Aleksandra Kendereski

Growth hormone secretion after the administration of GHRP-6 or GHRH combined with GHRP-6 does not decline in late adulthood

OBJECTIVE Growth hormone (GH) secretion in middle and late adulthood declines with age. However, the precise mechanisms causing this impairment in OH release are unknown. HIs‐D‐Trp‐Ala‐Trp‐D‐Phe‐Lys‐NH2(GHRP‐6) Is a synthetic compound that releases OH in a dose related and specific manner in several species, including man. In order to gain a further Insight Into disrupted GH secretion in late adulthood, we evaluated GH responses to GHRP‐6 or GHRH, administered either alone or in combination, in healthy young and late adulthood groups of subjects.

Leptin levels and insulin sensitivity in obese and non-obese patients with polycystic ovary syndrome

The study was conducted to assess leptin levels and insulin sensitivity in obese and non-obese patients with polycystic ovary syndrome (PCOS). Twenty-two women with PCOS and 19 control healthy women were included in the study, divided into obese and non-obese groups. Leptin was determined using Linco Research radio-immunoassay while insulin sensitivity was calculated from intravenous glucose tolerance tests with frequent blood sampling using MINMOD analysis. Significantly higher basal leptin levels were found in obese compared to non-obese PCOS (31.76 +/- 3.06 vs. 10.42 +/- 2.31 ng/ml; p < 0.05) as well as in obese in comparison to non-obese controls (29.16 +/- 5.06 vs 8.51 +/- 0.88 ng/ml; p < 0.05). A negative correlation was found between insulin sensitivity and leptin levels in both obese (r = -0.2480; p > 0.05) and non-obese PCOS groups (r = -0.4620; p > 0.05). In conclusion, high serum leptin, insulin and testosterone levels together with reduced insulin sensitivity were found in obese PCOS women, suggesting that high leptin levels could be a characteristic of the obese PCOS phenotype.

Hypopituitarism as a late complication of hemorrhagic fever.

We report three patients who developed hypopituitarism as a late complication of hemorrhagic fever with renal syndrome (HFRS). Their past history, physical examination, and endocrine investigation confirmed hypopituitarism. Magnetic resonance imaging of the pituitary revealed atrophic pituitary gland with an empty sella. Hemorrhagic fever is endemic in certain regions of the Balkans, and this preliminary report suggests the importance of investigating the endocrine status in every patient who survived HFRS.

Total ghrelin levels during acute insulin infusion in patients with polycystic ovary syndrome

Controversial data were reported concerning fasting ghrelin (decreased, normal or elevated) in polycystic ovary syndrome (PCOS). The aim of our study was to clarify ghrelin levels in non-obese, overweight, and obese PCOS patients; to investigate the effect of acute insulin infusion on ghrelin in PCOS as a chronic insulin-resistant state, with and without the impact of obesity, and to examine ghrelin-androgen interaction. In that order, we evaluated 1) ghrelin levels among 8 non-obese patients with PCOS [body mass index (BMI): 20.52±1.31 kg/m2], 8 overweight and obese patients with PCOS (BMI: 34.36±6.53 kg/m2) and their respective controls, 2) ghrelin suppression during euglycemic hyperinsulinemic clamp, and 3) ghrelin-androgen interrelationship. After overnight fast, 2-h euglycemic hyperinsulinemic clamp, was performed in all investigated women. Fasting ghrelin was significantly lower in non-obese PCOS than in controls (64.74±25.69 vs 108.36±52.60; p<0.05) as well as in overweight and obese PCOS in comparison with controls (38.71 ± 14.18 vs 98.77± 40.49; p<0.05). Insulin infusion significantly suppressed ghrelin in all subgroups of investigated women. Analysis of variance for repeatable measures confirmed that there was no significant difference in pattern of response between PCOS and controls. In conclusion, women with PCOS had lower fasting ghrelin and decreased insulin sensitivity independently of their BMI, compared to the controls. In addition, there were no differences between fasting ghrelin levels among non-obese, overweight, and obese women with PCOS. During euglycemic hyperinsulinemic clamp, ghrelin decreased in all studied groups to a similar extent, implying that, compared to chronic hyperinsulinemia, acute hyperinsulinemia reduces ghrelin levels independently of the degree of insulin resistance.

Immunological resistance to human biosynthetic insulin--effects of immunosuppression and plasmapheresis.

A 55-year-old gentleman, after being treated for a short time with a diet and with Chlorpropamide, was switched to purified porcine insulin due to ketonuria and ketoacidosis. After a year the patient developed immunological insulin resistance (mean daily insulin dose: 3.72 U/kg body weight; anti-insulin antibodies 78%). In order to lower anti-insulin antibodies human recombinant DNA insulin was introduced into further therapy. Contrary to expectations, the patient did not reduce whatsoever his anti-insulin antibodies and his daily insulin dose increased up to 5.63 U/kg body weight. Introduction of combined immunosuppressive therapy (prednisone plus azathioprine) together with plasmapheresis resulted in rapid lowering of daily insulin requirement and reduction in anti-insulin antibodies. Immunosuppressive therapy was continued with 10 mg of prednisone and a year later the patients insulin daily requirement was 0.66 U/kg BW while his antibodies were 18%. The possible causes of insulin resistance to human recombinant DNA insulin are discussed as well as the advantage of combined immunosuppressive therapy together with plasmapheresis that was used for rapid lowering of insulin daily requirement and anti-insulin antibodies titer.

The sequential administration of growth hormone‐releasing hormone followed 120 minutes later by hexarelin, as an effective test to assess the pituitary GH reserve in man

OBJECTIVE GH deficiency, either in children or in adults, is a clinically relevant problem. The diagnosis is based on dynamic tests of GH secretion, which are clear cut on a group basis but highly problematic for individual diagnosis. The controversy surrounding the diagnosis of GH deficiency reflects the absence of a gold standard dynamic test. The synthetic hexapeptide hexarelin and GHRH stimulate GH secretion using different mechanisms. A sequential test has been devised using the administration of GHRH as first stimulus followed 120 minutes later by hexarelin. The two aims of the study were (a) to evaluate the interaction of GHRH and hexarelin, and (b) to devise a sequential test of GH reserve.

Ectopic calcitonin secretion in a woman with large cell neuroendocrine lung carcinoma

OBJECTIVE: Serum calcitonin (CT) is a sensitive but not specific marker for medullary thyroid carcinoma (MTC). There are a large number of conditions that may elevate CT levels. CASE REPORT: Herein we present the case of a 47-year old woman with Hashimoto thyroiditis, goiter, cervical lymphadenopathy and high CT and CEA levels. After surgical extirpation of the lymph node neuroendocrine cancer metastasis was suspected. Computed tomography of the chest showed a tumor mass on the right lung. Bronchoscopy was performed and pathological and immunohistochemical analysis revealed large cell neuroendocrine lung cancer (LCNEC). After chemotherapy, significant reduction of tumor mass was achieved with a moderate decrease in CT levels in parallel. CONCLUSIONS: We present a female with LCNEC, a condition which is usually observed in older men (7th decade) and is not associated with CT secretion. Hashimoto thyroiditis is associated with increased incidence of different types of cancers (e.g. thyroid, colon). No reports at present exist on the incidence of lung cancers in patients with thyroid disease.

The effect of parathyroidectomy on insulin sensitivity in patients with primary hyperparathyroidism - an never ending story?

Previous studies demonstrated insulin resistance and increased prevalence of impaired glucose tolerance and type 2 diabetes mellitus in patients with primary hyperparathyroidism (PHPT). The effect of curative parathyroidectomy on insulin sensitivity was associated with conflicting results depending on which method for measuring the insulin sensitivity has been used. There was no improvement using HOMA and QUICKI while minimal model demonstrated significant improvement in insulin sensitivity. The aim of our study was to evaluate the insulin sensitivity before and after parathyroidectomy in patients with PHPT using a euglycemic clamp. 44 patients with PHPT and 11 age and body mass index matched healthy controls participated in study protocol. Before surgery M values and HOMA IR suggest insulin resistance in patients with PHPT. There was no difference in M index (3.74±1.89 vs. 4.62±2.27, p>0.05), HOMA IR (2.94±1.39 vs. 3.29±0.81, p>0.05), AUC glucose (863.0±261.3 vs. 842.3±165.5, p>0.05), AUC insulin (7068.7±4159.0 vs. 7229.6±2581.7, p>0.05), ISI (4.73±2.77 vs. 4.25±2.94, p>0.05) and AIR (47.89±32.05 vs. 38.96±21.20, p>0.05) between patients with PHPT and HC. There was significant improvement in insulin sensitivity after parathyroidectomy but both preoperative and postoperative M values were not significantly different in comparison to HC. There were no significant changes in HOMA IR, AUC glucose, AUC insulin, ISI and AIR before and after therapy. In conclusion, we observed significant improvement in insulin sensitivity after parathyroidectomy in patients with PHPT. There was no difference in parameters of insulin secretion before and after parathyroidectomy in patients with PHPT.

Pitfalls in diagnosing a small cystic insulinoma: a case report

Insulinoma is a rare pancreatic endocrine tumour and is typically sporadic and solitary. Over 90% of all insulinomas are benign. Cystic insulinomas are also rare. It is not difficult to determine the site of such neoplasm, as cystic insulinomas are usually 4–10 cm in diameter. We present the case of a patient with a histologically confirmed cystic insulinoma diagnosed after approximately 10 years of hypoglycaemia symptoms. This case is unique because of the small size (2.2 cm) of the tumour. Endoscopic ultrasound (EUS) was useful for localizing this tumour.

Low leptin level in an obese hyperandrogenic woman – potential marker for androgen-secreting tumor

Hyperandrogenism in postmenopausal women is due to ovarian hyperthecosis or an androgen-secreting ovarian/adrenal tumor. Making the correct diagnosis might be complicated due to the possible existence of an adrenal neoplasm secreting testosterone only, ectopic ovarian tissue or ectopic luteinizing hormone/human chorionic gonadotropin receptors in the adrenals, as well as the relatively low sensitivity of imaging techniques (computed tomography, magnetic resonance imaging) and vein catheterization for this type of pathology. We present the case of an obese postmenopausal woman with metabolic syndrome, hyperandrogenism (high testosterone levels, suppressed gonadotropins), adrenal macronodular hyperplasia and Leydig-cell ovarian tumor. At presentation she had low leptin levels despite high body fat content. After a catheter study left adrenalectomy was carried out but hyperandrogenism persisted. Then, bilateral oophorectomy with hysterectomy was performed and a small Leydig-cell tumor was found in the left ovary. Postoperatively, testosterone and gonadotropin levels were normal (postmenopausal) and leptin level became elevated without change in body mass index or body fat content. In conclusion, we speculate that low leptin levels in obese hyperandrogenic women might be a marker for androgen-secreting tumors.