MKMichal Kršek

Michal Kršek

*This is an algorithmically generated author record based on publicly available information.

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Previous Organizations / Institutes

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Michal Kršek has a total of 247 co-authors. Here are the top co-authors by number of shared publications:


Latest Publications

  • Thyroid Hormone Treatment for Hypercholesterolemia in Euthyroid Patients: Results From a European Survey of Thyroid Specialists

    by Juan C. Galofré, Juan J. Díez, Roberto Attanasio, Endre V. Nagy, Tomasz Bednarczuk, Enrico Papini, Miloš Žarković, Roberto Negro, Petros Perros, Ersin Akarsu, et al.

    Objective: A relationship among hypothyroidism and lipid disorders is well established. However, current evidence and guidelines do not support the use of thyroid hormones (TH) in euthyroid patients with hyperlipidaemia as potential harms are considerable. This European survey investigated the use of TH in euthyroid patients with severe hypercholesterolemia as a complementary treatment.Design: Data were derived from the THESIS (Treatment of Hypothyroidism in Europe by Specialists) project that surveyed TH use. Univariable and multivariable analyses were used to explore associations.Results: Out of 17,232 invitations, 5695 (33.0%) valid responses were received, and of these, 328 (5.8%) stated that TH are indicated in euthyroid patients with severe hypercholesterolemia. Univariable analyses disclosed significant differences and associations: (a) more non‐endocrinologists (8.9%) than endocrinologist (5.4%) used TH (p < 0.001), (b) the number of hypothyroid patients treated per year was inversely related to use of TH (p = 0.024), (c) members of international endocrine/thyroid societies were more likely to use TH than non‐members (p < 0.001), (d) significant variations by country and geographical region (p < 0.001), and (e) inverse relationship between gross national income per capita (GNIPC) and TH use (p < 0.001). Multivariable analyses yielded significant associations between use of TH, and male gender, specialty and GNIPC (p < 0.001).Conclusions: This study suggests that a small but noteworthy minority of European thyroid specialists may be using TH to treat of severe hypercholesterolemia in euthyroid patients. If confirmed, this finding highlights the importance of raising awareness among thyroid specialists, professional societies, and healthcare providers to ensure adherence to evidence‐based practices.


  • Thyroid hormones for euthyroid patients with simple goiter growing over time: a survey of European thyroid specialists

    by Enrico Papini, Roberto Attanasio, Miloš Žarković, Endre Vezekenyi Nagy, Roberto Negro, Petros Perros, Juan Carlos Galofré, Chagit Adler Cohen, Ersin Akarsu, Maria Alevizaki, et al.

    Background Treatment of simple goiter (SG) growing over time with thyroid hormone (TH) therapy is discouraged by international guidelines. Purpose To ascertain views of European thyroid specialists about TH treatment for euthyroid patients with growing SG and explore associations with management choice. Methods Online survey on the use of TH for growing SG among thyroid experts from 28 European countries. Results The response rate was 31.5% (5430/17,247). Most respondents were endocrinologists. Twenty-eight percent asserted that TH therapy may be indicated in euthyroid patients with a growing SG. National and regional differences were noted, from 7% of positive responses in The Netherlands to 78% in Czech Republic (p < 0.0001). TH was more frequently prescribed by respondents over 40 years old (OR 1.77, 2.13, 2.41 if 41–50, 51–60, >60, respectively), and working in areas of former iodine insufficiency (OR 1.24, 95% CI 1.03–1.50). TH was less frequently prescribed by endocrinologists (OR 0.77, 95% CI 0.62-0.94) and respondents working in Southern Europe (OR 0.40, 95% CI 0.33–0.48), Northern Europe (OR 0.28, 95% CI 0.22–0.36) and Western Asia (OR 0.16, 95% CI 0.11–0.24) compared to Western Europe. Associations with respondents’ sex, country, availability of national thyroid guidelines, and gross national income per capita were absent or weak. Conclusions Almost a third of European thyroid specialists support treating SG with TH, contrary to current guidelines and recommendations. This calls for urgent attention.


  • Open Access

    Treatment of Obesity with Thyroid hormones in Europe. Data from the THESIS* Collaboration

    by J. C. Galofré, J. J. Díez, R. Attanasio, E. V. Nagy, R. Negro, E. Papini, P. Perros, M. Žarković, E. Akarsu, M. Alevizaki, et al.

    Purpose: The use of thyroid hormones (TH) to treat obesity is unsupported by evidence as reflected in international guidelines. We explored views about this practice, and associations with respondent characteristics among European thyroid specialists. Methods: Specialists from 28 countries were invited to a survey via professional organisations. The relevant question was whether “Thyroid hormones may be indicated in biochemically euthyroid patients with obesity resistant to lifestyle interventions”. Results: Of 17,232 invitations 5695 responses were received (33% valid response rate; 65% women; 90% endocrinologists). Of these, 290 (5.1%) stated that TH may be indicated as treatment for obesity in euthyroid patients. This view was commoner among non-endocrinologists (8.7% vs. 4.7%, p < 0.01), private practice (6.5% vs. 4.5%, p < 0.01), and varied geographically (Eastern Europe, 7.3%; Southern Europe, 4.8%; Western Europe, 2.7%; and Northern Europe, 2.5%). Respondents from Northern and Western Europe were less likely to use TH than those from Eastern Europe (p < 0.01). Gross national income (GNI) correlated inversely with this view (OR 0.97, CI: 0.96–0.97; p < 0.001). Having national guidelines on hypothyroidism correlated negatively with treating obesity with TH (OR 0.71, CI: 0.55–0.91). Conclusions: Despite the lack of evidence, and contrary to guidelines’ recommendations, about 5% of respondents stated that TH may be indicated as a treatment for obesity in euthyroid patients resistant to life-style interventions. This opinion was associated with (i) respondent characteristics: being non-endocrinologist, working in private practice, treating a small number of hypothyroid patients annually and (ii) national characteristics: prevalence of obesity, Eastern Europe, low GNI and lack of national hypothyroidism guidelines.


  • Use of levothyroxine for euthyroid, thyroid antibody positive women with infertility: Analyses of aggregate data from a survey of European thyroid specialists (Treatment of Hypothyroidism in Europe by Specialists: An International Survey)

    by Roberto Negro, Miloš Žarković, Roberto Attanasio, Laszlo Hegedüs, Endre V. Nagy, Enrico Papini, Ersin Akarsu, Maria Alevizaki, Göksun Ayvaz, Tomasz Bednarczuk, et al.

    Objectives: The use of levothyroxine (LT4) treatment aiming to improve fertility in euthyroid women with positive thyroid peroxidase antibodies (TPOAb) is not supported by the available evidence. The aim of the study was to document the use of LT4 by European thyroid specialists in such patients.Design: The data presented derive from Treatment of Hypothyroidism in Europe by Specialists, an International Survey (THESIS), a questionnaire conducted between 2019 and 2021 to document the management of hypothyroidism by European thyroid specialists. Here, we report the aggregate results on the use of LT4 in infertile, euthyroid women with positive TPOAb.Results: A total of 2316/5406 (42.8%) respondents stated that LT4 may be indicated in TPOAb positive euthyroid women with infertility. The proportion of those replying positively to this question varied widely across different countries (median 39.4, range 22.9%–83.7%). In multivariate analyses males (OR: 0.8; CI: 0.7–0.9) and respondents >60 years (OR: 0.7; 0.6–0.8) were the least inclined to consider LT4 for this indication. Conversely, respondents managing many thyroid patients (“weekly” [OR: 1.4; CI: 1.0–1.9], “daily” [OR: 1.8; CI: 1.3–2.4]) and practicing in Eastern Europe (OR: 1.5; CI: 1.3–1.9) were most likely to consider LT4.Conclusions: A remarkably high number of respondents surveyed between 2019 and 2021, would consider LT4 treatment in TPOAb positive euthyroid women with infertility. This view varied widely across countries and correlated with sex, age and workload, potentially influencing patient management. These results raise concerns about potential risks of overtreatment.


  • Diagnostic tests for Cushing's syndrome differ from published guidelines: data from ERCUSYN

    by Elena Valassi, Holger Franz, Thierry Brue, Richard A Feelders, Romana Netea-Maier, Stylianos Tsagarakis, Susan M Webb, Maria Yaneva, Martin Reincke, Michael Droste, et al.

    Objective: To evaluate which tests are performed to diagnose hypercortisolism in patients included in the European Registry on Cushing’s syndrome (ERCUSYN), and to examine if their use differs from the current guidelines. Patients and methods: We analyzed data on the diagnostic tests performed in 1341 patients with Cushing’s syndrome (CS) who have been entered into the ERCUSYN database between January 1, 2000 and January 31, 2016 from 57 centers in 26 European countries. Sixty-seven percent had pituitary-dependent CS (PIT-CS), 24% had adrenal-dependent CS (ADR-CS), 6% had CS from an ectopic source (ECT-CS) and 3% were classified as having CS from other causes (OTH-CS). Results: Of the first-line tests, urinary free cortisol (UFC) test was performed in 78% of patients, overnight 1 mg dexamethasone suppression test (DST) in 60% and late-night salivary cortisol (LSaC) in 25%. Use of LSaC increased in the last five years as compared with previous years (P < 0.01). Use of HDDST was slightly more frequent in the last 5 years as compared with previous years (P < 0.05). Of the additional tests, late-night serum cortisol (LSeC) was measured in 62% and 48-h 2 mg/day low-dose dexamethasone suppression test (LDDST) in 33% of cases. ACTH was performed in 78% of patients. LSeC and overnight 1 mg DST supported the diagnosis of both PIT-CS and ADR-CS more frequently than UFC (P < 0.05). Conclusions: Use of diagnostic tests for CS varies across Europe and partly differs from the currently available guidelines. It would seem pertinent that a European consensus be established to determine the best diagnostic approach to CS, taking into account specific inter-country differences with regard to the availability of diagnostic tools.


  • Magnetic resonance imaging and histology correlation in Cushing's disease

    by Václav Masopust, David Netuka, Vladimír Beneš, Martin Májovský, Tomáš Belšán, Ondřej Bradáč, Daniel Hořínek, Mikuláš Kosák, Václav Hána, Michal Kršek

    We continuously look for new techniques to improve the radicality of resection and to eliminate the negative effects of surgery. One of the methods that has been implemented in the perioperative management of Cushing's disease was the combination of three magnetic resonance imaging (MRI) sequences: SE, SPGR and fSPGR. We enrolled 41 patients (11 males, 30 females) diagnosed with Cushing's disease. A 3D tumour model with a navigation console was developed using each SPGR, fSPGR and SE sequence. The largest model was then used. In all cases, a standard four-handed, bi-nostril endoscopic endonasal technique was used. Endocrinological follow-up evaluation using morning cortisol sampling was performed for 6-34 months in our study. In total, 36 patients (88%) were disease-free following surgery. Our results indicate we achieved 100% sensitivity of MR. Overall, the conformity of at least one donor site, as compared with the places designated on MR, was in 78% of patients. We searched the place of compliance in individual locations. There is a consensus in individual locations in 63 of the 123 cases (or 56%). The correlation gamma function at a 5% significance level was then 0.27. The combination of MR sequences (SE, SPGR, fSPGR), neuronavigation system and iMRI led to increased sensitivity of up to 100%. Specificity reached 56% in our study. We found a high success rate in surgical procedure in terms of the correlation between MR findings and histology, which leads to remission of Cushing's disease.


    • 1 July 2016
      • Vol. 37  (3) , 233-238

    The role of early cortisol level in the assessment of the radicality of resection in central Cushing's disease.

    by Vaclav Masopust, David Netuka, Daniel Horinek, Mikulas Kosak, Vaclav Hana, Michal Krsek

    To increase radicality and avoid surgical complications new treatment options are under investigation. One of the promising possibilities is to assess early morning cortisol levels on the first and second postoperative day. We enrolled 34 patients (9 males, 25 females) diagnosed with Cushing's disease. Blood samples to determine cortisol level were taken always at 06:00 and sent to the lab. The samples were taken on the first and second postoperative day. For all patients, standard four-handed, a bi-nostril endoscopic endonasal technique was used. Endocrinological follow-up (6-34 months) was performed using morning cortisol sampling. In total, 36 patients (88%) were disease-free post-surgery. In the group with early postoperative levels of morning cortisol of less than 463 nmol/L, only 2 of 29 patients (7%) exceeded the final morning level of cortisol at follow-up. In patients with early postoperative cortisol levels between 17 nmol/l and 234 nmol/l all subjects showed normal postoperative cortisol levels. In 30 of 34 patients (88%), the level of cortisol was within normal limits. The prediction importance of early measurement of cortisol is 93% for patients with early postoperative cortisol levels of less than 463 nmol/L. The prediction importance of early measurement of cortisol is 100% for patients with early postoperative cortisol levels from 17 to 234 nmol/L. The monitoring of early morning cortisol levels seems to be an important tool in the management of central Cushing's disease.

  • Intraoperative Magnetic Resonance Imaging During Endoscopic Transsphenoidal Surgery of Growth Hormone-Secreting Pituitary Adenomas

    by David Netuka, Martin Májovský, Václav Masopust, Tomáš Belšán, Josef Marek, Michal Kršek, Václav Hána, Jana Ježková, Vladimír Beneš


  • Prolactin response to an acute bromocriptine suppression test (ABST) following surgical debulking of macroprolactinomas

    by Lora Kirigin, Mateja Strinović, Gorana Mirošević, Darko Stipić, Vatroslav Čerina, Jana Ježková, Ludmila Brunerova, Michal Kršek, Milan Vrkljan

  • The Possible Role of mRNA Expression Changes of GH/IGF-1/Insulin Axis Components in Subcutaneous Adipose Tissue in Metabolic Disturbances of Patients With Acromegaly

    by V. Touskova, J. Klouckova, V. Durovcova, Z. Lacinova, P. Kavalkova, P. Trachta, M. Kosak, M. Mraz, D. Haluzikova, V. Hana, et al.

    We explored the effect of chronically elevated circulating levels of growth hormone (GH)/insulin-like-growth-factor-1 (IGF-1) on mRNA expression of GH/IGF-1/insulin axis components and p85alpha subunit of phosphoinositide-3-kinase (p85alpha) in subcutaneous adipose tissue (SCAT) of patients with active acromegaly and compared these findings with healthy control subjects in order to find its possible relationships with insulin resistance and body composition changes. Acromegaly group had significantly decreased percentage of truncal and whole body fat and increased homeostasis model assessment-insulin resistance (HOMA-IR). In SCAT, patients with acromegaly had significantly increased IGF-1 and IGF-binding protein-3 (IGFBP-3) expression that both positively correlated with serum GH. P85alpha expression in SCAT did not differ from control group. IGF-1 and IGFBP-3 expression in SCAT were not independently associated with percentage of truncal and whole body fat or with HOMA-IR while IGFBP-3 expression in SCAT was an independent predictor of insulin receptor as well as of p85alpha expression in SCAT. Our data suggest that GH overproduction in acromegaly group increases IGF-1 and IGFBP-3 expression in SCAT while it does not affect SCAT p85alpha expression. Increased IGF-1 or IGFBP-3 in SCAT of acromegaly group do not appear to contribute to systemic differences in insulin sensitivity but may have local regulatory effects in SCAT of patients with acromegaly.