Manel Puig-Domingo

The Exon 3-Deleted Growth Hormone Receptor Is Associated with Better Response to Pegvisomant Therapy in Acromegaly

CONTEXT The deletion of exon 3 in the GH receptor (GHR) has been associated with a different biochemical picture and response to therapy in acromegaly. OBJECTIVE The aim of the study was to determine whether or not the GHR genotype influences the efficacy of pegvisomant treatment. DESIGN AND SETTING A cross-sectional study was conducted in six Spanish university hospitals. PATIENTS Forty-four acromegalic patients with active disease and resistance to somatostatin analogs participated in the study. RESULTS The prevalence of the full-length GHR and the exon 3-deleted GHR homozygous and heterozygous genotypes was 41, 2, and 57%, respectively. There were no differences in IGF-I or GH pre-pegvisomant levels related to GHR genotype. The exon 3-deleted patients required approximately 20% lower doses of pegvisomant per kilogram of weight (28 +/- 11 compared to 22 +/- 7 mg per kg of weight; P = 0.033) to normalize IGF-I. A stepwise multivariate linear regression analysis (R(2) = 0.27; P = 0.003) identified male gender (beta = -0.79; P = 0.03) and d3-GHR genotype (beta = -0.64; P = 0.007) as the only significant predictors of the dose of pegvisomant per kilogram of weight. In addition, d3-GHR carriers required fewer months for IGF-I normalization (P < 0.01). A stepwise multivariate linear regression analysis (R(2) = 0.40; P = 0.001) revealed that the only significant predictor of the time to IGF-I normalization was the dose of pegvisomant per kilogram of weight (beta = 0.451; P = 0.001). CONCLUSIONS The exon 3 deletion in the GHR predicts an improved response to pegvisomant therapy in acromegaly.

Effect of age and frailty on ghrelin and cholecystokinin responses to a meal test

BACKGROUND Ghrelin and cholecystokinin (CCK) are among the peripheral signals that regulate hunger and satiety. OBJECTIVE The objective was to assess whether ghrelin and CCK responses to a standard nutritional load are related to age and frailty. DESIGN Ghrelin, CCK, insulin, glucose, and 4-h visual analog hunger scale curves after a standard nutritional load test (380 kcal) were described and compared between 3 groups: old (>75 y) and frail persons (group A), old (>75 y) but nonfrail persons (group B), and young (25-65 y) adults (group C). RESULTS Frail persons showed no postprandial ghrelin suppression, and old subjects, frail and nonfrail, showed no significant postprandial ghrelin recovery compared with young adults. Frailty was also associated with lower fasting ghrelin concentrations. No differences in fasting CCK were observed between young and old persons; however, postprandial CCK concentrations were enhanced in young persons, whereas no frailty effect on the CCK curve was observed in the old subjects. No correlations between mean ghrelin and hunger values over time were found, but strong negative correlations were shown between CCK and hunger (group A: r(s) = -0.88, P = 0.009; group B: r(s) = -0.86, P = 0.014; group C: r(s) = -0.71, P = 0.071) and insulin and hunger (group A: r(s) = -0.901, P = 0.006; group B: r(s) = -0.964, P < 0.001; group C: r(s) = -0.929, P = 0.003). CONCLUSIONS Advanced age determines a poorer ghrelin postprandial recuperation phase, a reduced CCK postprandial response, and an exaggerated postprandial insulin release. A loss of ghrelin prandial rhythm is present in old frail persons. The impaired response of these hunger regulatory hormones with age might contribute to the mechanisms of anorexia associated with aging.

Long-term treatment of acromegalic patients resistant to somatostatin analogues with the GH receptor antagonist pegvisomant: its efficacy in relation to gender and previous radiotherapy

CONTEXT Pegvisomant is an effective treatment for somatostatin analogue-resistant acromegaly, but the determinants defining the response to this treatment are largely unknown. OBJECTIVE To investigate the efficacy of pegvisomant treatment in resistant acromegalic patients (e.g. serum IGF1 at least 1.25 x upper normal limit) in a clinical setting and the factors conditioning this response. DESIGN AND SETTING A retrospective cross-sectional study performed in six Spanish University hospitals from 2004 to 2007. Patients Forty-four acromegalic patients (61.4% female, mean age: 49+/-14), 95% of whom had undergone pituitary surgery and 61% having received pituitary radiotherapy. The mean follow-up was 22.7+/-11.2 months. Main outcome measures IGF1 levels reflected treatment efficacy, and the influence of gender, age, weight, previous radiotherapy and duration of treatment was assessed. RESULTS IGF1 normalisation was achieved in 84% of the patients. Male gender (P<0.05), previous irradiation (P<0.05) and the treatment duration (r=0.364, P<0.02) were associated with a better response to pegvisomant therapy. There was a significant decrease in HbA1c (P<0.001) and in the mean insulin dose (P<0.01) in acromegalic diabetic patients. Although 25% of patients experienced mild adverse events, pegvisomant was only withdrawn in four patients due to side effects (two cases of tumour growth, one liver dysfunction and one headache). CONCLUSIONS Long-term pegvisomant is a very effective therapy in resistant acromegaly. Male gender and prior radiotherapy influence the therapeutic response rate.

Utility of 99mTc‐sestamibi scintigraphy as a first‐line imaging procedure in the preoperative evaluation of hyperparathyroidism

OBJECTIVE The use of preoperative imaging in patients with hyperparathyroidism remains controversial. Many of the available techniques are insufficiently sensitive and specific to justify their routine use. We have evaluated the Sensitivity and specificity of 99mTc‐sestamibi scintigraphy in the management of patients with different forms of hyperparathyroidism.

Magnetic Resonance Imaging as a Predictor of Response to Somatostatin Analogs in Acromegaly after Surgical Failure

CONTEXT Transsphenoidal surgery is considered first-line therapy for acromegaly; however, there is often a need for adjunctive therapy. Somatostatin analogs (SSA) have greatly improved the effectiveness of medical treatment, but one third of patients are resistant. OBJECTIVE The aim was to evaluate whether magnetic resonance imaging (MRI) signal could predict long-term response to SSA in patients with active acromegaly after neurosurgery. PATIENTS AND METHODS Sixty-two patients who were active acromegalic after surgery were included in this retrospective study. Remaining pituitary tumor was classified as hyper-, iso-, or hypointense by evaluating T2-weighted MRI signal. Treatment with SSA at maximal effective doses was prescribed and evaluated at 6 and 12 months by monitoring IGF-I, GH, and T2 MRI. RESULTS Complete response to SSA treatment (defined as normal IGF-I) at 6 months was observed in 30%, partial response (defined as IGF-I between 2 and 3 sd score) in 15%, and no response in 55% of patients. At 12 months, 28, 20, and 52% were observed, respectively. MRI signal was hypointense in 40%, hyperintense in 48%, and isointense in 12%. At 6 months, complete response to SSA was observed in 71% of cases having hypointense MRI signal and in 20% of hyperintense (P = 0.04). At 12 months, 62% of hypointense remained well controlled, whereas in the hyperintense group, good, partial, or no response results did not change from that observed at 6 months (P = 0.04). CONCLUSION In active acromegalic patients after surgery, a hypointense T2-weighted MRI signal is associated with a better response to SSA treatment at 6 and 12 months.

Reference Values for Thyroid Function Tests in Pregnant Women Living in Catalonia, Spain

Early detection of thyroid dysfunction during pregnancy is crucial to avoid fetal disturbances. Maternal hypothyroidism and=or maternal hypothyroxinemia can lead to impairment of fetal cerebral development (1). The pregnant state induces important changes in thyroid physiology (2), including an increase in thyroid binding globulin levels, a transient decrease in free thyroxine, a decrease in thyroid-stimulating hormone (TSH) at first trimester related to b-human chorionic gonadotropin (HCG) rise, and an increase in renal iodine clearance. These modifications of thyroid homeostasis determine specific thyroid hormone circulating patterns according to gestational age; this changing scenario in thyroid gestational physiology challenges the diagnosis of thyroid dysfunction in pregnant women because of the lack of precise reference values (RVs) obtained in specific populations and for each of the trimesters. The RVs of the available commercial kits for thyroid hormones are almost always related to the general population and therefore are not valid for pregnant women. Although there is a necessity to have specific RVs for thyroid hormones during pregnancy and during each trimester, only a few studies have been published covering specific geographical areas (3–14). Because of this relative lack of data, we conducted a study to determine the RVs of thyroid hormones in a population of pregnant women from Catalonia (Spain). Two hundred and seventy-six pregnant women were recruited consecutively in the first trimester of gestation and a further 130 women were selected in their final trimester. Their mean age was 29 4 years; 4.7% were multiparus and the rest were nulliparus or uniparus. Women previously treated with thyroxine or with a known thyroid disorder or had a family history of thyroid disorder were excluded. More than 90% of these women were born in Spain, and the rest in Morocco, Peru, and Ecuador. All were living in the same location for at least 2 years before the study. The study group covered different geographical areas of Catalonia, including the Pyrenees and a costal area where there is an acceptable iodinated status for the general population, as shown by recent epidemiologic studies aimed at investigating this condition (15). Recruitment was made through the gynecological services at primary healthcare centers and hospitals where pregnant women were being monitored. Of the 276 women initially contacted, samples were available from 220 in the first trimester and from 60 of those 220, for the third trimester measurement. Of these 220 women recruited in the first trimester, 43.1% were usual consumers of iodinated salt, while 13.4% had taken pharmacologic supplements of 150 mg potassium iodide (KI) during the first trimester and 53.3% thereafter. The study was approved by the Ethics Committee of Hospital Dos de Maig, Barcelona. Written consent was obtained from all the participants. Samples were taken during a fasting state at week 9 for the first trimester and at week 32 for the third trimester. A quimioluminescent assay (Advia Centaur, Bayer Tarrytown, NY) was used to measure free thyroxine (FT4) (RVs for nonpregnant: 0.8–2 ng=dL; intrassay coefficient of variation (CV): 5.4%), TSH (RVs for nonpregnant: 0.4–4 mU=mL; intrassay CV: 5.1%), and antiperoxidase antibodies (TPO abs) (positive> 60 IU=mL; intrassay CV: 6.6%). Total thyroxine (TT4) was measured with a radioimmunoassay (RIA) method (Diagnostic Systems Laboratories, Webster, TX; interand intrassay CVs: 7.4% and 5.1%) only in the first trimester. Urinary iodine was determined by the method described by Pino et al. (16) with interand intrassay CVs of 15.5% and 12.6%. For the calculation of RVs of FT4, TSH, and TT4, a nonparametric method was applied, in which the ordinal value despite the real value was used. The calculated reference

High Prevalence of Growth Hormone Deficiency in Severe Fibromyalgia Syndromes

CONTEXT Fibromyalgia (FM) is characterized by widespread pain and fatigue and is considered a syndrome with different pathogenic mechanisms. Controversial data on GH axis disturbances have been published. Some preliminary trials have shown promising effects of GH therapy on tender points and quality of life in FM. AIM The aim was to study the patterns of GH secretion/sensitivity in a cohort of severe FM patients. SETTING The study was conducted in five tertiary hospitals. METHODS A total of 493 FM women (1990 American College of Rheumatology criteria) recruited from five centers, having more than 16 tender points, Fibromyalgia Impact Questionnaire scores above 75, more than 1 yr of stable medication (serotonin reuptake inhibitors, amitriptyline, and opioids), and body mass index below 35 kg/m(2) underwent baseline IGF-I/GH determinations; an insulin tolerance test (ITT) and a modified IGF-I generation test were performed in those cases showing IGF-I of 150 microg/liter or less. RESULTS A total of 169 of the 493 patients (34.2%) showed IGF-I of 150 microg/liter or less. Mean peak GH during ITT was 13.3 +/- 9.9 ng/ml in 127 patients in which the test was performed. In 22 of 127 (17.3%), ITT peak GH was 5 microg/ml or less, and in eight of them (6.3%), the peak GH was 3 ng/ml or less. Mean baseline GH (n = 127) was 1.47 +/- 2.58 ng/dl, and eight of 120 (6.8%) showed an insufficient IGF-I response (<50% over baseline) to the IGF-I generation test. CONCLUSION FM patients show a high prevalence of GH axis dysfunction. A significant number of patients show biochemical patterns of GH deficiency as well as some degree of GH resistance and might be potential candidates for substitution treatment.

Successful treatment of vitamin D unresponsive hypoparathyroidism with multipulse subcutaneous infusion of teriparatide

OBJECTIVE Hypoparathyroidism is usually controlled with calcium and vitamin-D supplements; in very few cases this treatment fails and teriparatide may be an alternative. We report the first case of hypoparathyroidism refractory to vitamin-D therapy requiring multipulse teriparatide treatment. CASE REPORT A 53 year-old woman presented severe hypocalcemia and hypomagnesemia after thyroidectomy. Preoperatively, mild hypercalciuria was detected with parathyroid hormone (PTH) 69 pg/ml (normal 10-45) and 25-OH-vitamin D 9 ng/ml (normal 20-40) and normal levels of magnesium. No response was seen with oral and i.v. calcium and magnesium, or even with 5 microg calcitriol/day, suggesting a vitamin-D resistance status. Calcium sensor and vitamin-D receptor gene mutation studies were negative. INTERVENTIONS AND RESULTS The following treatments were tried: i) s.c. recombinant human PTH (rhPTH) 1-34 plus oral calcitriol, calcium, and magnesium, was partially effective, but symptoms resumed 4 h after the injection of 20 microg rhPTH; stable calcemia was not achieved even with 4-6 injections/day of teriparatide; ii) two trials of heterologous parathyroid transplant were performed but rejection was detected 3 months after; iii) i.v. magnesium decreased rhPTH requirements but i.m. administration was not tolerated and iv) multipulse s.c. infusion of teriparatide achieved complete normalization of serum calcium, phosphate, magnesium, calciuria and magnesuria with relatively low rhPTH doses (25-35 microg/day) for more than a year. CONCLUSIONS Vitamin-D unresponsiveness leads to uncontrolled hypocalcemia when postsurgical hypoparathyroidism occurs; in situations of no response to usual or higher doses of vitamin-D and s.c. injections of rhPTH, treatment with teriparatide multipulse s.c. infusor is an effective and safe alternative.

DNA methylation profiling of well-differentiated thyroid cancer uncovers markers of recurrence free survival.

Thyroid cancer is a heterogeneous disease with several subtypes characterized by cytological, histological and genetic alterations, but the involvement of epigenetics is not well understood. Here, we investigated the role of aberrant DNA methylation in the development of well‐differentiated thyroid tumors. We performed genome‐wide DNA methylation profiling in the largest well‐differentiated thyroid tumor series reported to date, comprising 83 primary tumors as well as 8 samples of adjacent normal tissue. The epigenetic profiles were closely related to not only tumor histology but also the underlying driver mutation; we found that follicular tumors had higher levels of methylation, which seemed to accumulate in a progressive manner along the tumorigenic process from adenomas to carcinomas. Furthermore, tumors harboring a BRAF or RAS mutation had a larger number of hypo‐ or hypermethylation events, respectively. The aberrant methylation of several candidate genes potentially related to thyroid carcinogenesis was validated in an independent series of 52 samples. Furthermore, through the integration of methylation and transcriptional expression data, we identified genes whose expression is associated with the methylation status of their promoters. Finally, by integrating clinical follow‐up information with methylation levels we propose etoposide‐induced 2.4 and Wilms tumor 1 as novel prognostic markers related to recurrence‐free survival. This comprehensive study provides insights into the role of DNA methylation in well‐differentiated thyroid cancer development and identifies novel markers associated with recurrence‐free survival.

The implications of iodine and its supplementation during pregnancy in fetal brain development.

Iodine is an essential trace element for life. Its biological effects are a consequence of its incorporation to the thyroid hormones, which play a crucial role in fetal organogenesis, and in particular in brain development. This takes place during early gestation and involves delicate targeting throughout the central nervous system, including adequate neuronal growth, migration and myelinization at different sites, such as the cerebral cortex and neocortex, visual and auditory cortex, hippocampus and cerebellum. Pregnancy is characterized by an increased demand of thyroid hormones by the feto-placental unit in order to fulfill the necessary requirements of thyroid hormone action for normal fetal development. Up until week 20, the fetal thyroid is not fully active and therefore is completely dependent on the maternal thyroxine supply. Thus, the maternal thyroid has to adapt to this situation by producing about 1.5 fold more thyroxine. This requires that enzymatic gland machinery works normally as well as an adequate iodine intake, the principal substrate for thyroid hormone synthesis. Biological consequences of iodine related maternal hypothyroxinemia are currently very well known, by both experimental models and by clinical and epidemiological evidences. The associated disturbances parallel the degree of maternal thyroxine deficiency, ranging from increased neonatal morbi-mortality and severe mental dysfunction, to hyperactivity, attention disorders and a substantial decrease of IQ of an irreversible nature in the progeny of mothers suffering a deprivation of iodine during pregnancy. As a consequence, iodine deficiency is the leading preventable cause of mental impaired function in the world, affecting as many as 2 billion people (35.2% of the entire population). Prevention of fetal iodine deficiency - a problem of pandemic proportions- is feasible, provided that an iodine supply of 200-300 μg/day to the mother is ensured, before and throughout gestation as well as during the lactating period.