RESUMO
BACKGROUND: Results in neonatal screening programs aiming at detection of congenital adrenal hyperplasia (CAH) can only report elevated levels of 17-hydroxy-progesterone (17-OHP), without being able to differentiate presence or absence of salt loss. AIM: To predict presence or absence of salt loss in newborn infants with CAH. METHODS: The first specimen of suspected CAH in samples sent from People's Democratic Republic of Laos (Lao PDR) was investigated for known mutations in CAH associated with salt loss. RESULTS: Molecular genetic diagnosis revealed mutations associated with loss of function in both alleles; however, the infant was clinically unaffected even without any corticosteroid substitution therapy. CONCLUSIONS: Although molecular genetic methods can theoretically predict loss of function in CAH, our infant was clinically unaffected even without therapy at 6 years of age. We speculate that in CAH, remaining enzyme activity can be sufficiently high, despite the presence of loss of function mutations, which do not affect infants clinically.
Assuntos
17-alfa-Hidroxiprogesterona/sangue , Hiperplasia Suprarrenal Congênita/enzimologia , Hiperplasia Suprarrenal Congênita/genética , Mutação/genética , Esteroide 21-Hidroxilase/genética , Hiperplasia Suprarrenal Congênita/sangue , Alelos , Humanos , Recém-Nascido , Laos , Biologia Molecular , Triagem Neonatal , Valor Preditivo dos TestesAssuntos
Endocrinologistas , Endocrinologia/história , Docentes de Medicina , Pediatria , Criança , Hipotireoidismo Congênito/diagnóstico , Hipotireoidismo Congênito/etiologia , Hipotireoidismo Congênito/história , Endocrinologistas/história , Endocrinologia/educação , Endocrinologia/organização & administração , Docentes de Medicina/história , História do Século XX , História do Século XXI , Humanos , Recém-Nascido , Triagem Neonatal/história , Pediatria/educação , Pediatria/história , Pediatria/organização & administração , Sociedades Médicas/história , Sociedades Médicas/organização & administraçãoRESUMO
Blood sampling for newborn screening cannot be standardized as for example blood collection in adults after an overnight fast. Therefore the influence of postprandial changes and individual variation is valuable information for the assessment of sensitivity and specificity of newborn screening for certain disorders. We have analyzed 92 pairs of dried blood samples taken pre- and one hour postprandially, respectively. We have determined the mean increase in metabolite concentration and calculated its significance. Individual variation after an overnight fast in healthy adults (n = 3) was between 12 and 32% (SD). Postprandial increases of acylcarnitines were mostly not significant and not exceeding 10%. Postprandial increase of amino acids was highly significant for most proteinogenic amino acids, but not for all. With the collected data we were able to estimate that mainly decreased levels of methionine and, to a lesser extent, of free carnitine could be "masked" by postprandial increases of the respective metabolites, and could therefore lead to false negative results for the detection of disorders of cobalamin metabolism and carnitine transporter deficiency.
Assuntos
Aminoácidos/sangue , Carnitina/análogos & derivados , Erros Inatos do Metabolismo/diagnóstico , Triagem Neonatal , Período Pós-Prandial , Adulto , Biomarcadores/sangue , Coleta de Amostras Sanguíneas , Carnitina/sangue , Reações Falso-Negativas , Reações Falso-Positivas , Humanos , Recém-Nascido , Erros Inatos do Metabolismo/sangue , Pessoa de Meia-Idade , Triagem Neonatal/métodos , Valor Preditivo dos Testes , Regulação para Cima , Adulto JovemRESUMO
We aim to determine long-term intellectual outcome of adolescents with early high-dose treated congenital hypothyroidism (CH). Sixty-three prospectively followed children with CH were assessed at age of 14 y with the Wechsler Intelligence Scale for Children-Revised and compared with 175 healthy controls. Median age at onset of treatment was 9 d (range 5-18 d) and median starting dose of levothyroxine (L-T4) was 14.7 microg/kg/d (range 9.9-23.6 microg/kg/d). Full-scale intelligence quotient (IQ) was significantly lower than in controls after adjustment for socioeconomic status (SES) and gender (101.7 versus 111.4; p < 0.0001). Children with athyreosis had a lower performance IQ than those with dysgenesis (adjusted difference 7.6 IQ scores, p < 0.05). Lower initial thyroxine (T4) levels correlated with poorer IQ (r = 0.27, p = 0.04). Lower SES was associated with poorer IQ, in particular in children with CH (interaction, p = 0.03). Treatment during childhood was not related to IQ at age 14 y. Adolescents with CH manifest IQ deficits when compared with their peers despite early high-dose treatment and optimal substitution therapy throughout childhood. Those adolescents with athyreosis and lower SES are at particular risk for adverse outcome. Therefore, early detection of intellectual deficits is mandatory in children with CH.
Assuntos
Desenvolvimento do Adolescente/efeitos dos fármacos , Hipotireoidismo Congênito/tratamento farmacológico , Inteligência/efeitos dos fármacos , Disgenesia da Tireoide/tratamento farmacológico , Glândula Tireoide/anormalidades , Tiroxina/administração & dosagem , Adolescente , Estudos de Casos e Controles , Hipotireoidismo Congênito/sangue , Hipotireoidismo Congênito/diagnóstico , Hipotireoidismo Congênito/psicologia , Feminino , Humanos , Recém-Nascido , Testes de Inteligência , Masculino , Triagem Neonatal , Estudos Prospectivos , Suíça , Disgenesia da Tireoide/sangue , Disgenesia da Tireoide/diagnóstico , Disgenesia da Tireoide/psicologia , Glândula Tireoide/metabolismo , Tireotropina/sangue , Tiroxina/sangue , Fatores de Tempo , Resultado do TratamentoRESUMO
CONTEXT: Thyroglobulin (Tg) may be a valuable indicator of improving thyroid function in children after salt iodization. A recently developed Tg assay for use on dried whole blood spots (DBS) makes sampling practical, even in remote areas. OBJECTIVE: The study aim was to develop a reference standard for DBS-Tg, establish an international reference range for DBS-Tg in iodine-sufficient children, and test the standardized DBS-Tg assay in an intervention trial. DESIGN, PARTICIPANTS, AND INTERVENTIONS: Serum Tg reference material of the European Community Bureau of Reference (CRM-457) was adapted for DBS and its stability tested over 1 yr. DBS-Tg was determined in an international sample of 5- to 14-yr-old children (n = 700) who were euthyroid, anti-Tg antibody negative, and residing in areas of long-term iodine sufficiency. In a 10-month trial in iodine-deficient children, DBS-Tg and other indicators of iodine status were measured before and after introduction of iodized salt. RESULTS: Stability of the CRM-457 Tg reference standard on DBS over 1 yr of storage at -20 and -50 C was acceptable. In the international sample of children, the third and 97th percentiles of DBS-Tg were 4 and 40 microg/liter, respectively. In the intervention, before introduction of iodized salt, median DBS-Tg was 49 microg/liter, and more than two thirds of children had DBS-Tg values greater than 40 microg/liter. After 5 and 10 months of iodized salt use, median DBS-Tg decreased to 13 and 8 microg/liter, respectively, and only 7 and 3% of children, respectively, had values greater than 40 microg/liter. DBS-Tg correlated well at baseline and 5 months with urinary iodine and thyroid volume. CONCLUSIONS: The availability of reference material and an international reference range facilitates the use of DBS-Tg for monitoring of iodine nutrition in school-age children.
Assuntos
Iodo/sangue , Valores de Referência , Tireoglobulina/análise , Testes de Função Tireóidea/normas , Adolescente , Criança , Pré-Escolar , Deficiências Nutricionais/dietoterapia , União Europeia/organização & administração , Feminino , Humanos , Iodo/deficiência , Iodo/uso terapêutico , Iodo/urina , Masculino , Padrões de Referência , Cloreto de Sódio na Dieta/uso terapêutico , Doenças da Glândula Tireoide/dietoterapia , Testes de Função Tireóidea/métodos , Organização Mundial da Saúde/organização & administraçãoRESUMO
BACKGROUND: Many industrialized countries struggle to maintain adequate iodine intake because of changes in dietary habits and the food supply. In Switzerland, because of declining iodine intakes in children and pregnant women, the iodine concentration in table salt was increased from 15 to 20 mg/kg. OBJECTIVE: We evaluated Swiss iodine nutrition after the 1999 increase in the salt iodine concentration. DESIGN: In 1999 and 2004, a 3-stage probability proportionate-to-size cluster sampling was done to obtain a representative national sample of primary schoolchildren and pregnant women. Urine and household salt were collected for iodine measurement. The frequency of elevated thyrotropin concentrations found in the newborn screening program was evaluated before and after the increase. RESULTS: In 1999, median urinary iodine (UI) concentrations among children (n = 610) and pregnant women (n = 511) were 115 microg/L (range: 5-413 microg/L) and 138 microg/L (range: 5-1881 microg/L), respectively, which indicated marginal iodine status. In 2004, median UI concentrations among children (n = 386) and pregnant women (n = 279) were 141 microg/L (range: 0-516 microg/L) and 249 microg/L (range: 8-995 microg/L), respectively (P < 0.01). Newborn thyrotropin concentrations >5 mU/L decreased from 2.9% in 1992-1998 (n = 259 035) to 1.7% in 1999-2004 (n = 218 665) (P < 0.0001). CONCLUSIONS: A 25% increase in iodine concentration in iodized table salt markedly improved iodine status in Switzerland, which showed the value of monitoring and adjusting iodine concentrations in national salt programs. The frequency of newborn thyrotropin concentrations >5 mU/L appears to be a sensitive indicator of iodine nutrition during pregnancy.
Assuntos
Iodo/administração & dosagem , Gravidez/metabolismo , Cloreto de Sódio na Dieta/administração & dosagem , Criança , Feminino , Humanos , Iodo/urina , Masculino , Estudos Prospectivos , Tireotropina/sangueRESUMO
In developing countries, children are at high risk for both the iodine deficiency disorders (IDD) and vitamin A deficiency (VAD). The study aim was to determine the effects of VAD and vitamin A (VA) supplementation on thyroid function in an area of endemic goiter. In a double-blind, randomized, 10-month trial, Moroccan children with IDD and VAD (n = 138) were given iodized salt and either VA (200,000 IU) or placebo at 0 and 5 months. At 0, 5, and 10 months, measurements of VA status and thyroid function were made. At baseline, increasing VAD severity was a predictor of greater thyroid volume and higher concentrations of TSH and thyroglobulin (P < 0.001). In children with VAD, the odds ratio for goiter was 6.51 (95% confidence interval, 2.94, 14.41). VAD severity was also a strong predictor of higher concentrations of total T(4) (P < 0.001); the odds ratio for hypothyroidism in VAD was 0.06 (95% confidence interval, 0.03, 0.14). During the intervention, mean thyroglobulin, median TSH, and the goiter rate significantly decreased in the VA-treated group compared with those in the placebo group (P < 0.01). The findings indicate that VAD in severely IDD-affected children increases TSH stimulation and thyroid size and reduces the risk for hypothyroidism. This effect could be due to decreased VA-mediated suppression of the pituitary TSHbeta gene. In IDD- and VAD-affected children receiving iodized salt, concurrent VA supplementation improves iodine efficacy.
Assuntos
Bócio/fisiopatologia , Glândula Tireoide/fisiopatologia , Deficiência de Vitamina A/tratamento farmacológico , Vitamina A/administração & dosagem , Adolescente , Criança , Estudos Transversais , Suplementos Nutricionais , Método Duplo-Cego , Feminino , Humanos , Masculino , Hormônios Tireóideos/sangue , Deficiência de Vitamina A/fisiopatologiaRESUMO
Newborn screening for congenital adrenal hyperplasia (CAH) is justified by the sometimes difficult clinical diagnosis and the risks associated with missed diagnosis, particularly the life-threatening salt-wasting crisis. In Switzerland, nationwide screening for CAH by measuring 17-hydroxyprogesterone levels in dried blood spots was introduced in 1992. At the Zurich University Children's Hospital, 50% of the population of Switzerland is screened. The aim of the study was to evaluate the efficiency of the Zurich screening program. Between January 1, 1993, and May 31, 2001, 333,221 newborns were screened for CAH. Thirty-one newborns had CAH (incidence, 1 in 10,749); 30 were detected through screening (sensitivity, 97%). A recall for suspected CAH was performed in only 60 cases, corresponding to a very low recall rate (0.0018%). In 30 recalls CAH was confirmed (positive predictive value, 50%; specificity, 99.99%). Fifteen of 31 patients profited from screening, as CAH had not been recognized clinically. The timely availability of screening results made therapy possible within the first week of life in most cases and helped in preventing salt-wasting crisis in all patients. With a sensitivity of 97%, a specificity of 99.99%, and a positive predictive value of 50%, the Zurich neonatal screening program for CAH can be considered highly reliable.
Assuntos
Hiperplasia Suprarrenal Congênita/diagnóstico , 17-alfa-Hidroxiprogesterona/sangue , Hiperplasia Suprarrenal Congênita/epidemiologia , Reações Falso-Positivas , Feminino , Idade Gestacional , Humanos , Incidência , Recém-Nascido , Masculino , Triagem Neonatal , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Suíça/epidemiologiaRESUMO
BACKGROUND: In programs to control iodine deficiency disorders (IDD), sustainability is a major concern. IDD has recently recurred in countries where salt iodization programs have lapsed. OBJECTIVE: The objective of the study was to describe the evolution of thyroid dysfunction after the discontinuation of salt iodization in a cohort of children in an area of severe endemic goiter. DESIGN: Moroccan children (aged 6-16 y, n = 159) with severe IDD received iodized salt (IS) for 1 y. Because of practical and financial constraints, including a lack of infrastructure and electricity at the production site, salt iodization abruptly ceased. The children were followed for another 14 mo, and concentrations of urinary iodine, thyrotropin, total thyroxine, and thyroglobulin and thyroid volume were measured. RESULTS: Before iodization, median urinary iodine was 18 microg/L, 88% of children had elevated serum thyroglobulin concentrations, and 72% were goitrous. One year after the introduction of IS, median urinary iodine and thyroglobulin concentrations had normalized, mean thyroid volume had decreased by 34%, and median thyrotropin and mean total thyroxine concentrations were improved. Five months after the discontinuation of salt iodization, median urinary iodine had fallen to 20 microg/L. Fourteen months after the discontinuation of salt iodization, the rate of goiter was again similar to the rate before salt iodization; median thyrotropin and thyroglobulin concentrations were sharply higher than before the introduction of IS (P < 0.001); and the prevalence of hypothyroidism was 10%, compared with 3% before the introduction of IS (P < 0.001). CONCLUSIONS: In IDD-affected areas, cessation of salt iodization is associated with a rapid deterioration of thyroid function in school-age children. These findings underline the importance of sustainability in IDD control and the vulnerability of children to even short-term lapses in IS programs.
Assuntos
Bócio/epidemiologia , Iodo/deficiência , Hormônios Tireóideos/sangue , Adolescente , Criança , Feminino , Bócio/etiologia , Humanos , Iodo/provisão & distribuição , Iodo/urina , Masculino , Marrocos/epidemiologia , Cloreto de Sódio na Dieta/provisão & distribuiçãoRESUMO
BACKGROUND: Serum thyroglobulin appears to be a sensitive marker of thyroid dysfunction in endemic goiter. However, its value as an indicator of thyroid status in children after the introduction of iodized salt has not been tested. OBJECTIVE: The objective was to optimize and validate a thyroglobulin assay on dried whole blood spots and to evaluate thyroglobulin as an indicator of thyroid response to iodized salt. DESIGN: A standardized, commercially available, sandwich fluoroimmunometric serum thyroglobulin assay was adapted for use on blood spots and validated in Swiss children. In a 1-y prospective study in 377 goitrous Moroccan children aged 6-15 y, the assay was used to measure thyroglobulin before and after the introduction of iodized salt. Urinary iodine, thyroid volume, thyrotropin, and thyroxine were measured, and regression was done with thyroglobulin as the dependent variable. RESULTS: Correlation between the blood spot and serum assays was excellent (r = 0.98). The SD of the difference between the blood spot and serum assays was 3.8 micro g/L; the median CVs for the blood spot assay in controls and samples were 6.3% and 14.4%, respectively. Median thyroglobulin was 24.5 (range: 0-328.8) micro g/L at baseline and fell significantly after the introduction of iodized salt to 6.2 (0-83.1) and 4.4 (0-47.1) micro g/L at 5 and 12 mo, respectively (P < 0.0001). Regression of urinary iodine and thyroid volume on thyroglobulin was highly significant at baseline and at 5 mo (P < 0.001). CONCLUSION: Thyroglobulin, measured in dried whole blood spots, may be a valuable indicator of improving thyroid function in children after supplementation with iodized salt.
Assuntos
Bócio Endêmico/tratamento farmacológico , Bócio Endêmico/fisiopatologia , Iodo/administração & dosagem , Cloreto de Sódio na Dieta/administração & dosagem , Cloreto de Sódio na Dieta/uso terapêutico , Tireoglobulina/análise , Testes de Função Tireóidea , Glândula Tireoide/fisiopatologia , Adolescente , Criança , Feminino , Bócio Endêmico/sangue , Testes Hematológicos/métodos , Humanos , Masculino , Marrocos , Instituições AcadêmicasRESUMO
BACKGROUND: In many developing countries, children are at high risk of both goiter and iron deficiency anemia. OBJECTIVE: In a series of studies in northern Morocco, we developed and tested a dual-fortified salt (DFS) containing iodine and microencapsulated iron. DESIGN: To establish the DFS fortification concentration, we measured salt intake by 3-d weighed food records and estimated iron bioavailability from the local diet by using published algorithms. We then formulated a DFS containing 25 micro g iodine/g salt (as potassium iodide) and 1 mg iron/g salt (as ferrous sulfate hydrate encapsulated with partially hydrogenated vegetable oil). After storage and acceptability trials, we compared the efficacy of the DFS to that of iodized salt in a 9-mo, randomized, double-blind trial in iodine-deficient, 6-15-y-old children (n = 377). RESULTS: Mean salt intake in school-age children was 7-12 g/d, and estimated iron bioavailability from the local diet was 0.4-4.3%. After storage for 20 wk, the DFS and iodized salt were not significantly different in iodine content, and color stability was acceptable when the compounds were added to local meals. During the efficacy trial, urinary iodine concentrations and thyroid volumes improved significantly (P < 0.001 and < 0.05, respectively) from baseline in both groups. At 40 wk, mean hemoglobin concentrations in the DFS group had increased by 14 g/L (P < 0.01), and serum ferritin, transferrin receptor, and zinc protoporphyrin concentrations were significantly better (P < 0.05) in the DFS group than in the iodized salt group. The prevalence of iron deficiency anemia in the DFS group decreased from 35% at baseline to 8% at 40 wk (P < 0.001). CONCLUSION: A DFS containing iodine and encapsulated iron can be an effective fortification strategy.
Assuntos
Anemia Ferropriva/prevenção & controle , Alimentos Fortificados , Bócio/prevenção & controle , Iodo/uso terapêutico , Ferro da Dieta/uso terapêutico , Cloreto de Sódio na Dieta/uso terapêutico , Adolescente , Adulto , Idoso , Anemia Ferropriva/complicações , Anemia Ferropriva/epidemiologia , Disponibilidade Biológica , Criança , Pré-Escolar , Método Duplo-Cego , Composição de Medicamentos , Feminino , Manipulação de Alimentos/métodos , Bócio/complicações , Bócio/epidemiologia , Humanos , Ferro da Dieta/farmacocinética , Masculino , Pessoa de Meia-Idade , Marrocos/epidemiologia , Prevalência , Glândula Tireoide/efeitos dos fármacos , Fatores de Tempo , Resultado do TratamentoRESUMO
BACKGROUND: In many developing countries, children are at high risk of both goiter and iron deficiency anemia. Iron deficiency adversely affects thyroid metabolism and may reduce the efficacy of iodine prophylaxis in areas of endemic goiter. OBJECTIVE: The aim of this study was to determine whether iron supplementation in goitrous, iron-deficient children would improve their response to iodized salt. DESIGN: We conducted a randomized, double-blind, placebo-controlled trial in 5-14-y-old children in Côte d'Ivoire. Goitrous, iron-deficient children (n = 166) consuming iodized salt (10-30 mg I/kg salt at the household level) were supplemented with either iron (60 mg Fe/d, 4 d/wk for 16 wk) or placebo. At 0, 1, 6, 12, and 20 wk, we measured hemoglobin, serum ferritin, serum transferrin receptor, whole-blood zinc protoporphyrin, thyrotropin, thyroxine, urinary iodine, and thyroid gland volume (by ultrasonography). RESULTS: Hemoglobin and iron status at 20 wk were significantly better after iron treatment than after placebo (P < 0.05). At 20 wk, the mean reduction in thyroid size in the iron-treated group was nearly twice that in the placebo group (x +/- SD percentage change in thyroid volume from baseline: -22.8 +/- 10.7% compared with -12.7 +/- 10.1%; P < 0.01). At 20 wk, goiter prevalence was 43% in the iron-treated group compared with 62% in the placebo group (P < 0.02). There were no significant differences between groups in whole-blood thyrotropin or serum thyroxine at baseline or during the intervention. CONCLUSIONS: Iron supplementation improves the efficacy of iodized salt in goitrous children with iron deficiency. A high prevalence of iron deficiency among children in areas of endemic goiter may reduce the effectiveness of iodine prophylaxis.
Assuntos
Anemia Ferropriva/tratamento farmacológico , Bócio Endêmico/tratamento farmacológico , Iodo/uso terapêutico , Ferro/uso terapêutico , Cloreto de Sódio na Dieta/uso terapêutico , Adolescente , Anemia Ferropriva/complicações , Anemia Ferropriva/epidemiologia , Criança , Pré-Escolar , Côte d'Ivoire/epidemiologia , Método Duplo-Cego , Feminino , Bócio Endêmico/complicações , Bócio Endêmico/epidemiologia , Hemoglobinas/efeitos dos fármacos , Humanos , Masculino , Prevalência , Tireotropina/sangue , Tiroxina/sangue , Resultado do TratamentoRESUMO
BACKGROUND: In many developing countries, children are at high risk for both goiter and anemia. In areas of subsistence farming in rural Africa, salt is one of the few regularly purchased food items and could be a good fortification vehicle for iodine and iron, provided that a stable yet bioavailable iron fortificant is used. OBJECTIVE: We tested the efficacy of salt dual-fortified with iodine and micronized ferric pyrophosphate for reducing the prevalence of iodine and iron deficiencies in children. DESIGN: In rural northern Morocco, we fortified local salt with 25 microg I (as potassium iodate)/g salt and 2 mg Fe (as micronized ferric pyrophosphate; mean particle size = 2.5 microm)/g salt. After storage and acceptability trials, we compared the efficacy of the dual-fortified salt (DFS) with that of iodized salt in a 10-mo, randomized, double-blind trial in iodine-deficient 6-15-y-old children (n = 158) with a high prevalence of anemia. RESULTS: After storage for 6 mo, there were no significant differences in iodine content or color lightness between the DFS and iodized salt. During the efficacy trial, the DFS provided approximately 18 mg Fe/d; iron absorption was estimated to be approximately 2%. After 10 mo of treatment in the DFS group, mean hemoglobin increased by 16 g/L (P < 0.01), iron status and body iron stores increased significantly (P < 0.01), and the prevalence of iron deficiency anemia decreased from 30% at baseline to 5% (P < 0.001). In both groups, urinary iodine (P < 0.001) and thyroid volume (P < 0.01) improved significantly from baseline. CONCLUSION: A DFS containing iodine and micronized ferric pyrophosphate can be an effective fortification strategy in rural Africa.
Assuntos
Anemia Ferropriva/prevenção & controle , Fenômenos Fisiológicos da Nutrição Infantil , Difosfatos/uso terapêutico , Alimentos Fortificados , Bócio/prevenção & controle , Iodo/uso terapêutico , Ferro/uso terapêutico , Cloreto de Sódio na Dieta/uso terapêutico , Adolescente , Fenômenos Fisiológicos da Nutrição do Adolescente , Anemia Ferropriva/epidemiologia , Disponibilidade Biológica , Criança , Difosfatos/farmacocinética , Método Duplo-Cego , Feminino , Manipulação de Alimentos/métodos , Bócio/epidemiologia , Humanos , Absorção Intestinal , Iodo/farmacocinética , Ferro/farmacocinética , Ferro da Dieta/farmacocinética , Ferro da Dieta/uso terapêutico , Masculino , Marrocos/epidemiologia , Prevalência , Saúde da População Rural , Cloreto de Sódio na Dieta/farmacocinética , Glândula Tireoide/efeitos dos fármacos , Fatores de Tempo , Resultado do TratamentoRESUMO
OBJECTIVE: In many developing countries, children are at high risk for both goiter and anemia. Iron (Fe) deficiency adversely effects thyroid metabolism and reduces efficacy of iodine prophylaxis in areas of endemic goiter. The study aim was to determine if co-fortification of iodized salt with Fe would improve efficacy of the iodine in goitrous children with a high prevalence of anemia. DESIGN AND METHODS: In a 9-month, randomized, double-blind trial, 6-15 year-old children (n=377) were given iodized salt (25 microg iodine/g salt) or dual-fortified salt with iodine (25 microg iodine/g salt) and Fe (1 mg Fe/g salt, as ferrous sulfate microencapsulated with partially hydrogenated vegetable oil). RESULTS: In the dual-fortified salt group, hemoglobin and Fe status improved significantly compared with the iodized salt group (P<0.05). At 40 weeks, the mean decrease in thyroid volume measured by ultrasound in the dual-fortified salt group (-38%) was twice that of the iodized salt group (-18%) (P<0.01). Compared with the iodized salt group, serum thyroxine was significantly increased (P<0.05) and the prevalence of hypothyroidism and goiter decreased (P<0.01) in the dual-fortified salt group. CONCLUSION: Addition of encapsulated Fe to iodized salt improves the efficacy of iodine in goitrous children with a high prevalence of anemia.
Assuntos
Anemia Ferropriva/complicações , Bócio/complicações , Bócio/tratamento farmacológico , Iodo/uso terapêutico , Deficiências de Ferro , Ferro/administração & dosagem , Cloreto de Sódio na Dieta/uso terapêutico , Adolescente , Cápsulas , Criança , Método Duplo-Cego , Combinação de Medicamentos , Sinergismo Farmacológico , Feminino , Hemoglobinas/análise , Humanos , Ferro/sangue , Ferro/uso terapêutico , Masculino , Glândula Tireoide/diagnóstico por imagem , Glândula Tireoide/efeitos dos fármacos , Tiroxina/sangue , UltrassonografiaRESUMO
To determine if introduction of iodized salt induces thyroid autoimmunity in goitrous children, we conducted a prospective trial in iodine-deficient Moroccan schoolchildren (n = 323). Local salt was iodized at 25 microg iodine per gram of salt and distributed to households. Before introduction of iodized salt and at 10, 20, 40, and 52 weeks, we measured antithyroid peroxidase antibodies (TPO-Ab), antithyroglobulin antibodies (Tg-Ab), urinary iodine (UI), and thyroid hormones, and examined the thyroid using ultrasound. At baseline, median UI was 17 microg/L and the prevalence of goiter and hypothyroidism was 72% and 18%, respectively. Provision of iodized salt maintained median UI at 150-200 microg/L for the year (p < 0.0001). There was a significant increase in mean total thyroxine (T(4)) and a significant reduction in the prevalence of hypothyroidism (p < 0.001). There was a transient increase in the prevalence of detectable antibodies after introduction of iodized salt (p < 0.0001) with levels returning to baseline at 1 year. Only congruent with 1% of children had elevated TPO-Ab and none had elevated Tg-Ab over the course of the study, and no child with elevated TPO-Ab had abnormal thyrotropin (TSH) or T(4) concentrations. None developed clinical or ultrasonographic evidence of thyroid autoimmune disease and/or iodine-induced hypothyroidism or hyperthyroidism. Rapid introduction of iodized salt does not provoke significant thyroid autoimmunity in severely iodine-deficient children followed for 1 year.
Assuntos
Iodo/efeitos adversos , Iodo/deficiência , Cloreto de Sódio na Dieta/efeitos adversos , Tireoidite Autoimune/induzido quimicamente , Tireoidite Autoimune/epidemiologia , Adolescente , Anticorpos/análise , Criança , Feminino , Bócio/epidemiologia , Bócio/prevenção & controle , Humanos , Iodeto Peroxidase/imunologia , Iodo/urina , Masculino , Marrocos/epidemiologia , Estudos Prospectivos , Cloreto de Sódio na Dieta/uso terapêutico , Tireoglobulina/sangue , Tireoglobulina/imunologia , Testes de Função Tireóidea , Glândula Tireoide/diagnóstico por imagem , Tireotropina/sangue , Tiroxina/sangue , UltrassonografiaRESUMO
The purpose of neonatal screening is to find those that have a high risk for a disorder and therefore need further action for diagnosis and treatment. The separation of the high-risk and low-risk groups is typically achieved by establishing cut-off values for interpretation of the test result. The guidelines should preferably include both a low cut-off and a high cut-off value, with a grey zone between them. The width of the grey zone can be used for defining the quality required by the assay. The present work is based on the use of the EZ Rules software (from Westgard QC, Madison, WI), which automatically selects control rules. The user enters the needed parameters, such as the precision (as % CV) and bias of the assay. By using the grey zone as the medical decision interval the program will calculate possible control rules for the assay. The program was used to calculate the control rule for the AutoDELFIA neoTSH assay (from PerkinElmer Wallac, Turku, Finland). The grey zone was taken as 10 - 20 mU/L TSH, which is the recommendation of the American Academy of Pediatrics (Pediat. 91, 1203 - 1209). The entered parameters were: a total imprecision of 9%, which is typically seen with the AutoDELFIA neoTSH kit, a bias of 0% and a preanalytical variation of 20%. With the number of controls chosen as two, as often is used, a 1 3.0 s rule can be applied. The program also gives alternative control rules. Many laboratories lack a documented definition of the required quality, and tend to use a 2 SD control rule, which however leads to many unnecessary rejections. The EZ Rules program provides a tool for selection of QC rules. With the quality of the AutoDELFIA neoTSH kit two controls and a 1 3.0 s rule is sufficient. Runs are rejected only if one control out of two exceeds the 3.0 SD limit.
Assuntos
Autoanálise/normas , Triagem Neonatal/normas , Controle de Qualidade , Gestão da Qualidade Total , Humanos , Recém-Nascido , Triagem Neonatal/métodos , Valores de Referência , SoftwareRESUMO
The possibility of measuring thyroid hormones from blood dried on filter paper opened the way to identifying neonates with congenital hypothyroidism (CH) already in the first days of life. Consequently the early initiation of adequate replacement therapy opened the way to an effective prevention of mental retardation. Timely and complete specimen collection, transport logistics, rapid analysis and communication of results are key points for the organization of a CH newborn screening program. Close collaboration between laboratory and treating specialists is necessary to ensure an adequate treatment and follow-up of babies identified by CH screening programs. Topics for further investigations remain in the fields of which forms of CH should be identified by screening (only severe or also very mild forms) and on the long-term outcome of the individuals identified by CH screening.
Assuntos
Hipotireoidismo Congênito/diagnóstico , Triagem Neonatal/métodos , Glândula Tireoide/fisiopatologia , Hormônios Tireóideos/sangue , Hipotireoidismo Congênito/sangue , Hipotireoidismo Congênito/fisiopatologia , Humanos , Recém-Nascido , Manejo de EspécimesRESUMO
OBJECTIVE: The aim was to formulate practice guidelines for the diagnosis and management of congenital hypothyroidism (CH). EVIDENCE: A systematic literature search was conducted to identify key articles relating to the screening, diagnosis, and management of CH. The evidence-based guidelines were developed with the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) system, describing both the strength of recommendations and the quality of evidence. In the absence of sufficient evidence, conclusions were based on expert opinion. CONSENSUS PROCESS: Thirty-two participants drawn from the European Society for Paediatric Endocrinology and five other major scientific societies in the field of pediatric endocrinology were allocated to working groups with assigned topics and specific questions. Each group searched the literature, evaluated the evidence, and developed a draft document. These papers were debated and finalized by each group before presentation to the full assembly for further discussion and agreement. RECOMMENDATIONS: The recommendations include: worldwide neonatal screening, approaches to assess the cause (including genotyping) and the severity of the disorder, the immediate initiation of appropriate L-T4 supplementation and frequent monitoring to ensure dose adjustments to keep thyroid hormone levels in the target ranges, a trial of treatment in patients suspected of transient CH, regular assessments of developmental and neurosensory functions, consulting health professionals as appropriate, and education about CH. The harmonization of diagnosis, management, and routine health surveillance would not only optimize patient outcomes, but should also facilitate epidemiological studies of the disorder. Individuals with CH require monitoring throughout their lives, particularly during early childhood and pregnancy.
Assuntos
Hipotireoidismo Congênito/diagnóstico , Hipotireoidismo Congênito/tratamento farmacológico , Triagem Neonatal/normas , Educação de Pacientes como Assunto , Tiroxina/uso terapêutico , Hipotireoidismo Congênito/sangue , Relação Dose-Resposta a Droga , Endocrinologia , Europa (Continente) , Humanos , Recém-Nascido , Pediatria , Índice de Gravidade de Doença , Sociedades Médicas , Hormônios Tireóideos/sangueRESUMO
OBJECTIVE: The aim was to formulate practice guidelines for the diagnosis and management of congenital hypothyroidism (CH). EVIDENCE: A systematic literature search was conducted to identify key articles relating to the screening, diagnosis, and management of CH. The evidence-based guidelines were developed with the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) system, describing both the strength of recommendations and the quality of evidence. In the absence of sufficient evidence, conclusions were based on expert opinion. CONSENSUS PROCESS: Thirty-two participants drawn from the European Society for Paediatric Endocrinology and five other major scientific societies in the field of pediatric endocrinology were allocated to working groups with assigned topics and specific questions. Each group searched the literature, evaluated the evidence, and developed a draft document. These papers were debated and finalized by each group before presentation to the full assembly for further discussion and agreement. RECOMMENDATIONS: The recommendations include: worldwide neonatal screening, approaches to assess the cause (including genotyping) and the severity of the disorder, the immediate initiation of appropriate L-T4 supplementation and frequent monitoring to ensure dose adjustments to keep thyroid hormone levels in the target ranges, a trial of treatment in patients suspected of transient CH, regular assessments of developmental and neurosensory functions, consulting health professionals as appropriate, and education about CH. The harmonization of diagnosis, management, and routine health surveillance would not only optimize patient outcomes, but should also facilitate epidemiological studies of the disorder. Individuals with CH require monitoring throughout their lives, particularly during early childhood and pregnancy.
Assuntos
Hipotireoidismo Congênito/diagnóstico , Hipotireoidismo Congênito/terapia , Hipotireoidismo Congênito/sangue , Consenso , Humanos , Recém-Nascido , Programas de Rastreamento , Tireotropina/sangue , Tiroxina/sangueRESUMO
BACKGROUND: From January 2011 onward, the Swiss newborn screening (NBS) program has included a test for cystic fibrosis (CF). In this study, we evaluate the first year of implementation of the CF-NBS program. METHODS: The CF-NBS program consists of testing in two steps: a heel prick sample is drawn (= Guthrie test) for measurement of immunoreactive trypsinogen (IRT) and for DNA screening. All children with a positive screening test are referred to a CF center for further diagnostic testing (sweat test and genetic analysis). After assessment in the CF center, the parents are given a questionnaire. All the results of the screening process and the parent questionnaires were centrally collected and evaluated. RESULTS: In 2011, 83 198 neonates were screened, 84 of whom (0.1%) had a positive screening result and were referred to a CF center. 30 of these 84 infants were finally diagnosed with CF (positive predictive value: 35.7%). There was an additional infant with CF and meconium ileus whose IRT value was normal. The 31 diagnosed children with CF correspond to an incidence of 1 : 2683. The average time from birth to genetically confirmed diagnosis was 34 days (range: 13-135). 91% of the parents were satisfied that their child had undergone screening. All infants receiving a diagnosis of CF went on to receive further professional care in a CF center. CONCLUSION: The suggested procedure for CF-NBS has been found effective in practice; there were no major problems with its implementation. It reached high acceptance among physicians and parents.