The interplay between prolactin and cardiovascular disease.

Hyperprolactinemia can be caused by several conditions and its effects on the hypothalamic-pituitary-gonadal axis are understood in more detail. Nevertheless, in recent decades, other metabolic effects have been studied and data pointed to a potential increased cardiovascular disease (CVD) risk. A recent study showed a decrease in total and LDL- cholesterol only in men with prolactinoma treated with dopamine agonists (DA) supporting the previous results of a population study with increased CVD risk in men harboring prolactinoma. However, other population studies did not find a correlation between prolactin (PRL) levels and CVD risk or mortality. There is also data pointing to an increase in high-density lipoprotein levels, and decreases in triglycerides, carotid-intima-media thickness, C-reactive protein, and homocysteine levels in patients with prolactinoma on DA treatment. PRL was also implicated in endothelial dysfunction in pre and postmenopausal women. Withdrawal of DA resulted in negative changes in vascular parameters and an increase in plasma fibrinogen. It has been shown that PRL levels were positively correlated with blood pressure and inversely correlated with dilatation of the brachial artery and insulin sensitivity, increased homocysteine levels, and elevated D-dimer levels. Regarding possible mechanisms for the association between hyperprolactinemia and CVD risk, they include a possible direct effect of PRL, hypogonadism, and even effects of DA treatment, independently of changes in PRL levels. In conclusion, hyperprolactinemia seems to be associated with impaired endothelial function and DA treatment could improve CVD risk. More studies evaluating CVD risk in hyperprolactinemic patients are important to define a potential indication of treatment beyond hypogonadism.

Brazilian multicenter study on pegvisomant treatment in acromegaly.

OBJECTIVE: Investigate the therapeutic response of acromegaly patients to pegvisomant (PEGV) in a real-life, Brazilian multicenter study. SUBJECTS AND METHODS: Characteristics of acromegaly patients treated with PEGV were reviewed at diagnosis, just before and during treatment. All patients with at least two IGF-I measurements on PEGV were included. Efficacy was defined as any normal IGF-I measurement during treatment. Safety data were reviewed. Predictors of response were determined by comparing controlled versus uncontrolled patients. RESULTS: 109 patients [61 women; median age at diagnosis 34 years; 95.3% macroadenomas] from 10 Brazilian centers were studied. Previous treatment included surgery (89%), radiotherapy (34%), somatostatin receptor ligands (99%), and cabergoline (67%). Before PEGV, median levels of GH, IGF-I and IGF-I % of upper limit of normal were 4.3 µg/L, 613 ng/mL, and 209%, respectively. Pre-diabetes/diabetes was present in 48.6% and tumor remnant in 71% of patients. Initial dose was 10 mg/day in all except 4 cases, maximum dose was 30 mg/day, and median exposure time was 30.5 months. PEGV was used as monotherapy in 11% of cases. Normal IGF-I levels was obtained in 74.1% of patients. Glycemic control improved in 56.6% of patients with pre-diabetes/diabetes. Exposure time, pre-treatment GH and IGF-I levels were predictors of response. Tumor enlargement occurred in 6.5% and elevation of liver enzymes in 9.2%. PEGV was discontinued in 6 patients and 3 deaths unrelated to the drug were reported. CONCLUSIONS: In a real-life scenario, PEGV is a highly effective and safe treatment for acromegaly patients not controlled with other therapies.

Brazilian multicenter study on pegvisomant treatment in acromegaly

ABSTRACT Objective Investigate the therapeutic response of acromegaly patients to pegvisomant (PEGV) in a real-life, Brazilian multicenter study. Subjects and methods Characteristics of acromegaly patients treated with PEGV were reviewed at diagnosis, just before and during treatment. All patients with at least two IGF-I measurements on PEGV were included. Efficacy was defined as any normal IGF-I measurement during treatment. Safety data were reviewed. Predictors of response were determined by comparing controlled versus uncontrolled patients. Results 109 patients [61 women; median age at diagnosis 34 years; 95.3% macroadenomas] from 10 Brazilian centers were studied. Previous treatment included surgery (89%), radiotherapy (34%), somatostatin receptor ligands (99%), and cabergoline (67%). Before PEGV, median levels of GH, IGF-I and IGF-I % of upper limit of normal were 4.3 µg/L, 613 ng/mL, and 209%, respectively. Pre-diabetes/diabetes was present in 48.6% and tumor remnant in 71% of patients. Initial dose was 10 mg/day in all except 4 cases, maximum dose was 30 mg/day, and median exposure time was 30.5 months. PEGV was used as monotherapy in 11% of cases. Normal IGF-I levels was obtained in 74.1% of patients. Glycemic control improved in 56.6% of patients with pre-diabetes/diabetes. Exposure time, pre-treatment GH and IGF-I levels were predictors of response. Tumor enlargement occurred in 6.5% and elevation of liver enzymes in 9.2%. PEGV was discontinued in 6 patients and 3 deaths unrelated to the drug were reported. Conclusions In a real-life scenario, PEGV is a highly effective and safe treatment for acromegaly patients not controlled with other therapies.

The impact of sleep apnea treatment on carbohydrate metabolism in patients with acromegaly.

Sleep Apnea is highly prevalent and may contribute to insulin resistance in patients with acromegaly. The primary aim of this study was to assess the impact of sleep apnea treatment with a continuous positive air pressure (CPAP) device on insulin resistance evaluated by hyperinsulinemic euglycemic clamp (HEC). A prospective, randomized, open label, placebo-controlled, crossover study was performed at a tertiary outpatient pituitary center. Twelve acromegalic subjects on somatostatin analogs (SA) with a recent diagnosis of moderate to severe sleep apnea were randomized to CPAP therapy or to nasal dilator adhesive (NDA) with placebo effect for 3 months and then crossed over for another 3 months period without washout. Assessment of HEC, mathematical insulin resistance indexes (HOMA, HOMA2 and QUICKI), GH, IGF-1, HbA1c and free fat acids were performed. A significant reduction on insulin resistance was demonstrated by HEC at the end of the study in patients on CPAP (HEC, pre- and post-CPAP: 4.27 vs. 6.10 mg/Kg/min, P = 0.032). This reduction was not observed in NDA group (HEC, pre- and post-adhesive: 5.53 vs. 5.19 mg/Kg/min, P = 0.455). There was no significant difference on HbA1c or on peripheral insulin resistance indexes in both treatments. CPAP promoted a significant increase on peripheral insulin sensitivity in acromegalic patients with moderate to severe sleep apnea on SA use. Our results support the concept that sleep apnea plays an important role on glucose metabolism. Insulin resistance indexes were unable to detect this finding.

Tumores hipofisários secretores de TSH: relato de dois casos e revisão da literatura / TSH-secreting pituitary tumors: two case reports and literature review

INTRODUÇÃO: Tumores hipofisários secretores de hormônio estimulante da tireoide (TSH), tireotropinomas, são raros e correspondem a menos de 2 por cento de todos os adenomas da hipófise. Manifestam-se clinicamente com sintomas e sinais de tireotoxicose, eventualmente associados a sintomas compressivos, sobretudo visuais, devido ao efeito de massa do tumor. Esses tumores se caracterizam pela presença de níveis séricos elevados de hormônios tireoidianos e níveis séricos elevados, ou inapropriadamente normais, de TSH. Frequentemente, ao diagnóstico, há relato de tratamento prévio cirúrgico, medicamentoso e/ou ablativo, por hipótese de hipertireoidismo primário por doença de Graves. OBJETIVO: Relatar dois casos de tireotropinomas acompanhados na Unidade de Neuroendocrinologia do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo (HC-FMUSP) e revisar a literatura visando ao manejo desta afecção. CONCLUSÃO: Na presença de hormônios tireoidianos elevados e níveis de TSH inapropriadamente normais ou elevados, a possibilidade de adenoma hipofisário produtor de TSH deve ser considerada com vistas à realização da terapia adequada.

INTRODUCTION: TSH-secreting pituitary adenomas are rare pituitary functioning tumors accounting for less than 2 percent of the pituitary adenomas. The clinical feature consists of thyrotoxicosis occasionally associated to tumoral symptoms due to mass effect. The biochemical feature consists of elevated thyroid hormones levels and normal or high TSH concentrations. This disease is often wrongly diagnosed as Grave's disease, and the ablative therapy is frequently conducted prior to the diagnosis. OBJECTIVE: To report two cases followed in the Neuroendocrine Unit of Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo and to review the literature aiming at the management of this affection. CONCLUSION: In the presence of elevated thyroid hormone levels associated with inappropriate normal or increased TSH levels, the possibility of a TSH-secreting pituitary adenoma should be considered for the proper medical treatment.

[TSH-secreting pituitary tumors: two case reports and literature review]. / Tumores hipofisários secretores de TSH: relato de dois casos e revisão da literatura.

INTRODUCTION: TSH-secreting pituitary adenomas are rare pituitary functioning tumors accounting for less than 2% of the pituitary adenomas. The clinical feature consists of thyrotoxicosis occasionally associated to tumoral symptoms due to mass effect. The biochemical feature consists of elevated thyroid hormones levels and normal or high TSH concentrations. This disease is often wrongly diagnosed as Grave's disease, and the ablative therapy is frequently conducted prior to the diagnosis. OBJECTIVE: To report two cases followed in the Neuroendocrine Unit of Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo and to review the literature aiming at the management of this affection. CONCLUSION: In the presence of elevated thyroid hormone levels associated with inappropriate normal or increased TSH levels, the possibility of a TSH-secreting pituitary adenoma should be considered for the proper medical treatment.

Absence of effects of long-term growth hormone replacement therapy on insulin sensitivity in adults with growth hormone deficiency of childhood-onset (GHDA-CO).

In order to assess long-term efficacy and safety of GH therapy in GHDA-CO, we studied 20 patients (8 female, 12 male; mean age 24.6+/-6.2 years) treated with GH for up to 24 months. The assessment (IGF-1, IGFBP3, lipid profile, body composition, glycated hemoglobin, oral glucose tolerance test, ISI-HOMA and ISI-composite derived from OGTT) was carried out before GH and every 3 months during the first year of treatment, and then every 6 months. We observed a significant increase of IGF-1, lean mass and HDL levels and a decrease in LDL levels. Fasting glucose presented a significant increase, within the normal range, after 6 months, returning to pre-treatment levels at 9 months with no further alteration. Fasting insulin, the areas under the glucose and insulin curves, ISI-HOMA and ISI-composite did not vary significantly. We conclude that long-term GH therapy improved body composition and lipid profile, without altering ISI in this cohort of patients with GHDA-CO.