(th) post-operative day. In group B, the respective UFC values were 12,851 +/- 16,278 microg/d and 223 +/- 235 microg/d. In both of these groups, the mean UFC did not fall into the normal range during the first ten post-operative days. On none of the post-operative days, was there a significant difference between the UFC of groups A and B. The UFC values of group C dropped from 177 +/- 157 microg/d on the day of surgery to 87 +/- 61 microg/d on post-operative day six, reaching the normal range from the 2(nd) post-operative day onwards. All UFC values of group C were significantly lower than those of group A and B. None of the evaluated clinical, laboratory and MRI parameters, as disclosed by uni- and multivariate analysis, showed any significant influence on the peri-operative UFC values.

CONCLUSIONS

The peri-operative UFC of pituitary adenoma patients with preserved HPA was very high, as compared to patients with degenerative lumbar disc disease. The present study showed for the first time, that the proposed regimen of peri-operative corticoid replacement therapy used in patients with pituitary adenomas and impaired HPA raised cortisol levels to match the physiological increase of UFC in patients with pituitary adenoma surgery and preserved HPA. However, although statistically not significant, the UFC of patients with pituitary adenomas and preserved HPA seemed considerably higher on the day of surgery than in patients with pituitary adenomas and HPA impairment. Although there is no evidence to make it mandatory, administration of 150 mg instead of 100 mg HC substitution on the day of pituitary adenoma surgery in patients with HPA impairment may be prudent.

Prospective evaluation of a protocol for reduced glucocorticoid replacement in transsphenoidal pituitary adenomectomy: prophylactic glucocorticoid replacement is seldom necessary

BACKGROUND

Most pituitary surgery centres prescribe perioperative glucocorticoids to subjects undergoing transsphenoidal pituitary adenomectomy (TSA), despite reports suggesting this may be unnecessary. Evidence-based guidelines for glucocorticoid use in TSA have recently been published but there are no prospective studies of their utility.

OBJECTIVE

To implement and assess a protocol for reduced glucocorticoid replacement for subjects undergoing TSA.

DESIGN

Prospective and retrospective cohort study in an Australian pituitary surgery centre.

PATIENTS AND MEASUREMENTS

Clinical and biochemical data for 56 TSAs performed for non-ACTH-secreting tumours between March 2004 and April 2006 were prospectively collected and compared with data for 47 TSAs performed between October 2001 and November 2003, before implementation of the protocol. In the prospective cohort, a postoperative days 1-3 morning serum cortisol threshold of 250 nmol/l (91 microg/dl) was used to guide long-term glucocorticoid requirement.

RESULTS

Implementation of the protocol was associated with significant reductions in dose and duration of glucocorticoid treatment post TSA in 44 'low-risk' cases (no preoperative glucocorticoid use or evidence of pituitary apoplexy). In two low-risk cases, long-term glucocorticoid replacement was required despite postoperative cortisol greater than 250 nmol/l. Following the remaining 42 low-risk operations, glucocorticoid was not prescribed on hospital discharge on the basis of morning serum cortisol > 250 nmol/l and no clinical evidence of hypocortisolism. None of these 42 cases required glucocorticoid treatment for hypocortisolism following surgery. Short synacthen tests were performed in 35 of these subjects a minimum of 6 months after surgery and were normal. Use of the protocol was not associated with differences in postoperative complications.

CONCLUSIONS

Reduced glucocorticoid replacement in TSA is safe and reduces patient exposure to glucocorticoids and their potential adverse events. The occurrence of hypocortisolism in two low-risk subjects with serum cortisol > 250 nmol/l highlights the importance of daily clinical assessment when using this protocol.

Subclinical Cushing's syndrome

Subclinical Cushing's syndrome (CS) is attracting increasing interest since the serendipitous discovery of an adrenal mass has become a rather frequent event owing to the routine use of sophisticated radiologic techniques. Cortical adenoma is the most frequent type of adrenal incidentaloma accounting for approximately 50% of cases in surgical series and even greater shares in medical series. Incidentally discovered adrenal adenomas may secrete cortisol in an autonomous manner that is not fully restrained by pituitary feedback, in 5 to 20% of cases depending on study protocols and diagnostic criteria. The criteria for qualifying subclinical cortisol excess are controversial and presently there is no consensus on a gold standard for the diagnosis of this condition. An increased frequency of hypertension, central obesity, impaired glucose tolerance, diabetes and hyperlipemia has been described in patients with subclinical CS; however, there is still no clear demonstration of the long-term complications of this condition whose management remains largely empirical. Either adrenalectomy or careful observation associated with treatment of the metabolic syndrome have been suggested as treatment options.

The growth hormone/insulin-like growth factor-I axis in exercise and sport

The syndrome of adult GH deficiency and the effects of GH replacement therapy provide a useful model with which to study the effects of the GH/IGF-I axis on exercise physiology. Measures of exercise performance including maximal oxygen uptake and ventilatory threshold are impaired in adult GH deficiency and improved by GH replacement, probably through some combination of increased oxygen delivery to exercising muscle, increased fatty acid availability with glycogen sparing, increased muscle strength, improved body composition, and improved thermoregulation. In normal subjects, in addition to the long-term effects of GH/IGF-I status, there is evidence that the acute GH response to exercise is important in regulating substrate metabolism after exercise. Administration of supraphysiological doses of GH to athletes increases fatty acid availability and reduces oxidative protein loss, particularly during exercise, and increases lean body mass. Despite a lack of evidence that these metabolic effects translate to improved performance, GH abuse by athletes is widespread. Tests to detect GH abuse have been developed based on measurement in serum of 1) indirect markers of GH action, and 2) the relative proportions of the two major naturally occurring isoforms (20 and 22kDa) of GH. There is evidence that exercise performance and strength are improved by administration of GH and testosterone in combination to elderly subjects. The potential benefits of GH in these situations must be weighed against potential adverse effects.

Modulation of glucocorticoid metabolism by the growth hormone - IGF-1 axis

The growth hormone-insulin-like growth factor 1 (GH-IGF-1) axis plays an important role in modulating the peripheral metabolism of glucocorticoids mainly through its effect on the isoenzyme 11 beta-hydroxysteroid dehydrogenase 1 (11beta-HSD1) which, in vivo, functions as a reductase catalysing the conversion of cortisone to cortisol. Several in vivo and ex vivo studies have shown that the GH-IGF-I system inhibits the expression and activity of 11beta-HSD1 in adipose tissues and the liver resulting in reduced local regeneration of cortisol. This interaction has clinically significant implications as it may at least partly explain the phenotypes of acromegaly and adult GH deficiency and the effects that treatment of these conditions has on body composition. In addition, by accelerating the peripheral metabolism of cortisol, GH therapy may precipitate adrenal insufficiency in susceptible hypopituitary patients, and endocrinologists should be mindful of this phenomenon when starting hypopituitary patients on GH replacement therapy.

Hypopituitarism and mortality in pituitary adenoma

BACKGROUND AND OBJECTIVE

Previous studies on hypopituitarism and mortality have concluded that insufficient pituitary function is associated with decreased survival. For several reasons the results are difficult to compare - particularly because definitions and treatment of hypopituitarism have varied and various underlying disorders have been included. The purpose was to assess the relationship between mortality and pituitary function.

PATIENTS AND DESIGN

One hundred and sixty consecutive patients (99 men and 61 women) with functionless, suprasellar pituitary adenoma. All were operated on transsphenoidally during the period 1985-1996. Additional radiotherapy was given to 29 patients. Mortality was calculated 12.4 years (median, range 8.1-19.9) after operation. Postoperative hormonal deficits were treated in most, though GH substitution was given only to a minority of patients.

RESULTS

Postoperatively 30% of the patients had normal pituitary function (normal adrenocortical, thyroid and gonadal function), 26% were panhypopituitary and 36% had partial pituitary insufficiency. Forty-one patients had died (34.7 expected) yielding a standard mortality ratio (SMR) of 1.18 (95% confidence limits (CI) 0.87-1.60). SMR was significantly increased in women (1.97, CI 1.20-3.21) but not in men (0.83, CI 0.55-1.26). SMR in patients with normal pituitary function, panhypopituitarism and partial insufficiency were not different from that in the general population. SMR in hypopituitary women was substantially higher than in men with pituitary insufficiency. Treatment with growth hormone in GH-deficient patients did not influence survival.

CONCLUSION

Pituitary surgery for nonfunctioning adenoma and subsequent pituitary insufficiency had no effect on mortality in men, but was associated with significantly increased mortality in women. Suboptimal hormonal substitution in women may play a role.

Evaluation of pituitary function in the fatigued patient: a review of 59 cases

OBJECTIVE

The aim of this study was to review the results of dynamic pituitary testing in patients presenting with fatigue.

METHODS

We reviewed clinical histories and insulin tolerance test (ITT) results of 59 patients who presented with fatigue and other symptoms of glucocorticoid insufficiency over a 4-year period. All patients referred for ITT had an early-morning cortisol level of <400 nM and a low or normal ACTH level.

RESULTS

Peak cortisol and GH responses following insulin-induced hypoglycaemia were normal in only seven patients (12%). Median age of the remaining 52 patients was 47 years (range, 17-67 years); all but five were female. Common presenting symptoms were neuroglycopaenia (n = 47), depression (n = 37), arthralgia and myalgia (n = 28), weight gain (n = 25), weight loss (n = 9), postural dizziness (n = 15) and headaches (n = 13). Other medical history included autoimmune disease (n = 20; particularly Hashimoto's thyroiditis, Graves' disease and coeliac disease), postpartum (n = 8) and gastrointestinal (n = 2) haemorrhage and hyperprolactinaemia (n = 13). 31 subjects had peak cortisol levels of <500 nM (suggestive of ACTH deficiency; 18 of whom had levels < 400 nM) and a further six had indeterminate results (500-550 nM). The remaining 15 subjects had normal cortisol responses (median 654 nM; range, 553-1062 nM) but had low GH levels following hypoglycaemic stimulation (5.9 mU/l; 3-11.6 mU/l).

CONCLUSION

Our results suggest that patients presenting with fatigue and symptoms suggestive of hypocortisolism should be considered for screening for secondary adrenal insufficiency, particularly in the presence of autoimmune disease or a history of postpartum or gastrointestinal haemorrhage. Whether physiological glucocorticoid replacement improves symptoms in this patient group is yet to be established.

Why is the management of glucocorticoid deficiency still controversial: a review of the literature

All endocrinologists would like to make glucocorticoid replacement therapy for their hypoadrenal patients as physiological as possible. Many would like the reassurance of a method of monitoring such treatment to confirm that they are achieving this aim. Advances in our knowledge of the normal physiology are relevant to our attempts to do this. The cortisol production rate in normal subjects is lower than was previously believed. The normal pattern of glucocorticoid secretion includes both a diurnal rhythm and a pulsatile ultradian rhythm. Glucocorticoid access to nuclear receptors is 'gated' by the 11-beta-hydroxysteroid dehydrogenase enzymes, which interconvert active cortisol and inactive cortisone. Such complexities make the target of physiological glucocorticoid replacement therapy hard to achieve. The available evidence suggests that conventional treatment of hypoadrenal patients may result in adverse effects on some surrogate markers of disease risk, such as a lower bone mineral density than age-sex matched controls, and increases in postprandial glucose and insulin concentrations. Although the quality of life of hypoadrenal patients may be impaired, there is no evidence of an improvement on higher doses of steroids, although quality of life is better if the hydrocortisone dose is split up, with the highest dose taken in the morning. Thus the evidence suggests that most patients may safely be treated with a low dose of glucocorticoid (e.g. 15 mg hydrocortisone daily) in two or three divided doses, with education about the appropriate action to take in the event of intercurrent illnesses.

Subclinical Cushing's syndrome in adrenal incidentalomas

This article reviews the available evidence on subclinical Cushing's syndrome in patients who have adrenal incidentalomas. The authors' aim is to present up-to-date information on the most relevant issues of subclinical Cushing's syndrome by addressing the many uncertainties and controversies surrounding this ill-defined endocrine condition.

Diagnosis and treatment of hypopituitarism: an update

Diagnosis and treatment of patients with hypopituitarism needs careful clinical evaluation and individual optimization. Symptoms of hypopituitarism are variable, often insidious in onset and dependent on the degree of hormone deficiency. Diagnosis of hypopituitarism can be straightforward by measuring reduced basal hormone levels. Frequently, dynamic stimulation tests are indicated in equivocal basal hormone levels or to diagnose partial hormone deficiencies. Knowledge of the use and limitations of these dynamic tests is mandatory for proper interpretation. Hormone replacement therapy should be individualized, taking into account possible interactions. Persisting symptoms and reduced quality of life are frequently reported, explained by, at least in part, intrinsic imperfections of hormone replacement strategies in mimicking normal hormone secretion. In the present overview, the principles of diagnosis and treatment of hypopituitarism are discussed.