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Free access

Prospective evaluation of aldosterone LC-MS/MS-specific cutoffs for the saline infusion test

Charlotte Michaela Fries, Yoon Ju Bae, Nada Rayes, Benjamin Sandner, Berend Isermann, Michael Stumvoll, Valentina Fagotto, Martin Reincke, Martin Bidlingmaier, Vogel Mandy, Jürgen Kratzsch, and Wiebke Kristin Fenske

Objective

Liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) has become state of the art for the quantitative analysis of steroid hormones. Although method comparisons show that aldosterone measurement using LC-MS/MS yields considerably lower levels than immunoassays (IAs), method-specific cutoff values for primary aldosteronism (PA) are largely missing. Objective of this study was to analyze the diagnostic accuracy of proposed LC-MS/MS-specific cutoff values for the saline infusion test (SIT).

Design and methods

From 2016 to 2019, 104 consecutive patients suspected of PA underwent the SIT and captopril challenge test in the tertiary medical center at the University Hospital of Leipzig, Germany. Patients with positive case confirmation underwent adrenal imaging and adrenal venous sampling for subtype classification.

Results

Overall, proposed assay-specific PACLC-MS/MS cutoff values for the SIT achieved higher diagnostic accuracy than established PACIA values with a sensitivity and specificity of 87.5% (95% CI: 71.0–96.5) and 97% (95% CI: 89.6–99.6) for a cutoff of 120 pmol/L and 93.8% (95% CI: 79.2–99.2) and 92.5% (95% CI: 83.4–97.5) for a cutoff of 94 pmol/L. The most accurate post-SIT PACLC-MS/MS cutoff value in this study was 83 pmol/L, yielding a sensitivity and specificity of 96.9% (95% CI: 83.8–99.9) and 92.5% (95% CI: 83.4–97.5), respectively.

Conclusions

The present data confirm the need for the implication of lower method-specific aldosterone cutoff values for the diagnosis of PA with LC-MS/MS based aldosterone measurement.

Free access

Pharmacokinetics and pharmacodynamics of GH: dependence on route and dosage of administration

Alexandra Keller, Zida Wu, Juergen Kratzsch, Eberhard Keller, Werner F Blum, Astrid Kniess, Rainer Preiss, Jens Teichert, Christian J Strasburger, and Martin Bidlingmaier

Objective: Pharmacokinetic and pharmacodynamic data after recombinant human GH (rhGH) administration in adults are scarce, but necessary to optimize replacement therapy and to detect doping. We examined pharmacokinetics, pharmacodynamics, and 20 kDa GH after injection of rhGH at different doses and routes of administration.

Design: Open-label crossover study with single boluses of rhGH.

Methods: Healthy trained subjects (10 males, 10 females) received bolus injections of rhGH on three occasions: 0.033 mg/kg s.c., 0.083 mg/kg s.c., and 0.033 mg/kg i.m. Concentrations of 22 and 20 kDa GH, IGF-I, and IGF-binding proteins (IGFBP)-3 were measured repeatedly before and up to 36 h after injection.

Results: Serum GH maximal concentration (C max) and area under the time-concentration curve (AUC) were higher after i.m. than s.c. administration of 0.033 mg/kg (C max 35.5 and 12.0 μ g/l; AUC 196.2 and 123.8). C max and AUC were higher in males than in females (P < 0.01) and pharmacodynamic changes were more pronounced. IGFBP-3 concentrations showed no dose dependency. In response to rhGH administration, 20 kDa GH decreased in females and remained suppressed for 14–18 h (low dose) and 30 h (high dose). In males, 20 kDa GH was undetectable at baseline and throughout the study.

Conclusions: After rhGH administration, pharmacokinetic parameters are mainly influenced by route of administration, whereas pharmacodynamic variables and 20 kDa GH concentrations are determined mainly by gender. These differences need to be considered for therapeutic use and for detection of rhGH doping.

Free access

Assessment of lung function in a large cohort of patients with acromegaly

Sylvère Störmann, Bodo Gutt, Josefine Roemmler-Zehrer, Martin Bidlingmaier, Rudolf M Huber, Jochen Schopohl, and Matthias W Angstwurm

Objective

Acromegaly is associated with increased mortality due to respiratory disease. To date, lung function in patients with acromegaly has only been assessed in small studies, with contradicting results. We assessed lung function parameters in a large cohort of patients with acromegaly.

Design

Lung function of acromegaly patients was prospectively assessed using spirometry, blood gas analysis and body plethysmography. Biochemical indicators of acromegaly were assessed through measurement of growth hormone and IGF-I levels. This study was performed at the endocrinology outpatient clinic of a tertiary referral center in Germany.

Methods

We prospectively tested lung function of 109 acromegaly patients (53 male, 56 female; aged 24–82 years; 80 with active acromegaly) without severe acute or chronic pulmonary disease. We compared lung volume, air flow, airway resistance and blood gases to normative data.

Results

Acromegaly patients had greater lung volumes (maximal vital capacity, intra-thoracic gas volume and residual volume: P < 0.001, total lung capacity: P = 0.006) and showed signs of small airway obstruction (reduced maximum expiratory flow when 75% of the forced vital capacity (FVC) has been exhaled: P < 0.001, lesser peak expiratory flow: P = 0.01). There was no significant difference between active and inactive acromegaly. Female patients had significantly altered lung function in terms of subclinical airway obstruction.

Conclusions

In our cross-sectional analysis of lung function in 109 patients with acromegaly, lung volumes were increased compared to healthy controls. Additionally, female patients showed signs of subclinical airway obstruction. There was no difference between patients with active acromegaly compared with patients biochemically in remission.

Free access

Acute administration of acyl, but not desacyl ghrelin, decreases blood pressure in healthy humans

Cecilia J Zhang, Martin Bidlingmaier, Mekibib Altaye, Laura C Page, David D’Alessio, Matthias H Tschöp, and Jenny Tong

Objective

To compare the effects of acyl ghrelin (AG) and desacyl ghrelin (DAG) on blood pressure (BP), heart rate (HR) and other autonomic parameters in healthy humans and to elucidate the hormonal mechanisms through which AG could exert its cardiovascular effects.

Design

Seventeen healthy participants underwent frequent monitoring of systolic (sBP) and diastolic blood pressure (dBP), HR, respiratory rate (RR) and body surface temperature (Temp) during continuous infusion of AG, DAG, combined AG + DAG or saline control before and during an IV glucose tolerance test on 4 separate days. Plasma catecholamines, renin and aldosterone levels were also measured. Differences in outcome measures between treatment groups were assessed using mixed-model analysis.

Results

Compared to the saline control, AG and combined AG + DAG infusions decreased sBP, dBP, mean arterial blood pressure (MAP), HR and Temp. In contrast, DAG infusion did not alter BP, RR or Temp, but did decrease HR. The AG and AG + DAG infusions also raised plasma aldosterone levels compared to saline (P < 0.001) without affecting renin or catecholamine levels.

Conclusions

The decrease in BP, HR, RR and Temp with AG infusion suggests mediation through the autonomic nervous system. The lack of response to DAG suggests that these autonomic effects require activation of the ghrelin receptor.

Open access

11-Oxygenated C19 steroids are the predominant androgens responsible for hyperandrogenemia in Cushing’s disease

Hanna F Nowotny, Leah Braun, Frederick Vogel, Martin Bidlingmaier, Martin Reincke, Lea Tschaidse, Matthias K Auer, Christian Lottspeich, Stefan A Wudy, Michaela F Hartmann, James Hawley, Joanne E Adaway, Brian Keevil, Katharina Schilbach, and Nicole Reisch

Background

Symptoms of hyperandrogenism are common in patients with Cushing’s disease (CD), yet they are not sufficiently explained by androgen concentrations. In this study, we analyzed the contribution of 11-oxygenated C19 steroids (11oxC19) to hyperandrogenemia in female patients with CD.

Methods

We assessed saliva day profiles in females with CD pre (n  = 23) and post (n  = 13) successful transsphenoidal surgery, 26 female controls, 5 females with CD treated with metyrapone and 5 treated with osilodrostat for cortisol, cortisone, androstenedione (A4), 11-hydroxyandrostenedione (11OHA4), testosterone (TS), 11-ketotestosterone (11KT), as well as metabolites of classic and 11-oxygenated androgens in 24-h urine. In addition, morning baseline levels of gonadotropins and estradiol, sex hormone-binding globulin, cortisol and dehydroepiandrosterone sulfate (DHEAS) in serum and adrenocorticotrophic hormone in plasma in patients and controls were investigated.

Results

Treatment-naïve females with CD showed a significantly elevated area under the curve of 11OHA4 and 11KT in saliva throughout the day compared to controls (11OHA4 mean rank difference (mrd) 18.13, P = 0.0002; 11KT mrd 17.42; P = 0.0005), whereas A4, TS and DHEAS were comparable to controls. Gonadotropin concentrations were normal in all patients with CD. After transsphenoidal surgery, 11oxC19 and their metabolites dropped significantly in saliva (11OHA4 P < 0.0001; 11KT P = 0.0010) and urine (11-oxo-androsterone P = 0.0011; 11-hydroxy-androsterone P < 0.0001), treatment with osilodrostat and metyrapone efficaciously blocked 11oxC19 synthesis.

Conclusion

Hyperandrogenemia in CD is predominantly caused by excess of 11oxC19 steroids.

Free access

Association of plasma aldosterone with the metabolic syndrome in two German populations

Anke Hannemann, Christa Meisinger, Martin Bidlingmaier, Angela Döring, Barbara Thorand, Margit Heier, Petra Belcredi, Karl-Heinz Ladwig, Henri Wallaschofski, Nele Friedrich, Sabine Schipf, Jan Lüdemann, Rainer Rettig, Jörg Peters, Henry Völzke, Jochen Seissler, Felix Beuschlein, Matthias Nauck, and Martin Reincke

Objective

The aim of this study was to analyze the potential association of the plasma aldosterone concentration (PAC) with the metabolic syndrome (MetS) and its components in two German population-based studies.

Methods

We selected 2830 and 2901 participants (31–80 years) from the follow-ups of the Study of Health in Pomerania (SHIP)-1 and the Cooperative Health Research in the Region of Augsburg (KORA) F4 respectively. MetS was defined as the presence of at least three out of the following five criteria: waist circumference ≥94 cm (men (m)) and ≥80 cm (women (w)); high-density lipoprotein (HDL) cholesterol <1.0 mmol/l (m) and <1.3 mmol/l (w); blood pressure ≥130/85 mmHg or antihypertensive treatment; non-fasting glucose (SHIP-1) ≥8 mmol/l, fasting glucose (KORA F4) ≥5.55 mmol/l or antidiabetic treatment; non-fasting triglycerides (SHIP-1) ≥2.3 mmol/l, fasting triglycerides (KORA F4) ≥1.7 mmol/l, or lipid-lowering treatment. We calculated logistic regression models by comparing the highest study- and sex-specific PAC quintiles versus all lower quintiles.

Results

MetS was common with 48.1% (m) and 34.8% (w) in SHIP-1 and 42.7% (m) and 27.5% (w) in KORA F4. Our logistic regression models revealed associations of PAC with MetS, elevated triglycerides, and decreased HDL cholesterol in SHIP-1 and KORA F4.

Conclusions

Our findings add to the increasing evidence supporting a relation between aldosterone and MetS and suggest that aldosterone may be involved in the pathophysiology of MetS and lipid metabolism disorders.

Free access

Determinants of the growth hormone nadir during oral glucose tolerance test in adults

Katharina Schilbach, Christina Gar, Andreas Lechner, Shiva Sophia Nicolay, Laura Schwerdt, Michael Haenelt, Jakob Dal, Jens-Otto Lunde Jørgensen, Sylvère Störmann, Jochen Schopohl, and Martin Bidlingmaier

Objective

Growth hormone (GH) nadir (GHnadir) during oral glucose tolerance test (OGTT) is an important tool in diagnosing acromegaly, but data evaluating the need to adjust cut-offs to biological variables utilizing today's assay methods are scarce. We therefore investigated large cohorts of healthy subjects of both sexes to define normal GHnadir concentrations for a modern, sensitive, 22 kD-GH-specific assay.

Design

Multicenter study with prospective and retrospective cohorts (525 healthy adults: 405 females and 120 males).

Methods

GH concentrations were measured by the IDS-iSYS immunoassay after oral application of 75 g glucose.

Results

GHnadir concentrations (µg/L) were significantly higher in lean and normal weight subjects (group A) compared to overweight and obese subjects (group B); (males (M): A vs B, mean: 0.124 vs 0.065, P = 0.0317; premenopausal females without estradiol-containing OC (OC-EE) (FPRE): A vs B, mean: 0.179 vs 0.092, P < 0.0001; postmenopausal women (FPOST): A vs B, mean: 0.173 vs 0.078, P < 0.0061). Age, glucose metabolism and menstrual cycle had no impact on GHnadir. However, premenopausal females on OC-EE (FPREOC) exhibited significantly higher GHnadir compared to all other groups (all P < 0.0001). BMI had no impact on GHnadir in FPREOC (A vs B, mean: 0.624 vs 0.274, P = 0.1228).

Conclusions

BMI, sex and OC-EE intake are the major determinants for the GHnadir during OGTT in healthy adults. Using a modern sensitive GH assay, GHnadir concentrations in healthy subjects are distinctly lower than cut-offs used in previous guidelines for diagnosis and monitoring of acromegaly.

Open access

MOD-4023, a long-acting carboxy-terminal peptide-modified human growth hormone: results of a Phase 2 study in growth hormone-deficient adults

Christian J Strasburger, Peter Vanuga, Juraj Payer, Marija Pfeifer, Vera Popovic, László Bajnok, Miklós Góth, Veˇra Olšovská, L‘udmila Trejbalová, Janos Vadasz, Eyal Fima, Ronit Koren, Leanne Amitzi, Martin Bidlingmaier, Oren Hershkovitz, Gili Hart, and Beverly M K Biller

Objective

Growth hormone (GH) replacement therapy currently requires daily injections, which may cause distress and low compliance. C-terminal peptide (CTP)-modified growth hormone (MOD-4023) is being developed as a once-weekly dosing regimen in patients with GH deficiency (GHD). This study’s objective is to evaluate the safety, pharmacokinetics (PK), pharmacodynamics (PD) and efficacy of MOD-4023 administered once-weekly in GHD adults.

Design

54 adults with GHD currently treated with daily GH were normalized and randomized into 4 weekly dosing cohorts of MOD-4023 at 18.5%, 37%, 55.5% or 123.4% of individual cumulative weekly molar hGH dose. The study included 2 stages: Stage A assessed the effectiveness and PK/PD profiles of the 4 dosing regimens of MOD-4023. Stage B was an extension period of once-weekly MOD-4023 administration (61.7% molar hGH content) to collect further safety data and confirm the results from Stage A.

Results

Dose-dependent response was observed for both PK and PD data of weekly MOD-4023 treatment. Insulin-like growth factor I (IGF-I) SDS levels were maintained within normal range. The 18.5% cohort was discontinued due to low efficacy. MOD-4023 was well tolerated and exhibited favorable safety profile in all dose cohorts. The reported adverse events were consistent with known GH-related side effects.

Conclusions

Once-weekly MOD-4023 administration in GHD adults was found to be clinically effective while maintaining a favorable safety profile and may obviate the need for daily injections. Weekly GH injections may improve compliance and overall outcome. The promising results achieved in this Phase 2 study led to a pivotal Phase 3 trial, which is currently ongoing.

Free access

Measurements of plasma metanephrines by immunoassay vs liquid chromatography with tandem mass spectrometry for diagnosis of pheochromocytoma

Dirk Weismann, Mirko Peitzsch, Anna Raida, Aleksander Prejbisz, Maria Gosk, Anna Riester, Holger S Willenberg, Reiner Klemm, Georg Manz, Timo Deutschbein, Matthias Kroiss, Roland Därr, Martin Bidlingmaier, Andrzej Januszewicz, Graeme Eisenhofer, and Martin Fassnacht

Background

Reports conflict concerning measurements of plasma metanephrines (MNs) for diagnosis of pheochromocytomas/paragangliomas (PPGLs) by immunoassays compared with other methods. We aimed to compare the performance of a commercially available enzyme-linked immunoassay (EIA) kit with liquid chromatography–tandem mass spectrometric (LC–MS/MS) measurements of MNs to diagnose PPGLs.

Methods

In a substudy of a prospective, multicenter trial to study the biochemical profiles of monoamine-producing tumors, we included 341 patients (174 males and 167 females) with suspected PPGLs (median age 54 years), of whom 54 had confirmed PPGLs. Plasma MNs were measured by EIA and LC–MS/MS, each in a specialized laboratory.

Results

Plasma normetanephrine (NMN) and MN were measured 60 and 39% lower by EIA than by LC–MS/MS. Using upper cut-offs stipulated for the EIA, diagnostic sensitivity was only 74.1% at a specificity of 99.3%. In contrast, use of similar cut-offs for MN and overall lower age-adjusted cut-offs for NMN measured by LC–MS/MS returned a diagnostic sensitivity and specificity of 98.1 and 99.7%. Areas under receiver-operating characteristic curves, nevertheless, indicated comparable diagnostic performance of the EIA (0.993) and LC–MS/MS (0.985). Diagnostic sensitivity for the EIA increased to 96.2% with a minimal loss in specificity (95.1%) following use of cut-offs for the EIA adapted to correct for the negative bias.

Conclusions

The EIA underestimates plasma MNs and diagnostic sensitivity is poor using commonly stipulated cut-offs, resulting in a high risk for missing patients with PPGLs. Correction of this shortcoming can be achieved by appropriately determined cut-offs resulting in comparable diagnostic performance of EIA and LC–MS/MS assays.

Free access

Efficacy of 12-month treatment with the GH receptor antagonist pegvisomant in patients with acromegaly resistant to long-term, high-dose somatostatin analog treatment: effect on IGF-I levels, tumor mass, hypertension and glucose tolerance

Annamaria Colao, Rosario Pivonello, Renata S Auriemma, Maria Cristina De Martino, Martin Bidlingmaier, Francesco Briganti, Fabio Tortora, Pia Burman, Ione A Kourides, Christian J Strasburger, and Gaetano Lombardi

Objective: We aimed to investigate the efficacy of pegvisomant in patients with acromegaly resistant to long-term (≧ 24-month), high-dose treatment with octreotide-LAR (40 mg/month) or lanreotide (120 mg/month).

Design: This was an open, prospective study.

Subjects and Methods: We studied 16 patients with acromegaly (nine women; aged 28–61 years). The main outcome measures were IGF-I levels, blood pressure, glucose tolerance and safety (liver function and tumor size). Pegvisomant was given at doses of 10–40 mg s.c. daily. Dose titration was performed every month by IGF-I assay.

Results: Three patients spontaneously stopped pegvisomant treatment after 6–9 months because of poor compliance; from the measurement of serum pegvisomant, another patient was found not to inject herself properly. After 6 months, IGF-I levels decreased by 63 ± 19% (767.8 ± 152.9 vs 299.8 ± 162.9 μg/l, P < 0.0001, t-test); serum IGF-I levels normalized in 57%. After 12 months, IGF-I levels normalized in nine (75%) patients and were reduced by over 50% in another three (25%). The mean tumor volume remained stable during the study (1198 ± 1234 vs 1196 ± 1351 mm3, P = 0.37): it did not change ( ± 25% vs basal) in nine patients, increased by 39.4% and 40.8% in two and decreased by 30.8–46.5% in four. The total/high-density lipoprotein (HDL):cholesterol ratio (from 4.4 ± 1.0 to 3.7 ± 0.6, P= 0.0012), glucose levels (from 5.6 ± 1.2 to 4.4 ± 1.4 mmol/l, P = 0.026), insulin levels (from 12.4 ± 6.7 to 8.1 ± 3.0 mUl/l, P = 0.0023) and homeostasis model assessment (HOMA) index (from 3.4 ± 2.1 to 1.9 ± 1.0, P = 0.0017) decreased.

Conclusions: Treatment for 12 months with pegvisomant normalized IGF-I levels, and improved cardiovascular risk parameters and insulin sensitivity in patients with acromegaly resistant to long-term, high-dose treatment with somatostatin analogs. The tolerance of treatment was good.