Modified-release hydrocortisone to provide circadian cortisol profiles

Context: Cortisol has a distinct circadian rhythm regulated by the brain's central pacemaker. Loss of this rhythm is associated with metabolic abnormalities, fatigue, and poor quality of life. Conventional glucocorticoid replacement cannot replicate this rhythm. Objectives: Our objectives were to define key variables of physiological cortisol rhythm, and by pharmacokinetic modeling test whether modified-release hydrocortisone (MR-HC) can provide circadian cortisol profiles. Setting: The study was performed at a Clinical Research Facility. Design and Methods: Using data from a cross-sectional study in healthy reference subjects (n = 33), we defined parameters for the cortisol rhythm. We then tested MR-HC against immediate-release hydrocortisone in healthy volunteers (n = 28) in an open-label, randomized, single-dose, cross-over study. We compared profiles with physiological cortisol levels, and modeled an optimal treatment regimen. Results: The key variables in the physiological cortisol profile included: peak 15.5 mu g/dl (95% reference range 11.7-20.6), acrophase 0832 h(95% confidence interval 0759-0905), nadir less than 2 mu g/dl (95% reference range 1.5-2.5), time of nadir 0018 h (95% confidence interval 2339-0058), and quiescent phase (below the mesor) 1943-0531 h. MR-HC 15 mg demonstrated delayed and sustained release with a mean (SEM) maximum observed concentration of 16.6 (1.4) mu g/dl at 7.41 (0.57) h after drug. Bioavailability of MR-HC 5, 10, and 15 mg was 100, 79, and 86% that of immediate-release hydrocortisone. Modeling suggested that MR-HC 15-20 mg at 2300 h and 10 mg at 0700 h could reproduce physiological cortisol levels. Conclusion: By defining circadian rhythms and using modern formulation technology, it is possible to allow a more physiological circadian replacement of cortisol. (J Clin Endocrinol Metab 94: 1548-1554, 2009

Adaptor protein-2 sigma subunit mutations causing familial hypocalciuric hypercalcaemia type 3 (FHH3) demonstrate genotype-phenotype correlations, codon bias and dominant-negative effects

The adaptor protein-2 sigma subunit (AP2σ2) is pivotal for clathrin-mediated endocytosis of plasma membrane constituents such as the calcium-sensing receptor (CaSR). Mutations of the AP2σ2 Arg15 residue result in familial hypocalciuric hypercalcaemia type 3 (FHH3), a disorder of extracellular calcium (Ca(2+) o) homeostasis. To elucidate the role of AP2σ2 in Ca(2+) o regulation, we investigated 65 FHH probands, without other FHH-associated mutations, for AP2σ2 mutations, characterized their functional consequences and investigated the genetic mechanisms leading to FHH3. AP2σ2 mutations were identified in 17 probands, comprising 5 Arg15Cys, 4 Arg15His and 8 Arg15Leu mutations. A genotype-phenotype correlation was observed with the Arg15Leu mutation leading to marked hypercalcaemia. FHH3 probands harboured additional phenotypes such as cognitive dysfunction. All three FHH3-causing AP2σ2 mutations impaired CaSR signal transduction in a dominant-negative manner. Mutational bias was observed at the AP2σ2 Arg15 residue as other predicted missense substitutions (Arg15Gly, Arg15Pro and Arg15Ser), which also caused CaSR loss-of-function, were not detected in FHH probands, and these mutations were found to reduce the numbers of CaSR-expressing cells. FHH3 probands had significantly greater serum calcium (sCa) and magnesium (sMg) concentrations with reduced urinary calcium to creatinine clearance ratios (CCCR) in comparison with FHH1 probands with CaSR mutations, and a calculated index of sCa × sMg/100 × CCCR, which was ≥ 5.0, had a diagnostic sensitivity and specificity of 83 and 86%, respectively, for FHH3. Thus, our studies demonstrate AP2σ2 mutations to result in a more severe FHH phenotype with genotype-phenotype correlations, and a dominant-negative mechanism of action with mutational bias at the Arg15 residue

Significant benefits of AIP testing and clinical screening in familial isolated and young-onset pituitary tumors

Context Germline mutations in the aryl hydrocarbon receptor-interacting protein (AIP) gene are responsible for a subset of familial isolated pituitary adenoma (FIPA) cases and sporadic pituitary neuroendocrine tumors (PitNETs). Objective To compare prospectively diagnosed AIP mutation-positive (AIPmut) PitNET patients with clinically presenting patients and to compare the clinical characteristics of AIPmut and AIPneg PitNET patients. Design 12-year prospective, observational study. Participants & Setting We studied probands and family members of FIPA kindreds and sporadic patients with disease onset ≤18 years or macroadenomas with onset ≤30 years (n = 1477). This was a collaborative study conducted at referral centers for pituitary diseases. Interventions & Outcome AIP testing and clinical screening for pituitary disease. Comparison of characteristics of prospectively diagnosed (n = 22) vs clinically presenting AIPmut PitNET patients (n = 145), and AIPmut (n = 167) vs AIPneg PitNET patients (n = 1310). Results Prospectively diagnosed AIPmut PitNET patients had smaller lesions with less suprasellar extension or cavernous sinus invasion and required fewer treatments with fewer operations and no radiotherapy compared with clinically presenting cases; there were fewer cases with active disease and hypopituitarism at last follow-up. When comparing AIPmut and AIPneg cases, AIPmut patients were more often males, younger, more often had GH excess, pituitary apoplexy, suprasellar extension, and more patients required multimodal therapy, including radiotherapy. AIPmut patients (n = 136) with GH excess were taller than AIPneg counterparts (n = 650). Conclusions Prospectively diagnosed AIPmut patients show better outcomes than clinically presenting cases, demonstrating the benefits of genetic and clinical screening. AIP-related pituitary disease has a wide spectrum ranging from aggressively growing lesions to stable or indolent disease course

Pharmacological and physiological studies of anterior·pituitary hormones secretion (GH, ACTH and TSH) in cranially irradiated adult cancer survivors with radiation-induced hypothalamic- pituitary dysfunction

THE UNIVERSITY OF MANCHESTER ABSTRACT OF THESIS submitted by Ken Darzy for the Degree of M.D. and entitled 'Pharmacological and physiological studies of anterior pituitary hormones secretion (GH, ACTH and TSH) in cranially irradiated adult cancer survivors with radiation-induced hypothalamic-pituitary dysfunction'. Month and Year of submission: June 2008. This thesis describes the dynamics of GH, ACTH/Cortisol and TSH/T4 secretion in adult cancer survivors irradiated for non-pituitary brain tumours or leukaemia. Stimulated and physiological hormonal secretions were studied simultaneously. It was shown that, in patients with severe radiation-induced GH deficiency diagnosed by failure to pass both the ITT and the GHRH + AST, pulsatile GH secretion and diurnal rhythm are preserved, yet with severe amplitude attenuation and an overall feminised pattern of GH secretion characterized by relatively higher inter-peak levels (tonic secretion) and increased secretory disorderliness, as measured by ApEn. Patients with normal individual peak GH responses to the ITT and the GHRH+AST still showed evidence of damage to the h-p axis, as the overall mean GH responses were reduced by 50%. However, spontaneous fed and fasting GH secretion in this group was fully maintained both individually and at a group level compared with a matched control group. This finding argues against the previously held belief that somatotroph dysfunction is primarily due to radiation-induced GHRH deficiency, as the combined effect of reduced GHRH and secondary somatotroph atrophy would be expected to result in reduced spontaneous GH secretion. It was, therefore, concluded that radiation causes direct pituitary damage and that endogenous hyperstimulation of the h-p axis mediated by a compensatory increase in GHRH release restores normality of GH secretion in these patients with partially damaged somatotrophic axis (compensated GHD). Based on the findings in some patients, it was also suggested that 'near maximal' endogenous hyper-stimulation and GHRH release may limit further stimulation with the ITT, so much so, that a failed ITT response can occur in the presence of normal GHRH+AST response and normal spontaneous GH secretion. . These findings in adults has lead to the suggestion that failure of the hyperstimulated partially damaged h-p axis to increase GH secretion during periods of increased demand, such as growth and puberty may explain what has previously been described as radiation-induced GH neurosecretory dysfunction. It was reasonable to conclude that unlike the ITT, a failed response to the GHRH+AST almost always indicated GHD in the irradiated adult. On the contrary, failure to pass the ITT reflects 'a potential failure of the h-p axis to respond to increased demands and therefore it should remain the gold standard guide for the need for GH replacement therapy in children. Adult cancer survivors with normal ACTH reserve indicated by normal cortisol responses to the ITT have showed parallel and significant increases in fed and fasting 24-hour integrated cortisol concentrations and secretion rates with no change in half-life. This has been attributed to a pro-active h-p-adrenal axis with increased CRH-ACTH release mediated by the direct effects of radiation on the axis or perhaps the higher level of chronic stress in cancer survivors. In addition, euthyroid adult cancer survivors have significantly increased stimulated and integrated 24-hour TSH levels, especially in spinally irradiated patients with severe GHD. There was no change in the TSH bioactivity and the increase in TSH levels could be attributed to subclinical thyroidal damage, GHD-induced reduction in somatostatin tone and/or radiation-induced reduction in somatostatin and dopamine tone. The maximum TSH surge in the. 24-hour profile was slightly but significantly reduced. The subnormal nocturnal TSH surge seen in some patients reflected a shift in the timing of the peak and/or nadir TSH levels rather than a genuine loss of the TSH diurnal rhythm, as similarly seen in some normal individuals. This finding argues against the existence of so-called hidden central hypothyroidism. In summary, this thesis has provided novel insights into the pathophysilogy and site of radiation damage and its relevance to the clinical application ofthe diagnostic tests currently in use.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Efficacy and safety of dapagliflozin in patients with inadequately controlled type 1 diabetes (DEPICT-1):24 week results from a multicentre, double-blind, phase 3, randomised controlled trial

Background Dapagliflozin is a sodium-glucose cotransporter-2 inhibitor approved for the treatment of type 2 diabetes. We aimed to assess the efficacy and safety of dapagliflozin as an add-on to adjustable insulin in patients with inadequately controlled type 1 diabetes. Methods DEPICT-1 was a double-blind, randomised, parallel-controlled, three-arm, phase 3, multicentre study done at 143 sites in 17 countries. Eligible patients were aged 18–75 years and had inadequately controlled type 1 diabetes (HbA1cbetween ≥7·7% and ≤11·0% [≥61·0 mmol/mol and ≤97·0 mmol/mol]) and had been prescribed insulin for at least 12 months before enrolment. After an 8 week lead-in period to optimise diabetes management, patients were randomly assigned (1:1:1) using an interactive voice response system to dapagliflozin 5 mg or 10 mg once daily, given orally, or matched placebo. Randomisation was stratified by current use of continuous glucose monitoring, method of insulin administration, and baseline HbA1c. The primary efficacy outcome was the change from baseline in HbA1cafter 24 weeks of treatment in the full analysis set, which consisted of all randomly assigned patients who received at least one dose of study drug. An additional 55 patients who were incorrectly and non-randomly allocated to only dapagliflozin treatment groups were included in the safety analysis set. This study was registered with ClinicalTrials.gov, number NCT02268214; data collection for the present analysis was completed on Jan 4, 2017, and a 28 week extension phase is ongoing. Findings Between Nov 11, 2014, and April 16, 2016, 833 patients were assigned to treatment groups and included in safety analyses (dapagliflozin 5 mg [n=277] vs dapagliflozin 10 mg [n=296] vs placebo [n=260]; 778 of these patients were randomly assigned and included in the full analysis set for efficacy analyses (259 vs 259 vs 260; difference due to randomisation error affecting 55 patients). Mean baseline HbA1cwas 8·53% (70 mmol/mol; SD 0·67% [7·3 mmol/mol]). At week 24, both doses of dapagliflozin significantly reduced HbA1ccompared with placebo (mean difference from baseline to week 24 for dapagliflozin 5 mg vs placebo was −0·42% [95% CI −0·56 to −0·28; p<0·0001] and for dapagliflozin 10 mg vs placebo was −0·45% [−0·58 to −0·31; p<0·0001]). Among patients in the dapagliflozin 5 mg (n=277), dapagliflozin 10 mg (n=296), and placebo (n=260) groups, the most common adverse events were nasopharyngitis (38 [14%] vs 36 [12%] vs 39 [15%]), urinary tract infection (19 [7%] vs 11 [4%] vs 13 [5%]), upper respiratory tract infection (15 [5%] vs 15 [5%] vs 11 [4%]), and headache (12 [4%] vs 17 [6%] vs 11 [4%]). Hypoglycaemia occurred in 220 (79%), 235 (79%), and 207 (80%) patients in the dapagliflozin 5 mg, dapagliflozin 10 mg, and placebo groups, respectively; severe hypoglycaemia occurred in 21 (8%), 19 (6%), and 19 (7%) patients, respectively. Adjudicated definite diabetic ketoacidosis occurred in four (1%) patients in the dapagliflozin 5 mg group, five (2%) in the dapagliflozin 10 mg group, and three (1%) in the placebo group. Interpretation Our results suggest that dapagliflozin is a promising adjunct treatment to insulin to improve glycaemic control in patients with inadequately controlled type 1 diabetes. Funding AstraZeneca and Bristol-Myers Squibb

Landscape of Familial Isolated and Young-Onset Pituitary Adenomas: Prospective Diagnosis in AIP Mutation Carriers.

Familial isolated pituitary adenoma (FIPA) due to aryl hydrocarbon receptor interacting protein (AIP) gene mutations is an autosomal dominant disease with incomplete penetrance. Clinical screening of apparently unaffected AIP mutation (AIPmut) carriers could identify previously unrecognized disease.This article is freely available via PubMed Central. Click on the 'Additional Link' above to access the full text