RESUMO
OBJECTIVES: To compare neurodevelopmental outcomes in severe and moderate congenital hypothyroidism (CH) among 3 different initial L-thyroxine doses and to examine the effect of the time to thyroid function normalization on neurodevelopmental outcomes. STUDY DESIGN: Neurodevelopmental assessments of 31 subjects included the Mullen Scales of Early Learning, Wechsler Preschool and Primary Scale of Intelligence-Revised, Wechsler Intelligence Scale for Children, Wide-Range Achievement Test, and Child Behavioral Checklist. RESULTS: Subjects started on higher initial L-thyroxine doses (50 mug) had full-scale IQ scores 11 points higher than those started on lower (37.5 mug) initial doses. However, verbal IQ, performance IQ, and achievement scores did not differ among the 3 treatment cohorts. Subjects with moderate CH had higher full-scale IQ scores than subjects with severe CH, regardless of the initial treatment dose. Subjects who took longer than 2 weeks to normalize thyroid function had significantly lower cognitive, attention, and achievement scores than those who achieved normal thyroid function at 1 or 2 weeks of therapy. CONCLUSIONS: Initial L-thyroxine dose and faster time to normalization of thyroid function are important to optimal neurodevelopmental outcome. In severe CH, it is important to choose an initial dose at the higher end of the recommended range to achieve these goals.
Assuntos
Desenvolvimento Infantil , Hipotireoidismo Congênito/tratamento farmacológico , Deficiências do Desenvolvimento/prevenção & controle , Tireotropina/sangue , Tiroxina/sangue , Tiroxina/farmacologia , Análise de Variância , Criança , Comportamento Infantil , Pré-Escolar , Hipotireoidismo Congênito/etnologia , Hipotireoidismo Congênito/fisiopatologia , Deficiências do Desenvolvimento/epidemiologia , Relação Dose-Resposta a Droga , Escolaridade , Seguimentos , Humanos , Inteligência , Índice de Gravidade de DoençaRESUMO
OBJECTIVES: To determine the type and frequency of thyroid disorders detected in infants with low thyroxine (T4) and nonelevated thyroid-stimulating hormone (TSH) screening test results in the Northwest Regional Newborn Screening Program (NWRNSP) over the 20-year period from May 1975 to May 1995 and to determine the effect of follow-up of these infants on the overall recall rate. STUDY DESIGN: The NWRNSP requests a serum specimen in infants with an absolute T4 level < 38.6 nmol/L (< 3 mg/dl) and in infants with two filter paper T4 concentrations less than the 3%, regardless of the TSH concentration. We conducted a retrospective analysis of infants who were followed up because of low T4 and nonelevated TSH concentrations on newborn screening. To determine the effect of follow-up of infants with low T4 levels, nonelevated TSH concentrations on the recall rate, we selected 1 year (1994) for review. Serum sample requests were evaluated to determine the reason for the request. RESULTS: Over this 20-year period, the NWRNSP detected 450 infants with primary hypothyroidism among 1,747,805 infants screened (1:3,884). Of these, 416 were detected on the basis of low T4 levels and nonelevated TSH screening test results, whereas an additional 34 infants with primary hypothyroidism and 29 infants with hypopituitary hypothyroidism were detected as a result of follow-up of low T4 levels and nonelevated TSH screening test results. This included 25 infants with delayed TSH rise (1:67,226), 9 infants with mild hypothyroidism (TSH levels < 25 mU/L) (1:194,212), 29 infants with hypopituitary hypothyroidism (1:60,269), and 434 infants with T4-binding globulin deficiency (1:4,027). Excluding those with T4-binding globulin deficiency, the false-positive rate was 43.5:1. This compares with an overall false-positive rate of 12:1 for our screening program. CONCLUSION: Follow-up of infants with low T4 and nonelevated TSH concentration on screening led to the detection of 63 additional infants with hypothyroidism, for an overall frequency of 1:27,743. We believe this yield justifies continued follow-up of infants with low T4 levels, nonelevated (TSH) screening test results in our program.
Assuntos
Hipotireoidismo/diagnóstico , Triagem Neonatal , Testes de Função Tireóidea , Reações Falso-Positivas , Seguimentos , Humanos , Lactente , Recém-Nascido , Estudos Retrospectivos , Tireotropina , Tiroxina/sangueRESUMO
Physician and clinic charges for diagnosing growth hormone deficiency (GHD) in children are not generally known, whereas the charges for purchasing growth hormone (GH) are known. We recently surveyed the charges submitted to third-party payers for diagnosing GHD in five pediatric endocrine clinics throughout the United States: the Albert Einstein College of Medicine, Baylor College of Medicine, Health Science Schools of the State University of New York at Buffalo, Oregon Health Sciences University, and the University of Chicago. The financial data analyzed included charges for physician services and for GH testing. Different approaches to the medical examination of children with suspected GHD at these clinics prevented any comparison of physician or GH testing charges. However, the charges for diagnosing GHD could be determined for each pediatric endocrine clinic if the methods of examination were not considered. Contractual adjustments, net revenues, costs, and net margins were not surveyed. Subjective comments from the study sites suggest significantly reduced reimbursement amounts. We conclude that the total charges for diagnosing GHD submitted to third-party payers at these institutions averaged $1719.
Assuntos
Atenção à Saúde/economia , Transtornos do Crescimento/diagnóstico , Transtornos do Crescimento/tratamento farmacológico , Hormônio do Crescimento/deficiência , Hormônio do Crescimento/uso terapêutico , Criança , Pré-Escolar , Honorários Médicos/estatística & dados numéricos , Humanos , Seguro Saúde/economiaRESUMO
We examined the results of the Northwest Regional Screening Program from May 1975 to June 1991 to determine the prevalence of inherited thyroxine-binding globulin (TBG) deficiency and its effect on thyroid hormone concentrations in infants. Serum thyroxine (T4), triiodothyronine resin uptake (T3RU), and thyrotropin values were requested of physicians caring for all infants with a single filter paper T4 level < 38.6 nmol/L (3 micrograms/dl) or a T4 level < 3rd percentile on two filter paper tests (at birth and 2 to 6 weeks of age). From 1,367,724 infants screened in five states, TBG deficiency, an X-linked disorder, was identified in 317 infants (285 boys). For the entire screening program the calculated frequency of TBG deficiency was 1:4315 infants (1:2400 for boys). In Oregon, where 95% of infants have two screening tests performed, the calculated frequency was somewhat higher (1:3080 infants; 1712 boys) and is probably more accurate. The mean serum T4 concentration for TBG-deficient boys was 41.9 nmol/L (3.26 micrograms/dl); 31% had values < 25.7 nmol/L (2.0 micrograms/dl). The mean serum T4 concentration for TBG-deficient girls was 60.2 nmol/L (4.68 micrograms/dl), with none < 2.0 micrograms/dl. The mean T3RU value was 0.472 in TBG-deficient boys, and 0.412 in TBG-deficient girls; the T3RU value was > 0.55 in 24% of TBG-deficient boys but was > 0.55 in only one girl. Free serum T4 levels were normal in all 56 TBG-deficient infants studied, and TBG levels were low in all 20 infants studied. Inherited TBG deficiency is common in boys in the Northwest, with a frequency of 1:1700 and a male/female ratio of 8.9:1. Boys with TBG deficiency have mild, moderate, or severe alterations in total T4 and T3RU values, but severe deficiency is rare in girls.
Assuntos
Triagem Neonatal , Proteínas de Ligação a Tiroxina/deficiência , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Noroeste dos Estados Unidos/epidemiologia , Oregon/epidemiologia , Prevalência , Fatores Sexuais , Tireotropina/sangue , Tiroxina/sangue , Proteínas de Ligação a Tiroxina/análise , Tri-Iodotironina/sangueRESUMO
We examined the results of the Northwest Regional Screening Program (NWRSP) over its first 10 years to determine whether the detection of hypopituitary hypothyroidism is a justified advantage of the primary thyroxine (T4)-supplemental thyroid-stimulating hormone (TSH) screening strategy, and to determine whether all such infants will be detected by this screening approach. Between May 1975 and May 1985, the NWRSP screened 850,431 infants, detecting 192 infants with primary hypothyroidism (1:4429) and eight with hypopituitary hypothyroidism (1:106,304). In 11 additional infants, TSH deficiency, not detected by the screening program, was diagnosed on recognition of clinical features over the same period. Thyroid hormone treatment was begun in seven of the 11 infants prior to obtaining the screening sample results because of clinical symptoms of hypopituitarism, including hypoglycemia, persistent jaundice, microgenitalia, diabetes insipidus, midface hypoplasia, cleft lip or palate, or abnormalities of vision. The other four infants were not detected despite clinical features of hypopituitarism (in retrospect) and low serum T4 with TSH concentration below assay sensitivity on at least one screening sample. The most accurate assessment of total cases comes from Oregon, where all cases of congenital hypopituitarism are referred to our center; we estimate a frequency of 1:29,000. In our experience, a combination of newborn T4-supplemental TSH screening measurements and recognition of clinical features of hypopituitarism is the optimal strategy for detecting infants with congenital hypopituitary hypothyroidism.
Assuntos
Hipopituitarismo/epidemiologia , Hipotireoidismo/epidemiologia , Programas de Rastreamento , Hipotireoidismo Congênito , Feminino , Humanos , Hipopituitarismo/sangue , Hipopituitarismo/complicações , Hipopituitarismo/congênito , Hipotireoidismo/sangue , Hipotireoidismo/complicações , Lactente , Recém-Nascido , Masculino , Tireotropina/sangue , Tiroxina/sangueAssuntos
Síndrome da Sela Vazia/induzido quimicamente , Hipopituitarismo/induzido quimicamente , Hipotireoidismo/tratamento farmacológico , Criança , Humanos , Hipotireoidismo/diagnóstico por imagem , Masculino , Hormônios Tireóideos/sangue , Tiroxina/efeitos adversos , Tomografia Computadorizada por Raios XRESUMO
To determine the frequency with which hypothyroidism develops during human growth hormone therapy and to corroborate its onset with blood lipid changes, we measured growth rate, serum T4 and T3, and plasma cholesterol, triglyceride, and lipoprotein concentrations at 4-month intervals for a year in two subgroups of hGH-deficient children. The first group was initially euthyroxinemic (n = 16), and the second was TSH deficient and therefore already receiving thyroxine (n = 15). Basal plasma concentrations of total and low-density lipoprotein cholesterol and, to a lesser extent, plasma triglycerides were increased in both groups compared with an age-matched reference group. Basal plasma cholesterol levels were not statistically different in the euthyroxinemic and thyroxine-treated subgroups, and hGH treatment for a year did not lower lipid values in either subgroup. With hGH replacement, 25% of the euthyroxinemic patients experienced a slowdown in growth rate (3.2 +/- 0.7 cm/yr) associated with decreasing T4 (4.8 +/- 1.1 micrograms/dl) and increasing cholesterol concentrations (218 +/- 23 mg/dl); with thyroxine treatment, the growth rate improved (6.9 +/- 2.2 cm/yr), T4 increased (10.0 +/- 4.0 micrograms/dl), and cholesterol decreased (173 +/- 44 mg/dl, P less than 0.05). Although our results do not justify routine thyroid replacement, they do indicate that hypothyroxinemia and hypercholesterolemia may precede the growth slowdown during hGH treatment, and the need to monitor thyroid function at this time.
Assuntos
Hormônio do Crescimento/uso terapêutico , Hiperlipidemias/induzido quimicamente , Hipotireoidismo/induzido quimicamente , Adolescente , Criança , Pré-Escolar , Colesterol/sangue , Creatina Quinase/sangue , Feminino , Crescimento/efeitos dos fármacos , Hormônio do Crescimento/efeitos adversos , Hormônio do Crescimento/deficiência , Humanos , Hiperlipidemias/fisiopatologia , Hipotireoidismo/fisiopatologia , Lipídeos/sangue , Masculino , Tireotropina/deficiência , Tiroxina/sangue , Tiroxina/deficiência , Tiroxina/uso terapêutico , Triglicerídeos/sangue , Tri-Iodotironina/sangueRESUMO
Pilot programs for screening of newborn infants for congenital hypothyroidism began in North America in 1972. To date, the five oldest programs (Quebec, Pittsburgh, Toronto, Oregon Regional, and New England Regional) have screened 1,046,362 infants. A total of 277 infants with congenital hypothyroidism have been detected and seven have been missed, resulting in a total of 284 affected infants in the screened population and an overall incidence of one in 3,684 live births. Of the affected infants, 246 were determined to have primary hypothyroidism, an incidence of one in 4,254 births. Ten infants with secondary-tertiary hypothyroidism were detected in Quebec, Oregon, and Toronto, an incidence of one in 68,200 births. Of all the infants with primary hypothyroidism who were adequately studied, 63% were determined to have aplastic or hypoplastic glands, 14% normal or enlarged glands, and 23% ectopic thyroid tissue. The estimated minimum incidence of infants with TBG deficiency is one in 8,913 births. Only 8 of the 277 detected infants were suspected clinically to have congenital hypothyroidism prior to the time of confirmation of the diagnosis at 4 to 8 weeks of age. The cost of screening varied from $0.70 to $1.60 per infant, depending on which costs were included in the estimate. Preliminary evidence from Quebec suggests that infants treated in the program have normal developmental testing scores at 18 months of age.