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Prof. Dr. med. Katharina Schilbach

Faculty of Applied Healthcare Sciences

Professors

Professor

Professor of Clinical Medicine

LA 27-2.17

0991/3615-8297

consulting time

Wednesday afternoons (2-6 pm), appointment by e-mail.

publications

Sortierung:

Journal article

Katharina Schilbach
M. Bidlingmaier

Pitfalls in the lab assessment of hypopituitarism.

In: Reviews in Endocrine & Metabolic Disorders vol. 25 pg. 457-465

13.04.2024 (2024)

DOI: 10.1007/s11154-024-09881-1

show abstract

The diagnostic approach to hypopituitarism involves many disciplines. Clinical symptoms rarely are specific. Imaging techniques are helpful but cannot prove the specific functional defects. Therefore, the definitive diagnosis of pituitary insufficiency is largely based on laboratory tests. However, also laboratory methods come with inherent limitations, and it is essential for the clinician to know and recognize typical pitfalls. Most factors potentially impairing the quality of hormone measurements are introduced in the preanalytical phase, i.e. before the hormones are measured by the laboratory. For example, the timing of blood drawing with respect to circadian rhythm, stress, and medication can have an influence on hormone concentrations. During the actual analysis of the hormones, cross-reactions with molecules present in the sample presenting the same or similar epitopes than the intended analyte may affect immunoassays. Interference can also come from heterophilic or human anti-animal antibodies. Unexpected problems can also be due to popular nutritional supplements which interfere with the measurement procedures. An important example in this respect is the interference from biotin. It became only clinically visible when the use of this vitamin became popular among patients. The extreme serum concentrations reached when patients take it as a supplement can lead to incorrect measurements in immunoassays employing the biotin-streptavidin system. To some extent, hormone analyses using liquid chromatography mass spectrometry (LCMS) can overcome problems, although availability and cost-effectiveness of this method still imposes restrictions. In the post-analytical phase, appropriateness of reference intervals and cut-offs with respect to the specific analytical method used is of outmost importance. Furthermore, for interpretation, additional biological and pharmacological factors like BMI, age and concomitant diseases must be considered to avoid misinterpretation of the measured concentrations. It is important for the clinician and the laboratory to recognize when one or more laboratory values do not match the clinical picture. In an interdisciplinary approach, the search for the underlying cause should be initiated.

Journal article

N. Unger
M. Theodoropoulou
Katharina Schilbach

Klinisch aktive Hypophysentumoren.

In: Innere Medizin (Heidelberg, Germany) vol. 65 pg. 672-680

13.06.2024 (2024)

DOI: 10.1007/s00108-024-01729-9

show abstract

The widespread use of diagnostic imaging has led to an increase in the incidence of pituitary tumors. The majority of incidentalomas are hormone-inactive (HI) pituitary microadenomas. The most common clinically relevant pituitary adenomas are prolactin-secreting, followed by HI, and far less common are growth hormone (GH)-, adrenocorticotropic hormone (ACTH)- and thyroid-stimulating hormone (TSH)-secreting adenomas. Pituitary adenomas are usually benign, although aggressive growth and invasion occurs in individual cases. Very rarely, they give rise to metastases and are then termed pituitary carcinomas. All pituitary tumors require endocrine testing for pituitary hormone excess. In addition to the medical history and clinical examination, laboratory diagnostics are very important. Symptoms such as irregular menstruation, loss of libido or galactorrhea often lead to the timely diagnosis of prolactinomas, and hyperprolactinemia can easily confirm the diagnosis (considering the differential diagnoses). Diagnosis is more difficult for all other hormone-secreting pituitary adenomas (acromegaly, Cushing's disease, TSHoma), as the symptoms are often non-specific (i.e., headaches, weight gain, fatigue, joint pain). Furthermore, comorbidities such as hypertension, diabetes, and depression are such widespread diseases that pituitary adenomas are rarely considered as the underlying cause. Timely diagnosis and appropriate treatment have a significant impact on morbidity, mortality, and quality of life. Therefore, the role of primary care physicians is very important for achieving an early diagnosis. In addition, patients with pituitary adenomas should always be referred to endocrinologists to ensure optimal diagnosis as well as treatment. Durch die Zunahme der bildgebenden Untersuchungen nimmt auch die Diagnosehäufigkeit hypophysärer Raumforderungen (Hypophyseninzidentalome) zu. Ein Großteil der Inzidentalome sind hormoninaktive Hypophysenmikroadenome, gefolgt von zystischen Raumforderungen und prolaktinsezernierenden Adenomen. Weitaus seltener sind Adenome, die Wachstumshormon (GH) oder adrenokortikotropes Hormon (ACTH) sezernieren, und TSHome, das heißt Adenome, die thyreoideastimulierendes Hormon (TSH) produzieren. Hypophysenadenome sind in der Regel gutartige Tumoren, wobei in einzelnen Fällen ein aggressives Wachstum auftreten kann. Treten Metastasen auf, spricht man von Hypophysenkarzinomen. Bei jedem Hypophysentumor ist es unerlässlich, eine Hormonaktivität auszuschließen. Neben Anamnese und klinischer Untersuchung steht hier die Labordiagnostik im Vordergrund. Bei Prolaktinomen führen Symptome wie Zyklusstörungen, Libidoverlust oder Galaktorrhö in der Regel schnell zur Diagnosestellung, und eine Hyperprolaktinämie bestätigt die Diagnose (unter Beachtung der Differenzialdiagnosen). Bei den übrigen hormonaktiven Hypophysenadenomen (Akromegalie, Morbus Cushing, TSHom) kann sich die Diagnosestellung verzögern, da die Symptome zum Teil unspezifisch sind (beispielsweise Kopfschmerzen, Gewichtszunahme, Abgeschlagenheit, Gelenkschmerz), obwohl die klinischen Stigmata eindrücklich sein können. Des Weiteren stellen die Komorbiditäten, etwa Hypertonie, Diabetes oder Depression, Volkskrankheiten dar, sodass primär nicht an eine dieser seltenen Hypophysenentitäten gedacht wird. Frühzeitige Diagnosestellung und Therapieeinleitung haben einen maßgeblichen Einfluss auf Morbidität, Mortalität und Lebensqualität. Daher ist die Rolle der betreuenden Internistinnen und Internisten, die früh an eine entsprechende Diagnose denken sollten, von großer Bedeutung. Um eine optimale Diagnostik und Therapie zu gewährleisten, sollten Patientinnen und Patienten mit Hypophysenadenomen immer durch Endokrinologinnen und Endokrinologen (mit-)betreut werden.

Journal article

K. Wang
L. Schober
A. Fischer
N. Bechmann
J. Maurer
L. Peischer
et int.
Katharina Schilbach
et al.

Opposing Effects of Cannabidiol in Patient-derived Neuroendocrine Tumor, Pheochromocytoma/Paraganglioma Primary Cultures.

In: The Journal of Clinical Endocrinology and Metabolism vol. 109 pg. 2892-2904

(2024)

DOI: 10.1210/clinem/dgae241

show abstract

CONTEXT Treatment options for advanced neuroendocrine tumors (NETs), pheochromocytomas and paragangliomas (PPGLs) are still limited. In recent years, antitumor effects of cannabinoids have been reported; however, there are only very limited data available in NETs or PPGLs. OBJECTIVE Investigation of the effects of cannabidiol (CBD) on patient-derived human NET/PPGL primary cultures and on NET/PPGL cell lines. METHODS We established primary cultures derived from 46 different patients with PPGLs (n = 35) or NETs (n = 11) who underwent tumor resection at 2 centers. Treatment of patient primary cultures with clinically relevant doses (5 µM) and slightly higher doses (10 µM) of CBD was performed. RESULTS We found opposing effects of 5 µM CBD: significant antitumor effects in 5/35 (14%) and significant tumor-promoting effects in 6/35 (17%) of PPGL primary cultures. In terms of antitumor effects, cluster 2-related PPGLs showed significantly stronger responsivity to CBD compared to cluster 1-related PPGLs (P = .042). Of the cluster 2-related tumors, NF1 PPGLs showed the strongest responsivity (4/5 PPGL primary cultures with a significant decrease in cell viability were NF1-mutated). We also found opposing effects of 10 µM CBD in PPGLs and NETs: significant antitumor effects in 9/33 of PPGL (27%) and 3/11 of NET (27%) primary cultures and significant tumor-promoting effects in 6/33 of PPGL (18%) and 2/11 of NET (18%) primary cultures. CONCLUSION We suggest a potential novel treatment option for some NETs/PPGLs but also provide evidence for caution when applying cannabinoids as supportive therapy for pain or appetite management to cancer patients and possibly as health supplements.

Journal article

A.-L. Lecoq
Katharina Schilbach
L. Rocher
S. Trabado
Briot, K. Herrou, J.
et al.

Metabolically healthy obesity in adults with X-linked hypophosphatemia.

In: European Journal of Endocrinology vol. 191 pg. 156-165

(2024)

DOI: 10.1093/ejendo/lvae089

show abstract

OBJECTIVES X-linked hypophosphatemia (XLH) is characterized by increased concentrations of circulating fibroblast growth factor 23 (FGF-23) resulting in phosphate wasting, hypophosphatemia, atypical growth plate and bone matrix mineralization. Epidemiologic studies suggest a relationship between FGF-23, obesity, and metabolic dysfunction. The prevalence of overweight and obesity is high in children with XLH. We aimed to evaluate the prevalence of obesity and metabolic complications in adults with XLH. METHODS We conducted a prospective cohort study in adult XLH patients from a single tertiary referral center. The proportion of patients with a BMI >25 kg/m2 was the main outcome measure. Body fat mass percentage (FM%) and adipose tissue surfaces were secondary outcome measures. Glucose homeostasis (plasma glucose and insulin concentrations after fasting and 2 hours after an oral glucose tolerance test) was explored in a subgroup of patients and compared with age-, sex-, and BMI-matched healthy controls. RESULTS Among 113 evaluated patients, 85 (75%) were female and 110 (97%) carried a PHEX mutation. Sixty-three (56%) patients were overweight or obese, with a median BMI of 25.3 [IQR, 22.7; 29.2] kg/m2. BMI was correlated with FM%, abdominal and thigh subcutaneous and intra-abdominal adipose tissue surfaces. The prevalence of impaired fasting glucose, impaired glucose tolerance, and diabetes was not different between XLH patients and matched controls. CONCLUSION The prevalence of overweight and obesity is high among XLH patients and is associated with excess fat mass. However, the prevalence of glucose homeostasis abnormalities is not increased in patients compared to healthy controls, suggesting that metabolically healthy overweight or obesity predominates.

Journal article

O. Tausendfreund
M. Bidlingmaier
S. Martini
K. Müller
M. Rippl
Katharina Schilbach
R. Schmidmaier
M. Drey

Growth hormone treatment in aged patients with comorbidities: A systematic review.

In: Growth Hormone & IGF Research : official journal of the Growth Hormone Research Society and the International IGF Research Society vol. 75 pg. 101584

09.03.2024 (2024)

DOI: 10.1016/j.ghir.2024.101584

show abstract

OBJECTIVE Hormonal substitution with growth hormone in aged patients remains a debated research topic and is rarely initiated in clinical practice. This reluctance may originate from concerns about adverse effects and the uncritical use as an anti-aging agent. Nevertheless, beneficial effects for selected patients suffering from certain acute and chronic illnesses could justify its use at an advanced age. This systematic review analyzes randomized controlled studies of GH interventions in older patients with different comorbidities to assess both, beneficial and harmful effects. DESIGN A systematic search strategy was implemented to identify relevant studies from PubMed, MEDLINE, and The Cochrane Library. INCLUSION CRITERIA participants aged over 65 years, randomized controlled trials involving human growth hormone (GH) and presence of at least one additional comorbidity independent of a flawed somatotropic axis. RESULTS The eight eligible studies encompassed various comorbidities including osteoporosis, frailty, chronic heart failure, hip fracture, amyotrophic lateral sclerosis and hemodialysis. Outcomes varied, including changes in body composition, physical performance, strength, bone mineral density, cardiovascular parameters, quality of life and housing situation. Study protocols differed greatly in GH application frequency (daily, 2nd day or 3×/week), doses (0.41 mg-2.6 mg; mean 1.3 mg per 60 kg patient) and duration (1-12 months; mean 7 months). Mild dose-related side effects were reported, alongside noticeable positive impacts particularly on body composition, functionality, and quality of life. CONCLUSION Despite limited evidence, GH treatment might offer diverse benefits with few adverse effects. Further research with IGF-I dependent indication and clear outcomes, incorporating IGF-I dependent GH titration in older adults is warranted.

Journal article

Frederick Vogel
Leah Braun
Sharmilee Vetrivel
Ru Zhang
Stephanie Zopp
Andrea Oßwald
Elisabeth Nowak
Katharina Schilbach
Martin Bidlingmaier
Petra Zimmermann
Felix Beuschlein
Michaela Hartmann
Stefan Wudy
Anna Riester
Martin Reincke

Polymorphism in the Drug Transporter Gene ABCB1 as a Potential Disease Modifier in Cortisol-Producing Adrenal Adenomas.

In: Experimental and Clinical Endocrinology & Diabetes : official journal, German Society of Endocrinology [and] German Diabetes Association vol. 132 pg. 608-613

18.09.2024 (2024)

DOI: 10.1055/a-2408-0718

show abstract

INTRODUCTION Endogenous hypercortisolism presents with variable phenotypes. Etiological factors accounting for the level of hypercortisolism or varying severity of associated comorbidities are lacking. Recently, the adrenal ATP-binding cassette B1 (ABCB1) gene was identified as a modulator of glucocorticoid secretion. OBJECTIVE To evaluate the effect of ABCB1 polymorphism rs2032582 on steroid metabolome and clinical phenotypes in patients with endogenous hypercortisolism. METHODS In this cross-sectional cohort study, 137 patients prospectively enrolled in the German Cushing's registry were included (41 with ACTH-producing pituitary adenoma, 21 with cortisol-producing adrenal adenoma, and 75 with excluded hypercortisolism). In all patients, ABCB1 polymorphism was analyzed using a TaqMan genotyping assay, glucocorticoid metabolite excretion in 24-hour urine samples was analyzed by gas chromatography-mass spectrometry, and the clinical phenotype was assessed systematically. RESULTS In patients with cortisol-producing adrenal adenomas, but not in patients with ACTH-producing pituitary adenomas, homozygous major allele GG of ABCB1 polymorphism rs2032582 was associated with higher overall cortisol metabolite secretion (median 13515 [IQR 10347; 25669] µg/24h vs. 9645 [6146; 10732] µg/24h in minor homo- and heterozygotes, p=0.036) and elevated major cortisol metabolites αTHF, THF and THE (9339 [6929; 17789] µg/24h vs. 6288 [4184; 7455] µg/24h, p=0.045). Moreover, these patients showed higher mean arterial pressure (116 [111; 131] mmHg in major homozygotes vs. 105 [96; 112] mmHg in minor homo- and heterozygotes, p=0.036). CONCLUSION The genotype of drug transporter gene ABCB1 rs2032582 polymorphism is associated with the degree of cortisol metabolite secretion in cortisol-producing adrenal adenomas and could, therefore, represent a modifier of disease severity in this context.

Journal article

A. Giustina
N. Biermasz
F. Casanueva
M. Fleseriu
P. Mortini
C. Strasburger
A. Lely
J. Wass
S. Melmed
G. Banfi
A. Barkan
A. Beckers
M. Bidlingsmaier
C. Boguszewski
et int.
Katharina Schilbach
et al.

Correction: consensus on criteria for acromegaly diagnosis and remission.

In: Pituitary vol. 27 pg. 88

06.12.2023 (2024)

DOI: 10.1007/s11102-023-01373-w

Journal article

Katharina Schilbach
G. Raverot

Does size really matter? A closer look at the absolute size of growth hormone-secreting pituitary adenomas.

In: Pituitary vol. 27 pg. 440-443

30.08.2024 (2024)

DOI: 10.1007/s11102-024-01449-1

Journal article

S. Störmann
S. Meyhöfer
J. Groener
J. Faust
Katharina Schilbach
J. Seufert
B. Vergès

Management of pasireotide-induced hyperglycemia in patients with acromegaly: An experts' consensus statement.

In: Frontiers in Endocrinology vol. 15 pg. 1348990

09.02.2024 (2024)

DOI: 10.3389/fendo.2024.1348990

show abstract

Pasireotide is a somatostatin analogue for the treatment of acromegaly, a chronic condition caused by excess growth hormone. Despite the therapeutic benefits of pasireotide as a second-line treatment for inadequately controlled acromegaly, a major concern is its hyperglycemic side-effect. Here, we provide guidance on how to select appropriate patients with acromegaly for treatment with pasireotide. We summarize baseline characteristics of patients at high risk for pasireotide-associated hyperglycemia and recommend a monitoring strategy based on the risk profile. Self-monitoring of blood glucose levels (SMBG), measurements of fasting plasma glucose (FPG), postprandial plasma glucose (PPG) and regular HbA1c measurements are the foundation of our proposed monitoring approach. The pathophysiology of pasireotide-induced hyperglycemia involves decreased secretion of the incretin hormones GIP (glucose-dependent insulinotropic polypeptide) and GLP-1 (glucagon-like peptide-1). Our expert recommendations address the specific pathophysiology of pasireotide-induced hyperglycemia by recommending the incretin-based therapeutics dipeptidyl peptidase-4 inhibitors (DPP-4i) and glucagon-like peptide-1 receptor agonists (GLP-1 RA) in all appropriate patients as an alternative to first-line monotherapy with metformin. Furthermore, we emphasize the importance of adequate control of acromegaly, excellent diabetes education, nutrition and lifestyle guidance and advise to consult expert diabetologists in case of uncertainty in the management of patients with hyperglycemia under pasireotide.

core competencies

Specialist in internal medicine, endocrinology, diabetology and nutrittional medicine

Forschungs- und Lehrgebiete

Teaching Areas:

Internal Medicine
Endocrinology
Diebetology
Medical history taking and medical interviewing

Research Areas:

rare causes of common diseases
diseases of the pituitary and hypothalamus
growth hormone-dependent diseases