Papers by Ricardo García-Mayor
The Journal of Clinical Endocrinology and Metabolism, Sep 1, 1997
It is commonly accepted that at least in girls puberty starts when a minimum level of body mass o... more It is commonly accepted that at least in girls puberty starts when a minimum level of body mass or a certain amount of body fat are present. However the precise signal by which adipose stores inform the hypothalamus of the degree of energetic reserves is unknown. Leptin is a hormone produced by the adipocytes to regulate food intake and energy expenditure at the hypothalamic level. To understand whether leptin is the adipose tissue signal that allows puberty, 789 normal children of both sexes, age 5-15 yr, were transversally studied. Leptin levels, as well as gonadal and gonadotropins levels, were analyzed in addition to the determination of auxological parameters. In an age-related analysis, leptin levels in girls rose from 5-15 yr (from 4.3 Ϯ 0.4 to 8.5 Ϯ 0.9 g/L) in parallel with body weight. Boys always had lower leptin levels than girls (3.3 Ϯ 0.3 g/L at 5 yr), but they rose in parallel with weight until 10 yr (5.3 Ϯ 0.7 g/L), when a striking decrease was observed until 15 yr (3.0 Ϯ 0.3 g/L). In girls, leptin was the first hormone to rise followed by FSH and later by LH
Journal of Thyroid Research, 2012
To analyze some factors that could influence the outcome of patients with PTMC. Material and Meth... more To analyze some factors that could influence the outcome of patients with PTMC. Material and Methods. This is a longitudinal observational study. All patients diagnosed and treated for papillary thyroid microcarcinoma at the University Hospital of Vigo, between January 1994 and December 2003, were included in the present study. Demographic characteristics, tumour characteristics, TNM stage, rate of recurrence, and treatment with 131 I were the study variables. Results. Ninety-one patients (75 females) with an average age of 47.7±13.4 years, range 19-81, were studied. Initial tumour staging was T1 in 90 patients and T4a in 1 case. Initial lymph node involvement was present in 4 cases (4.4%). We only found one case with distant metastases at diagnosis. Postsurgical evaluation of thyroid specimens revealed that 28 (30.7%) tumours were multifocal. The average size of the tumour was 0.44 ± 0.25 cm, range 0.1-1. Univariate analysis reveals a statistically significant association between tumour multifocality and postsurgical 131 I therapy with the recurrence rate. In the multivariate analysis only multifocality (P = 0.037, HR 5.7) was a significant risk factor for the recurrence rate. Conclusions. Our results indicate that tumour multifocality is an independent predictor of relapse but neither the tumour size nor postsurgical 131 I therapy.
PubMed, Nov 1, 2009
We report a case of a patient with longstanding Behçet disease, with neurological symptoms predom... more We report a case of a patient with longstanding Behçet disease, with neurological symptoms predominantly, who became hospitalized for adrenal insufficiency, caused by isolated deficiency of corticotropin (DAACTH). DAACTH is a typical characteristic of hypophysitis, reported in association with many autoimmune diseases. Nevertheless, hypothalamic-pituitary injury in Behçet disease is exceptional. We review the literature and possible mechanisms of this association until now not reported.
The Endocrine Society's 92nd Annual Meeting, June 19–22, 2010 - San Diego, 2010
Revista Clínica Española, 2010
Resumen Estudio descriptivo retrospectivo de 14 pacientes con un diagno ´stico histolo ´gico de p... more Resumen Estudio descriptivo retrospectivo de 14 pacientes con un diagno ´stico histolo ´gico de paraganglioma (PGL) recogidos en el Hospital Universitario de Vigo, Pontevedra, durante los u ´ltimos 25 an ˜os. Hemos analizado las caracterı ´sticas clı ´nicas y la evolucio ´n de esta serie de enfermos. Resultados: La forma de presentacio ´n de los 14 pacientes fue por efecto masa en 10, clı ´nica adrene ´rgica en 3 e incidental en uno. Algunos enfermos con PGL simpa ´ticos (PGLS) (6/9) y PGL parasimpa ´ticos (PGLPS) (2/5) presentaron clı ´nica de hiperproduccio ´n adrene ´rgica antes del diagno ´stico. La determinacio ´n de catecolaminas urinarias fue positiva en los 4 enfermos con PGLPS en quienes se determino ´. El taman ˜o tumoral medio fue de 37,8718,9 mm, sin diferencias entre los PGLS y los PGLPS. Dos PGLS fueron malignos. La evolucio ´n resulto ´favorable en 11 pacientes, 2 pacientes con PGLS fallecieron y el tumor de un paciente con PGLPS intracraneal no se pudo extirpar en su totalidad. Conclusiones: Los PGL se presentan con frecuencia clı ´nica adrene ´rgica secundaria a la produccio ´n de catecolaminas. Las caracterı ´sticas de estos tumores aconsejan un estudio detallado en un a ´mbito especializado antes de la cirugı ´a.
International Journal of Endocrinology & Metabolism, 2012
Evaluation whether the A/G +49 SNP marker of the CTLA gene is associated with GD in a Spanish pop... more Evaluation whether the A/G +49 SNP marker of the CTLA gene is associated with GD in a Spanish population, and associations between the CTLA4 genotype and clinical characteristics of Grave patients could permit choosing the more appropriate treatment regimen and predict the post-treatment outcome of these patients.
Updates in the Understanding and Management of Thyroid Cancer, 2012
Accurate statistics on cancer occurrence and outcome are essential both for the purposes of resea... more Accurate statistics on cancer occurrence and outcome are essential both for the purposes of research and for planning and evaluation programmes for cancer control . Although tumours of thyroid account for only 1% of the overall human cancer burden, they represent the most common malignancies of the endocrine system and pose a significant challenge to pathologists, surgeons and endocrinologists. Among epithelial tumors, carcinomas of follicular cell origin far outnumber those of C-cell origin. The vast majority of carcinomas of follicular cell origin are indolent malignancies with 10 year survivals in excess of 90 %. Thyroid follicular epithelial-derived cancers are divided into three categories: papillary cancer, follicular cancer and anaplastic cancer. Papillary and follicular cancers are considered differentiated cancers, and patients with these tumours are often treated similarly despite numerous biologic differences. Most anaplastic (undifferentiated) cancers appear to arise from differentiated cancers. Other malignant diseases of the thyroid include medullary thyroid cancer (which can be familial, either as part of the multiple endocrine neoplasia type 2 syndrome or isolated familial medullary thyroid cancer), primary thyroid lymphoma, or metastases from breast, colon, or renal cancer or melanoma. In countries with adequate iodine intake, differentiated thyroid cancer accounts for more than 85% of all cases, being the most common type papillary (60-80%). Tumor histology is a critical determinant of patient outcomes; differentiated thyroid cancer is associated with the best survival rate and medullary and anaplastic have significantly poorer outcomes . Certain subtypes, such as the tall and columnar cell variants of papillary cancer and the insular variant of follicular cancer are more common in older patients with higher stage disease and have a worse prognosis than usual forms of thyroid cancer. The traditional separation of thyroid cancer into the major groups of papillary, follicular, medullary and undifferentiated (anaplastic) carcinoma, based on morphology and clinical www.intechopen.com Updates in the Understanding and Management of Thyroid Cancer 2 features, is strongly supported by advances in molecular studies showing the involvement of distinct genes in these four groups, with little overlap (DeLellis & Williams, 2004). Numerous staging systems have been created in an attempt to accurately prognosticate outcomes for individual patients; two careful studies have compared the efficacy of the various staging systems and found that none is superior . Consequently, the European Thyroid Association (ETA) and the American Thyroid Association (ATA) (Cooper et al., 2009) have recommended the use of the Tumour, Node, Metastasis (TNM) classification of the American Joint Commission on Cancer (AJCC) and the International Union Against Cancer because it is universally available and widely accepted for other disease sites. An interesting feature of the TNM staging system compared to other classifications is the age factor. While the staging of head and neck cancers relies exclusively in the anatomical extent of disease, it is not possible to follow this pattern for the particular group of malignant tumors that arise in the thyroid gland. The effect of age is such significance in behavior and prognosis, that both the histologic diagnosis and the age of the patient are included in the staging system for these tumors. The AJCC classification is based on the TNM system, which relies on assessing three components: (1) extent of the primary tumour (T), ( ) absence or presence of regional lymph node metastases (N), and (3) absence or presence of distant metastases (M). The fifth edition , (Table ) was revised as the sixth edition , (Table ). A major alteration was the reclassification of tumour staging (T). For differentiated (papillary and follicular) and medullary tumours confined to the parenchyma of the thyroid gland without extrathyroidal extension, there is no evidence to suggest that using a size cutoff of 1 cm provides better prognostic stratification compared with the 2-cm cut-off used for www.intechopen.com An Epidemiological Analysis of Thyroid Cancer in a Spanish Population: Presentation, Incidence and Survival 3 other head and neck sites. Therefore, fifth edition T1 (<1 cm) and T2 (between 1 and 4 cm) were redefined as sixth edition T1 (<2 cm) and T2 (between 2 and 4 cm). In the sixth edition, T3 includes not only large tumours (4 cm or more) but also tumours with minimal extension, and T4 consists of T4a and T4b. The fact that diverse outcomes may be expected in these two g r o u p s o f p a t i e n t s i s n o w r e c o g n i z e d i n t h e s i x t h edition: tumors that involve the sternothyroid muscle are classified as T3, while extension to larynx, trachea, oesophagus, recurrent laryngeal nerve, or subcutaneous soft tissue, all of which are surgically resectable, is classified as T4a. Tumours that invade the prevertebral fascia or encase the carotid artery or mediastinal great vessels are not resectable for cure, and these patients are staged T4b. Thus, the sixth edition divides fifth edition T4 tumors into T3 (minimal invasion), T4a (extended invasion), and T4b (more extensive unresectable invasion) tumours according to the degree of extrathyroid extension. The degree of extension has been closely related to adverse prognoses. Therefore, the sixth edition is expected to predict more accurately different outcomes in patients with extrathyroid extension compared with the fifth edition.
Thyroid, 2009
Background: Thyroid cancer incidence is increasing throughout the world. Most studies attribute t... more Background: Thyroid cancer incidence is increasing throughout the world. Most studies attribute this rise entirely to the increase in papillary carcinoma, the most common thyroid malignancy in iodine-sufficient areas. A variety of nonetiological factors such as changes in clinical practice may affect the incidence of thyroid cancer and some researchers have suggested that this rise is only apparent due to an increase in diagnostic activity. Since data on the epidemiology of thyroid cancer in Spain are scarce, the main goal of this study was to analyze changes in thyroid cancer presentation, incidence, and prevalence in Vigo (northwestern Spain) between 1978 and 2001, and to investigate the relationship between the incidence rates and trends in tumor size and thyroid surgery. Methods: In this descriptive epidemiologic study, an analysis was carried out on new thyroid cancer cases obtained from the Pathology Registry of the University Hospital of Vigo (500,000 inhabitants). Trends in age, sex, thyroid surgery, histological type, tumor size, and incidence rates were calculated. The prevalence of thyroid cancer was determined in three cross-sectional surveys. Results: The rate of population undergoing thyroid surgery significantly increased over time. Out of 322 new primary thyroid cancers, papillary thyroid cancer (PTC) was the predominant type (76%). The age-standardized incidence rate shows a significant increase in females: 1.56 per 100,000 year (1978 to 1985) to 3.83 (1986 to 1993) and 8.23 (1994 to 2001); and in males: 0.33, 1.19, and 2.65, respectively. PTC was mainly responsible for this pattern and was the result of both the increase in micropapillary thyroid carcinoma (MPTC) incidence and in PTC measuring more than 1 cm. Besides MPTC cases, no significant variations were observed in tumor size over time. Conclusions: In northwestern Spain, the incidence of thyroid cancer is increasing. These data should be taken into account when planning health resources for these patients. Our results may reflect the contribution that other factors, besides increased diagnostic activity, have made to the rise in thyroid cancer incidence in our region. Additional studies are needed to explain the rise in PTC incidence throughout the world and to search for potential risk factors that are currently unrecognized.
The Endocrinologist, 2008
ABSTRACT Incidentally found adrenal masses are increasingly frequent because of increased use of ... more ABSTRACT Incidentally found adrenal masses are increasingly frequent because of increased use of imaging procedures. The management of these neoplasms remains controversial. Adrenal incidentalomas are usually less than 4 cm in diameter. We present a young man with an 8 × 5 cm adrenal mass. A 24-year-old man was referred to our clinic with an adrenal mass discovered incidentally during a CT scan for an undefined pulmonary radiologic finding. Hormonal evaluation was normal. Gonadotrophins, thyroid function tests, urinary cortisol, and catecholamines were normal. Laparotomy and right adrenalectomy was performed without complication. The mass proved to be a ganglioneuroma (GN). GN is a rare tumor. GN can appear along the sympathetic paravertebral chain, the sympathetic paraganglia, or in the adrenal medulla (15%-30%). The prognosis is generally good.
Journal of Pediatric Endocrinology and Metabolism, 1993
) secretion is regulated by a complex system of central and peripheral signals. Recently, a new G... more ) secretion is regulated by a complex system of central and peripheral signals. Recently, a new GH-releasing hexapeptide (His-D-Trp-Ala-Trp-D-Phe-Lys-NH 2 ) called GHRP-6 which specifically releases GH has been studied. In the present work the mechanism of action of GHRP-6 has been addressed in experimental animal models as well as in obese subjects. GHRP-6 releases GH independently of the hypothalamic factors GHRH and somatostatin and is a powerful GH releaser in obesity.
European Journal of Endocrinology, 1997
Sex-based differences in serum leptin concentrations have been reported in adolescence and adulth... more Sex-based differences in serum leptin concentrations have been reported in adolescence and adulthood. To discover when such differences were generated, serum leptin concentrations were measured in umbilical cord blood from 46 healthy infants and in the mother's blood at delivery. Considering the respective body weights of the mothers and infants (68.5 +/- 1.3 kg and 3.3 +/- 0.0 kg), umbilical cord concentrations of leptin were disproportionately high in the infants (9.4 +/- 1.2 micrograms/l) compared with those in the mothers (18.7 +/- 1.3 micrograms/l). There was a wide variation in the infants leptin values (1.2 +/- 56.8 micrograms/l) that did not correlate with height, weight, cephalic circumference, or any other growth-related parameter. The most striking differences emerged when results were analysed by sex: umbilical cord concentrations of leptin in the girls (12.9 +/- 2.2 micrograms/l) were significantly (P < 0.01) greater than those in the boys (6.8 +/- 0.9 micrograms...
Clinical Endocrinology, 2002
The diagnosis of GH deficiency in adults is based on the provocative testing of GH secretion. Whe... more The diagnosis of GH deficiency in adults is based on the provocative testing of GH secretion. When testing a patient with suspected GH deficiency, clinicians assess the whole secretory curve and select the GH peak as an index of secretory capability. This procedure is time consuming and the determination of GH in several samples is necessary. The combined administration of growth hormone releasing hormone (GHRH) plus growth hormone releasing peptide-6 (GHRP-6) is an effective test of GH secretion, and it has been unambiguously demonstrated that the elicited GH peak is capable of segregating normal GH secretion subjects from GH deficient patients on an individual basis. The GHRH + GHRP-6 test biochemically classifies patients into three groups; those with a stimulated GH peak &amp;amp;amp;amp;gt;/= 20 micro g/l are considered normal and those with peaks at &amp;amp;amp;amp;lt;/= 10 micro g/l as GH deficient. The group comprising individuals between these parameters is considered uncertain, and the results are further interpreted according to clinical information, or by other tests. As the GHRH + GHRP-6 test induces GH peaks consistently in the first 30 minutes, the working hypothesis assessed in this study was whether a single determination of GH 30 minutes after stimulus could provide the same clinical classification as the whole secretory curve. Three hundred and forty-nine adult subjects (146 patients with organic pituitary disease and 203 healthy subjects) were studied. All were administered GHRH 1 micro g/kg i.v. plus GHRP-6 1 micro g/kg i.v. at 0 minutes, and blood samples were obtained at regular intervals. GH was determined in all samples. GHRH + GHRP-6-evoked GH peaks in controls and patients were not correlated with GH basal values, making this determination useless for test validation. In contrast, an excellent correlation was observed between GH values at 30 minutes and the GH peaks (r = 0.994, P &amp;amp;amp;amp;lt; 0.0001). When comparing the 30-minute GH values against the peaks, the biochemical classification changed from normal toward uncertain in only five out of 203 control subjects, which is without clinical relevance according to Bayes theorem. Similarly, when the 30-minute value was used instead of the peak in GH deficient patients, only two out of 146 patients moved from the uncertain area toward the GH deficient one. Thus, better diagnostic classification was provided for patients. The GHRH + GHRP-6 test is a convenient, safe and reliable, provocative test of GH reserve in adults, which can be reduced to a single fixed GH determination 30 minutes after stimulus.
Endocrinología y Nutrición, 1999
Endocrine Disorders in Thalassemia, 1995
Intensive transfusion regimens have significantly improved the prognosis for patients with thalas... more Intensive transfusion regimens have significantly improved the prognosis for patients with thalassemia major. However, growth failure and hypogonadism are still major problems. Growth failure is generally accepted as beginning at the age of 10, with a marked decline in the growth rate after the age of 12–14 years [1, 2]. A recent report shows that height impairment occurs before the age of 10 [3]. While it is possible that delayed puberty may be responsible for the failure to grow during the physiological period of puberty, factors determining precocious growth impairment are less clear. Endocrine studies in young children have frequently, but not always, revealed the presence of a normal GH response to provocative stimuli. However, low plasma insulin-like growth factor-1 (IGF-1) activity was found in several studies [4, 5]. The aim of the present study was to investigate the relationship between GH response to pharmacological stimuli, the levels of IgF-1, and final height in thalassemic patients.
Type 1 Diabetes - Complications, Pathogenesis, and Alternative Treatments
International Journal of Obesity, 1999
OBJECTIVE: To determine the prevalence of overweight children and its modi®cations over a period ... more OBJECTIVE: To determine the prevalence of overweight children and its modi®cations over a period of 10 y and whether changes in overweight prevalence is similar in the inland and coastal areas in our country. DESIGN: Cross-sectional study in two stages, the initial survey being in 1985 and the second in 1995. SUBJECTS: 1131 children (827 and 304 from coastal and inland areas respectively) in the initial survey, and 903 children (695 and 208 from coastal and inland areas) in the second survey, of both sexes, aged from 6 to 15 y were selected by a random process from the total school population in the Province of Pontevedra, Northwestern Spain. MEASUREMENTS: Overweight was de®ned in terms of body mass index (BMI), using Spanish standards. Children having BMI at or above the 85th percentile were classed as overweight and at or above the 95th percentile as very overweight. RESULTS: Overall prevalence of overweight and very overweight were signi®cantly higher in the second survey than in the ®rst, 18.1% vs 11.7%, P`0.05 for overweight prevalence and 6.8% vs 2.7%, P`0.05 for very overweight prevalence respectively. When we compared modi®cations in overweight prevalence over the period 10 y between the inland and coastal areas of our country, increase prevalence was observed in the inland area 9.8% vs 19.7%, P`0.05 for initial and secondary surveys respectively, whereas in the coastal area overweight prevalence remains stable, 20.2% vs 17.6%, P b 0.05. CONCLUSION: An increased prevalence of overweight children of both sexes in over a period of 10 y was observed, however, this increase was particularly caused by an increased prevalence in the inland area whereas in coastal area it remained stable. We speculate that differences in overweight prevalence between both areas might be due to differences in physical activity associated with different degrees in technological development between inland and coastal areas.
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Papers by Ricardo García-Mayor