PREDICTIVE MARKERS FOR POSTSURGICAL MEDICAL MANAGEMENT OF ACROMEGALY: A SYSTEMATIC REVIEW AND CONSENSUS TREATMENT GUIDELINE.

Objective: To clarify the selection of medical therapy following transsphenoidal surgery in patients with acromegaly, based on growth hormone (GH)/insulin-like growth factor 1 (IGF-1) response and glucometabolic control. Methods: We carried out a systematic literature review on three of the best studied and most practical predictive markers of the response to somatostatin analogues (SSAs): somatostatin receptor (SSTR) expression, tumor morphologic classification, and T2-weighted magnetic resonance imaging (MRI) signal intensity. Additional analyses focused on glucose metabolism in treated patients. Results: The literature survey confirmed significant associations of all three factors with SSA responsiveness. SSTR expression appears necessary for the SSA response; however, it is not sufficient, as approximately half of SSTR2-positive tumors failed to respond clinically to first-generation SSAs. MRI findings (T2-hypo-intensity) and a densely granulated phenotype also correlate with SSA efficacy, and are advantageous as predictive markers relative to SSTR expression alone. Glucometabolic control declines with SSA monotherapy, whereas GH receptor antagonist (GHRA) monotherapy may restore normoglycemia. Conclusion: We propose a decision tree to guide selection among SSAs, dopamine agonists (DAs), and GHRA for medical treatment of acromegaly in the postsurgical setting. This decision tree employs three validated predictive markers and other clinical considerations, to determine whether SSAs are appropriate first-line medical therapy in the postsurgical setting. DA treatment is favored in patients with modest IGF-1 elevation. GHRA treatment should be considered for patients with T2-hyperintense tumors with a sparsely granulated phenotype and/or low SSTR2 staining, and may also be favored for individuals with diabetes. Prospective analyses are required to test the utility of this therapeutic paradigm. Abbreviations: DA = dopamine agonist; DG = densely granulated; GH = growth hormone; GHRA = growth hormone receptor antagonist; HbA1c = glycated hemoglobin; IGF-1 = insulin-like growth factor-1; MRI = magnetic resonance imaging; SG = sparsely granulated; SSA = somatostatin analogue; SSTR = somatostatin receptor.

Infrasellar pituitary gangliocytoma causing Cushing's syndrome.

INTRODUCTION: Pituitary gangliocytomas are uncommon neuronal tumours that may present with endocrine disorders, the most frequent being acromegaly caused by growth hormone hypersecretion. Cushing's syndrome is very rarely seen with gangliocytomas. MATERIAL AND METHODS: We report the unique case of a 62 year-old woman whose clinical picture and endocrine testing clearly demonstrated adrenocorticotropin (ACTH)-dependent Cushing's syndrome. Pituitary magnetic resonance imaging showed a 12-mm homogeneous, infra- and retrosellar mass first diagnosed as pituitary macroadenoma. Transsphenoidal surgery was performed and allowed complete resection of the tumour with sparing of normal anterior pituitary. Very low postoperative serum cortisol and ACTH levels were observed in the early postoperative period and the patient is still in remission 18 months after surgery, thus demonstrating that the resected lesion was entirely responsible for the clinical picture. RESULTS: Histological and immunocytochemical analyses demonstrated a benign tumour composed of mature neuronal cells suggestive of a gangliocytoma, expressing both ACTH and corticotropin-releasing hormone (CRH). The tumour was surrounded by a rim of pituitary tissue containing ACTH-producing endocrine cells. Careful analysis of the resected lesion did not reveal any pituitary microadenoma. We search literature for similar cases and retraced only nine cases of gangliocytomas associated with Cushing's syndrome. In most of them, the tumour was combined with either pituitary corticotroph adenoma or hyperplasia. CONCLUSIONS: Our case represents a unique case of an infrasellar pituitary gangliocytoma which was able to cause Cushing's syndrome by both direct ACTH production and CRH-induced stimulation of neighbour normal corticotroph cells.

Outcome of prolactinoma after pregnancy and lactation: a study on 73 patients.

CONTEXT: Prolactinoma is the most frequent pituitary tumour among women of child-bearing age. Only a few studies have addressed the outcome of prolactinoma after pregnancy. OBJECTIVE: To study remission, defined as prolactin normalization without medical treatment, after pregnancy and lactation in women with prolactinoma. PATIENTS AND METHODS: A retrospective study conducted in 2 Belgian academic centres including 73 patients (54 microprolactinomas and 19 macroprolactinomas) with 104 pregnancies continuing beyond first trimester. Dopamine agonists were stopped in early pregnancy in all treated cases. Prolactin level and adenoma size at pituitary magnetic resonance imaging (MRI) were recorded before pregnancy and throughout follow-up. RESULTS: Thirty of 73 women (41%) were in remission after a median follow-up of 22 months after delivery or cessation of lactation. Adenoma size at diagnosis was smaller in women in remission (5 vs 8 mm). There was a nonsignificant higher rate of remission for microprolactinomas than for macroprolactinoma (46% vs 26%). The first pituitary MRI after pregnancy and lactation showed no tumour and a decreased adenoma size in 23% and 39% of women, respectively. MRI normalization was associated with remission. The number of pregnancies per woman as well as breastfeeding and its duration did not influence remission rate. CONCLUSION: More than 40% of women with previous diagnosis of prolactinoma have normal PRL level without medical treatment for a median follow-up of 22 months after pregnancy and lactation. The likelihood of remission is associated with a smaller initial adenoma size and normalization of pituitary MRI after pregnancy.

Age differences in expectations and readiness regarding lifestyle modifications in individuals at high risk of diabetes.

OBJECTIVE: The main objective of this study was to determine whether expectations and readiness to modify eating habits and physical activity (PA) level are different between young and older individuals with prediabetes who agreed to participate in a lifestyle modification program. DESIGN: Cross-sectional analysis. SETTING: Primary care or referral center. PARTICIPANTS: Adults between ages 27 and 78 years (N=74) were tested before starting a 12-month lifestyle intervention. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: The visual analog scale questionnaire was used to assess expectations and readiness (ie, intentions, conviction, and self-confidence) to modify the PA level and eating habits. The PA level was assessed with a pedometer and eating habits with a questionnaire. Analyses were stratified by the age group: <60 years old versus ≥60 years old. RESULTS: Body mass loss expectations in terms of goal (-22.9% vs -17.9% of the current body mass; P=.04), acceptable (-15.6% vs -9.4%; P=.01), and failure (-7.6% vs -3.8%; P=.05) in future body mass loss were all greater for the younger group. Despite no significant age group difference in the initial PA level and eating habits, the youngest group had a greater intention to increase the PA level (89% vs 81%; P=.004) and to eat healthier (90% vs 85%; P=.001). Finally, the PA level and the consumption of fruits and vegetables, but not body mass, were associated with intentions or self-confidence to make some lifestyle modifications within age groups. CONCLUSIONS: In individuals at high risk for diabetes, increasing age is associated with lower expectations and reduced readiness with regard to lifestyle modifications. Thus, age should be considered when planning a lifestyle modification program.

General receptor for phosphoinositides 1, a novel repressor of thyroid hormone receptor action that prevents deoxyribonucleic acid binding.

Thyroid hormone receptors (TRs) bind to response elements (TREs) located in the promoter region of target genes and modulate their transcription. The effects of TRs require the presence of coregulators that act as adaptor molecules between TRs and complexes that are involved in chromatin remodeling or that directly contact the basal transcription machinery. Using the yeast two-hybrid system, we identified a new interacting partner for TRs: GRP1 (general receptor for phosphoinositides-1), a nucleotide exchange factor, which had never been shown to interact with nuclear receptors. We reconfirmed the interaction between TRs and GRP1 in yeast and glutathione-S-transferase pull-down assays, and determined the areas of TRs and GRP1 involved in the interaction. Coimmunoprecipitation studies demonstrated that the interaction between GRP1 and TRs takes place in the cytoplasm and the nucleus of mammalian cells. To assess functional consequences of the interaction, we used transient transfection of CV-1 cells with TR and GRP1 expression vectors and luciferase reporter genes. On positive TREs, GRP1 decreased activation by 45-60%. On the negative TREs it increased repression by blunting the activation in the absence of T3, except for TRbeta2, which was not affected. Using EMSA, we have determined that addition of GRP1 diminishes the formation of TR/TR homodimers and TR/retinoid X receptor heterodimers on TREs, which could explain the effect of GRP1 on transcription. Furthermore, protein interaction assays using increasing concentrations of double-stranded TREs show a dose-dependent decrease of the interaction between GRP1 and TRs. The homo/heterodimers formed by TRs and retinoic X receptor-alpha were not influenced by the presence of GRP1, also suggesting that GRP1 interferes directly with DNA binding. Taken together, these data provide evidence that GRP1 is a new corepressor for TRs, which modulates both positive and negative regulation by T3 by decreasing TR-complex formation on TREs.