[Treatment of acromegaly - data from the German Acromegaly Register]

Acromegaly is a rare disease in which chronic growth hormone overproduction (usually from an anterior pituitary adenoma) leads to various systemic complications. The management of acromegaly and the comorbidities of the disease is complex and requires a multidisciplinary approach. Early diagnosis is extremely important, as then the chances of a complete cure are significantly higher. The operation is the therapy of first choice and should be performed at a specialized center with an experienced neurosurgeon. With good patient information and guidance, the drug therapy of acromegaly patients in specialized practices and clinics can usually lead to biochemical control and thereby normalization of mortality risk. As with numerous rare diseases, care in specialized centers and recording and evaluation in registry studies can contribute to better patient care and the optimization of therapy and diagnostic guidelines. We assume that with the help of the German Acromegaly Registry, which currently includes more than 2500 patients with acromegaly, we will be able to present a realistic picture of the care situation in Germany in the coming years.

Fractionated radiotherapy and radiosurgery in acromegaly: analysis of 352 patients from the German Acromegaly Registry

BACKGROUND

If biochemical control of acromegaly is not achieved by operation and medication, radiotherapy may be indicated.

OBJECTIVE

To describe fractionated radiotherapy (FRT) and stereotactic radiosurgery (SRS) regarding excess of IGF-1 and pituitary function.

DESIGN AND METHODS

A retrospective analysis of 352 patients (4126 patient-years) from the German Acromegaly Registry was performed. Follow-up was 1.0-45.1 years after radiotherapy. Therapeutic success was defined by low or normal IGF-1 according to center-specific reference ranges without (= remission) or on (= controlled disease) suppressive medication.

RESULTS

Time between radiotherapy and last follow-up was 13.0 ± 8.2 years for FRT (n = 233) and 8.9 ± 5.0 years for SRS (n = 119, P < 0.001). Median (IQR) basal growth hormone before radiotherapy was 6.3 (2.9-16.2) ng/mL for FRT and 3.5 (1.8-6.9) ng/mL for SRS (P < 0.001). Mean time in uncontrolled state was 3.0 years after FRT and 2.1 years after SRS (95% CI for the difference is 0.1 to 1.6 years, P = 0.021). The 10-year calculated remission rate was 48% for FRT and 52% for SRS (95% CI for the difference is -18 to 26% age points, P = 0.74) and the respective controlled disease rate was 23 and 26%. The odds ratio for adrenocorticotropic or thyreotropic insufficiency was 0.54 (95% CI: 0.30-1.00, P = 0.049) in SRS compared to FRT patients.

CONCLUSION

Both after FRT and SRS about 75% of patients with acromegaly are in remission or controlled after 10 years. A slightly faster achievement of target values was observed after SRS. The rate of pituitary insufficiency in FRT patients is significantly higher.

[Update - Calcium Metabolism]

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.

Daily adjustment of glucocorticoids by patients with adrenal insufficiency

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.

Personality Traits and Physical Complaints in Patients With Acromegaly: A Cross Sectional Multi-Center Study With Analysis of Influencing Factors

Objective: Acromegalic patients display a distinct neuropsychological profile and suffer from chronic physical complaints. We aimed to investigate in more detail these aspects in acromegalic patients, dependent on influencing factors like disease activity, age, sex, chronic medication, surgery, pituitary radiation, pituitary insufficiency and comorbidities. Design: Cross sectional, multicentric. Methods: 129 patients (M/W 65/64, 58.3 ± 12.7 years, 53/76 with active/controlled disease). Acromegalic patients completed the following inventories: NEO-FFI, IIP-D, and the Giessen Complaints List (GBB-24), after written informed consent. Age, sex, IGF-1 concentrations, comorbidities, treatment modalities and pituitary insufficiency were documented. Results: Acromegalic patients or specific patient-subgroups were more agreeable, neurotic, exploitable/permissive, introverted/socially avoidant, non-assertive/insecure, nurturant and less open to experience, cold/denying, domineering, compared to normal values from the healthy population (controls). Multivariable analysis demonstrated that these overall results were due to the specific patient subgroups as patients on chronic medication, with arthrosis and pituitary insufficiency. Disease activity was only associated with the trait nurturant. Higher scores for introversion were associated with arthrosis. Lower domineering was independent of any disease- or treatment related variable or comorbidity. The GBB inventory showed overall higher scores in patients, with higher scores for exhaustion and general complaints being associated with pituitary insufficiency, coronary heart disease and history of malignancy in the multivariable analysis. Joint complaints were independent of any disease- or treatment- related variable. Conclusions: We define new aspects of a distinct neuropsychological profile in patients with acromegaly, which are largely independent of disease activity. Chronic physical complaints are more pronounced in patients than in controls, with exhaustion and general complaints showing no association with disease activity.

The Effects of Different Isocaloric Oral Nutrient Solutions on Psychophysical, Metabolic, Cognitive, and Olfactory Function in Young Male Subjects

Food intake influences human cognition, olfaction, hunger, and food craving. However, little research has been done in this field to elucidate the effects of different nutrients. Thus, the goal of our study was to investigate the effects of oral ingestion of different nutrient solutions on olfactory, cognitive, metabolic and psychophysical function. Twenty healthy men participated in our study employing a double-blind, cross-over, repeated measurement design. Participants were tested on four different study days. Each day participants received, in randomized order, one of three isocaloric (protein, carbohydrate or fat 600 kcal, 1,500 mL) solutions or a placebo. Olfactory and cognitive tests (monitoring only) were conducted three times, i.e., 60 min before the beginning of nutrient intake, following oral ingestion of the solution and 60, and 240 min after. Psychophysical and metabolic function tests (active grehlin, desacyl ghrelin, insulin, glucagon, glucose, triglyceride, urea) were performed 7 times on each examination day (observation period: −60 min, 0 = solution intake, +60, +120, +180, +240, and +300 min). Ratings of hunger and food craving significantly differed over the observation period with lowest ratings following application of the protein solution. Highest ratings of craving were found following placebo intake. We further observed a significant positive correlation of active grehlin with hunger and fat, protein and sweets craving for each nutrient solution. Active grehlin significantly correlated with carbohydrate craving for carbohydrate and fat solution and with vegetable craving for fat solution only. Hunger hormone levels, hunger and food craving ratings demonstrated that the hierarchical order that appears in satiating efficiencies of isovolumetric-isocaloric ingested macronutrients is protein > fat > carbohydrate. Our study reveals that the type of nutrient exerts a significant influence on metabolic parameters, hunger and food craving.

Incidence of myocardial infarction and stroke in acromegaly patients: results from the German Acromegaly Registry

PURPOSE

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.

METHODS

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.

RESULTS

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 < 0.001). No association was seen between radiation therapy and stroke.

CONCLUSIONS

For acromegaly patients being treated at specialized centres, the incidence of MIs and strokes does not seem to differ from the general population. Certainty regarding such statements requires large, prospective studies however.

Polycystic Ovary Syndrome (PCOS) in Juvenile and Adult Type 1 Diabetes in a German/Austrian Cohort

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<0.001). PCOS patients had higher BMI-SDS (0.92±0.11 vs. 0.38±0.01, p<0.001), metformin and oral contraceptives were used more frequently (p<0.001). A1c levels were significantly lower (7.92 +/- 0.23% vs. 8.43±0.01%, p<0.05) despite of lower insulin requirements (0.76±0.04 IU/kg/d vs. 0.84±0.00 IU/kg/d, p<0.05). In the PCOS group, higher rates of dyslipidemia (63.4 vs. 48.7%, p =0.032) and thyroid disorders (42.2% vs. 21.2%, p<0.001) were present. 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.

The Effects of a Normal Rate versus a Slow Intervalled Rate of Oral Nutrient Intake and Intravenous Low Rate Macronutrient Application on Psychophysical Function – Two Pilot Studies

Stomach distension and energy per time are factors influencing satiety. Moreover, different rates of nutrient intake induce different stomach distension. The goal of our studies was to elucidate the influence of different oral rates of nutrient intake (normal rate versus slow intervalled rate; study I) and intravenous low rate macronutrient application (protein, carbohydrate, fat) or placebo (study II) on psychophysical function. The pilot studies investigated the effects of 1) study I: a mixed nutrient solution (1/3 protein, 1/3 fat, 1/3 carbohydrates) 2) study II: intravenous macronutrient infusions (protein, carbohydrate, fat) or placebo on psychophysical function (mood, hunger, food craving, alertness, smell intensity ratings and hedonic ratings) in human subjects. In study I 10 male subjects (age range: 21–30 years) completed the study protocol participating in both test conditions and in study II 20 male subjects (age range: 19–41 years) completed the study protocol participating in all test conditions. Additionally, metabolic function was analyzed and cognitive and olfactory tests were conducted twice starting 100 min before the beginning of the intervention and 240 min after. Psychophysical (mood, hunger, fat-, protein-, carbohydrate-, sweets- and vegetable-craving), alertness and metabolic function tests were performed seven times on each examination day. Greater effects on hunger and food cravings were observed for normal rate of intake compared to slow intervalled rate of intake and intravenous low rate macronutrient application. Our findings potentially confirm that volume of the food ingested and a higher rate of energy per time contribute to satiety during normal rate of food intake, while slow intervalled rate of food intake and intravenous low rate macronutrient application showed no effects on satiation. Our results motivate the view that a certain amount of volume of the food ingested and a certain energy per time ratio are necessary to reduce hunger and food craving.

T2-weighted MRI signal predicts hormone and tumor responses to somatostatin analogs in acromegaly

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 < 0.001). Tumor shrinkage on SSA was also significantly greater in the T2-hypo-intense group (38%) compared with the T2-iso- and hyper-intense groups (8% and 3%, respectively; P < 0.0001). The response to SSA correlated with the calculated T2 intensity: the lower the T2-weighted intensity, the greater the decrease in random GH (P < 0.0001, r = 0.22), IGF-1 (P < 0.0001, r = 0.14) and adenoma volume (P < 0.0001, 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.

Heterozygous inactivating CaSR mutations causing neonatal hyperparathyroidism: function, inheritance and phenotype

BACKGROUND

Homozygous 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 heterozygous CaSR mutations cause neonatal hyperparathyroidism (NHPT) clinically similar to NSHPT but with only moderately elevated serum calcium.

METHODS

A literature survey was conducted to identify patients with heterozygous CaSR mutations and NHPT. The common NHPT CaSR mutants R185Q and R227L were compared with 15 mutants causing only FHH in the heterozygous state. We studied in vitro calcium 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.

RESULTS

All 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 concentrations in vitro showed a high correlation with patients' serum calcium concentrations in vivo, which is similar in NHPT and FHH patients with the same genotype. Pedigrees of FHH families revealed that paternal inheritance per se does not necessarily lead to NHPT but may only cause FHH.

CONCLUSIONS

There is a significant correlation between in vitro functional 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 Calcium-Sensing Receptor Mutations: Prospects for Future Treatment with Calcilytics

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.

Screening for Acromegaly in Patients with Carpal Tunnel Syndrome: A Prospective Study (ACROCARP)

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.

Clinical Impact of the Current WHO Classification of Pituitary 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.

Emerging Histopathological and Genetic Parameters of Pituitary Adenomas: Clinical Impact and Recommendation for Future WHO Classification

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.

Achievement of treatment goals for secondary prevention of myocardial infarction or stroke in 29,325 patients with type 2 diabetes: a German/Austrian DPV-multicenter analysis

BACKGROUND

To analyze whether medical care is in accordance with guidelines for secondary prevention of myocardial infarction (MI), or stroke in patients with type 2 diabetes from Germany and Austria.

METHODS

29,325 patients (≥ 20 years of age) with type 2 diabetes and MI, or stroke, documented between 2006 and 2015 were selected from the Diabetes-Patienten-Verlaufsdokumentation database. We analyzed medication, clinical characteristics, and lifestyle factors according to national secondary prevention guidelines in patients with MI, or stroke, separately.

RESULTS

HbA1C <7.5 % was achieved in 64.9 % (MI), and in 61.1 % (stroke) of patients. LDL <100 mg/dl was documented in 56.2 % (MI), and in 42.2 % (stroke). Non-smoking was reported in 92.0 % (MI), and in 93.1 % (stroke), physical activity in 9.6 % (MI), and 5.5 % (stroke). Target values of blood pressure (<130/80 mmHg in MI, 120/70-140/90 in stroke) were reached in 67.0 % (MI), and in 89.9 % (stroke). Prescription prevalence of inhibitors of platelet aggregation (IPA) was 50.7 % (MI), and 31.7 % (stroke). 57.0 % (MI), and 40.1 % (stroke) used statins, 65.1 % (MI), and 65.8 % (stroke) used any type of antihypertensives, and ACE inhibitors were prescribed in 49.7 % (MI), and 41.3 % (stroke). A body mass index (BMI) <27 kg/m(2) and the use of beta blockers were only recommended in subjects with MI. Of the patients with MI, 32.0 % had a BMI <27 kg/m(2), and 59.5 % used beta blockers.

CONCLUSIONS

Achievement of treatment goals in secondary prevention of MI, or stroke in subjects with type 2 diabetes needs improvement. Target goals were met more frequently in patients with MI compared to subjects with stroke. Especially the use of IPA was very low in patients with stroke. There remains great potential to reduce the risk of repeated macrovascular events and premature death, as well as to increase patients' quality of life.

GENETICS IN ENDOCRINOLOGY: Gain and loss of function mutations of the calcium-sensing receptor and associated proteins: current treatment concepts

The calcium-sensing receptor (CASR) is the main calcium sensor in the maintenance of calcium metabolism. Mutations of the CASR, 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 about in vitro effects 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.

Seasonal Variation in Blood Pressure in 162,135 Patients With Type 1 or Type 2 Diabetes Mellitus

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<.001). Interestingly, seasonal variation in diastolic BP was larger in T1DM than in T2DM (1.24/0.64 mm Hg, P<.001). A sex difference was observed in T1DM only, while age differences occurred in both types of diabetes. Correlations between BP and potentially related factors such as outdoor temperature indicated that reasons underlying BP seasonality are likely to be complex and vary by subgroup.

The Incidence of Cancer Among Acromegaly Patients: Results From the German Acromegaly Registry

CONTEXT

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.

OBJECTIVE

The objective was to determine whether the overall and site-specific incidence of cancer is comparable to that of the general population.

DESIGN AND SETTING

Data from the German Acromegaly Registry for 446 patients (6656 person-years from diagnosis) treated in seven specialized endocrine centers were analyzed.

MAIN OUTCOME MEASURE

Standard incidence ratios (SIRs) were calculated as compared to the general population.

RESULTS

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 ranges <1, 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).

CONCLUSIONS

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.

Failure to achieve disease control in acromegaly: cause analysis by a registry-based survey

CONTEXT

Disease 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.

OBJECTIVE

To investigate reasons for failure to achieve disease control in long-standing acromegaly.

DESIGN AND METHODS

Survey 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%).

RESULTS

Median 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.

CONCLUSIONS

Main 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.

Adrenal cortical insufficiency--a life threatening illness with multiple etiologies

BACKGROUND

The clinical signs of adrenal cortical insufficiency (incidence, ca. 25 per million per year; prevalence, ca. 400 per million) are nonspecific, and misdiagnoses are therefore common. Glucocorticoid substitution therapy has been in use for 50 years but is not a wholly adequate treatment. Our understanding of this disease remains incomplete in many ways.

METHOD

We selectively searched the Medline database for publications on adrenal cortical insufficiency, with particular attention to studies from the year 2000 onward (search terms: "adrenal insufficiency" or "Addison's disease" or "hypopituitarism").

RESULTS

Hydrocortisone substitution therapy is often given in doses of 10-25 mg/day, timed according to the circadian rhythm. Gastrointestinal and other, febrile infections account for 30-50% of life-threatening adrenocortical crises. Such crises affect 8 of 100 persons with adrenal cortical insufficiency per year and must be treated by the immediate administration of glucocorticoids and fluids. When persons with adrenal cortical insufficiency are acutely ill or are otherwise under unusual stress, they may need additional amounts of hydrocortisone, often in the range of 5-10 mg but occasionally as high as 200 mg. The sustained administration of excessive amounts of steroid can shorten patients lives by several years. Inappropriate substitution therapy can cause other major medical conditions, such as metabolic syndrome and osteoporosis.

CONCLUSION

Important measures for the prevention of adrenocortical crises include improved care by treating physicians, education of patients and their families, the provision of emergency identifying documents, and the prescription of glucocorticoid emergency kits.

Amino alcohol- (NPS-2143) and quinazolinone-derived calcilytics (ATF936 and AXT914) differentially mitigate excessive signalling of calcium-sensing receptor mutants causing Bartter syndrome Type 5 and autosomal dominant hypocalcemia

INTRODUCTION

Activating calcium sensing receptor (CaSR) mutations cause autosomal dominant hypocalcemia (ADH) characterized by low serum calcium, inappropriately low PTH and relative hypercalciuria. Four activating CaSR mutations cause additional renal wasting of sodium, chloride and other salts, a condition called Bartter syndrome (BS) type 5. Until today there is no specific medical treatment for BS type 5 and ADH. We investigated the effects of different allosteric CaSR antagonists (calcilytics) on activating CaSR mutants.

METHODS

All 4 known mutations causing BS type 5 and five ADH mutations were expressed in HEK 293T cells and receptor signalling was studied by measurement of intracellular free calcium in response to extracellular calcium ([Ca2+]o). To investigate the effect of calcilytics, cells were stimulated with 3 mM [Ca2+]o in the presence or absence of NPS-2143, ATF936 or AXT914.

RESULTS

All BS type 5 and ADH mutants showed enhanced signalling activity to [Ca2+]o with left shifted dose response curves. In contrast to the amino alcohol NPS-2143, which was only partially effective, the quinazolinone calcilytics ATF936 and AXT914 significantly mitigated excessive cytosolic calcium signalling of all BS type 5 and ADH mutants studied. When these mutants were co-expressed with wild-type CaSR to approximate heterozygosity in patients, ATF936 and AXT914 were also effective on all mutants.

CONCLUSION

The calcilytics ATF936 and AXT914 are capable of attenuating enhanced cytosolic calcium signalling activity of CaSR mutations causing BS type 5 and ADH. Quinazolinone calcilytics might therefore offer a novel treatment option for patients with activating CaSR mutations.

Frequency of AIP gene mutations in young patients with acromegaly: a registry-based study

CONTEXT

Familial and sporadic GH-secreting pituitary adenomas are associated with mutations in the aryl hydrocarbon receptor-interacting protein (AIP) gene. Patients with an AIP mutation (AIPmut) tend to have more aggressive tumors occurring at a younger age.

OBJECTIVE

The objective of the study was to investigate the frequency of AIPmut in patients diagnosed at 30 years of age or younger.

DESIGN

The German Acromegaly Registry database (1795 patients in 58 centers) was screened for patients diagnosed with acromegaly at 30 years of age or younger (329 patients). Sixteen centers participated and 91 patients consented to AIPmut analysis.

INTERVENTION

DNA was analyzed by direct sequencing and multiplex ligation dependent probe amplification Main outcome Measures: The number of patients with AIPmut was measured.

RESULTS

Five patients had either a mutation (c.490C>T, c.844C>T, and c.911G>A, three males) or gross deletions of exons 1 and 2 of the AIP gene (n = 2, one female). The overall frequency of an AIPmut was 5.5%, and 2.3% or 2.4% in patients with an apparently sporadic adenoma or macroadenoma, respectively. By contrast, three of four patients (75%) with a positive family history were tested positive for an AIPmut. Except for a positive family history, there were no significant differences between patients with and without an AIPmut.

CONCLUSIONS

The frequency of AIPmut in this registry-based cohort of young patients with acromegaly is lower than previously reported. Patients with a positive family history should be tested for an AIPmut, whereas young patients without an apparent family history should be screened, depending on the individual cost to benefit ratio.

[Quality of life of young adults after a growth hormone therapy with childhood onset]

INTRODUCTION

Little is known about the health-related quality of life of young adults with childhood onset idiopathic growth hormone deficiency or neurosecretory dysfunction of growth hormone secretion, who have been treated with recombinant human growth hormone (GH).

METHODS

Patients were diagnosed and treated with human growth hormone at the University Children´s Hospital in Erlangen (n=85). The data of both groups were merged for analysis, because no difference between idiopathic growth hormone deficiency and neurosecretory dysfunction of growth hormone secretion in auxological. Data were found. Health-related quality of life was cross- sectionally assessed after the end of growth hormone therapy with the Short Form-36 Health Survey and the Nottingham Health Profiles for which population based norm data are available.

RESULTS

At the time of the survey, the patients (53 m, 32 f) were 23.5 ± 4.6 years old. At start of GH therapy, age was 10.5 ± 2.8 and at the end 16.3 ± 1,4 years. At start, height SDS was -3.20 ± 1.06. GH dose was 0,026 ± 0,012 mg/kg/d (daily s. c.-injections). The increase in height SDS after the end of GH therapy was 1.69 ± 1.22.  Compared to the reference population, patients reported significantly lower scores on the scales energy level, vitality, social functioning, indicating a greater social isolation, a stronger emotional reaction, an increased loss of mobility and a worse psychological state.

CONCLUSION

Young adults report specific impairments after completion of GH therapy.

A homozygous CaSR mutation causing a FHH phenotype completely masked by vitamin D deficiency presenting as rickets

CONTEXT

Heterozygous inactivating calcium-sensing receptor (CaSR) mutations lead to familial hypocalciuric hypercalcemia (FHH), whereas homozygous mutations usually cause neonatal severe hyperparathyroidism.

OBJECTIVE

The objective of the study was to investigate the pathophysiological mechanisms of a homozygous inactivating CaSR mutation identified in a 16-year-old female.

DESIGN

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.

RESULTS

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.

CONCLUSION

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.

Molecular and functional properties of densely and sparsely granulated GH-producing pituitary adenomas

OBJECTIVE

GH-producing pituitary adenomas display two distinct morphological patterns of cytoplasmic GH-containing secretory granules, namely the densely and sparsely granulated somatotroph adenoma subtype. It is unknown whether these morphological variants reflect distinct pathophysiological entities at the molecular level.

METHODS

In 28 GH-producing adenoma tissues from a consecutive set of patients undergoing pituitary surgery for acromegaly, we studied the GH granulation pattern, the expression of somatostatin receptor subtypes (SSTR) as well as the calcium, cAMP and ZAC1 pathways in primary adenoma cell cultures.

RESULTS

The expression of GSP oncogene was similar between densely and sparsely granulated somatotroph adenoma cells. There were no differences in the calcium, cAMP and ZAC1 pathways as well as in their regulation by SSTR agonists. SSTR2 was exclusively expressed in densely but not in sparsely granulated tumours (membrane expression 86 vs 0%; cytoplasmic expression 67 vs 0%). By contrast, expression of SSTR5 was only found in sparsely but not in densely granulated somatotroph adenomas (membrane expression 29 vs 0%; cytoplasmic expression 57 vs 0%).

CONCLUSIONS

Our results indicate that different granulation patterns in GH-producing adenomas do not reflect differences in pathways and factors pivotal for somatotroph differentiation and function. In vitro, the vast majority of both densely and sparsely granulated tumour cells were responsive to SSTR activation at the molecular level. Sparsely granulated adenomas lacking SSTR2, but expressing SSTR5, might be responsive to novel SSTR agonists with increased affinity to SSTR5.

Cystic fibrosis-related diabetes compared with type 1 and type 2 diabetes in adults

BACKGROUND

With increasing life expectancy of patients with cystic fibrosis (CF), secondary diabetes becomes more prevalent. It appears to be the most common co-morbidity in persons with cystic fibrosis. Therefore, the objective of our study was to describe characteristics of cystic fibrosis-related diabetes compared with type 1 and 2 diabetes (T1DM/T2DM) in adults.

METHODS

Data from 218 436 patients >18 years with cystic fibrosis (n = 401), T1DM (n = 32,409) or T2DM (n = 185 626) in the multicenter Diabetes-Patienten-Verlaufsdokumentation or prospective documentation of diabetes patients registry were analysed.

RESULTS

Diabetes onset [median (interquartile range)] in cystic fibrosis [18.70 (15.50-25.30) years] was between T1DM [16.40 (10.50-31.80) years] and T2DM [58.50 (48.80-68.00) years], with female preponderance. Body mass index (BMI) and glycosylated haemoglobin (HbA1c ) were lowest (19.6 [18.1-21.5] kg/m(2) )/50 mmol/mol (6.73%) versus T1DM (24.4 [22.1-27.4])/62 mmol/mol (7.83%) vs. T2DM (29.6 [26.1-33.9])/54 mmol/mol (7.06%); all p < 0.01. A total of 78.6% of cystic fibrosis patients with diabetes received insulin. Insulin dose (0.74 IE/kg bodyweight) was not significantly different from T1DM (0.73) and T2DM (0.76). Frequency of vascular complications, adjusted for confounding effects, across the groups was different: Hypertension (CFRD 16.1% vs. T1DM 24.0% vs. T2DM 32.2%; all p < 0.01), retinopathy (CFRD 10.7% vs. T1DM 10.4% vs. T2DM 10.5%, not significant), nephropathy (CFRD 25.2% vs. T1DM 17.2% vs. T2DM 24.7%; only T1DM/T2DM; p < 0.01).

CONCLUSION

CFRD is a uniquely complex entity with clear differences from T1DM and T2DM in adults.

Activation of the Ca²+-sensing receptor induces deposition of tight junction components to the epithelial cell plasma membrane

The Ca(2+)-sensing receptor (CaSR) belongs to the G-protein-coupled receptor superfamily and plays essential roles in divalent ion homeostasis and cell differentiation. Because extracellular Ca(2+) is essential for the development of stable epithelial tight junctions (TJs), we hypothesized that the CaSR participates in regulating TJ assembly. We first assessed the expression of the CaSR in Madin-Darby canine kidney (MDCK) cells at steady state and following manipulations that modulate TJ assembly. Next, we examined the effects of CaSR agonists and antagonists on TJ assembly. Immunofluorescence studies indicate that endogenous CaSR is located at the basolateral pole of MDCK cells. Stable transfection of human CaSR in MDCK cells further reveals that this protein co-distributes with β-catenin on the basolateral membrane. Switching MDCK cells from low-Ca(2+) medium to medium containing a normal Ca(2+) concentration significantly increases CaSR expression at both the mRNA and protein levels. Exposure of MDCK cells maintained in low-Ca(2+) conditions to the CaSR agonists neomycin, Gd(3+) or R-568 causes the transient relocation of the tight junction components ZO-1 and occludin to sites of cell-cell contact, while inducing no significant changes in the expression of mRNAs encoding junction-associated proteins. Stimulation of CaSR also increases the interaction between ZO-1 and the F-actin-binding protein I-afadin. This effect does not involve activation of the AMP-activated protein kinase. By contrast, CaSR inhibition by NPS-2143 significantly decreases interaction of ZO-1 with I-afadin and reduces deposition of ZO-1 at the cell surface following a Ca(2+) switch from 5 µM to 200 µM [Ca(2+)]e. Pre-exposure of MDCK cells to the cell-permeant Ca(2+) chelator BAPTA-AM, similarly prevents TJ assembly caused by CaSR activation. Finally, stable transfection of MDCK cells with a cDNA encoding a human disease-associated gain-of-function mutant form of the CaSR increases the transepithelial electrical resistance of these cells in comparison to expression of the wild-type human CaSR. These observations suggest that the CaSR participates in regulating TJ assembly.

GLP-1 analogues as a new treatment option for hypothalamic obesity in adults: report of nine cases

BACKGROUND

Patients with hypothalamic pathology often develop morbid obesity, causing severe metabolic alterations resulting in increased morbidity and mortality. Glucagon-like peptide-1 (GLP-1) analogues improve glycaemic control in type 2 diabetic patients and cause weight loss in obese patients by yet unknown mechanisms. Here we tested whether GLP-1 analogues were also effective in the treatment of obesity and associated metabolic alterations in patients with hypothalamic disease.

METHODS

Nine patients (eight with type 2 diabetes mellitus) with moderate to severe hypothalamic obesity were treated with GLP-1 analogues for up to 51 months. Body weight, homeostasis model assessment - insulin resistance (HOMA-IR), HbA1c and lipids were assessed.

RESULTS

Eight patients experienced substantial weight loss (-13.1±5.1 kg (range -9 to -22)). Insulin resistance (HOMA-IR -3.2±3.5 (range -9.1 to 0.8)) and HbA1c values (-1.3±1.4% (range -4.5 to 0.0)) improved under treatment (24.3±18.9 months (range 6 to 51)). Five patients reported increased satiation in response to the treatment. Two of the eight patients complained about nausea and vomiting and one of them abandoned therapy because of sustained gastrointestinal discomfort after 6 months. One patient suffered from intolerable nausea and vomiting and discontinued treatment within 2 weeks.

CONCLUSION

GLP-1 analogues can cause substantial and sustained weight loss in obese patients with hypothalamic disease. This offers a new approach for medical treatment of moderate to severe hypothalamic obesity and associated metabolic alterations.

Long-term outcome in patients with acromegaly: analysis of 1344 patients from the German Acromegaly Register

BACKGROUND

Acromegaly is a rare disease with significant morbidity and increased mortality. Epidemiological data about therapeutic outcome under 'real life' conditions are scarce.

OBJECTIVE

To describe biochemical long-term outcome of acromegaly patients in Germany.

DESIGN AND METHODS

Retrospective 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.

RESULTS

Nine 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.

CONCLUSION

The 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.

Adrenarche and puberty in children with classic congenital adrenal hyperplasia due to 21-hydroxylase deficiency

There have been only a few studies on adrenarche in girls with classic congenital adrenal hyperplasia (CAH) showing that dehydroepiandrosterone sulfate (DHEAS) levels did not rise at the physiological age of adrenarche.

OBJECTIVE

Longitudinal analysis of serum DHEAS levels and Tanner stages in CAH children.

DESIGN

We studied 98 CAH patients (52 females), aged between 1 month and 18.0 years. All patients had genetically proven classic CAH and received steroid substitution therapy.

RESULTS

Serum DHEAS levels did not differ between CAH children and healthy children from the age of 1 year until 5-6 years. Beginning at the age of 7-8 years, there was a continuous but blunted increase in DHEAS levels in CAH boys and girls compared to healthy children. There was no correlation of DHEAS levels with the genotype, glucocorticoid dosage, auxological data, or quality of metabolic control. Pubarche (PH2) as well as gonadarche (G2) and thelarche (B2) occurred significantly earlier in CAH boys and girls than in the reference group, but timing of menarche was normal.

CONCLUSIONS

Pubarche and adrenarche are dissociated in classic CAH: earlier pubarche, gonadarche and thelarche, respectively, in both sexes contrast with the absence of typical adrenarche.

Craniopharyngioma in adults

Craniopharyngiomas are slow growing benign tumors of the sellar and parasellar region with an overall incidence rate of approximately 1.3 per million. During adulthood there is a peak incidence between 40 and 44 years. There are two histopathological types, the adamantinomatous and the papillary type. The later type occurs almost exclusively in adult patients. The presenting symptoms develop over years and display a wide spectrum comprising visual, endocrine, hypothalamic, neurological, and neuropsychological manifestations. Currently, the main treatment option consists in surgical excision followed by radiation therapy in case of residual tumor. Whether gross total or partial resection should be preferred has to be balanced on an individual basis considering the extent of the tumor (e.g., hypothalamic invasion). Although the overall long-term survival is good it is often associated with substantial morbidity. Preexisting disorders are often permanent or even exacerbated by treatment. Endocrine disturbances need careful replacement and metabolic sequelae should be effectively treated. Regular follow-up by a multidisciplinary team is a prerequisite for optimal outcome of these patients.

(23)Na magnetic resonance imaging of tissue sodium

Hypertension is linked to disturbed total-body sodium (Na(+)) regulation; however, measuring Na(+) disposition in the body is difficult. We implemented (23)Na magnetic resonance spectroscopy ((23)Na-MR) and imaging technique ((23)Na-MRI) at 9.4T for animals and 3T for humans to quantify Na(+) content in skeletal muscle and skin. We compared (23)Na-MRI data with actual tissue Na(+) content measured by chemical analysis in animal and human tissue. We then quantified tissue Na(+) content in normal humans and in patients with primary aldosteronism. We found a 29% increase in muscle Na(+) content in patients with aldosteronism compared with normal women and men. This tissue Na(+) was mobilized after successful treatment without accompanying weight loss. We suggest that, after further refinements, this tool could facilitate understanding the relationships between Na(+) accumulation and hypertension. Furthermore, with additional technical advances, a future clinical use may be possible.