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A finely balanced control system keeps the extracellular calcium concentration within narrow limits. Disorders of calcium metabolism are often based on altered parathormone levels. Symptoms are not always clear, sometimes they are even missing: the more it is important to know possible associated diseases. The author presents basics, current diagnostics and concrete therapy options. Central hormone for the regulation of the calcium balance is the parathyroid hormone. With decreasing calcium, PTH leads to an increase in extracellular free calcium concentration in three ways. The classic symptoms of pHPT (polyuria, polydipsia, “stone, leg, and stomach pain”) are rare now, as the condition is diagnosed much earlier. Treatment of choice in all symptomatic patients with pHPT is surgery. FHH and pHPT are both characterized by hypercalcaemia and increased parathyroid hormone. The differential diagnosis of urinary calcium excretion, which is usually lower in FHH but normal or elevated in pHPT, is crucial. In primary hypoparathyroidism, parathyroid failure interferes with calcium homeostasis at a central location. Consequences are hypocalcaemia, hyperphosphatemia and lack of active vitamin D. Due to increased urinary calcium excretion, patients with ADH are at high risk for kidney stones, nephrocalcinosis and the development of renal insufficiency. Recently, rhPTH 1-84 has been available for the treatment of hypoparathyroidism. However, long-term data is still lacking to provide a safe indication, considering potential effects and side effects.

Bayern weist von allen deutschen Bundeslandern die hochste Inzidenz des Schilddrusenkarzinoms (SDK) auf. Das SDK ist derzeit der haufigste endokrine Tumor und fur ca. 2 % aller invasiven Malignome in Bayern verantwortlich. Aufgrund des in den letzten 15 Jahren beobachteten SDK-Inzidenzanstiegs bei gleichzeitig abfallender SDK-Mortalitat besteht der Verdacht auf Uberdiagnostik mittels Schilddrusen(SD)-Sonographie. Anhand von Routinedaten der kassenarztlichen Versorgung wurde eine okologische Studie auf Kreisebene in Bayern zur Untersuchung einer moglichen Assoziation zwischen der Haufigkeit der SD-Sonographie einerseits sowie der SDK-Pravalenz bei allen Versicherten der AOK bzw. der bayernweiten SDK-Inzidenz andererseits im Jahr 2013 stratifiziert nach Geschlecht mittels Korrelations- und Regressionsanalyse durchgefuhrt. Erganzend wurde die Haufigkeit sonstiger SD-Diagnostik sowie von SD-Resektionen analysiert. Es bestand eine masige Assoziation bei Frauen (Korrelationskoeffizient [rS], 0,40) und Mannern (rS, 0,31) zwischen der Haufigkeit der SD-Sonographie einerseits sowie der SDK-Pravalenz andererseits bei AOK-Versicherten in Bayern. Pro 1000 zusatzlich durchgefuhrte SD-Sonographien stieg die Anzahl pravalenter SDK-Erkrankungen bei Frauen um 5,4 bzw. bei Mannern um 4,5 an (95 %-Konfidenzintervall [KI]; Frauen 2,5–8,3; Manner 1,2–7,8). Dies entspricht einem Anstieg der absoluten SDK-Pravalenz um eins pro 185 (Frauen) bzw. um eins pro 222 (Manner) zusatzlich durchgefuhrte SD-Sonographien. Der Betrag aller anderen untersuchten Assoziationen lag unter 0,2. Diese Ergebnisse geben erste Hinweise auf das Vorliegen einer Uberdiagnostik als eine der Ursachen des beobachteten SDK-Inzidenzanstiegs bei rucklaufiger SDK-Mortalitat. Eine Bestatigung dieser Ergebnisse anhand groserer Bevolkerungsgruppen und separat nach Tumorgrose, histologischem Subtyp sowie anhand des zeitlichen Verlaufs der beobachteten Assoziation wird empfohlen.

Acromegaly is a rare disease generally brought about by a benign tumour in the pituitary and characterized by growth hormone (GH) and insulin-like growth factor 1 (IGF-1) excess. Increased mortality has been related to cardiovascular events that could be linked to these hormones and patients suffer from high rates of diabetes and hypertension. In this study, we examine if the incidence of myocardial infarction (MI) and stroke differ from that of the general population. Data from the German Acromegaly Registry in seven specialized endocrine centres were analysed (n = 479, 56% female, 46 years old at diagnosis, 5549 person-years from diagnosis). Standardized incidence ratios (SIR) were calculated as compared to the general population. MI and stroke incidences were very close to those of the general population with an SIR (95% CI) of 0.89 (0.47–1.52, p = 0.80) for MI and 1.17 (0.66–1.93, p = 0.61) for stroke. Acromegaly was uncontrolled in 16% of patients with MI or stroke versus 21% in those without (p = 0.56). Prevalence of hypertension at the initial visit was much higher in those with MI or stroke than those without (94 vs. 43%, p

A finely balanced control system keeps the extracellular calcium concentration within narrow limits. Disorders of calcium metabolism are often based on altered parathormone levels. Symptoms are not always clear, sometimes they are even missing: the more it is important to know possible associated diseases. The author presents basics, current diagnostics and concrete therapy options. Central hormone for the regulation of the calcium balance is the parathyroid hormone. With decreasing calcium, PTH leads to an increase in extracellular free calcium concentration in three ways. The classic symptoms of pHPT (polyuria, polydipsia, "stone, leg, and stomach pain") are rare now, as the condition is diagnosed much earlier. Treatment of choice in all symptomatic patients with pHPT is surgery. FHH and pHPT are both characterized by hypercalcaemia and increased parathyroid hormone. The differential diagnosis of urinary calcium excretion, which is usually lower in FHH but normal or elevated in pHPT, is crucial. In primary hypoparathyroidism, parathyroid failure interferes with calcium homeostasis at a central location. Consequences are hypocalcaemia, hyperphosphatemia and lack of active vitamin D. Due to increased urinary calcium excretion, patients with ADH are at high risk for kidney stones, nephrocalcinosis and the development of renal insufficiency. Recently, rhPTH 1-84 has been available for the treatment of hypoparathyroidism. However, long-term data is still lacking to provide a safe indication, considering potential effects and side effects.

BACKGROUND Patients with adrenal insufficiency (AI) require lifelong glucocorticoid (GC) replacement. AI patients need to adjust GC dosage in response to stressful events and illness in order to prevent life-threatening adrenal crisis (AC). AIM To evaluate self-management of patients with AI. METHODS Four German centres, which are using patient's diary as part of their routine clinical practice, instructed AI patients to prospectively document any discomfort, intercurrent illness or stressful events as well as changes in GC therapy on a daily basis. Diaries of 80 patients (44 females, 52.9 ± 15.9 years, 34 primary AI) were collected and analysed. A symptom score sheet was used to evaluate severity of discomfort. RESULTS In total, 34 074 patient days (93.4 years) were recorded. 4622 days with discomfort were documented. On 35% of those days (n = 1621), patients increased their GC dose (4.8% of all days). Patients who recorded discomfort had a median of four episodes of discomfort, which lasted a median of 2 days. Women documented significantly more episodes of discomfort than men (P = 0.014). Low-to-median symptom scores resulted in GC increase by 50%-60%, whereas high symptom scores and/or fever resulted in doubling GC daily dose. However, dose increase was only 55% in situations indicating gastrointestinal (GI) infection. CONCLUSION Severe discomfort did not always result in dose increase, especially in GI infection. However, low symptom scores resulted in an inappropriate GC increase in some patients. This underscores an urgent need for improved training methods. Keeping daily records might be a useful tool for continued and individualized patient education.

Seasonal variation in blood pressure (BP) has been observed in different populations. However, only few studies have focused on BP seasonality in diabetic patients. This study examined the seasonal patterns in BP in 62,589 patients with type 1 diabetes mellitus (T1DM) and in 99,546 patients with type 2 diabetes mellitus (T2DM) from the German/Austrian Diabetes Follow-up Registry. Adjusted mean BP values revealed seasonal cycles of 12 months, with higher BP in colder months. Using harmonic regression models, the estimated systolic BP difference throughout the year was 2.28/2.48 mm Hg in T1DM/T2DM (both P

In cystic fibrosis-related diabetes (CFRD), energy needs differ from type 1 (T1D) or type 2 diabetes, and endogenous insulin secretion is not totally absent. We analyzed whether daily carbohydrate intake, its diurnal distribution and insulin requirement per 11 g of carbohydrate differ between CFRD and T1D.Anonymized data of 223 CFRD and 36,780 T1D patients aged from 10 to30 years from the multicenter diabetes registry DPV were studied. Carbohydrate intake and insulin requirement were analyzed using multivariable regression modeling with adjustment for age and sex. Moreover, carbohydrate intake was compared to the respective recommendations (CFRD: energy intake 130% of general population with 45% carbohydrates; T1D: carbohydrate intake 50% of total energy).After demographic adjustment, carbohydrate intake (238 ± 4 vs. 191 ± 1 g/d, p0.001) and meal-related insulin (0.52 ± 0.02 vs. 0.47 ± 0.004 IU/kg*d, p = 0.001) were higher in CFRD, whereas basal insulin (0.27 ± 0.01 vs. 0.38 ± 0.004 IU/kg*d, p0.001) and total insulin requirement per 11 g of carbohydrate (1.15 ± 0.06 vs. 1.70 ± 0.01 IU/d, p0.001) were lower compared to T1D. CFRD patients achieved 62% [Q1;Q3: 47; 77] of recommended carbohydrate intake and T1D patients 60% [51; 71] of age- and gender-specific recommended intake (p0.001). CFRD and T1D patients had a carbohydrate intake below healthy peers (79% [58; 100] and 62% [52; 74], p0.001). The circadian rhythm of insulin sensitivity persisted in CFRD and the diurnal distribution of carbohydrates was comparable between groups.In pediatric and young adult patients, carbohydrate intake and insulin requirement differ clearly between CFRD and T1D. However, both CFRD and T1D patients seem to restrict carbohydrates.

BACKGROUND: Cushing's disease is a rare debilitating endocrine disorder for which few prospective interventional studies have been done. We report results of the first phase 3 trial assessing long-acting intramuscular pasireotide in patients with Cushing's disease. METHODS: In this phase 3 clinical trial we recruited patients aged 18 years or older with persistent, recurrent, or de-novo (non-surgical candidates) Cushing's disease who had a mean urinary free cortisol (mUFC) concentration (from three 24 h samples) of 1·5-5·0 times the upper limit of normal (ULN), a normal or greater than normal morning plasma adrenocorticotropic hormone concentration, and a pituitary source of Cushing's syndrome, from 57 sites across 19 countries. Exclusion criteria included previous pasireotide treatment, mitotane therapy within 6 months, and pituitary irradiation within 10 years. We randomly allocated patients 1:1 (block size of four) using an interactive-response-technology system to intramuscular pasireotide 10 mg or 30 mgevery 4 weeks for 12 months (in the core phase). We stratified randomisation by screening mUFC concentration (1·5 to

Context While an association between PCOS and type 2 diabetes is well established, to date there have been few data on clinical care of type 1 diabetes (T1D) patients with PCOS. Objective The aim of our study was to characterize T1D patients with the comorbidity of PCOS within the DPV cohort with regard to diabetes phenotype, therapy and metabolic control. Design and Setting Clinical data from the prospective German/Austrian DPV cohort on patients with T1D and documented PCOS (n=76) were compared to female T1D controls (n=32,566) in reproductive age. Results The age at T1D manifestation in PCOS patients was later than in the control group (14.9±8.2 vs. 11.8±7.0 years, p Discussion While patients with T1D and comorbid PCOS showed features of a “type 1.5 diabetes” phenotype, insulin requirements per kg body weight were not higher and metabolic control was better, which could be explained only partially by additional metformin therapy. A more precise genetic and metabolic characterisation of these patients is needed to answer open questions on the underlying autoimmune process and residual ß-cell function.

Heterozygous inactivating calcium-sensing receptor (CaSR) mutations lead to familial hypocalciuric hypercalcemia (FHH), whereas homozygous mutations usually cause neonatal severe hyperparathyroidism.The objective of the study was to investigate the pathophysiological mechanisms of a homozygous inactivating CaSR mutation identified in a 16-year-old female.Clinical, biochemical, and genetic analyses of the index patient and her family were performed. Functional capacity of CaSRQ459R and CaSR mutants causing FHH (Q27R, P39A, S417C) or neonatal severe hyperparathyroidism (W718X) was assessed. Activation of the cytosolic calcium pathway and inhibition of PTH-induced cAMP signaling were measured.A 16-year-old girl presented with adolescent rickets, vitamin D deficiency, and secondary hyperparathyroidism. Vitamin D treatment unmasked features resembling FHH, and genetic testing revealed a homozygous CaSRQ459R mutation. Two apparently healthy siblings were homozygous for CaSRQ459R and had asymptomatic hypercalcemia and hypocalciuria. The CaSRQ459R mutation leads to mild functional inactivation in vitro, which explains the FHH-like phenotype in homozygous family members and the grossly exaggerated PTH response to vitamin D deficiency in the index case. The patient's parents and two other siblings were heterozygous, had normal serum calcium and PTH, but had marked hypocalciuria, which appeared to be associated with impaired in vitro activation of the calcium signaling pathway by CaSRQ459R. The Q459R mutation responded well to calcimimetic treatment in vitro.CaSR mutations causing mild functional impairment can lead to FHH, even in homozygous patients. The skeletal deformities in the index case were mainly due to severe vitamin D deficiency, and the CaSR mutation did not appear to have played a major independent role in the skeletal phenotype.

L’etude ACRONIS (CSOM230CIC05) a pour objectif de fournir des donnees de vraie-vie de l’utilisation de PAS-LP, chez des patients traites depuis ≥ 6 mois (partie retrospective) ou traites a partir de l’inclusion (partie prospective). Nous presentons ici les resultats de la partie retrospective. L’âge moyen des patients recrutes (n = 60) etait de 45,4 ans avec 55 % de femmes. La duree moyenne de suivi depuis le diagnostic etait de 53,2 mois (σ = 54,5 mois) ; 83,3 % avaient eu une chirurgie hypophysaire, 40,0 % une radiotherapie et 98,3 % un traitement medicamenteux (73,3 % octreotide, 31,7 % lanreotide, 53,3 % pegvisomant, 48,3 % d’agonistes dopaminergiques). Parmi les patients, 23,3 % et 13,3 % etaient diabetiques ou prediabetiques respectivement avant la prescription de PAS-LP. Au total, 81,4 % des patients ont debute PAS-LP a 40 mg. Apres une duree moyenne de 8,2 mois, 32,2 % avaient vu leur dose augmentee et 5,1 % diminuee. Apres 6 mois, l’IGF-1 etait normalise chez 42,5 % des patients (n = 40). La normalisation de l’IGF-1 et une GH Ces resultats preliminaires de l’etude ACRONIS confirment en pratique clinique l’efficacite et la tolerance de PAS-LP chez les patients acromegales precedemment non controles par SSA de premiere generation.

Ipilimumab is besides the BRAF inhibitor vemurafenib the first officially approved medical treatment for metastatic melanoma, which results in improved survival. Ipilimumab leads to a release of a CTLA4-mediated inhibition of T-cell immunoreactions. Therefore, patients may also suffer from immune-related adverse events affecting different organs, which are typically treated by high-dose corticosteroids. Ipilimumab-induced hypophysitis (iH) has been reported in up to 17% of melanoma patients in clinical trials. Here we present 5 patients with metastatic melanoma and 2 patients with prostate cancer who developed hypophysitis after ipilimumab therapy. Patients were treated by high-dose corticosteroid therapy resulting in the resolution of local inflammation but not of pituitary deficiencies. Partial or complete hypopituitarism remained in all patients. Pharmacotherapy with high-dose corticosteroids caused complications in 5 patients, necessitating hospitalization in 4. 2 of the 3 patients with progressive disease died, while 3 patients had stable disease and 1 patient showed tumor regression after discontinuation of ipilimumab. In summary, with regard to safety and simplicity of hormonal substitution therapy we have to scrutinize high-dose corticosteroid therapy, though it only improves inflammation but not neuro-endocrine function and may cause further morbidity. Regression of the tumor depends on the ipilimumab-mediated immune events, in which high-dose and long-term corticosteroid therapy for iH appears to be counter-intuitive. Herein, we discuss screening and the diagnostic as well as therapeutic management of iH in metastatic cancer patients from an endocrinologic perspective.

BackgroundAcromegaly is a rare disease with significant morbidity and increased mortality. Epidemiological data about therapeutic outcome under ‘real life’ conditions are scarce.ObjectiveTo describe biochemical long-term outcome of acromegaly patients in Germany.Design and methodsRetrospective data analysis from 1344 patients followed in 42 centers of the German Acromegaly Register. Patients' data were collected 8.6 (range 0–52.6) years after diagnosis. Controlled disease was defined by an IGF1 within the center-specific reference range.ResultsNine hundred and seventeen patients showed a normalized IGF1 (157 (range 25–443) ng/ml). In patients with a diagnosis dated back >2 years (n=1013), IGF1 was normalized in 76.9%. Of the patients, 19.5% had an elevated IGF1 and a random GH ≥1 ng/ml, 89% of the patients had at least one surgical intervention, 22% underwent radiotherapy, and 43% received medical treatment. After surgery 38.8% of the patients were controlled without any further therapy. The control rates were higher in surgical centers with a higher caseload (P=0.034). Of the patients with adjunctive radiotherapy 34.8% had a normal IGF1 8.86 (0–44.9) years post irradiation, 65.2% of the medically treated patients were controlled, and 47.2% of the patients with an elevated IGF1 received no medical therapy.ConclusionThe majority of acromegaly patients were controlled according to their IGF1 status. Long-term outcome could be improved by exploiting medical treatment options especially in patients who are not controlled by surgery and/or radiotherapy.

BackgroundHomozygous inactivating mutations of the calcium-sensing receptor (CaSR) lead to neonatal severe hyperparathyroidism (NSHPT), whereas heterozygous inactivating mutations result in familial hypocalciuric hypercalcemia (FHH). It is unknown why in some cases heterozygousCaSRmutations cause neonatal hyperparathyroidism (NHPT) clinically similar to NSHPT but with only moderately elevated serum calcium.MethodsA literature survey was conducted to identify patients with heterozygousCaSRmutations and NHPT. The common NHPT CaSR mutants R185Q and R227L were compared with 15 mutants causing only FHH in the heterozygous state. We studiedin vitrocalcium signaling including the functional consequences of co-expression of mutant and wild-type (wt) CaSR, patients’ phenotype, age of disease manifestation and mode of inheritance.ResultsAll inactivating CaSR mutants impaired calcium signaling of wt-CaSR regardless of the patients’ clinical phenotype. The absolute intracellular calcium signaling response to physiologic extracellular calcium concentrationsin vitroshowed a high correlation with patients’ serum calcium concentrationsin vivo, which is similar in NHPT and FHH patients with the same genotype. Pedigrees of FHH families revealed that paternal inheritanceper sedoes not necessarily lead to NHPT but may only cause FHH.ConclusionsThere is a significant correlation betweenin vitrofunctional impairment of the CaSR at physiologic calcium concentrations and the severity of alterations in calcium homeostasis in patients. Whether a particular genotype leads to NHPT or FHH appears to depend on additional predisposing genetic or environmental factors. An individual therapeutic approach appears to be warranted for NHPT patients.

Activating mutations of the G protein-coupled receptor, calcium-sensing receptor (CaSR), cause autosomal dominant hypocalcemia and Bartter syndrome type 5. These mutations lower the set-point for extracellular calcium sensing, thereby causing decreased parathyroid hormone secretion and disturbed renal calcium handling with hypercalciuria. Available therapies increase serum calcium levels but raise the risk of complications in affected patients. Symptom relief and the prevention of adverse outcome is currently very difficult to achieve. Calcilytics act as CaSR antagonists that attenuate its activity, thereby correcting the molecular defect of activating CaSR proteins in vitro and elevating serum calcium in mice and humans in vivo, and have emerged as the most promising therapeutics for the treatment of these rare and difficult to treat diseases.

The review assesses immunohistochemical findings of somatostatin receptors and of metalloproteinases in different pituitary adenoma types and the significance of molecular genetic data. Current evidence does not support routine immunohistochemical assessment of somatostatin or dopamine receptor subtype expression on hormone-secreting or nonfunctioning pituitary adenomas. Further prospective studies are needed to define its role for clinical decision making. Until then we suggest to restrict membrane receptor profiling to individual cases or for study purposes. The problems of adenoma expansion and invasion are discussed. Despite partially contradictory publications, proteases clearly play a major role in permission of infiltrative growth of pituitary adenomas. Therefore, detection of at least MMP-2, MMP-9, TIMP-2, and uPA seems to be justified. Molecular characterization is important for familial adenomas, adenomas in MEN, Carney complex, and McCune-Albright syndrome and can gain insight into pathogenesis of sporadic adenomas.

WHO classifications should be used for comparing the results from different groups of pathologist and clinicians by standardized histopathological methods. Our present report describes the important parameters of pituitary adenoma pathology as demand of the WHO classification for correlation to endocrine data and prognosis. The combination of HE stain based structures with immunostainings for pituitary hormones allows subclassification of adenomas as the best method not only for correlations to clinical hyperfunctions but also for statements to the sensitivity of drug therapies (somatostatin analogs, dopamine agonists). GH-, PRL- and ACTH-secreting pituitary adenomas are further classified based on the size and number of their secretory granules by electron microscopy, or as is mostly the case nowadays by cytokeratin staining pattern, into densely and sparsely granulated. Granulation pattern may be considered for the prediction of treatment response in patients with GH-secreting adenomas, since the sparsely granulated subtype was shown to be less responsive to somatostatin analog treatment. For prognosis, it is important to identify aggressive adenomas by measurements of the Ki-67 index, of the number of mitoses, and of nuclear expression of p53. Among the criteria for atypical adenomas, high Ki-67 labeling index and invasive character are the most important adverse prognostic factors. Promising molecular markers have been identified that might supplement the currently used proliferation parameters. For defining atypical adenomas in a future histopathological classification system, we propose to provide the proliferative potential and the invasive character separately.

Early diagnosis of acromegaly prevents irreversible comorbidities and facilitates surgical cure. Carpal tunnel syndrome (CTS) is common in acromegaly and patients have often undergone surgery for CTS prior to the diagnosis of acromegaly. We hypothesized that screening CTS-patients for acromegaly could facilitate active case-finding. We prospectively enrolled 196 patients [135 women, 56.9 (range 23–103) years] who presented with CTS for surgery. Patients were asked about 6 symptoms suggestive of acromegaly using a questionnaire calculating a symptom score (0–6 points), and insulin-like-growth factor 1 (IGF-1) was measured. If IGF-1 was increased, IGF-1 measurement was repeated, and random growth hormone (GH) and/or an oral glucose tolerance test (OGTT) with assessment of GH-suppression were performed. The mean symptom score was 1.7±1.3 points. Three patients reported the maximal symptom score of 6 points, but none of them had an increased IGF-1. There was no correlation between the symptom score and IGF-1-SDS (standard deviation score) (r=0.026; p=0.71). Four patients had an IGF-1>2 SDS. In 2 patients acromegaly was ruled out using random GH and OGTT. One patient had normal IGF-1 and random GH at follow-up. One patient refused further diagnostics. In this prospective cohort of patients with CTS, the observed frequency of acromegaly was at most 0.51% (95% CI 0.03 to 2.83%). In this prospective study, none of the 196 patients with CTS had proven acromegaly. Thus, we see no evidence to justify general screening of patients with CTS for acromegaly.

Summary Objective Autosomal dominant hypocalcaemia or hypoparathyroidism is caused by activating mutations of the calcium-sensing receptor (CaSR). Treatment with calcium and vitamin D often worsens hypercalciuria and nephrocalcinosis, and renal impairment can result. Our aim was to describe the phenotypic variance of this rare disorder in a large series and to evaluate the outcome after long-term treatment. Design Nationwide retrospective collaborative study. Patients We describe 25 patients (14 men and 11 women), 20 belonging to 11 families and five single cases. Measurements Activating CaSR mutations and clinical and biochemical findings were evaluated. Results Nine different missense mutations of the CaSR, including one novel variant (M734T), were found. Twelve patients (50%) were symptomatic, 9 (36%) had basal ganglia calcifications and 3 (12%) had nephrocalcinosis. Serum calcium was decreased (1·87 ± 0·13 mm), and PTH was decreased (n = 19) or inappropriately low (n = 4). The occurrence of hypocalcaemic symptoms at diagnosis was related to the degree of hypocalcaemia. The occurrence of features like calcification of basal ganglia or kidney calcification did not correlate with the severity of hypocalcaemia or the age at diagnosis. The most common treatment was calcitriol (median dosage 0·6 μg/day), and the mean duration of therapy was 7·1 years (max. 26 years). Hypercalcaemic episodes rarely occurred, and the rate of kidney calcifications was remarkably low (12%). Conclusion This series increases the limited knowledge of mutations and phenotypes of this rare disorder. Mutation analysis of the CaSR gene facilitates patient and family management. Low dosages of calcitriol resulted in less frequent renal calcifications.

CONTEXT: Growth hormone (GH) measurements during an oral glucose tolerance test (OGTT) are essential for the diagnosis and follow-up management of acromegaly. However, both 100 g glucose (OGTT(100) ) and 75 g glucose (OGTT(75) ) test variants are in clinical use. Whether the tests are interchangeable concerning GH nadir and test interpretation is unclear. Furthermore, information on test reproducibility and the impact of gender is scarce. OBJECTIVE: To compare both tests in acromegalic patients and to evaluate test reproducibility with respect to gender. DESIGN, SUBJECTS AND METHODS: OGTT(100) and OGTT(75) were performed on two consecutive days in 54 acromegalic patients (46·9 ± 1·8 years, 30 women). OGTT(75) was repeated on three different occasions in 11 healthy men and 13 healthy women at different phases of the menstrual cycle. RESULTS: GH nadirs were comparable between tests [2·40 ± 0·52 (OGTT(100) ) and 2·46 ± 0·54 μg/l (OGTT(75) ); P = 0·356]. There were no differences at any time point in the mean values of GH, serum glucose or insulin between the two test variants. Test interpretation was highly consistent between the OGTT(100) and OGTT(75) [area under the receiver operated curve (ROC) = 0·995]. In men, GH, insulin and glucose measurements during OGTT(75) were highly reproducible. In women, however, basal and GH nadirs were significantly higher midcycle (P < 0·05). CONCLUSIONS: In acromegalic patients, there is no difference in GH nadirs and test interpretation after the ingestion of 100 g or 75 g glucose. The OGTT(75) is highly reproducible in men, but in women, it should be performed preferably in the early follicular phase.

It has been shown that changes in IGF-I and IGFBP levels in children with classical congenital adrenal hyperplasia due to 21-hydroxylase deficiency (CAH) are correlated with different states of metabolic control. Our approach was to analyze the serum levels of IGF-I, IGFBP-3, their molar ratio IGF-I:IGFBP-3 (MR), and ALS in a cohort of CAH children and adolescents, and their associations with different clinical and biochemical parameters.56 patients, aged between 5.6 and 19.0 years were studied cross-sectionally. All patients had genetically proven CAH and received standard steroid substitution therapy. We measured serum levels of IGF-I, IGFBP-3, and ALS by commercial ELISA and calculated MR and assigned population-based SD scores (SDS).(median, quartiles) Overall IGF-I was not significantly altered (0.05 SDS, -1.21, 0.92), whereas IGFBP-3 was significantly elevated (1.50 SDS; 0.58, 1.95, p0.0001) compared to the reference population. Consecutively, MR was decreased (-0.64 SDS; -1.38, 0.32; p=0.0017). ALS was clearly decreased (-1.95 SDS; -3.075, -1.00; p0.0001). ALS, IGF-I, MR, and IGFBP-3 SDS were lower in pubertal than in prepubertal patients (p0.05). ALS SDS were lower in girls (p=0.0038). Correlation analyses (r(s), p) revealed correlations between MR/ALS and chronological age (-0.583,0.0001/-0.428, 0.0010), MR/ALS and Tanner stages (-0.500,0.0001/-0.334, 0.0118), MR/ALS and bone age (0.407, 0.0075/0.426, 0.0049), and between MR and ALS (0.405, 0.0020), respectively. For MR and ALS, we found no significant correlations for BMI, HOMA-IR, hydrocortisone and fludrocortisone dosage, or parameters of metabolic control.Our data provide evidence that the components of the trimeric IGF-I-IGFBP-3-ALS complex are altered in CAH children with possible implications on pubertal growth and final height.

ObjectiveLow circulating testosterone concentrations have been associated with insulin resistance (IR). Androgen action is mediated by the androgen receptor (AR) whose activity is modulated by a polymorphic CAG repeat sequence within exon 1. An interaction between testosterone and CAG repeat length (CAG length) with respect to IR has been described in women.ObjectiveWe investigated such a putative interaction between testosterone and the CAG length with respect to IR in men with normal glucose tolerance.DesignCross-sectional study.MethodsIn 113 non-diabetic men calculated free testosterone, the CAG length, and a multiplicative interaction term were investigated by multiple linear regression analysis for an association with IR, as indicated by homeostasis model assessment (HOMA %S).ResultsIn a multivariate regression analysis adjusted for age and body mass index, free testosterone, CAG length, and a multiplicative interaction term were significantly associated with IR (P=0.001, P=0.001, P=0.01 respectively). The model explained 36.6% of the variation of IR and predicted that in carriers with a CAG length of 23, changes in testosterone would only minimally affect IR. For CAG lengths longer than 23, however, an increase in testosterone would improve IR, namely the longer the CAG length, the greater the effect. In contrast, in the case of CAG lengths shorter than 23, the effect of increasing testosterone would be the opposite.ConclusionsIn men, testosterone and the AR CAG repeat length polymorphism interacted with respect to IR. The interpretation of the association between testosterone and IR seems to require consideration of the AR CAG repeat polymorphism.

Context and Objective: Activating mutations in the calcium-sensing receptor (CaSR) gene cause autosomal dominant hypocalcemia (ADH). The aims of the present study were the functional characterization of novel mutations of the CaSR found in patients, the comparison of in vitro receptor function with clinical parameters, and the effect of the allosteric calcilytic NPS-2143 on the signaling of mutant receptors as a potential new treatment for ADH patients. Methods: Wild-type and mutant CaSR (T151R, P221L, E767Q, G830S, and A844T) were expressed in human embryonic kidney cells (HEK 293T). Receptor signaling was studied by measuring intracellular free calcium in response to different concentrations of extracellular calcium ([Ca2+]o) in the presence or absence of NPS-2143. Results: All ADH patients had lowered serum calcium ranging from 1.7 to 2.0 mm and inadequate immunoreactive PTH and urinary calcium excretion. In vitro testing of CaSR mutations from these patients revealed exaggerated [Ca2+]o-induced cytosolic Ca2+ responses with EC50 values for [Ca2+]o ranging from 1.56 to 3.15 mm, which was lower than for the wild-type receptor (4.27 mm). The calcilytic NPS-2143 diminished the responsiveness to [Ca2+]o in the CaSR mutants T151R, E767Q, G830S, and A844T. The mutant P221L, however, was only responsive when coexpressed with the wild-type CaSR. Conclusion: Calcilytics might offer medical treatment for patients with autosomal dominant hypocalcemia caused by calcilytic-sensitive CaSR mutants.

Summary Objective Obesity and insulin resistance are key features of the metabolic syndrome. In euthyroidism, the relationships between TSH and insulin resistance or the metabolic syndrome are less clear. We investigated the associations between TSH and the features and prevalence of the metabolic syndrome in euthyroid German subjects. Methods In a cross-sectional study, glucose metabolism was defined by an oral glucose tolerance test (oGTT) (except for those with evident diabetes) in 1333 subjects with TSH values between 0·3 and 4·5 mU/l who did not take any thyroid medication. Lipid parameters were measured, blood pressure and anthromopmetric parameters were taken, and insulin resistance was quantified as HOMA%S. Results TSH was weakly correlated with BMI (R = 0·061, P = 0·025). This association remained significant after adjustment for sex, age, and impaired glucose metabolism (P = 0·002). Subjects with a TSH in the upper normal range (2·5–4·5 mU/l, n = 119) had a significantly higher BMI (30·47 ± 0·57 vs. 28·74 ± 0·18 kg/m2, P = 0·001) and higher fasting triglycerides (1·583 ± 0·082 vs. 1·422 ± 0·024 mmol/l, P = 0·023), and their likeliness for fulfilling the ATP III criteria of the metabolic syndrome was 1·7-fold increased (95% CI: 1·11– 2·60). Conclusion In euthyroidism, subjects with a TSH in the upper normal range (2·5–4·5 mU/l) were more obese, had higher triglycerides, and had an increased likeliness for the metabolic syndrome. Therefore, a TSH below 2·5 mU/l is associated with a favourable metabolic profile. Whether lowering TSH to levels below 2·5 mU/l improves metabolism needs to be investigated in intervention trials.

Growth hormone-deficient patients show deterioration of insulin sensitivity and beta cell function. High-dose growth hormone treatment often induces further impairment of insulin sensitivity, leading to an increase in insulin and glucose levels or even, in cases of preexisting beta cell defect, to overt diabetes. However, low-dose treatment may improve insulin sensitivity, although data in humans with detailed metabolic phenotyping are as yet not available. We postulated that long-term low-dose growth hormone replacement, restoring IGF-1 to the low-normal range, might beneficially affect glucose metabolism.We studied prospectively the metabolic responses to 24 and 48 weeks of growth hormone treatment in a small group of six adults with severe growth hormone deficiency (four men, two women; age 40-59 years; BMI 30.2 +/- 1 kg/m(2); mean growth hormone dose 0.3 +/- 0.04 mg/day). All participants underwent an oral glucose tolerance test, euglycaemic-hyperinsulinaemic clamp and hyperglycaemic-hyperinsulinaemic clamp plus i.v. L: -arginine on three occasions. Insulin sensitivity was measured by calculating the M value during the steady state of the euglycaemic-hyperinsulinaemic clamp. Insulin secretion and clearance were estimated from AUC(C-peptide), AUC(insulin) and their ratio at each phase of the hyperglycaemic-hyperinsulinaemic clamp.Growth hormone significantly improved insulin sensitivity (M value 13.8 +/- 2.6 [baseline] vs 19.6 +/- 2.6 [24 weeks] and 23.7 +/- 1.9 [48 weeks] micromol kg(-1) min(-1); p0.01). Although the insulin response to glucose and arginine decreased slightly, the disposition index, integrating insulin sensitivity and secretion, significantly increased (p0.01), indicating an improvement in whole-body glucose metabolism. Insulin clearance was not affected during treatment (p0.05).Our data indicate that long-term low-dose growth hormone treatment may improve insulin sensitivity and whole-body glucose metabolism in adults with severe growth hormone-deficiency.

Context: Insulin interacts with the GH-IGF system by a reciprocal regulation of IGF-binding proteins (IGFBP) and GH, which in turn regulate insulin sensitivity via bioactive IGF-I. This network is linked to metabolic syndrome and cardiovascular diseases. Objective: We evaluated the effect of glucose and insulin on IGFBP-1-4, particularly IGFBP-2, in the regulation of bioactive IGF-I and its relation to insulin resistance. Setting: The study was conducted at an endocrinology center. Research Design and Methods: Twenty-four healthy subjects (12 men; aged 21–72 yr; body mass index 25.9 ± 0.9 kg/m2) and 19 subjects with impaired glucose tolerance (IGT; eight men; aged 26–71 yr; body mass index 28.9 ± 1.2 kg/m2 ) were prospectively studied using oral glucose tolerance test and hyperinsulinemic euglycemic clamp. Results: During the clamp, insulin decreased IGF-I bioactivity in both IGT subjects and controls (−16.2 ± 2.8 and −13.9 ± 3.3%, respectively; P < 0.01). In addition, insulin increased IGFBP-2 and GH and decreased IGFBP-1 and -4 but did not alter total IGF-I, IGF-II, or IGFBP-3 levels. During the oral glucose tolerance test, GH and IGFBP-1 were markedly suppressed. Subjects with IGT showed more pronounced insulin resistance and lower GH, IGFBP-1, and IGFBP-2 levels (P < 0.05). In multiple regression analysis, IGFBP-2 was an independent predictor of insulin sensitivity (β = 0.36, P < 0.05) and IGF-I bioactivity (β = −0.5, P < 0.05). Conclusions: Our data indicate that insulin acutely decreases IGF-I bioactivity through differential modulation of IGFBPs. Furthermore, IGFBP-2 plays a central role in the insulin-IGF system cross talk and is closely linked to insulin resistance, thereby providing a further explanation for its association with the metabolic syndrome.

ATP released from damaged cells or by controlled secretion could be an important factor in the formation or remodeling of bone. In a variety of other tissues ATP has been shown to control cellular processes by acting on P2-purinoceptors and activating the calcium signaling pathway. Here we demonstrate for the first time that extracellular ATP increases the intracellular free calcium [Ca2+]i concentration in normal human osteoblasts and in SaOS-2 cells, a human osteosarcoma-derived cell line, but not in ROS 17/2.8 cells. The ATP-induced increase in [Ca2+]i was dose dependent, and the concentrations of ATP required were similar to those reported to regulate cellular functions in other cell types. Although ATP is metabolized rapidly by bone cells, the effects on [Ca2+]i appeared to be mediated directly by ATP rather than one of its metabolites. Adenosine 3-thiotriphosphate, a nonhydrolyzable analog of ATP, induced similar changes in [Ca2+]i. This indicates that P2-purinoceptors are present on osteoblast-like cells and that extracellular ATP from various sources might be an important factor in the regulation of osteoblast functions.

OBJECTIVE The aim of this analysis was to assess the prospective association of serum testosterone and dehydroepiandrosterone sulfate (DHEAS) levels with incident metabolic syndrome (MetS) in men. RESEARCH DESIGN AND METHODS Data were obtained from the Study of Health in Pomerania (SHIP), a population-based prospective cohort of adults aged 20–79 years. Analyses were conducted in 1,004 men without baseline MetS defined by National Cholesterol Education Program Adult Treatment Panel III guidelines. Testosterone and DHEAS were categorized by age-specific quartiles and Poisson regression models with relative risks (RRs) and 95% CIs were estimated. RESULTS After a median follow-up time of 5.0 years, 480 men (47.8%) developed MetS. Testosterone levels decreased with increasing number of MetS components. Testosterone in the lowest quartile predicted MetS (RR 1.38 [95% CI 1.13–1.69]), particularly among men aged 20–39 years (2.06 [1.29–3.29]), even after adjustment for age, smoking, alcohol consumption, physical activity, waist circumference, self-related health, and time of blood sampling. DHEAS levels were not related to incident MetS (0.99 [0.83–1.19]). CONCLUSIONS Low testosterone but not DHEAS predicts development of MetS in a population-based cohort of 1,004 men aged 20–79 years. Especially in young men aged 20–39 years, results suggest low testosterone as a strong predictor for incident MetS. Assessment of testosterone in young and middle-age men may allow early interventions in the general population.

GH-secreting pituitary adenomas can be hypo-, iso- or hyper-intense on T2-weighted MRI sequences. We conducted the current multicenter study in a large population of patients with acromegaly to analyze the relationship between T2-weighted signal intensity on diagnostic MRI and hormonal and tumoral responses to somatostatin analogs (SSA) as primary monotherapy. Acromegaly patients receiving primary SSA for at least 3 months were included in the study. Hormonal, clinical and general MRI assessments were performed and assessed centrally. We included 120 patients with acromegaly. At diagnosis, 84, 17 and 19 tumors were T2-hypo-, iso- and hyper-intense, respectively. SSA treatment duration, cumulative and mean monthly doses were similar in the three groups. Patients with T2-hypo-intense adenomas had median SSA-induced decreases in GH and IGF-1 of 88% and 59% respectively, which were significantly greater than the decreases observed in the T2-iso- and hyper-intense groups (P P P r = 0.22), IGF-1 (P r = 0.14) and adenoma volume (P r = 0.33). The T2-weighted signal intensity of GH-secreting adenomas at diagnosis correlates with hormone reduction and tumor shrinkage in response to primary SSA treatment in acromegaly. This study supports its use as a generally available predictive tool at diagnosis that could help to guide subsequent treatment choices in acromegaly.

Objective: Many polycystic ovary syndrome (PCOS) women suffer from adiposity and insulin resistance (IR), which play an important role in the development and maintenance of PCOS. Adipocyte fatty acid-binding protein (A-FABP) is mainly expressed in adipocytes, and circulating A-FABP has been associated with markers of obesity and IR. Thus, as observed with other adipose tissue derived factors, secreted A-FABP might be involved in the pathogenesis of obesity-associated disorders such as PCOS. Design: Plasma A-FABP concentrations were measured in 102 non-diabetic PCOS women, and associations with markers of obesity, IR, inflammation, and hyperandrogenism were investigated by correlation and multiple linear regression analyses. The effect of lifestyle intervention on A-FABP was studied in a second cohort of 17 obese PCOS women. Results: A-FABP correlated with body mass index (BMI; R = 0.694, P < 0.001), dual-energy X-ray-absorptiometry (DEXA) fat mass (R = 0.729, P < 0.001), DEXA lean body mass (R = 0.399, P = 0.001), HOMA %S (R = −0.435, P < 0.001), hsCRP (R = 0.355, P = 0.001), and free testosterone (fT; R = 0.230, P = 0.02). Adjusted for age, smoking, and glucose metabolism the association of A-FABP with HOMA %S was still significant (P < 0.001), whereas the associations with fT (P = 0.09) and hsCRP (P = 0.25) were not. Inclusion of BMI into the model abolished the impact of A-FABP on HOMA %S. In BMI-matched PCOS women (n = 20 pairs), neither HOMA %S (P = 0.3) nor fT (P = 0.6) were different despite different A-FABP levels (P < 0.001), and in 17 obese PCOS women undergoing a lifestyle intervention, changes in IR were not paralleled by changes in A-FABP. Conclusions: Circulating A-FABP was correlated with markers of obesity, but had no major impact on IR, inflammation, or hyperandrogenemia in PCOS women.

The calcium-sensing receptor (CASR) is the main calcium sensor in the maintenance of calcium metabolism. Mutations of theCASR, the G protein alpha 11 (GNA11) and the adaptor-related protein complex 2 sigma 1 subunit (AP2S1) genes can shift the set point for calcium sensing causing hyper- or hypo-calcemic disorders. Therapeutic concepts for these rare diseases range from general therapies of hyper- and hypo-calcemic conditions to more pathophysiology oriented approaches such as parathyroid hormone (PTH) substitution and allosteric CASR modulators. Cinacalcet is a calcimimetic that enhances receptor function and has gained approval for the treatment of hyperparathyroidism. Calcilytics in turn attenuate CASR activity and are currently under investigation for the treatment of various diseases. We conducted a literature search for reports about treatment of patients harboring inactivating or activating CASR, GNA11 or AP2S1 mutants and aboutin vitroeffects of allosteric CASR modulators on mutated CASR. The therapeutic concepts for patients with familial hypocalciuric hypercalcemia (FHH), neonatal hyperparathyroidism (NHPT), neonatal severe hyperparathyroidism (NSHPT) and autosomal dominant hypocalcemia (ADH) are reviewed. FHH is usually benign, but symptomatic patients benefit from cinacalcet. In NSHPT patients pamidronate effectively lowers serum calcium, but most patients require parathyroidectomy. In some patients cinacalcet can obviate the need for surgery, particularly in heterozygous NHPT. Symptomatic ADH patients respond to vitamin D and calcium supplementation but this may increase calciuria and renal complications. PTH treatment can reduce relative hypercalciuria. None of the currently available therapies for ADH, however, prevent tissue calcifications and complications, which may become possible with calcilytics that correct the underlying pathophysiologic defect.

Acromegaly is a rare disease characterized by high serum levels of GH and IGF-1. Animal studies have demonstrated links between these hormones and cancer, but data regarding cancer incidence among acromegaly patients are inconsistent. Moreover, therapy options have changed considerably since many of the aforementioned data were collected.The objective was to determine whether the overall and site-specific incidence of cancer is comparable to that of the general population.Data from the German Acromegaly Registry for 446 patients (6656 person-years from diagnosis) treated in seven specialized endocrine centers were analyzed.Standard incidence ratios (SIRs) were calculated as compared to the general population.Overall cancer incidence was slightly but not significantly lower than in the general population (SIR, 0.75; 95% confidence interval, 0.55 to 1.00; P = .051) and was not significantly higher for colorectal, breast, thyroid, prostate, and lung cancers. The SIRs of those with GH in the ranges1, 1-2.5, and ≥ 2.5 ng/mL were 0.75, 0.44, and 0.92, respectively (P = .94). There was not a significant dependence on normal vs elevated IGF-1 (P = .87), radiation therapy (P = .45), disease duration (P = .96), age at diagnosis (P = .15), or during a period of high GH and IGF-1 from 8 years before to 2 years after diagnosis of acromegaly (P = .41).Cancer screening strategies need to take incidence into account, which does not seem to be substantially higher in treated acromegaly patients than in the general population for any site of cancer.

Objective: Hyperandrogenism is a central feature of the polycystic ovary syndrome (PCOS) and might worsen insulin resistance (IR) often seen in PCOS. Androgens act through the androgen receptor (AR). A polymorphic CAG repeat sequence within the AR gene was reported to modulate its transactivation activity. Therefore, we investigated a putative interaction between testosterone and the CAG repeat length polymorphism with respect to IR. Design: In 63 PCOS women with normal glucose tolerance free testosterone, the biallelic CAG repeat length and a multiplicative interaction term were investigated by multiple linear regression analysis for an association with IR as indicated by the homeostasis model assessment of IR (HOMA-IR). Results: Free testosterone was correlated with HOMA-IR. The impact of testosterone on HOMA-IR was modified by the AR CAG length as indicated by an interaction term. This interaction remained significant after adjustment for smoking, age and body mass index. While there was a positive association of free testosterone with HOMA-IR, the interaction term was inversely associated. The model, which explained 42.5% of the variation of HOMA-IR predicted that in carriers of short CAG lengths, an increase in testosterone increased IR. This effect attenuated with rising biallelic CAG length until it turns into the opposite at a CAG length longer than 23. The results were confirmed by using CIGMA as another measure of IR. Conclusions: The association between testosterone and IR is modified by the CAG repeat polymorphism within the AR. Therefore, the evaluation of testosterone effects on IR seems to require consideration of the AR CAG repeat polymorphism in PCOS women.

OBJECTIVE—Cereal fiber intake is linked to reduced risk of type 2 diabetes in epidemiological observations. The pathogenic background of this phenomenon is unknown. Based on recent findings, we hypothesized that intake of purified insoluble oat fiber may improve whole-body insulin sensitivity. RESEARCH DESIGN AND METHODS—A randomized, controlled, single-blind, cross-over study was performed, and 17 overweight or obese subjects with normal glucose metabolism were analyzed. After consumption of nine macronutrient-matched portions of fiber-enriched bread (white bread enriched with 31.2 g insoluble fiber/day) or control (white bread) over a time period of 72 h, whole-body insulin sensitivity was assessed by euglycemic-hyperinsulinemic clamp. Energy intake was individually adjusted by providing standardized liquid meals. Hydrogen breath tests were performed to control for dietary adherence. RESULTS—When analyzing the entire cohort, whole-body glucose disposal was improved after fiber consumption (M value 6.56 ± 0.32 vs. 6.07 ± 0.27 mg · min−1 · kg−1; P = 0.043). Thirteen subjects had increased hydrogen breath test concentrations after fiber consumption, indicating probable dietary adherence. Restricting analysis to these subjects, improvements in M value (6.85 ± 0.34 vs. 6.06 ± 0.32 mg · min−1 · kg−1; P = 0.003) and insulin sensitivity, expressed as M/I ratio (M value divided by mean serum insulin at steady state: 3.73 ± 0.23 vs. 3.21 ± 0.27; P = 0.02), after fiber consumption were more pronounced. Plasma lipids, serum magnesium, ghrelin, and adiponectin concentrations, as well as substrate utilization and body weight, were not significantly changed by fiber intake (P > 0.15). CONCLUSIONS—Increased insoluble dietary fiber intake for 3 days significantly improved whole-body insulin sensitivity. These data suggest a potential mechanism linking cereal fiber intake and reduced risk of type 2 diabetes.

Gastrointestinal neuroendocrine tumours (NET) represent a heterogeneous tumour entity. The anti-neoplastic therapy of advanced NET disease is still unsatisfactory and innovative therapeutic approaches are needed. As NET frequently express insulin-like growth factors (IGFs) and their receptors (IGFR), known to promote survival, oncogenic transformation, tumour growth and spreading, the inhibition of the IGF/IGF-receptor system may offer possibilities for novel targeted treatment strategies of NET. Here, we studied the anti-neoplastic effects of an inhibition of the IGF-I receptor (IGF-1R) signalling in NET cells by the novel IGF-1R tyrosine kinase (TK) inhibitor NVP-AEW541, whose anti-neoplastic potency has not yet been tested in NET disease. Using two human NET cell lines with different growth characteristics, we demonstrated that NVP-AEW541 dose-dependently inhibited the proliferation of NET cells by inducing apoptosis and cell cycle arrest. Anti-neoplastic effects of NVP-AEW541 were also detected in primary cultures of human neuroendocrine gastrointestinal tumours. Apoptosis was characterized by activation of the apoptotic key enzyme, caspase-3, as well as by detection of changes in the expression of the pro- and anti-apoptotic proteins, BAX and Bcl-2, after NVP-AEW541 treatment. Cell cycle was arrested at the G1/S checkpoint. The anti-neoplastic effects of NVP-AEW541 involved the inactivation of ERK1/2. Induction of immediate cytotoxicity did not account for the anti-neoplastic effects of NVP-AEW541, as shown by measurement of lactate dehydrogenase release. Moreover, additive anti-neoplastic effects were observed when NVP-AEW541 was combined with cytostatics such as doxorubicin or the 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor, fluvastatin. This is the first report on the induction of apoptosis and cell cycle arrest by the IGF-1R-TK inhibitor, NVP-AEW541, in NET cells. The inhibition of the IGF/IGFR system appears to be a promising novel approach for future treatment strategies of NET disease.

Objective: Polycystic ovary syndrome (PCOS) is a risk factor for type 2 diabetes mellitus and screening for abnormal glucose metabolism has been recommended by an oral glucose tolerance test (OGTT). This procedure is time-consuming and inconvenient, limiting its general use. Therefore, an easy method is wanted to separate PCOS women with normal from those with potentially abnormal glucose metabolism. Design: Simple parameters obtained from 101 consecutive PCOS patients were assessed by receiver operating curve analysis for their ability to predict abnormal glucose metabolism. Results: Comparing discriminating parameters at defined sensitivities revealed that, assessed by homeostasis model assessment (HOMA), insulin resistance (HOMA%S) had the highest specificitiy. At a cut-off point of 73.1%, HOMA%S had a sensitivity of 95.5% and a specificity of 51.9%. Applying this cut-off separated 59 women who had a high probability of abnormal glucose metabolism from 42 women who were at low risk (less than 2.5%). Fasting insulin was the second-best parameter and had a similar specificity. A screening strategy which applies HOMA%S or fasting insulin could almost halve the number of OGTTs by directing them to those PCOS women most likely to be suffering from abnormal glucose metabolism. The negative predictive value of this strategy was 97%. The strategy was tested and confirmed in a second and independent cohort of 264 PCOS women. Conclusions: HOMA%S, or to a lesser extent fasting insulin, appears to allow for stratified metabolic screening of PCOS women with OGTT.

We examined the role of protein kinase C (PKC) for the generation of arginine-vasopressin (AVP)-linked Ca2+ oscillations in beta-cells (HIT-T15). Activation of PKC by phorbol-12,13-dibutyrate (PDBu) reduced the frequency and finally abolished AVP-induced Ca2+ oscillations. The PKC inhibitors Gö 6976, Ro-32-0432, or chelerythrine converted Ca2+ oscillations to a plateau-like rise in cytosolic free Ca2+, and PKC down-regulation reduced the percentage of cells exhibiting AVP-induced Ca2+ oscillations. Several mechanisms were identified by which PKC could exert feedback on the AVP-linked Ca2+ oscillator. PDBu, but not the PKC inhibitors, inhibited AVP-stimulated inositol 1,4,5-trisphosphate production and mobilization of internal Ca2+. Ca2+ influx through voltage-sensitive Ca2+ channels was attenuated by PDBu and PKC inhibitors, indicating complex PKC-dependent regulation of voltage-sensitive Ca2+ channels involving stimulatory as well as inhibitory components. Furthermore, AVP caused oscillatory translocation of yellow fluorescent protein (YFP)-tagged PKCalpha and PKCbetaIota to the plasma membrane, which paralleled the Ca2+ oscillations in single cells. Repetitive translocation of YFP-PKCalpha and -PKCbetaIota could also be elicited by repetitive release of caged Ca2+. By contrast, AVP-stimulated translocation of YFP-PKCepsilon was monophasic, not synchronized with Ca2+ oscillations, and could not be mimicked by release of caged Ca2+. In conclusion, undisturbed activation of PKCs is a necessary intermediate to generate or maintain AVP-induced Ca2+ oscillations in pancreatic beta-cells. The data further suggest that classical PKCs, predominantly by inhibition of inositol 1,4,5-trisphosphate production, provide the negative feedback required for AVP-induced Ca2+ oscillations to occur that is mediated by their repetitive activation by oscillating Ca2+ concentrations.

The effect of 8-bromocyclic AMP (8-Br-cAMP) and phorbol 12-myristate 13-acetate (PMA), a protein kinase C activator, on cytosolic free calcium concentration ([Ca2+]i) in normal rat anterior pituitary cells was examined. [Ca2+]i was monitored directly by the fluorescent indicator fura-2. 8-Br-cAMP as well as PMA elevated [Ca2+]i in a concentration-dependent manner. Forskolin (10 μmol/l), which activates adenylate cyclase, and 1-oleoyl-2-acetyl-glycerol (10 μmol/l), another activator of protein kinase C, also increased [Ca2+]i. Both the 8-Br-cAMP (2 mmol/l)- and the PMA (100 nmol/l)-induced increase in [Ca2+]i was dependent on the presence of extracellular calcium and could be inhibited by the calcium channel blockers Mg2+ and nifedipine, but not by ωonotoxin (100 nmol/l). The half-maximally inhibitory concentrations of Mg2+ and nifedipine were about 12 mmol/l and 160 nmol/l, respectively, for the [Ca2+]i response to 8-Br-cAMP (2 mmol/l), and were about 6 mmol/l and 400 nmol/1, respectively, for the PMA (100 nmol/1)-induced increase in [Ca2+]i. The sodium channel blocker tetrodotoxin (5 μmol/l) had no influence on the effect of 8-Br-cAMP (2 mmol/l) or PMA (100 nmol/l) on [Ca2+]i. After pretreatment for 3 min with PMA (100 nmol/l), the subsequent K+ (100 mmol/l)- or arachidonic acid (3 μmol/l)-induced increase in [Ca2+]i was decreased by about 50%. By contrast, pretreatment (3 min) with 8-Br-cAMP (2–10 mmol/1) markedly enhanced the subsequent [Ca2+]i response to K+ (100 mmol/l), and left the effect of arachidonic acid (3 μmol/l) on [Ca2+]i unimpaired. These data indicate that both cAMP- and diacylglycerol-mediated pathways increase [Ca2+ i in normal rat anterior pituitary cells via an influx of extracellular Ca2+ through dihydropyridine-sensitive, ω-conotoxin-insensitive voltage-dependent calcium channels. These second messengers may thus be involved in Ca2+ channel activation by hypothalamic releasing hormones. Effects of cAMP- or diacylglycerol-induced pathways on anterior pituitary function may not be independent of but be mediated also by changes in [Ca2+]i. However, substantial differences appear to exist in how cAMP and diacylglycerol influence voltage-dependent calcium channels.

ContextDisease control is a prime target in acromegaly treatment. This should be achievable in the vast majority of patients by available treatment options. For unknown reasons, however, a significant number of patients do not achieve disease control.ObjectiveTo investigate reasons for failure to achieve disease control in long-standing acromegaly.Design and methodsSurvey based on the German Acromegaly Registry database (1755 patients in 57 centres). Questionnaires were sent to 47 centres treating 178 patients with elevated disease markers (IGF1 and GH) at the last documented database visit out of 1528 patients with a diagnosis dated back ≥2 years. Thirty-three centres returned anonymised information for 120 patients (recall rate 67.4%).ResultsMedian age of the 120 patients (58 females) was 57 years (range 17–84). Ninety-four patients had at least one operation, 29 had received radiotherapy and 71 had been previously treated medically. Comorbidities were reported in 67 patients. In 61 patients, disease activity had been controlled since the last documented database visit, while 59 patients still had biochemically active disease. Reasons were patients' denial to escalate therapy (23.3%), non-compliance (20.6%), fluctuating insulin-like growth factor 1 (IGF-1) and growth hormone (GH) levels with normal values at previous visits (23.3%) and modifications in pharmacotherapy (15.1%). Therapy resistance (9.6%), drug side effects (4.1%) and economic considerations (4.1%) were rare reasons.ConclusionsMain reasons for long-standing active acromegaly were patients' lack of motivation to agree to therapeutic recommendations and non-compliance with medical therapy. Development of patient education programmes could improve long-term control and thus prognosis of acromegalic patients.