Michal Krsek

Gamma knife radiosurgery for acromegaly – long‐term experience

Objective  The Leksell gamma knife (LGK) is one of the treatment options for pituitary adenomas. We report on our long‐term experience treating acromegaly using LGK.

PLASMA GHRELIN LEVELS IN PATIENTS WITH SHORT BOWEL SYNDROME

Ghrelin is a novel peptide hormone which was identified as an endogenous growth hormone secretagogue. It is mainly secreted in THE stomach, but important sites of its secretion are other parts of the gastrointestinal tract. Ghrelin is thought to be involved not only in regulation of growth hormone secretion but also in regulation of food intake and nutritional status. This study was aimed to investigate the changes in plasma ghrelin levels in patients with short bowel syndrome. Twenty-four patients with malnutrition due to short bowel syndrome and eleven healthy controls were included in the study. They underwent clinical examination and assessment of plasma or serum levels of ghrelin leptin, soluble leptin receptor, IGF-I, IGFBP-1 and IGFBP-3. Plasma ghrelin levels were decreased in patients with short bowel syndrome ( p<0.01). Furthermore, decreased serum levels of IGF-I ( p<0.01) and IGFBP-3 ( p<0.001) were found in patients with short bowel syndrome. Other laboratory differences between both groups were not significant. No relationship between ghrelin and other determined variables was found. We conclude that plasma ghrelin levels are decreased in the group of patients with short bowel syndrome. It is probably because of a decrease in the tissue mass that is able to secrete ghrelin.

Regression of acromegalic left ventricular hypertrophy after lanreotide (a slow-release somatostatin analog)

A group of 13 acromegalic patients was treated with lanreotide for 18 months and followed-up echocardiographically; these patients showed significant correlations between the decrease of both growth hormone (GH) and insulin-like growth factor-1 and the decrease of left ventricular mass index. This documents a regression of left ventricular hypertrophy in acromegaly after lanreotide treatment, the degree of which is dependent on the magnitude of the decrease of GH and insulin-like growth factor-1 serum levels.

Perturbations in adiponectin, leptin and resistin levels in acromegaly: lack of correlation with insulin resistance

background Insulin resistance, impaired glucose tolerance and type 2 diabetes are common in acromegalic subjects. The mechanism underlying this insulin resistance is unclear.

Use of the Leksell gamma knife in the treatment of prolactinoma patients

Objective  Pharmacological treatment with dopaminergic agonists (DA) is the treatment of choice for prolactinomas. Surgical and radiation treatment is also indicated in certain situations. We describe our 12‐year experience in treating prolactinomas with the Leksell gamma knife (LGK).

Adipokine levels in Cushing's syndrome; elevated resistin levels in female patients with Cushing's syndrome

background  Cushings syndrome (CS) is associated with central adiposity, insulin resistance and impaired glucose homeostasis. Adipose tissue is thought to regulates glucose homeostasis via circulating adipokines, such as resistin, leptin and adiponectin, although their role in the insulin resistance associated with CS has not been established.

Plasma ghrelin levels and malnutrition: A comparison of two etiologies

Ghrelin is a peptide hormone that is involved in regulating growth hormone secretion as well as food intake and energy homeostasis. The aim of this study was to compare changes in plasma ghrelin levels in patients with malnutrition due to anorexia nervosa (AN) or short bowel syndrome (SBS). Blood samples for laboratory analyses were taken from 16 AN patients (plus 13 comparable healthy controls) and 27 SBS patients (plus 13 comparable healthy controls) after an overnight fast. In comparison with their respective control groups, plasma ghrelin levels were increased in the AN patients (p<0.05) and significantly decreased in the patients with SBS (p<0.01). These results suggest that quantitative ghrelin secretion in the gut wall is important in determining ghrelin concentrations in the systemic circulation.

The effects of growth hormone status on circulating levels of vascular growth factors

Background  Vascular growth factors are important not only in angiogenesis but also for the maintenance of normal endothelial integrity and function. Elevated levels of vascular endothelial growth factor (VEGF), angiopoietin‐2, hepatocyte growth factor (HGF), endostatin and angiogenin have been associated with endothelial dysfunction and atherosclerosis. Both acromegaly and growth hormone deficiency (GHD) are associated with endothelial dysfunction and changes in blood vessel morphology.

Is it possible to avoid hypopituitarism after irradiation of pituitary adenomas by the Leksell gamma knife

OBJECTIVE Radiation therapy is one of the treatment options for pituitary adenomas. The most common side effect associated with Leksell gamma knife (LGK) irradiation is the development of hypopituitarism. The aim of this study was to verify that hypopituitarism does not develop if the maximum mean dose to pituitary is kept under 15 Gy and to evaluate the influence of maximum distal infundibulum dose on the development of hypopituitarism. DESIGN AND METHODS We followed the incidence of hypopituitarism in 85 patients irradiated with LGK in 1993-2003. The patients were divided in two subgroups: the first subgroup followed prospectively (45 patients), irradiated with a mean dose to pituitary <15 Gy; the second subgroup followed retrospectively 1993-2001 and prospectively 2001-2009 (40 patients), irradiated with a mean dose to pituitary >15 Gy. Serum TSH, free thyroxine, testosterone or 17β-oestradiol, IGF1, prolactin and cortisol levels were evaluated before and every 6 months after LGK irradiation. RESULTS Hypopituitarism after LGK irradiation developed only in 1 out of 45 (2.2%) patients irradiated with a mean dose to pituitary <15 Gy, in contrast to 72.5% patients irradiated with a mean dose to pituitary >15 Gy. The radiation dose to the distal infundibulum was found as an independent factor of hypopituitarism with calculated maximum safe dose of 17 Gy. CONCLUSION Keeping the mean radiation dose to pituitary under 15 Gy and the dose to the distal infundibulum under 17 Gy prevents the development of hypopituitarism following LGK irradiation.

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

OBJECTIVE To evaluate which tests are performed to diagnose hypercortisolism in patients included in the European Registry on Cushings 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 Cushings 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.