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1.
Horm Res Paediatr ; 2024 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-38295778

RESUMO

INTRODUCTION: Menarche is the last stage of pubertal development, which coincides with the completion of longitudinal growth. As a consequence of the lack of national and up-to-date data related to post-menarcheal (PM) growth, the aim of our work was to evaluate post menarcheal growth in a group of contemporary healthy Chilean girls followed, prospectively, until 4 years post-menarche. METHODS: This study was nested within the GOCS cohort, in a prospective fashion. The girls were followed yearly after menarche for at least four years. We modeled each girl growth using a Super Imposition by Translation and Rotation (SITAR) model. RESULTS: A total of 534 girls were evaluated prospectively, 399 girls had height measured two years after menarche, 421 after three years, and 364 of 534 had height measured at four year post menarche. Expected height gained PM, in the complete study group was 6.6 ± 2.5 cm. We observed that the largest gain in height occurred after the first year PM (3.8 1.5 cm). According to the age of menarche, the group with earlier menarche (< 11 years old ) had a greater height gain in cm after four years PM ( 8.2± 3.2 cm ) and the smallest gain was among girls with menarche at an age older than 13 yr (4.4±1.6) ( p<0.001). Age at menarche was significantly associated with all post menarche growth patterns (size, timing and intensity), indicating that girls with older age at menarche grew taller, later and slower than girls with younger age at menarche. Adjusting PM growth pattern by BMI maintained all these association. Applying the SITAR model specifically , girls experiencing menarche after the age of 13 years exhibited slower growth , occurring slightly earlier and with less intensity when adjusted by BMI at menarche . CONCLUSION: In a national and updated dataset we observed that girls grew until 4 years post menarche an average of 6.6 ± 2.5 cm., with greatest gain occurring in the first year PM , (3.8 ± 1.5 cm). Age at menarche was associated with menarche growth patterns.

2.
Front Endocrinol (Lausanne) ; 12: 691240, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34149626

RESUMO

Noonan syndrome is characterized by multiple phenotypic features, including growth retardation, which represents the main cause of consultation to the clinician. Longitudinal growth during childhood and adolescence depends on several factors, among them an intact somatotrophic axis, which is characterized by an adequate growth hormone (GH) secretion by the pituitary, subsequent binding to its receptor, proper function of the post-receptor signaling pathway for this hormone (JAK-STAT5b and RAS/MAPK), and ultimately by the production of its main effector, insulin like growth factor 1 (IGF-1). Several studies regarding the function of the somatotrophic axis in patients with Noonan syndrome and data from murine models, suggest that partial GH insensitivity at a post-receptor level, as well as possible derangements in the RAS/MAPK pathway, are the most likely causes for the growth failure in these patients. Treatment with recombinant human growth hormone (rhGH) has been used extensively to promote linear growth in these patients. Numerous treatment protocols have been employed so far, but the published studies are quite heterogeneous regarding patient selection, length of treatment, and dose of rhGH utilized, so the true benefit of GH therapy is somewhat difficult to establish. This review will discuss the possible etiologies for the growth delay, as well as the outcomes following rhGH treatment in patients with Noonan syndrome.


Assuntos
Transtornos do Crescimento/tratamento farmacológico , Hormônio do Crescimento Humano/uso terapêutico , Síndrome de Noonan/tratamento farmacológico , Animais , Modelos Animais de Doenças , Transtornos do Crescimento/etiologia , Humanos , Camundongos , Síndrome de Noonan/complicações , Resultado do Tratamento
3.
Pediatr Diabetes ; 20(2): 197-201, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30575242

RESUMO

BACKGROUND: Recent studies have suggested that there is an earlier age of onset of puberty in healthy boys. However, no study has determined the age of pubertal development in boys with type 1 diabetes (T1D) and compared the results with a simultaneously recruited group of healthy children. OBJECTIVE: The aim of this study was to evaluate the age of pubertal events in boys with TD1 and determine whether the duration of diabetes, metabolic control or insulin dose are associated with the age of puberty in boys with T1D. METHODS: Boys aged 7 to 19 years with T1D (n = 148, age 12.9 ± 3.0 years) and healthy boys recruited from schools (n = 388 controls, age 12.8 ± 2.2 years) were studied. A pediatric endocrinologist evaluated pubertal development. RESULTS: Boys at genital Tanner stage 2 and the final stages of puberty (genital Tanner 4 and 5) were younger than the control group (P = 0.005, P = 0.003, and P = 0.015, respectively). Both groups of boys had a similar age of pubic Tanner stage development. There were no cases of pubertal delay observed in the T1D cohort. There was no association observed between metabolic control with pubertal timing. T1D adolescents had lower height-SDS than the C group at the final stages of puberty. CONCLUSIONS: Boys with T1D who are treated with modern insulin therapy appear to have an earlier age of onset and an earlier age of final pubertal events than a simultaneously studied group of healthy children. These data suggest that pubertal delay is not a frequent problem for male T1D patients.


Assuntos
Diabetes Mellitus Tipo 1/epidemiologia , Diabetes Mellitus Tipo 1/fisiopatologia , Puberdade Precoce/epidemiologia , Puberdade/fisiologia , Adolescente , Desenvolvimento do Adolescente/fisiologia , Idade de Início , Estatura/fisiologia , Estudos de Casos e Controles , Criança , Chile/epidemiologia , Estudos Transversais , Humanos , Masculino , Puberdade Precoce/etiologia , Maturidade Sexual/fisiologia , Adulto Jovem
4.
Pediatr Endocrinol Rev ; 16(Suppl 1): 100-104, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30378787

RESUMO

Noonan syndrome (NS) is a genetic disorder, which can present clinically with a variable phenotype. Proportional post natal short stature is a common manifestation of NS, with the majority of affected patients having an adult height below the third percentile. Some investigators have reported minor abnormalities in GH secretion and/or action, suggesting that recombinant growth hormone (rhGH) therapy may be useful for the treatment of their short stature. Our review of the literature regarding rhGH therapy in children with NS indicates that this therapy improves height velocity, but relatively few controlled clinical trials reporting adult height are available. rhGH treatment does not appear to be associated with adverse effects in these patients, but data on the possible development of malignancy during treatment are somewhat limited. Therefore, we believe that there is a need for large controlled clinical trials in patients with this condition, in order to accurately assess the effects of rhGH therapy over adult height.


Assuntos
Hormônio do Crescimento/uso terapêutico , Síndrome de Noonan , Estatura , Transtornos do Crescimento , Hormônio do Crescimento Humano , Humanos , Síndrome de Noonan/tratamento farmacológico
5.
J Pediatr Endocrinol Metab ; 30(5): 561-568, 2017 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-28593921

RESUMO

BACKGROUND: During puberty there is a physiologic increase in adrenal and ovarian androgens. It has been suggested that the somatotrophic axis may be related to the development of hyperandrogenism and anovulation in non-obese adult women with polycystic ovarian syndrome (PCOS). The objective of the study was to investigate whether ovarian androgen secretion in young postmenarchal girls is related to the function of their somatotropic axis. METHODS: This was a cross-sectional study of adolescent girls. We studied non-obese adolescent girls with hyperandrogenism (HA; n = 21) matched with control girls (C; n = 25) for chronological age, age at menarche and body mass index. We obtained a fasting blood sample for measurement of serum glucose, insulin, 17-hydroxyprogesterone (17OH-Prog), dehydroepiandrosterone-sulfate (DHEA-S), androstenedione, sex hormone-binding globulin (SHBG), total testosterone, IGF-I, IGF-II, IGFBP-1, IGFBP-3, ghrelin, leptin, AMH (antiMüllerian hormone), luteinizing hormone (LH) and follicle stimulating hormone (FSH) during the follicular phase of the menstrual period. We performed an oral glucose tolerance test to determine blood glucose, insulin and ghrelin levels and urine samples to measure urinary GH (growth hormone) levels. RESULTS: As expected, the hyperandrogenic girls had significantly higher Ferriman scores, basal total testosterone, free androgen index (FAI), androstenedione, AMH, and basal LH levels compared with the girls in controls. Serum IGF-I, IGF-II, IGFBP-3 and urinary GH did not differ between HA and C. There was a correlation between urinary GH and FAI in all girls (r 0.29, p < 0.05). In addition, in HA girls FAI correlated with insulin, homeostasis model assessment (HOMA) and ghrelin. CONCLUSIONS: We observed a correlation between urinary GH and FAI in the hyperandrogenic and control girls, suggesting that the function of the somatotrophic axis may influence the secretion of androgens in adolescent girls.


Assuntos
Hormônios/metabolismo , Hiperandrogenismo/patologia , Ovário/fisiopatologia , Receptores da Somatotropina/metabolismo , Adolescente , Índice de Massa Corporal , Estudos de Casos e Controles , Criança , Estudos Transversais , Feminino , Humanos , Hiperandrogenismo/metabolismo , Maturidade Sexual
6.
J Clin Endocrinol Metab ; 101(12): 4984-4993, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27710241

RESUMO

CONTEXT: Growth of short children in puberty is limited by the effect of estrogen on epiphyseal fusion. OBJECTIVES: To compare: 1) the efficacy and safety of aromatase inhibitors (AIs) vs GH vs AI/GH on increasing adult height potential in pubertal boys with severe idiopathic short stature (ISS); and 2) differences in body composition among groups. DESIGN: Randomized three-arm open-label comparator. SETTING: Outpatient clinical research. PATIENTS: Seventy-six pubertal boys [mean (SE) age, 14.1 (0.1) years] with ISS [height SD score (SDS), -2.3 (0.0)]. INTERVENTION: Daily AIs (anastrozole or letrozole), GH, or AI/GH for 24-36 months. OUTCOMES: Anthropometry, bone ages, dual x-ray absorptiometry, spine x-rays, hormones, safety labs. RESULTS: Height gain [mean (SE)] at 24 months was: AI, +14.0 (0.8) cm; GH, +17.1 (0.9) cm; AI/GH, +18.9 (0.8) cm (P < .0006, analysis of covariance). Height SDS was: AI, -1.73 (0.12); GH, -1.43 (0.14); AI/GH, -1.25 (0.12) (P < .0012). Those treated through 36 months grew more. Regardless of treatment duration, height SDS at near-final height [n = 71; age, 17.4 (0.2) years; bone age, 15.3 (0.1) years; height achieved, ∼97.6%] was: AI, -1.4 (0.1); GH, -1.4 (0.2); AI/GH, -1.0 (0.1) (P = .06). Absolute height change was: AI, +18.2 (1.6) cm; GH, +20.6 (1.5) cm; AI/GH, +22.5 (1.4) cm (P = .01) (expected height gain at -2.0 height SDS, +13.0 cm). AI/GH had higher fat free mass accrual. Measures of bone health, safety labs, and adverse events were similar in all groups. Letrozole caused higher T and lower estradiol than anastrozole. CONCLUSIONS: Combination therapy with AI/GH increases height potential in pubertal boys with ISS more than GH and AI alone treated for 24-36 months with a strong safety profile.


Assuntos
Inibidores da Aromatase/farmacologia , Composição Corporal , Estatura/efeitos dos fármacos , Nanismo/tratamento farmacológico , Hormônio do Crescimento/farmacologia , Avaliação de Resultados em Cuidados de Saúde , Puberdade , Adolescente , Anastrozol , Inibidores da Aromatase/administração & dosagem , Inibidores da Aromatase/efeitos adversos , Quimioterapia Combinada , Nanismo/diagnóstico por imagem , Hormônio do Crescimento/administração & dosagem , Hormônio do Crescimento/efeitos adversos , Humanos , Letrozol , Masculino , Nitrilas/administração & dosagem , Nitrilas/efeitos adversos , Nitrilas/farmacologia , Triazóis/administração & dosagem , Triazóis/efeitos adversos , Triazóis/farmacologia
7.
J Pediatr Endocrinol Metab ; 29(9): 1063-7, 2016 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-27544720

RESUMO

BACKGROUND: Menarche is the last stage of pubertal development, which coincides, with the completion of longitudinal growth. Our aim was to evaluate, post-menarcheal growth and clinical variables proposed to be associated with this growth. METHODS: In a prospective fashion, 106 healthy girls attending five different socioeconomic status (SES) schools of Santiago were randomly recruited. A pediatric endocrinologist obtained anthropometrics and registration of date at menarche every 6 months. The evolution of the girls' heights was assessed through mixed models adjusted to the SESes, parental height and body mass index (BMI). RESULTS: Sixty-three girls from a high socioeconomic status (HSS) and 50 from a low socioeconomic status (LSS) were followed. Four years post menarche, the girls reached a growth plateau and the average height gain was 5.2±2.5 cm. This gain was not associated with SES, BMI, nor with parental height (p=0.744). The only variable that modulated this gain was age at menarche (r=-0.1997, p=0.0332). There was an inverse correlation between height at the moment of menarche and the height reached after 4 years of follow-up adjusted to parental height (r=-0302, p=0.0011). CONCLUSIONS: Post-menarcheal growth ends 4 years post-event and is inversely correlated with the age at menarche and with the height at the moment of menarche independent of BMI, parental height and SES.


Assuntos
Estatura/fisiologia , Menarca/fisiologia , Maturidade Sexual/fisiologia , Adolescente , Desenvolvimento do Adolescente , Fatores Etários , Índice de Massa Corporal , Criança , Chile , Feminino , Seguimentos , Humanos , Estudos Longitudinais , Masculino , Estudos Prospectivos , Classe Social
8.
Growth Horm IGF Res ; 27: 18-27, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26843474

RESUMO

BACKGROUND/AIM: Responsiveness to GH in target cells is mediated by its receptor, which activates the Janus kinase-2 (JAK2) and STAT5 (signal transducers and activators of transcription 5) leading to the expression of IGF-1 and IGFALS. The aim of this study was to compare the GH signaling pathway in newborns and prepubertal boys. SUBJECTS AND METHODS: We determined the GHR protein content and the effect of stimulation with recombinant human GH (rhGH; 200ng/mL) on JAK2 and STAT5 phosphorylation in skin fibroblast cultures obtained from newborns and prepubertal boys. The transcript levels of IGFALS and IGF-I, were also studied and compared after 16h or 24h of stimulation with GH in both study groups. RESULTS: Newborn infants showed less GHR protein than the prepubertal boys. After rhGH stimulation, JAK2 and STAT5 phosphorylation was absent in skin fibroblasts from newborns, but was clearly detectable in prepubertal boys. After 16h of treatment with rhGH, IGFALS and IGF-I transcript levels increased in the prepubertal boys when compared to baseline. In newborns, however, we did not observe a response after 16 and 24h of rhGH stimulation. CONCLUSION: The significant attenuation of the GH signaling pathway observed in fibroblasts from newborn boys appears to be related to a reduction in GHR content and lack of phosphorylation of JAK2 and STAT5 in response to rhGH. This might impair STAT5 dimer formation, leading to a reduction in the transcript levels of IGFALS and IGF-I during the newborn period.


Assuntos
Proteínas de Transporte/metabolismo , Fibroblastos/metabolismo , Glicoproteínas/metabolismo , Hormônio do Crescimento Humano/metabolismo , Janus Quinase 2/metabolismo , Puberdade/metabolismo , Receptores da Somatotropina/metabolismo , Fator de Transcrição STAT5/metabolismo , Pele/metabolismo , Western Blotting , Proteínas de Transporte/genética , Células Cultivadas , Criança , Fibroblastos/citologia , Glicoproteínas/genética , Hormônio do Crescimento Humano/genética , Humanos , Recém-Nascido , Janus Quinase 2/genética , Masculino , Fosforilação , Puberdade/genética , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Receptores da Somatotropina/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fator de Transcrição STAT5/genética , Transdução de Sinais , Pele/citologia
9.
Rev Med Chil ; 143(3): 297-303, 2015 Mar.
Artigo em Espanhol | MEDLINE | ID: mdl-26005815

RESUMO

BACKGROUND: A secular trend towards a younger age of puberty onset has been reported in Chilean girls. AIM: To evaluate the age of onset of puberty and prevalence of early puberty in Chilean boys. MATERIAL AND METHODS: A pediatric endocrinologist examined 319 children attending schools in central Santiago. Pubertal development was assessed by testicular volume (TV) and genital inspection (GI) using Tanner graduation. Precocious and early puberty development was diagnosed if TV ≥ 4 ml or GI > stage 2 occurred in boys younger than 9 years and at 9-10 years of age, respectively. RESULTS: Pubertal onset occurred at 10.2 ± 1.5 years according to TV and at 11.1 ± 1.6 years according to GI (p < 0.01). Before the age of nine, 15.2% of children had a VT ≥ 4 ml, 3% had genital changes in GI and only 3% had both changes simultaneously. Early puberty was observed in 23.8% of children according to TV and 9.5% according to GI. However, no child of less than 11 years old had a TV ≥ 4 ml, genital changes and pubic hair simultaneously. Late pubertal stages occurred at the same age according to both criteria used. Body mass index z score was not associated with the age of pubertal onset. CONCLUSIONS: Testicular enlargement occurs one year earlier than changes in genitalia according to inspection. Testicular growth, but not late stages of puberty, are occurring one year earlier than previously reported in Chile 10 years ago.


Assuntos
Idade de Início , Genitália Masculina/crescimento & desenvolvimento , Puberdade/fisiologia , Maturidade Sexual/fisiologia , Testículo/crescimento & desenvolvimento , Adolescente , Distribuição por Idade , Índice de Massa Corporal , Criança , Chile , Genitália Masculina/anatomia & histologia , Humanos , Masculino , Puberdade Precoce/diagnóstico , Valores de Referência , Testículo/anatomia & histologia , Adulto Jovem
10.
Rev. méd. Chile ; 143(3): 297-303, mar. 2015. graf, tab
Artigo em Espanhol | LILACS | ID: lil-745626

RESUMO

Background: A secular trend towards a younger age of puberty onset has been reported in Chilean girls. Aim: To evaluate the age of onset of puberty and prevalence of early puberty in Chilean boys. Material and Methods: A pediatric endocrinologist examined 319 children attending schools in central Santiago. Pubertal development was assessed by testicular volume (TV) and genital inspection (GI) using Tanner graduation. Precocious and early puberty development was diagnosed if TV ≥ 4 ml or GI > stage 2 occurred in boys younger than 9 years and at 9-10 years of age, respectively. Results: Pubertal onset occurred at 10.2 ± 1.5 years according to TV and at 11.1 ± 1.6 years according to GI (p < 0.01). Before the age of nine, 15.2% of children had a VT ≥ 4 ml, 3% had genital changes in GI and only 3% had both changes simultaneously. Early puberty was observed in 23.8% of children according to TV and 9.5% according to GI. However, no child of less than 11 years old had a TV ≥ 4 ml, genital changes and pubic hair simultaneously. Late pubertal stages occurred at the same age according to both criteria used. Body mass index z score was not associated with the age of pubertal onset. Conclusions: Testicular enlargement occurs one year earlier than changes in genitalia according to inspection. Testicular growth, but not late stages of puberty, are occurring one year earlier than previously reported in Chile 10 years ago.


Assuntos
Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Apresentação de Antígeno , /imunologia , /imunologia , Diferenciação Celular/imunologia , Apresentação Cruzada , Bactérias Gram-Negativas/imunologia , Bactérias Gram-Positivas/imunologia , Imunidade Adaptativa , /patologia , /patologia , Imunidade Inata , Neutrófilos , Receptores de Antígenos de Linfócitos T gama-delta/imunologia
11.
Growth Horm IGF Res ; 24(4): 119-22, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24857397

RESUMO

BACKGROUND: The possible relationship between the circulating concentrations of T4 and GH sensitivity has not been elucidated. OBJECTIVE: The aim of this study is to evaluate the effect of levothyroxine supplementation on GH sensitivity in prepubertal boys with idiopathic short stature (ISS). METHODS: We selected 28 prepubertal boys with ISS (mean age 8.2±0.5years) and free T4 (Ft4) concentrations between the 3rd and the 25th percentiles (Ft4: 0.8-1.5ng/dl). They were randomly divided into two groups: Group A received thyroid supplementation (1-3µg/kg/day) for 120days, and Group B received placebo for the same period. To evaluate GH sensitivity, an IGF-I generation test (GH: 33µg/kg/day sc for 3days) was performed in both groups: under basal conditions, and after 120days of levothyroxine supplementation (or placebo). RESULTS: After thyroid supplementation, Group A had higher Ft4 concentrations compared with Group B (2.14±0.06 vs 1.48±0.06ng/dl, p=0.01), their growth velocity was significantly higher (2.3±0.1 vs 1.5±0.2cm/4months), and they exhibited a greater increase in IGF-I after GH administration (Group A: 32.5±3.8% vs Group B 17.3±2.6%). CONCLUSION: Supplementation with levothyroxine for 120days promotes an increase in growth velocity, and a greater IGF-I response to short-term GH administration in prepubertal boys with ISS and low-normal thyroid hormone concentrations.


Assuntos
Transtornos do Crescimento/tratamento farmacológico , Hormônio do Crescimento/uso terapêutico , Tiroxina/uso terapêutico , Estatura/efeitos dos fármacos , Criança , Humanos , Fator de Crescimento Insulin-Like I/análise , Masculino , Tiroxina/sangue , Tiroxina/farmacologia , Resultado do Tratamento
12.
Pediatr Diabetes ; 15(3): 198-205, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24118936

RESUMO

AIM: Conflicting results regarding testicular function in adults with type 1 diabetes (T1D) have been reported, but little is known about Leydig and Sertoli cell function during puberty in boys treated with multiple daily insulin doses. Our aim was to assess testicular function in boys with T1D. METHODS: Pubertal boys with T1D (n = 71) and healthy control boys (Control group; n = 104) who were 10-18 years were studied. Both groups were matched by pubertal stage, age, and BMI. Total testosterone (TT), calculated free testosterone (cfT), SHBG, inhibin B, AMH, and gonadotropin levels were determined. RESULTS: At the beginning of puberty, the T1D group had higher levels of SHBG (p = 0.003) and similar androgen levels than the Control group. At the end of puberty, higher TT, and cfT were observed in T1D compared to the Control group (p < 0.01 and p < 0.001, respectively). Gonadotropins and AMH were similar in both groups. Regression analysis showed that T1D was a significant factor, even after adjusting for Tanner stage and BMI-SDS, affecting TT, cFT, and SHBG levels. BMI-SDS was a significant factor affecting TT and SHBG levels. Higher HbA1c had a negative effect on total testosterone and cFT and a positive effect on SHBG levels in T1D boys. CONCLUSION: Adolescents with T1D do not exhibit hypogonadism, as shown by normal gonadotropin, testosterone, inhibin B, and AMH levels. However, in T1D boys, HbA1c and BMI-SDS had a negative association with testosterone levels. Elevated testosterone levels are observed during late puberty, which were not present earlier.


Assuntos
Diabetes Mellitus Tipo 1/complicações , Glândulas Endócrinas/fisiopatologia , Doenças do Sistema Endócrino/complicações , Hipogonadismo/complicações , Modelos Biológicos , Puberdade , Testículo/fisiopatologia , Adolescente , Biomarcadores/sangue , Criança , Chile , Diabetes Mellitus Tipo 1/sangue , Diabetes Mellitus Tipo 1/tratamento farmacológico , Diabetes Mellitus Tipo 1/fisiopatologia , Glândulas Endócrinas/efeitos dos fármacos , Glândulas Endócrinas/metabolismo , Doenças do Sistema Endócrino/induzido quimicamente , Doenças do Sistema Endócrino/prevenção & controle , Hemoglobinas Glicadas/análise , Hospitais Públicos , Hospitais Urbanos , Humanos , Hipoglicemiantes/efeitos adversos , Hipoglicemiantes/uso terapêutico , Hipogonadismo/induzido quimicamente , Hipogonadismo/prevenção & controle , Insulina/efeitos adversos , Insulina/uso terapêutico , Masculino , Puberdade/efeitos dos fármacos , Análise de Regressão , Testículo/efeitos dos fármacos , Testículo/metabolismo , Testosterona/análise , Testosterona/metabolismo
13.
J Pediatr Endocrinol Metab ; 26(9-10): 833-40, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23729600

RESUMO

AIM: Some cases of idiopathic short stature (ISS) may be caused by defects in the modulation of the negative feedback regulation of the growth hormone receptor (GHR)/ Janus kinase (JAK)2/signal transducers and activators of transcription (STAT)5 signaling pathway. The cytosolic tyrosine phosphatases, protein tyrosine phosphatase 1B (PTP1B) and Src homology 2 (SH2) domain-containing protein-tyrosine phosphatase-1 (SHP-1), the later which translocates to the nucleus after activation, interact with JAK2 in a GH-dependent manner. The possible contribution of PTP1B and SHP-1 to GH signaling in fibroblasts from ISS patients has not been studied. METHODS: We determined the basal protein content of PTP1B and SHP-1 in the presence of recombinant human GH (rhGH) for 24 h in skin fibroblast cultures, obtained from patients with ISS, and were compared with a normal height control children group. JAK2 activation was determined in both groups. RESULTS: JAK2 activation was delayed in fibroblasts from ISS patients compared to controls. Under basal conditions, the protein content of SHP-1 was lower in ISS, and after incubation with rhGH, it decreased in the non-nuclear and nuclear fraction of controls, but not in ISS patients. The protein content of PTP1B, however, increased in a similar fashion in fibroblasts from both ISS and control children. CONCLUSION: The delayed activation of JAK2 and the lack of response of SHP-1 after incubation with GH in fibroblasts from ISS patients, suggests that the growth retardation observed in some of these children may be mediated in part by this phosphotyrosine phosphatase.


Assuntos
Transtornos do Crescimento/enzimologia , Hormônio do Crescimento Humano/metabolismo , Janus Quinase 2/metabolismo , Proteína Tirosina Fosfatase não Receptora Tipo 1/metabolismo , Proteína Tirosina Fosfatase não Receptora Tipo 6/metabolismo , Transdução de Sinais , Pele/enzimologia , Estatura , Núcleo Celular/enzimologia , Núcleo Celular/metabolismo , Células Cultivadas , Criança , Desenvolvimento Infantil , Ativação Enzimática , Transtornos do Crescimento/metabolismo , Transtornos do Crescimento/patologia , Hormônio do Crescimento Humano/genética , Humanos , Janus Quinase 2/química , Cinética , Masculino , Fosforilação , Processamento de Proteína Pós-Traducional , Receptores da Somatotropina/agonistas , Receptores da Somatotropina/metabolismo , Proteínas Recombinantes/metabolismo , Pele/metabolismo , Pele/patologia
14.
Fertil Steril ; 94(5): 1822-6, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19796762

RESUMO

OBJECTIVE: To evaluate the prevalence and risk factors of menstrual cycle irregularities in adolescents with type 1 diabetes mellitus. DESIGN: Prospective diary of menstrual cycle. SETTING: Pediatric diabetes clinics and nearby schools. PATIENT(S): Adolescents with type 1 diabetes mellitus treated with multiple daily insulin doses (n = 56) and 56 healthy adolescents. MAIN OUTCOME MEASURE(S): Duration and variability of menstrual cycle. RESULT(S): Duration of the menstrual cycle was 48 ± 39 and 32 ± 7 days in girls with type 1 diabetes mellitus and controls, respectively. Oligomenorrhea (58.9% vs. 19.6%) and amenorrhea (10.7% vs. 1.8%) were more prevalent in girls with type 1 diabetes mellitus than in controls. Oligomenorrhea was observed in 53.3% of the girls with type 1 diabetes mellitus with optimal metabolic control. Girls with an HbA1c level of 7.6% to 8.9% exhibited increased cycle duration, menstrual cycle variability, and prevalence of oligomenorrhea compared with controls. Regression analysis showed that, for each point of increase in HbA1c, the menstrual cycle duration increased by 5.1 days. Cycle variability was associated with a higher daily insulin dose. CONCLUSION(S): Despite optimal metabolic control, a higher prevalence of oligomenorrhea was observed in girls with type 1 diabetes mellitus compared with controls. This is the first report to describe the high variability of the menstrual cycle in type 1 diabetes mellitus. HbA1c and insulin dose are important factors related to menstrual irregularities in type 1 diabetes mellitus.


Assuntos
Diabetes Mellitus Tipo 1/sangue , Diabetes Mellitus Tipo 1/tratamento farmacológico , Hemoglobinas Glicadas/metabolismo , Hipoglicemiantes/uso terapêutico , Insulina/uso terapêutico , Distúrbios Menstruais/epidemiologia , Adolescente , Amenorreia/epidemiologia , Estudos de Casos e Controles , Diabetes Mellitus Tipo 1/complicações , Relação Dose-Resposta a Droga , Feminino , Humanos , Ciclo Menstrual/fisiologia , Oligomenorreia/epidemiologia , Valor Preditivo dos Testes , Prevalência , Estudos Prospectivos , Fatores de Risco , Fatores de Tempo
15.
Rev. méd. Chile ; 135(11): 1429-1436, nov. 2007. graf, tab
Artigo em Espanhol | LILACS | ID: lil-472842

RESUMO

Background: A decline in the age of menarche was observed from early 1900s to the 1970s. However, it is not known if a further decline ocurred thereafter. Aim: To evaluate the age of menarche in girls from Santiago, Chile and its relationship with body mass index (BMI) and socioeconomic status. Material and Methods: We studied 1302 healthy girls aged 7 to 19 years. Age of menarche was evaluated through a questionnaire to the patient and her parents. Kaplan-Meier curves were used to determine age of menarche and Cox regression analysis was employed to evaluate the effect of the type of school and BMI on the age of menarche. Results: The mean age at menarche was 12.7±0.04 years. Girls from public and private schools had their period at 12.5±0.1 and 13.05±0.05 years respectively. A negative correlation between z scores for BMIand age of menarche was observed (r-0.3: p =0.001). Girls whose menarche occurred before 11.5 years had higher z scores for BMI and a larger proportion were overweight, compared to girls who had menarche later. Cox regression analysis showed that after adjusment for BMI, age of menarche was similar in both types of schools. Conclusions: Age of menarche is ocurring three months earlier in girls from public schools, which is associated with higher z scores for BMI. Type of school, a marker of socio-economic status in Chile, affects timing of menarche due to differences in body mass index.


Assuntos
Adolescente , Criança , Feminino , Humanos , Índice de Massa Corporal , Menarca/fisiologia , Obesidade/fisiopatologia , Classe Social , Estimativa de Kaplan-Meier , Idade de Início , Chile , Modelos de Riscos Proporcionais , Inquéritos e Questionários
16.
Rev Med Chil ; 135(11): 1429-36, 2007 Nov.
Artigo em Espanhol | MEDLINE | ID: mdl-18259654

RESUMO

BACKGROUND: A decline in the age of menarche was observed from early 1900s to the 1970s. However, it is not known if a further decline occurred thereafter. AIM: To evaluate the age of menarche in girls from Santiago, Chile and its relationship with body mass index (BMI) and socioeconomic status. MATERIAL AND METHODS: We studied 1302 healthy girls aged 7 to 19 years. Age of menarche was evaluated through a questionnaire to the patient and her parents. Kaplan-Meier curves were used to determine age of menarche and Cox regression analysis was employed to evaluate the effect of the type of school and BMI on the age of menarche. RESULTS: The mean age at menarche was 12.7+/-0.04 years. Girls from public and private schools had their period at 12.5+/-0.1 and 13.05+/-0.05 years respectively. A negative correlation between z scores for BMI and age of menarche was observed (r-0.3: p =0.001). Girls whose menarche occurred before 11.5 years had higher z scores for BMI and a larger proportion were overweight, compared to girls who had menarche later. Cox regression analysis showed that after adjustment for BMI, age of menarche was similar in both types of schools. CONCLUSIONS: Age of menarche is occurring three months earlier in girls from public schools, which is associated with higher z scores for BMI. Type of school, a marker of socio-economic status in Chile, affects timing of menarche due to differences in body mass index.


Assuntos
Índice de Massa Corporal , Menarca/fisiologia , Obesidade/fisiopatologia , Classe Social , Adolescente , Idade de Início , Criança , Chile , Feminino , Humanos , Estimativa de Kaplan-Meier , Modelos de Riscos Proporcionais , Inquéritos e Questionários
17.
Pediatr Diabetes ; 5(4): 182-9, 2004 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-15601360

RESUMO

OBJECTIVES: We assessed pubertal development, height, weight, and waist-to-hip ratio (WHR), an index of central adiposity during puberty, in girls with type-1 diabetes mellitus (T1DM), compared to a contemporary control group. METHODS: Pubertal development, weight, height and WHR were studied in 100 pubertal girls with T1DM, and were compared to a control group of 576 normal girls (C), recruited from schools with a similar socioeconomic level and ethnicity. The age of onset of various pubertal stages was estimated by using probit analysis. RESULTS: Breast Tanner stage 2 (BT2) began at 8.89 +/- 0.11 and 9.10 +/- 0.28 yr in C and T1DM, respectively. A delay of 6 months was observed in T1DM for BT3 and BT4 (p < 0.05). Menarche occurred 6 months later in girls with T1DM (p = 0.03). WHR decreased during puberty in C (p < 0.001), but not in T1DM. In girls with T1DM, the body mass index standard deviation score (BMI-SDS) increased throughout puberty (p < 0.001), but it was stable in C. In T1DM girls, BMI-SDS, but not hemoglobin A1c levels (HbA1c), was a significant determinant of pubertal development. Final height was similar in T1DM and C. CONCLUSIONS: Pubertal development in girls with T1DM occurred earlier than described in historical cohorts, but a later onset of menarche and final stages of breast development were observed. The increase in BMI-SDS and the stability of WHR in girls with T1DM during puberty suggest that this period may be critical for determining later weight gain and body composition in adult women with this condition.


Assuntos
Diabetes Mellitus Tipo 1/fisiopatologia , Puberdade , Aumento de Peso , Adolescente , Antropometria , Tamanho Corporal , Criança , Chile , Feminino , Hemoglobinas Glicadas/análise , Humanos , Menarca/fisiologia , Valores de Referência
18.
Rev Med Chil ; 132(7): 801-8, 2004 Jul.
Artigo em Espanhol | MEDLINE | ID: mdl-15379326

RESUMO

BACKGROUND: Recent studies in the United States have demonstrated that a significant proportion of girls show thelarche before the age of eight years. Nutritional status, geographic influences and racial factors are known to affect the timing of puberty. AIM: To evaluate the age of onset of puberty, development of secondary sexual characteristics and menarche in Chilean girls, and its relation to obesity and socioeconomic status. MATERIAL AND METHODS: Healthy girls attending elementary school, from first to ninth grade in Santiago, Chile, were studied. A pediatric endocrinologist evaluated pubertal development using Tanner classification. Breast development was assessed by inspection and breast palpation. Average age of onset of pubertal events was determined by probit analysis. RESULTS: A total of 758 girls, aged 5.8 to 16.1 years, were recruited. Obesity, defined as a BMI greater than 90th percentile, was found in 24.4%. The age of menarche was 12.7 years, the onset of Tanner stage 2 breast development and pubic hair was at 8.9 and 10.4 years, respectively. Sixteen percent of girls aged 7 to 7.9 years, had thelarche. Upper class girls showed a later onset of breast Tanner stage 4 stage than low-middle class girls. Obesity was not found in logistic regression analysis to be a significant predictive factor in the onset of puberty. CONCLUSIONS: The age of menarche has not changed in the last thirty years, but an earlier onset of thelarche has occurred. The high frequency of thelarche between 7 and 8 years suggests that the normal age of breast development should be revised.


Assuntos
Índice de Massa Corporal , Puberdade/fisiologia , Maturidade Sexual/fisiologia , Classe Social , Adolescente , Análise de Variância , Mama/crescimento & desenvolvimento , Criança , Chile , Estudos Transversais , Feminino , Cabelo/crescimento & desenvolvimento , Humanos , Menarca , Fatores Socioeconômicos
19.
Rev Med Chil ; 131(8): 857-64, 2003 Aug.
Artigo em Espanhol | MEDLINE | ID: mdl-14558239

RESUMO

BACKGROUND: During the last decade, the importance of glycemic control in the prevention of the microvascular complications of type 1 Diabetes Mellitus (DM1) was clearly demonstrated. AIM: To evaluate the metabolic and anthropometric results of a multidisciplinary intensified treatment program of DMI in children and adolescents. PATIENTS AND METHODS: Report of 54 patients treated during 2001. The intensified treatment consisted of: multiple daily doses of insulin, frequent glycemic control, nutritional, psychological and educational support, and permanent availability of a diabetes nurse for telephonic support. RESULTS: Thirty one patients were female, their mean age was 10.4 +/- 0.5 years old and 52% were experiencing puberty. Fifty three percent of the patients used 3 insulin doses per day, 95% changed rapid insulin dose based on glucose levels and 18% considered carbohydrates in their rapid insulin dosing. Mean glycosilated hemoglobin was 8.18 +/- 0.23% without differences by sex or pubertal status. Sex, pubertal stage and the number of insulin doses did not contribute to glycosilated hemoglobin changes. There were no differences in weight or BMI, but there was a decrease in height Z score from the admission to the program until the last control (0.1 +/- 0.1 vs--0.3 +/- 0.1 DS; p < 0.01). CONCLUSIONS: A modified intensified modality of DM1 therapy for pediatric patients in a public hospital in Chile is feasible, achieving similar metabolic control, compared to international large centers.


Assuntos
Diabetes Mellitus Tipo 1/terapia , Adolescente , Antropometria , Glicemia/metabolismo , Criança , Chile , Diabetes Mellitus Tipo 1/metabolismo , Feminino , Hemoglobinas Glicadas/análise , Humanos , Insulina/administração & dosagem , Masculino , Estatísticas não Paramétricas , Resultado do Tratamento
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