The contribution of serum cortisone and glucocorticoid metabolites to detrimental bone health in patients receiving hydrocortisone therapy.

BACKGROUND: Glucocorticoid therapy is the most common cause of iatrogenic osteoporosis. Less is known regarding the effect of glucocorticoids when used as replacement therapy on bone remodelling in patients with adrenal insufficiency. Enhanced intracellular conversion of inactive cortisone to active cortisol, by 11 beta-hydroxysteroid dehydrogenase type 1(11ß-HSD1) and other enzymes leading to alterations in glucocorticoid metabolism, may contribute to a deleterious effect on bone health in this patient group. METHODS: Study design: An open crossover prospective study randomizing ten hypopituitary men, with severe ACTH deficiency, to three commonly used hydrocortisone dose regimens. MEASUREMENTS: Following 6 weeks of each regimen, patients underwent 24-h serum cortisol/cortisone sampling, measurement of bone turnover markers, and a 24-h urine collection for measurement of urinary steroid metabolites by gas chromatography-mass spectrometry (GC-MS). Serum cortisone and cortisol were analysed by liquid chromatography-mass spectrometry (LC-MS). RESULTS: Dose-related and circadian variations in serum cortisone were seen to parallel those for cortisol, indicating conversion of ingested hydrocortisone to cortisone. The median area under the curve (AUC) of serum cortisone was significantly higher in patients on dose A (20 mg/10 mg) [670.5 (IQR 621-809.2)] compared to those on dose C (10 mg/5 mg) [562.8 (IQR 520.1-619.6), p = 0.01]. A negative correlation was observed between serum cortisone and bone formation markers, OC [1-49] (r = - 0.42, p = 0.03), and PINP (r = - 0.49, p = 0.01). There was a negative correlation between the AUC of night-time serum cortisone levels with the bone formation marker, OC [1-49] (r = - 0.41, p = 0.03) but there were no significant correlations between day-time serum cortisone or cortisol with bone turnover markers. There was a negative correlation between total urinary cortisol metabolites and the bone formation markers, PINP (r = - 0.39, p = 0.04), and OC [1-49] (r = - 0.35, p = 0.06). CONCLUSION: Serum cortisol and cortisone and total urinary corticosteroid metabolites are negatively associated with bone turnover markers in patients receiving replacement doses of hydrocortisone, with nocturnal glucocorticoid exposure having a potentially greater influence on bone turnover. TRIAL REGISTRATION: Irish Medicines Board Clinical Trial Number - CT900/459/1 and EudraCT Number - 2007-005018-37 . Registration date: 07-09-2007.

Low-dose hydrocortisone replacement is associated with improved arterial stiffness index and blood pressure dynamics in severely adrenocorticotrophin-deficient hypopituitary male patients.

OBJECTIVE: Increased cardiovascular and cerebrovascular morbidity and mortality in hypopituitary subjects may be linked to inappropriate glucocorticoid exposure; however, the pathophysiology remains unclear. We aimed to examine the effect of three commonly prescribed hydrocortisone (HC) regimens on vascular risk factors. DESIGN: An open crossover study randomising ten hypopituitary men with severe adrenocorticotrophic hormone deficiency to three HC dose regimens: dose A (20mg mane and 10mg tarde), dose B (10mg mane and 10mg tarde) and dose C (10mg mane and 5mg tarde). METHODS: Following 6 weeks on each regimen, participants underwent 24-h serum cortisol sampling, 24-h ambulatory blood pressure (BP) measurements, calculation of the Ambulatory Arterial Stiffness Index (AASI), oral glucose tolerance testing and fasting serum osteoprotegerin (OPG) sampling. RESULTS: There were no differences in 24-h BP between dose regimens and controls; however, low-dose HC replacement (dose C) was associated with the lowest AASI, indicating a less stiff arterial tree (P<0.05) compared with the other dose regimens. Loss of the physiologic nocturnal BP dip was more common in higher HC replacement regimens, although only significant for dose B compared with dose C (P=0.03). Twenty per cent of patients had abnormal glucose tolerance, but this was unrelated to dose regimen. OPG correlated strongly with 24-h BP in those on dose A only (r=0.65, P=0.04). CONCLUSION: Currently prescribed HC replacement doses do not result in significant differences in absolute BP levels or improvements in insulin sensitivity. However, lower HC doses may result in lower arterial stiffness and a more physiological nocturnal BP dip. Long-term studies are required to confirm these findings and evaluate their impact on vascular morbidity in this patient group.

Low-dose hydrocortisone replacement therapy is associated with improved bone remodelling balance in hypopituitary male patients.

OBJECTIVE: Glucocorticoid (GC) therapy is associated with adverse effects on bone metabolism, yet the effects of different GC physiological replacement regimens in hypopituitarism are not well characterised. We aimed to assess the effect of three hydrocortisone (HC) replacement dose regimens on bone turnover. STUDY DESIGN: An open cross-over study randomising ten hypopituitary men with severe acth deficiency to three commonly used HC dose regimens: dose A (20 mg mane and 10 mg tarde), dose B (10 mg mane and 10 mg tarde) and dose C (10 mg mane and 5 mg tarde). METHODS: Following 6 weeks of each regimen, the participants underwent 24-h serum cortisol sampling and measurement of bone turnover markers: bone-specific alkaline phosphatase, procollagen type I N-propeptide (PINP), intact osteocalcin (OC(1-49)), C-terminal cross-linking telopeptide (CTX-I) and tartrate-resistant acid phosphatase 5b (TRACP5b). Bone remodelling balance was estimated as an absolute ratio (PINP:CTX-I) and as an index using standardised scores derived from the matched controls. RESULTS: There were significant increases in the concentrations of the formation markers PINP (P=0.045) and OC(1-49) (P=0.006) and in the PINP:CTX-I ratio (P=0.015), and a more positive bone remodelling balance index (P=0.03) was observed in patients on the lowest dose C than in those on the highest dose A. Mean 24-h cortisol concentrations correlated negatively with CTX-I (r=-0.66 and P=0.04) and TRACP5b (r=-0.74 and P=0.01) in patients on dose B and with OC(1-49) (r=-0.66 and P=0.04) and CTX-I (r=-0.81 and P<0.01) in patients on dose C. In patients receiving the lower-dose regimen, trough cortisol concentrations correlated with increased bone formation and resorption. CONCLUSION: Low-dose HC replacement (10 mg mane and 5 mg tarde) is associated with increased bone formation and a positive bone remodelling balance. This may have a long-term beneficial effect on bone health.

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.

Hypothalamic-pituitary dysfunction after irradiation of nonpituitary brain tumors in adults.

CONTEXT: Hypothalamic-pituitary (HP) dysfunction is common in children treated with cranial radiotherapy (RT) for brain tumors, but there is little known about the risk of HP dysfunction in adults treated with RT for primary nonpituitary brain tumors. OBJECTIVE: The objective was to study the frequency of HP dysfunction in adults after RT for nonpituitary brain tumors. METHOD: We studied 56 adult patients who received external beam RT for primary nonpituitary brain tumors at time intervals of 12-150 months after RT. The control group consisted of 20 RT-naive patients with primary brain tumors. GH and adrenal axes were assessed using the insulin tolerance test or the glucagon stimulation test. Gonadotroph, thyrotroph, and lactotroph function were assessed using baseline blood measurements. The biological effective dose (BED) to the HP axis was calculated in the RT patients. RESULTS: Hypopituitarism was present in 41% of patients. The frequency of GH, ACTH, gonadotropin, and TSH deficiencies, and hyperprolactinemia was 32, 21, 27, 9, and 32%, respectively. Any degree of hypopituitarism and GH deficiency was significantly associated with longer time interval from RT and greater BED. However, gonadotropin deficiency and hyperprolactinemia were only related to BED, whereas ACTH deficiency was only significantly associated with the time interval from RT. One RT-naive patient was GH deficient. CONCLUSION: Adult patients treated with cranial irradiation for primary nonpituitary brain tumors are at high risk of hypopituitarism, which is time and dose dependent. Long-term surveillance and periodic evaluation are needed. We recommend that adult late effect clinics, similar to those for children, should be established.

Anterior pituitary dysfunction in survivors of traumatic brain injury.

Recent data suggest that anterior pituitary dysfunction after traumatic brain injury (TBI) is common. We sought to confirm the results of earlier studies in a larger cohort of patients with dynamic testing of pituitary function. We studied 102 consecutive TBI survivors (85 males; median age 28, range 15-65 yr) who had survived severe or moderate TBI (initial Glasgow Coma Scale score 3-13) at a median of 17 months (range 6-36) post event. GH and ACTH reserves were initially assessed using the glucagon stimulation test (GST). Normative data on GH and cortisol responses to the GST were obtained from 31 matched healthy controls. Patients with subnormal GH or cortisol responses were further evaluated, using the insulin tolerance test (ITT) or arginine + GHRH test for GH assessment and the ITT or 250-microg short synacthen test for the assessment of ACTH reserve. Patients were considered to be GH or ACTH deficient if they failed both the GST and the second provocative test. Baseline thyroid function, prolactin, IGF-I, gonadotropins, testosterone, or estradiol was performed in all patients and compared with local reference ranges.In controls, normal response to the GST was a stimulated GH peak of greater than 5 microg/liter and cortisol peak greater than 450 nmol/liter (16 microg/dl). Eighteen TBI patients (17.6%) had GH response to the GST less than 5 microg/liter, 11 of whom also failed the ITT or the arginine + GHRH tests. GH-deficient patients had significantly higher body mass index (P = 0.003), and lower IGF-I concentrations (P < 0.001), than GH-sufficient patients. Twenty-three patients (22.5%) had cortisol responses to GST less than 450 nmol/liter, 13 of whom also failed the ITT or short synacthen test. GH or ACTH deficiencies were not related to age, Glasgow Coma Scale score, or the presence of other pituitary hormone abnormalities (P > 0.05). Twelve patients (11.8%) had gonadotropin and one (1%) had thyrotrophin deficiencies. Twelve patients (11.8%) had hyperprolactinemia. Twenty-nine patients (28.4%) had at least one anterior pituitary hormone deficiency. This is the largest study, to date, of hypopituitarism after TBI and confirms a high prevalence of undiagnosed anterior pituitary hormone abnormalities in survivors of TBI. Hypopituitarism is a treatable cause of morbidity after TBI. In addition to conventional pituitary hormone replacement, the potential of GH treatment to enhance recovery needs to be examined in a prospective study.

Neuroendocrine dysfunction in the acute phase of traumatic brain injury.

BACKGROUND: Pituitary hormone abnormalities have been reported in up to 50% of survivors of traumatic brain injury (TBI) who were investigated several months or longer following the event. The frequency of pituitary dysfunction in the early post-TBI period is unknown. AIM: To evaluate the prevalence of anterior and posterior pituitary dysfunction in the early phase following TBI. SUBJECTS: Fifty consecutive patients admitted to the neurosurgical unit with severe or moderate TBI [initial Glasgow Coma Scale (GCS) score 3-13], and 31 matched healthy control volunteers were studied. METHODS: The glucagon stimulation test (GST) was performed at a median of 12 days (range 7-20) following TBI. Baseline thyroid function, PRL, IGF-1, gonadotrophins, testosterone or oestradiol, plasma sodium, plasma and urine osmolalities or the standard observed water deprivation test were performed. The control subjects underwent the GST for GH and cortisol responses; other parameters were compared to locally derived reference ranges. RESULTS: Control data indicated that peak serum GH of > 5 ng/ml and cortisol > 450 nmol/l following glucagon stimulation should be taken as normal. Nine TBI patients (18%) had GH response < 5 ng/ml (12 mU/l). Eight patients (16%) had peak cortisol responses < 450 nmol/l. Compared to controls, basal cortisol values were significantly lower in patients with subnormal cortisol responses to glucagon and significantly higher in patients with normal cortisol responses (P < 0.05). GH and cortisol deficiencies were unrelated to patient age, BMI, initial GCS or IGF-1 values (P > 0.05). Forty patients (80%) had gonadotrophin deficiency, with low sex steroid concentrations, which was unrelated to the presence of hyperprolactinaemia. In males there was a positive correlation between serum testosterone concentration and GCS (r = 0.32, P = 0.04). One patient had TSH deficiency. Hyperprolactinaemia was present in 26 patients (52%) and serum PRL levels correlated negatively with the GCS score (r =-0.36, P = 0.011). Thirteen patients (26%) had cranial diabetes insipidus (DI) and seven (14%) had syndrome of inappropriate ADH secretion. CONCLUSION: Our data show that post-traumatic neuroendocrine abnormalities occur early and with high frequency, which may have significant implications for recovery and rehabilitation of TBI patients.