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3.
Clin Chem Lab Med ; 50(5): 885-90, 2012 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-22628332

RESUMO

BACKGROUND: Establishment of reliable reference intervals remains valuable for confirming validity and advancing standardization across methods and populations. Moreover, knowledge of the measurement uncertainty (U) and of the reference change value (RCV) has important applications in clinical chemistry. METHODS: Starting from the information available in the laboratory data base (29,901 subjects) an initial selection was carried out by eliminating all subjects with a clinical or laboratory pathological report; data from 7581 0- to 20-year-old subjects (53.87% girls) remained in the study. These subjects, divided into nine age groups, were used to define reference distribution percentiles (2.5th, 50th and 97.5th) of serum thyrotropin (TSH), triiodothyronine (T3), thyroxine (T4), and free T4 (fT4), as well as U and RCV of these assays. RESULTS: In early infancy, T4 and fT4 values were higher than in the older age groups. Serum T4 95th percentile reference value, useful for the diagnosis of hyperthyroidism, was 142.9 in 20-year-old boys and 230.4 nmol/L in early infants and serum T3 95th percentile was 2.6 and 3.5 nmol/L, respectively, while fT4 2.5th percentile reference value, useful for the diagnosis of hypothyroidism, was 9.6 and 13.0 pmol/L, respectively. Serum TSH 97.5th percentile showed less age variation, 4.38-4.88 mIU/L. Performance of the four assays resulted in approximately 20% Us, reflecting simple and complex imprecision, trueness, analytical and functional sensitivity. RCV of serum TSH (58.6%) was larger than for thyroid hormones (28.3%-34.7%), probably due to the high biological variation of this hormone. CONCLUSIONS: We have established reference interval for TSH and thyroid hormones, as well as Us for assessing reliability of measurements, and RCVs to alert users on the presence of clinical significant changes.


Assuntos
Análise Química do Sangue/normas , Hormônios Tireóideos/sangue , Tireotropina/sangue , Adolescente , Fatores Etários , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Valores de Referência , Incerteza , Adulto Jovem
4.
Medicina (B Aires) ; 72(4): 291-7, 2012.
Artigo em Espanhol | MEDLINE | ID: mdl-22892080

RESUMO

Changes in the clinical presentation of diabetes mellitus in childhood and adolescence associated with obesity have resulted in an overlap of the two most common types of diabetes with a greater clinical heterogeneity. In order to characterize the type of diabetes at onset and assess the effect of obesity, 50 children with diabetes were studied. The patients were divided into two groups according to their nutritional status at diagnosis (over-weight/obese vs. normal weight). Insulin reserve was evaluated by measuring basal C-peptide and stimulated C-peptide in response to a mixed meal (MMTT) as well as HLA-DQB1 genotype, antibodies, and family history of risk factors for metabolic disease. Of all 50 patients, 38% was overweight/obese, 84% had a positive family history of metabolic syndrome, 82% had positive antibodies, and 100% were positive for the high-risk HLA-DQB1 genotype. No significant differences were found in fasting C-peptide or glycemic index/C-peptide levels between the two groups. In the overweight/obese group C-peptide response to MMTT showed higher levels at 60 and 120 minutes (p = 0.02 and 0.03) and the area under the curve for C-peptide was also higher (1.77 ng / ml vs. 5.5 ng/ ml, p = 0.0007) than in the normal-weight group. In conclusion, overweight/obese patients with type 1A diabetes had a greater pancreatic reserve, suggesting that nutritional status may accelerate disease onset.


Assuntos
Peptídeo C/sangue , Diabetes Mellitus Tipo 1/diagnóstico , Adolescente , Autoimunidade , Biomarcadores/sangue , Distribuição de Qui-Quadrado , Criança , Diabetes Mellitus Tipo 1/genética , Feminino , Genótipo , Glutamato Descarboxilase/sangue , Cadeias beta de HLA-DQ/sangue , Humanos , Anticorpos Anti-Insulina/sangue , Masculino , Síndrome Metabólica/complicações , Obesidade/complicações , Estudos Prospectivos , Proteínas Tirosina Fosfatases Classe 8 Semelhantes a Receptores/sangue , Fatores de Risco
5.
Clin Endocrinol (Oxf) ; 75(4): 427-35, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21609351

RESUMO

OBJECTIVE: To report genotype-phenotype correlation in a large cohort of patients. CONTEXT: Study of the CYP21A2 gene in 866 unrelated chromosomes of 21-hydroxylase deficiency in Argentinean patients with classic and nonclassic (NC) forms of congenital adrenal hyperplasia (CAH). METHODS: Eleven most common mutations were analysed by allele-specific polymerase chain reaction, restriction fragment length polymorphism (RFLP) or southern blot analysis. Gene sequencing was performed when no mutation was detected in one allele or the genotype-phenotype correlation was lacking. RESULTS: The 11-most-common-mutation screening allowed for the detection of 88·1% of affected alleles (80·3% in the NC and 95·2% in the classic forms). p.V281L, IVS2-13A/C>G (In2) and gene deletions and large gene conversions were the most prevalent mutations. In2 (35·2%) in salt wasting (SW), p.I172N (37·3%) in simple virilizing and p.V281L (54·1%) in NC CAH were the most prevalent mutations within the clinical forms. In 7/15 p.P30L mutation alleles, a chimeric CYP21A1P/CYP21A2 gene [PromCYP21A1P; p.P30L] was detected, while 6/15 represented a single-nucleotide substitution, and in 2/15 linkage with mutations, p.[P30L; V281L] and [p.P30L; IVS2-13A/C > G; p.Q318X] was found. In two SW patients, a novel nonsense mutation, p.Q41X, was observed. In three p.V281L mutation patients, the phenotype was more severe than predicted by genotype. Sequence analysis revealed an intronic alteration in the allele carrying the p.V281L mutation [IVS2 + 5G > A; p.V281L]. An aberrant splicing in this p.V281L mutated allele explains the clinical phenotype. CONCLUSIONS: A high percentage of CYP21A2 affected alleles is detected by the 11-mutation screening study. Genotype-phenotype correlation was high, but when the phenotype is more severe than predicted by genotype, presence of two alterations in one allele should be ruled out.


Assuntos
Hiperplasia Suprarrenal Congênita/genética , Esteroide 21-Hidroxilase/genética , Argentina , Análise Mutacional de DNA , Feminino , Genótipo , Humanos , Masculino , Mutação , Fenótipo
7.
J Perinat Med ; 39(1): 59-64, 2011 01.
Artigo em Inglês | MEDLINE | ID: mdl-20979446

RESUMO

INTRODUCTION: The term "euthyroid sick syndrome" (ESS) has been used to describe a pattern of thyroid hormone changes during the course of critical illness in adult patients without thyroid disease, often associated with reduced thyroid hormone secretion. OBJECTIVE: To describe the thyroid hormone profile in full-term newborns critically ill compared with thyroid hormone profile of healthy infants, and determine if alterations could be related to the severity of the disease and outcome. METHODS: A cross-sectional, observational, and prospective study of full-term infants admitted to the neonatal intensive care unit (NICU) of the Hospital de Pediatría J.P. Garrahan between July 2007 and April 2008. Serum T3, T4, and thyroid stimulating hormone (TSH) levels were measured at admission and severity of the disease was evaluated through SNAP, lactic acid, respiratory assistance and number of organs affected. RESULTS: Sick newborns showed significantly lower T3 and T4 levels compared with healthy infants [T3: -0.97 µg/dL (95% CI -0.89, -1.13) and T4: -4.37 µg/dL (95% CI -2.95, -5.78)]. Only 29 out of 94 (31%) infants presented a normal profile; 37 (39%) infants showed isolated low T3 levels, 20 (21%) infants had low T3 and T4 levels and eight (9%) infants had low TSH, T3, and T4. Of this latter group, five of eight (62%) children died suggesting a significantly higher risk of death for patients with low T3 associated with low T4 and TSH [Risk ratio (RR) 10.75 95% CI 3.93, 29]. CONCLUSIONS: Full-term sick newborns frequently have lower thyroid hormone levels than healthy ones. These observed thyroid hormones changes might be related to the underlying disease and could be used as a prognostic marker of the severity and fatal outcome of the patient.


Assuntos
Estado Terminal/mortalidade , Síndromes do Eutireóideo Doente/mortalidade , Recém-Nascido/sangue , Hormônios Tireóideos/sangue , Tireotropina/sangue , Argentina/epidemiologia , Estudos Transversais , Síndromes do Eutireóideo Doente/sangue , Síndromes do Eutireóideo Doente/diagnóstico , Feminino , Humanos , Doenças do Recém-Nascido/sangue , Doenças do Recém-Nascido/diagnóstico , Doenças do Recém-Nascido/mortalidade , Terapia Intensiva Neonatal , Masculino , Estudos Prospectivos
8.
Clin Endocrinol (Oxf) ; 73(4): 546-50, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20560980

RESUMO

INTRODUCTION: Prader-Willi syndrome (PWS) is a genetic disorder caused by the loss of expression of paternally transcribed genes in a highly imprinted region of chromosome 15q11-13. The clinical phenotype has been well characterized, mostly related to hypothalamic dysfunction. Even though central hypothyroidism has been documented in 20-30% of patients with PWS, thyroid function during the first 2 years of life has not been clearly defined. OBJECTIVE: To evaluate hypothalamic-pituitary-thyroid function in infant PWS patients. STUDY DESIGN: Eighteen patients with PWS, aged 0.16-2 years, were included in a prospective study. PWS diagnosis was based on clinical features and molecular analysis. Serum total (T) T4, free (F) T4, T3 and thyroid-stimulating hormone (TSH) were evaluated in the patients with PWS included in the study. Serum hormone values were compared to those of a large reference population of the same age. RESULTS: In 13 of 18 patients with PWS (72.2%), serum TT4 and/or FT4 levels were below the 2.5th percentile of the reference population, while in only one PWS patient serum T3 was below this cut-off. CONCLUSION: The results of this study suggest that transient or definitive thyrotropin-releasing hormone (TRH)-TSH thyroid axis dysfunction may frequently be present in infant PWS patients. Paediatricians should be aware of this dysfunction in this critical period of thyroid hormone action on neurological development.


Assuntos
Sistema Hipotálamo-Hipofisário/fisiopatologia , Síndrome de Prader-Willi/fisiopatologia , Glândula Tireoide/fisiopatologia , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Tireotropina/sangue , Hormônio Liberador de Tireotropina/fisiologia , Tiroxina/sangue
10.
J Pediatr Endocrinol Metab ; 23(8): 783-8, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21073121

RESUMO

We analyzed the ability of the BaF3 cell line bioassay to select patients with biologically inactive GH. We first evaluated the biological response of the Ba/F3-hGHR cells to rhGH additional doses from 10 to 5000 pg/ml. The concentration points corresponding to the linear part of the curve were selected. We then analyzed a group of sera, diluted like the standard, including the entire range of GH concentrations that can be analyzed by bioassay. The serum/standard area below the curve ratio was calculated. Serum GH immunoactivity determined by IMMULITE/GH bioactivity ratios was calculated. Our experimental data showed that GH-bioactivity/GH-immunoactivity ratios below 0.303 are indicative of a bioinactive GH molecule. This bioassay would recognize only extreme cases of GH bioinactivity, and it would not be a useful tool in the search for patients with altered forms of GH.


Assuntos
Bioensaio/métodos , Transtornos do Crescimento/sangue , Hormônio do Crescimento Humano/sangue , Adolescente , Animais , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Criança , Pré-Escolar , Feminino , Transtornos do Crescimento/diagnóstico , Hormônio do Crescimento Humano/imunologia , Hormônio do Crescimento Humano/farmacologia , Humanos , Masculino , Camundongos , Valor Preditivo dos Testes , Proteínas Recombinantes , Valores de Referência , Reprodutibilidade dos Testes
13.
J Pediatr Endocrinol Metab ; 22(3): 255-61, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19492582

RESUMO

Sex hormones are modulators of the GH/ IGF-I system. We have hypothesized that the inhibition of DHEAS in treated girls with congenital adrenal hyperplasia (CAH) might affect this modulation. We analyzed serum IGF-I, IGFBP-3 and DHEAS in 17 prepubertal (Pp) and 32 pubertal (Pu) girls with CAH, under hydrocortisone replacement therapy, in the presence of normal (Gr1) or high (Gr2) serum testosterone (T) and androstenedione (A) levels. All groups had appropriate normal controls. Serum DHEAS in patients with CAH was significantly lower than in the respective controls (p < 0.04), except for Pp CAH Gr2. Serum IGF-I, but not serum IGFBP-3, in CAH subgroups was significantly higher than in the respective controls (p < 0.05), except for Pp CAH Gr2. It is concluded that glucocorticoid treatment of girls with CAH results in hypofunction of the adrenal zona reticularis. Low levels of serum DHEAS could be involved in the regulation of IGF-I biological response in target tissues. Additional studies are necessary to confirm these findings.


Assuntos
Hiperplasia Suprarrenal Congênita/tratamento farmacológico , Anti-Inflamatórios/uso terapêutico , Sulfato de Desidroepiandrosterona/sangue , Hormônio do Crescimento/metabolismo , Terapia de Reposição Hormonal , Hidrocortisona/uso terapêutico , Fator de Crescimento Insulin-Like I/metabolismo , Hiperplasia Suprarrenal Congênita/metabolismo , Criança , Pré-Escolar , Feminino , Humanos , Fígado/efeitos dos fármacos , Fígado/metabolismo , Adeno-Hipófise/efeitos dos fármacos , Adeno-Hipófise/metabolismo , Puberdade , Testosterona/sangue
14.
J Clin Endocrinol Metab ; 104(10): 4323-4330, 2019 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-31135894

RESUMO

CONTEXT: The low-dose (1 µg) ACTH test (LDT) is widely used to assess central adrenal insufficiency (CAI); however, the serum cortisol cutoff value is controversial. Salivary cortisol (SC) may be a more accurate measurement for CAI. OBJECTIVE: To assess a new maximum cutoff value of serum cortisol after LDT in pediatric patients, taking into account serum and SC measurements. DESIGN AND SETTING: Prospective study in a pediatric tertiary referral center. WORKING HYPOTHESIS: The combined analysis of serum and SC response to LDT might improve LDT for CAI diagnosis. PARTICIPANT AND OUTCOME MEASUREMENT: A total of 145 pediatric patients underwent LDT. Serum and SC levels were measured. A central adrenal sufficient (CAS) response was established according to the reference serum cortisol cutoff value of ≥497 nmol/L. RESULTS: The LDT study showed central adrenal sufficiency in 72 patients and CAI in 73 patients. Considering the lower quartile of maximum SC value (21 nmol/L) in the CAS group, an intermediate CAI (InCAI) group and a real CAI (RCAI) group were defined. Regarding the median maximum value of serum cortisol levels in the InCAI group, a new serum cortisol cutoff value of 450 nmol/L was established. Furthermore, 91% of the patients in the RCAI group were below this cutoff value. CONCLUSION: The combined evaluation of maximum serum and SC levels to LDT might be useful to define an InCAI group and to avoid unnecessary hormone replacement therapy. However, rigorous patient follow-up is required.


Assuntos
Insuficiência Adrenal/diagnóstico , Hormônio Adrenocorticotrópico/farmacologia , Hidrocortisona/sangue , Sistema Hipófise-Suprarrenal/fisiopatologia , Glândulas Salivares/metabolismo , Adolescente , Insuficiência Adrenal/sangue , Hormônio Adrenocorticotrópico/sangue , Criança , Estudos de Coortes , Feminino , Humanos , Masculino , Pediatria , Sistema Hipófise-Suprarrenal/efeitos dos fármacos , Estudos Prospectivos , Curva ROC , Sensibilidade e Especificidade
16.
Acta bioquím. clín. latinoam ; 56(1): 75-80, ene. 2022. graf
Artigo em Espanhol | LILACS, BINACIS | ID: biblio-1402947

RESUMO

Resumen El objetivo de esta comunicación es proponer una guía de las formas decálculo de los intervalos de referencia (IR) en la población pediátrica ordenándolassegún su fortaleza metodológica. En primer lugar, el proceso recomendadopara definir un IR es el enfoque "directo", en el que se evalúanmuestras de sujetos considerados sanos. En segundo lugar, la convocatoria"indirecta", en la que a los resultados de las muestras de una base dedatos, se aplican criterios de exclusión y procesamientos estadísticos (métodosde Hoffmann y de Bhattacharya). Estos IR presentan poca diferenciacon los obtenidos por datos directos y se pueden considerar equivalentes,con la ventaja de su facilidad y sus costos más bajos. En tercer lugar, estánlos IR obtenidos de la bibliografía. La validación de los datos informadospor el fabricante es la última opción a tener en cuenta. Se reafirma laimportancia de contar con IR adecuados por sus aspectos clínicos y por laseguridad de los pacientes.


Abstract The aim of this communication is to propose a guide on the ways of calculating reference intervals (RI) in the pediatric population, ordering them according to their methodological strength. First, the recommended process to define an RI is the "direct" approach, in which samples of subjects considered healthy are evaluated. Secondly, the "indirect" approach, in which exclusion criteria and statistical processing are applied to the results ofthe samples in a database (Hoffmann and Bhattacharya methods). These RIs show little differences with those obtained by direct data and they can be considered equivalent, with the advantage of their ease and with lower costs. Thirdly, there are RIs that can be obtained from the bibliography. The validation of the data reported by the manufacturer is the last option to consider. The importance of having adequate RIs for their clinical aspects and for the safety of patients is reaffirmed.


Resumo O objetivo desta comunicação é propor um guia sobre as formas de cálculo dos intervalos de referência (IR) na população pediátrica, ordenando os mesmos de acordo com sua fortaleza metodológica. Emprimeiro lugar, o processo recomendado para definir um IR é a abordagem "direta", na qual sãoavaliadas amostras de indivíduos considerados saudáveis. Em segundo lugar, a abordagem "indireta",na qual critérios de exclusão e processamento estatístico (métodos de Hoffmann e Bhattacharya)são aplicados aos resultados das amostras em um banco de dados. Esses IR apresentam poucadiferença com os obtidos por dados diretos, podendo ser considerados equivalentes, com a vantagem de apresentarem facilidade e menor custo. Em terceiro lugar, os IR obtidos da bibliografia. A validadedos dados informados pelo fabricante é a última opção a ser considerada. A importância de termos IRadequados pelos seus aspectos clínicos e pela segurança dos pacientes é reafirmada.


Assuntos
Pediatria , Valores de Referência , Estatística , Segurança , Sistema Único de Saúde , Atrofias Musculares Espinais da Infância , Bases de Dados Bibliográficas , Comunicação , Custos e Análise de Custo , Estudo de Validação , Menores de Idade , Métodos
17.
J Clin Endocrinol Metab ; 88(3): 1389-93, 2003 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-12629134

RESUMO

The aim of this study was to analyze the possible implication of changes in the GH/IGF-I axis and in insulin sensitivity for the regulation of adrenal androgen secretion of normal prepubertal and adolescent girls. A total of 61 normal girls were evaluated in prepuberty [Group (Gr)1, n = 33; early (Gr1A, n = 16) and late (Gr1B, n = 17)]; puberty (Gr3, n = 28), early (Gr3A, n = 9) and late (Gr3B, n = 19); and during the transition between prepuberty and puberty (Gr2, n = 26). Insulin sensitivity was estimated by the fasting glucose/insulin ratio (G/I). In Gr1, G/I was significantly higher, and the mean serum IGF-I and serum dehydroepiandrosterone sulfate (DHEAS) were significantly lower than in Gr3 (P < 0.0001). Mean G/I in Gr1A and Gr3A was significantly higher than in Gr1B (P < 0.01) and Gr3B (P < 0.02), respectively, and ratios in Gr1B were also significantly higher than in Gr3A (P < 0.02). However, body mass index (BMI) in Gr1A, Gr1B, and Gr3A was not significantly different, although a significant increment was observed between late prepuberty (Gr1B) and late puberty (Gr3B; P < 0.0001). On the other hand, serum IGF-I levels in Gr1A and Gr3A were significantly lower than those in Gr1B (P < 0.01) and Gr3B (P < 0.02), respectively. The mean serum DHEAS level in Gr1A and Gr3A was significantly lower than in Gr1B (P < 0.01) and Gr3B (P < 0.02), respectively, and the level in Gr1B was also significantly lower than in Gr3A (P < 0.02). Correlation studies within Gr1, Gr2, and Gr3 were also performed. There was a significant positive correlation between serum DHEAS and age and a significant negative correlation between serum DHEAS and G/I in the three groups. However, a significant positive correlation between serum DHEAS and serum IGF-I was only found in Gr1. Furthermore, a significant negative correlation between BMI and the G/I was found in Gr2 and Gr3. Therefore, changes in insulin sensitivity might be involved in adrenal androgen synthesis both in prepuberty and in puberty, as well as during the transition from prepuberty to puberty. Changes in BMI suggest that adiposity might be a mediator of this effect, particularly during late puberty. On the other hand, the GH/IGF axis might be an important metabolic signal involved in the maturational changes of human adrenal androgens during prepuberty, at the time of adrenarche. Indeed, a significant negative correlation between G/I and serum IGF-I was found in Gr1, as well as in Gr2. In conclusion, the findings of this study indicate that the GH/IGF-I axis and insulin resistance might be involved in the mechanism of adrenarche during prepuberty in normal girls. Because these relationships had not been seen in boys, we proposed that prepubertal ovarian estrogens might be responsible for the sex difference. The relationship between insulin resistance and adrenal androgens persists during the transition from prepuberty to puberty, as well as during puberty.


Assuntos
Sulfato de Desidroepiandrosterona/sangue , Hormônio do Crescimento Humano/fisiologia , Fator de Crescimento Insulin-Like I/fisiologia , Insulina/farmacologia , Puberdade/fisiologia , Adolescente , Índice de Massa Corporal , Criança , Pré-Escolar , Estrogênios/fisiologia , Feminino , Humanos , Resistência à Insulina
18.
J Clin Endocrinol Metab ; 87(3): 1162-9, 2002 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11889181

RESUMO

In girls, but not in boys, pronounced adrenarche and precocious pubarche along with ovarian hyperandrogenism have been related to insulin resistance and reduced fetal growth. However, insulin secretion is increased during puberty in normal boys. The aim of this study was to analyze the possible implication of changes in the GH/IGF-I axis and in insulin sensitivity for the regulation of adrenal androgen secretion of normal prepubertal and adolescent boys. Fifty-six normal boys were divided into the following groups (Gr): Gr1, prepuberty (testicular volume, <4 cc; n = 33); and Gr3, puberty (testicular volume, 4-25 cc; n = 23). Gr1 was subdivided according to age into: Gr1A, early prepuberty (boys younger than 5.9 yr old; n = 16); and Gr1B, late prepuberty (prepubertal boys, 5.9 yr old or older; n = 17). Gr3 was subdivided according to testicular volume into: Gr3A, early puberty (testicular volume, 4-8 cc; n = 13); and Gr3B, late puberty (testicular volume, 10--25 cc; n = 10). To study hormonal changes during the transition between prepuberty and puberty, an additional group, Gr2 (n = 30), was defined by mixing Gr1B and Gr3A. Serum dehydroepiandrosterone sulfate (DHEAS), androstenedione (Delta(4)A), insulin, IGF-I, and glucose were determined after overnight fasting. Insulin sensitivity was estimated by the fasting glucose/insulin (G/I) ratio. There was a close correlation between fasting G/I ratio and QUICKI, a quantitative insulin sensitivity check index. Mean values for Gr1 and Gr3 as well as their subgroups were compared using t test. In Gr1, the mean fasting G/I ratio was significantly higher, and the mean serum IGF-I, serum DHEAS, and serum Delta(4)A levels were significantly lower than in Gr3 (P < 0.001). Mean fasting G/I ratios in Gr1A and Gr3A were not significantly different from those in Gr1B and Gr3B, respectively, but the fasting G/I ratio in Gr3A was significantly lower than that in Gr1B (P < 0006). Moreover, body mass index (BMI) in Gr3A was significantly higher than that in Gr1B (P < 0.01). On the other hand, mean serum IGF-I levels in Gr1A and Gr3A were significantly lower than those in Gr1B and Gr3B, respectively (P < 0.0001). The mean serum DHEAS level in Gr1A was significantly lower than that in Gr1B (P < 0.01), but no difference was found between Gr3A and Gr3B. The mean serum Delta(4)A in Gr1A was similar to that in Gr1B, but the mean serum Delta(4)A in Gr3A was significantly lower than that in Gr3B (P = 0.0001). Correlation studies within Gr1, Gr2, and Gr3 were also carried out. There was a significant positive correlation between serum DHEAS and age in Gr1 and Gr2, but not in Gr3. In Gr1, no significant correlation was found between serum DHEAS and fasting G/I ratio or between serum DHEAS and serum IGF-I, suggesting that adrenal steroidogenesis in male prepuberty is independent of insulin sensitivity or peripheral IGF-I. In Gr2, a significant negative correlation (P = 0.01) between serum DHEAS and the fasting G/I ratio was found, but not between serum DHEAS and serum IGF-I. Furthermore, a significant negative correlation between BMI and the fasting G/I ratio was also found. Therefore, changes in insulin sensitivity might be involved in adrenal androgen synthesis during the transition from prepuberty to puberty. Finally, in Gr3, DHEAS was not significantly correlated with the fasting G/I ratio or serum IGF-I. A significant negative correlation between serum Delta(4)A and the fasting G/I ratio was found in Gr2. In Gr2, but not in Gr3, there was a significant negative correlation between the fasting G/I ratio and age (P = 0.03) and between the fasting G/I ratio and serum IGF-I (P = 0.03). In conclusion, our data support the hypothesis that the GH/IGF-I axis and insulin sensitivity are not involved in the mechanism of adrenarche in boys. Insulin sensitivity and BMI, however, decrease at early puberty rather than at late puberty, and this change could be involved in modulating adrenal androgen steroidogenesis during the transition between late prepuberty and early puberty.


Assuntos
Glândulas Suprarrenais/metabolismo , Androgênios/sangue , Hormônio do Crescimento Humano/sangue , Fator de Crescimento Insulin-Like I/metabolismo , Insulina/fisiologia , Puberdade/sangue , Adolescente , Índice de Massa Corporal , Criança , Pré-Escolar , Humanos , Masculino , Valores de Referência
19.
Horm Res Paediatr ; 82(5): 332-7, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25359306

RESUMO

BACKGROUND: Central adrenal insufficiency (CAI) is due to a decrease of CRH and/or ACTH secretion. ACTH-dependent dehydroepiandrosterone sulphate (DHEAS) has been postulated as a possible marker of adrenal function in adult patients. AIMS: To evaluate the usefulness of basal serum DHEAS determination to diagnose CAI in pubertal patients with a suspected diagnosis of CAI. METHODS: Ninety-four pubertal patients suspected of having CAI were divided into two groups according to sufficient (group 1) or insufficient (group 2) low-dose ACTH test serum cortisol response. Concordance with low (<2.5th percentile) or normal (≥2.5th percentile) basal serum DHEAS levels for age and sex, respectively, was analysed. RESULTS: Fifty patients (53.2%) in group 1 and 44 (46.8%) in group 2 were included. The median value of serum DHEAS levels in group 2 (0.7 µmol/l, interquartile range 0.44-1.49) was significantly lower than in group 1 (2.13 µmol/l, interquartile range 0.87-3.5; p < 0.03). Nevertheless, serum basal DHEAS levels as a diagnostic marker of CAI showed 39% sensitivity and 80% specificity. CONCLUSION: In pubertal patients, basal serum DHEAS levels do not seem to be a useful tool to diagnose either sufficiency or insufficiency of secondary adrenal function.


Assuntos
Insuficiência Adrenal/sangue , Desidroepiandrosterona/sangue , Puberdade/sangue , Adolescente , Hormônio Adrenocorticotrópico/sangue , Adulto , Biomarcadores/sangue , Criança , Humanos , Hidrocortisona/sangue , Masculino
20.
J Clin Endocrinol Metab ; 98(1): E153-61, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23175692

RESUMO

CONTEXT: Steroid acute regulatory (StAR) protein is a mitochondria-targeted protein that is part of the transduceosome complex crucial for transport of cholesterol to mitochondria. Recessive mutations cause classic and nonclassic congenital lipoid adrenal hyperplasia. OBJECTIVE: The aim of this study was to report the clinical, hormonal, genetic, and functional data of a novel heterozygous mutation in the StAR gene found in a 46,XY patient with ambiguous genitalia and neonatal severe steroidogenic deficiency. PATIENT: Undetectable serum steroids with high ACTH and plasma renin activity but normal acute GnRH response were found in infancy. After gonadectomy (at 3 yr of age), serum LH and testosterone were undetectable, whereas FSH was normal but increased slowly afterward. Estrogen replacement therapy, started at 10.2 yr of age, suppressed gonadotropins (for 2 yr). However, after 1 month off estrogens, the patient showed castrated levels. At 11.9 yr old, after fludrocortisone withdrawal because of hypertension, plasma renin activity and aldosterone remained normal, suggesting mineralocorticoid recovery by a StAR-independent mechanism. RESULTS: We found a de novo heterozygous IVS-2A>G StAR mutation and the reported heterozygous p.G146A SF1 polymorphism with normal CYP11A1, FDXR, FDX1, VDAC1, and TSPO genes. The mutant StAR transcript lacked exon 2, resulting in the in-frame loss of amino acids 22 to 59 in the N-terminal mitochondrial targeting signal. In vitro, the mutant protein exhibited reduced StAR activity in a dominant-negative manner and almost no mitochondria localization. CONCLUSIONS: A misfolded p.G22_L59del StAR might interfere with wild-type StAR activity by blocking the transduceosome complex, causing an autosomal dominant form of StAR deficiency, explaining the clinical phenotype. We speculated that estrogen might have modulated mineralocorticoid function and pubertal maturation in a human natural model lacking endogenous steroid production.


Assuntos
Hiperplasia Suprarrenal Congênita/genética , Transtorno 46,XY do Desenvolvimento Sexual/genética , Mitocôndrias/metabolismo , Mutação de Sentido Incorreto , Fosfoproteínas/genética , Sinais Direcionadores de Proteínas/genética , Animais , Células COS , Criança , Chlorocebus aethiops , Transtornos do Desenvolvimento Sexual/genética , Feminino , Genes Dominantes/genética , Humanos , Recém-Nascido , Masculino , Mutação de Sentido Incorreto/fisiologia , Linhagem , Polimorfismo de Nucleotídeo Único/fisiologia , Estrutura Terciária de Proteína/genética , Transporte Proteico/genética
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