Total and Free Thyroid Hormone Concentrations in the Neonatal Period

PEDIATRICS ◽  
1974 ◽  
Vol 53 (2) ◽  
pp. 211-216
Author(s):  
Allen Erenberg ◽  
Dale L. Phelps ◽  
Robert Lam ◽  
Delbert A. Fisher

Radioimmunoassay measurements of serum concentrations of thyroxine (T4), triiodothyronine (T3), free T4 (FT4), free T3 (FT3), and thyroxine binding globulin (TBG) were conducted in full-term newborn infants between birth and 5 days of age. The mean concentrations of T4 and FT4 increased from cord blood levels of 11.9 µg/100 ml and 2.9 ng/100 ml to peak values of 16.2 µg/100 ml and 7 ng/100 ml by 24 to 48 hours of age. Mean serum total and free T3 concentrations increased from cord blood levels of 50.5 ng/100 ml and 146 pg/100 ml to peak values of 419 ng/100 ml and 1,260 pg/100 ml by 24 hours of age. Mean T3/T4 and FT3/FT4 ratios increased from 1/238 to 1/39 and from 1/20 to 1/6, respectively, during this period. By 72 to 126 hours, both the T4 and T3 concentrations had fallen somewhat. Mean serum TBG concentrations were unchanged and approximated 5.0 mg/100 ml during the first 5 days of life. These data confirm earlier reports that the normal newborn infant rapidly becomes chemically hyperthyroid in the neonatal period due to increased thyroid hormone secretion; this neonatal hyperthyroid state is due more to T3 than to T4. The data also confirm earlier reports that the fetus is T3 deficient due to a decreased capacity to monodeiodinate T4 to T3 in extrathyroidal tissues. The rapid increase in serum T3 after delivery at a time when the capacity to convert T4 to T3 is reduced suggests that the increment in serum T3 is due, predominantly, to increased T3 secretion from the thyroid gland stimulated by the neonatal TSH surge. Thus with parturition, the newborn infant is transformed from a state of chemical T3 deficiency to a state of chemical T3 thyrotoxicosis.

PEDIATRICS ◽  
1967 ◽  
Vol 39 (2) ◽  
pp. 294-296
Author(s):  
RONALD L. SEARCY ◽  
J. EDWARD BERK ◽  
SHINICHIRO HAYASHI ◽  
BRUCE D. ACKERMAN

The presence of measurable quantities of amylase in the serum of newborn infants or in serum derived from cord blood may be demonstrated through the use of a sensitive saccharogenic procedure that permits analysis of small quantities of serum. Serum amylase levels are highly variable during the early part of the neonatal period, but they usually tend to be close to or below the lower limits of normal established for adults. The origins of the serum amylase in the newborn infant remain to be elucidated.


1992 ◽  
Vol 68 (1) ◽  
pp. 67-75 ◽  
Author(s):  
Gen Komaki ◽  
Hajime Tamai ◽  
Toshio Mukuta ◽  
Nobuyuki Kobayashi ◽  
Kenji Mori ◽  
...  

Plasma concentrations of endothelium-associated proteins (EAP) (plasma fibronectin (PFN), angio-tensin-converting enzyme, factor VIII-related antigen (F VIII-R:Ag)) and tissue plasminogen activator and serum thyroid hormone concentrations were studied in nine patients with anorexia nervosa (AN), before and after weight gain. Before weight gain (-35.9 (se 2.3)% of standard body-weight) PFN was significantly reduced and F VIII-R:Ag was significantly increased in AN patients compared with the concentrations in control subjects (211.5 (se 14.9)v.274.7 (se 16.6) μg/ml,P< 0.05; 129.2 (se 14.1)v.88.2 (se 9.7)%,P<0.05 respectively). Serum triiodothyronine (T3) and free T3 levels were also significantly lower before weight gain in AN patients (0.85 (se 0.07)v.1.53 (se 0.08) nmol/l,P< 0.001; 2.57 (se 0.23)v.5.31 (se 0.34) pmol/l,P< 0.001 respectively), although serum thyroxine (T4), free T4, and thyrotropin concentrations were within the normal range throughout the study periods. Following weight gain, PFN and F VIII-R: Ag concentrations normalized as did the thyroid hormone levels. The incremental changes in PFN levels correlated significantly with those in serum thyroid hormone concentrations (T3,r0.79,P<0.01; free T3,r0.84,P< 0.01). These findings suggest that PFN levels may be directly related to serum T3 concentrations in AN patients.


1976 ◽  
Vol 35 (03) ◽  
pp. 712-716 ◽  
Author(s):  
D. Del Principe ◽  
G Mancuso ◽  
A Menichelli ◽  
G Maretto ◽  
G Sabetta

SummaryThe authors compared the oxygen consumption in platelets from the umbilical cord blood of 36 healthy newborn infants with that of 27 adult subjects, before and after thrombin addition (1.67 U/ml). Oxygen consumption at rest was 6 mμmol/109/min in adult control platelets and 5.26 in newborn infants. The burst in oxygen consumption after thrombin addition was 26.30 mμmol/109/min in adults and 24.90 in infants. Dinitrophenol did not inhibit the burst of O2 consumption in platelets in 8 out of 10 newborn infants, while the same concentration caused a decrease in 9 out of 10 adult subjects. Deoxyglucose inhibited the burst in O2 consumption in newborn infant and adult platelets by about 50%. KCN at the concentration of 10−4 M completely inhibited basal oxygen consumption but did not completely inhibit the burst after thrombin. At the concentration of 10−3 M, it inhibited both basal O2 consumption and the burst in infants and adult subjects.


2017 ◽  
Vol 6 (4) ◽  
pp. 200-205 ◽  
Author(s):  
Jan Calissendorff ◽  
Henrik Falhammar

Background Graves’ disease is a common cause of hyperthyroidism. Three therapies have been used for decades: pharmacologic therapy, surgery and radioiodine. In case of adverse events, especially agranulocytosis or hepatotoxicity, pre-treatment with Lugol’s solution containing iodine/potassium iodide to induce euthyroidism before surgery could be advocated, but this has rarely been reported. Methods All patients hospitalised due to uncontrolled hyperthyroidism at the Karolinska University Hospital 2005–2015 and treated with Lugol’s solution were included. All electronic files were carefully reviewed manually, with focus on the cause of treatment and admission, demographic data, and effects of iodine on thyroid hormone levels and pulse frequency. Results Twenty-seven patients were included. Lugol’s solution had been chosen due to agranulocytosis in 9 (33%), hepatotoxicity in 2 (7%), other side effects in 11 (41%) and poor adherence to medication in 5 (19%). Levels of free T4, free T3 and heart rate decreased significantly after 5–9 days of iodine therapy (free T4 53–20 pmol/L, P = 0.0002; free T3 20–6.5 pmol/L, P = 0.04; heart rate 87–76 beats/min P = 0.0007), whereas TSH remained unchanged. Side effects were noted in 4 (15%) (rash n = 2, rash and vomiting n = 1, swelling of fingers n = 1). Thyroidectomy was performed in 26 patients (96%) and one was treated with radioiodine; all treatments were without serious complications. Conclusion Treatment of uncontrolled hyperthyroidism with Lugol’s solution before definitive treatment is safe and it decreases thyroid hormone levels and heart rate. Side effects were limited. Lugol’s solution could be recommended pre-operatively in Graves’ disease with failed medical treatment, especially if side effects to anti-thyroid drugs have occurred.


2007 ◽  
Vol 92 (1) ◽  
pp. 208-211 ◽  
Author(s):  
Giorgos S. Metsios ◽  
Andreas D. Flouris ◽  
Athanasios Z. Jamurtas ◽  
Andres E. Carrillo ◽  
Demetrios Kouretas ◽  
...  

Abstract Context: Active smoking influences normal metabolic status and thyroid function. Objective: The objective was to assess experimentally the effects of 1 h of moderate passive smoking in a controlled simulated bar/restaurant environment on the metabolism and thyroid hormone levels in healthy nonsmokers. Participants: Eighteen (nine females, nine males) healthy individuals (mean ± sd: age, 25.3 ± 3.1 yr; height, 174.0 ± 10.1 cm; weight, 65.2 ± 13.7 kg) participated in the study. Design: In repeated-measures randomized blocks, participants visited the laboratory on 2 consecutive days. In the experimental condition, they were exposed to 1 h of moderate passive smoking at a carbon monoxide concentration of 23 ± 1 ppm in an environmental chamber, whereas in the control condition participants remained in the same chamber for 1 h breathing normal atmospheric air. Main Outcome Measures: In both conditions, cotinine serum and urine levels, resting energy expenditure (REE), as well as concentration of T3, free T4, and TSH were assessed before participants entered the chamber and immediately after their exit. Heart rate and blood pressure were tested in 10-min intervals during all REE assessments. Results: The mean ± sd difference of serum and urine cotinine levels (−0.27 ± 3.94 vs. 14.01 ± 6.54 and 0.05 ± 2.07 vs. 7.23 ± 3.75, respectively), REE (6.73 ± 98.06 vs. 80.58 ± 120.91) as well as T3 and free T4 (0.05 ± 0.11 vs. 0.13 ± 0.12 and 0.02 ± 0.15 vs. 0.22 ± 0.20) were increased in the experimental compared with the control condition at baseline and follow-up (P &lt; 0.05). No statistically significant variation was observed in the mean difference of the remaining parameters (P &gt; 0.05). Serum and urine cotinine values were linearly associated with REE (P &lt; 0.05). Conclusion: One hour of passive smoking at bar/restaurant levels is accompanied by significant increases in metabolism and thyroid hormone levels.


PEDIATRICS ◽  
1989 ◽  
Vol 83 (5) ◽  
pp. 785-789
Author(s):  
D. A. FISHER ◽  
B. L. FOLEY

Mass population screening of newborn infants for congenital hypothyroidism was introduced in 1974 and now is a routine and effective means of early diagnosis of congenital hypothyroidism throughout most of the industrialized world. A large number of affected infants and children have been treated with replacement thyroid hormone, and several reports of IQ measurements and functional assessments of 5-to 7-year-old treated children now are available. These reports document normal mean IQ values, satisfactory school performance, and minimal motor dysfunction in treated children. However, there have been reported correlations between lower IQ values and biologic parameters of the hypothyroid state in the neonatal period among several reported studies, and it is not yet clear whether early adequate treatment will reverse all of the effects of congenital hypothyroidism.


2011 ◽  
Vol 96 (6) ◽  
pp. E934-E938 ◽  
Author(s):  
Beverley M. Shields ◽  
Beatrice A. Knight ◽  
Anita Hill ◽  
Andrew T. Hattersley ◽  
Bijay Vaidya

Context: Thyroid function is known to play an important role in fetal neurological development, but its role in regulating fetal growth is not well established. Overt maternal and fetal thyroid disorders are associated with reduced birth weight. We hypothesized that, even in the absence of overt thyroid dysfunction, maternal and fetal thyroid function influence fetal growth. Aim: In normal, healthy pregnancies, we aimed to assess whether fetal thyroid hormone at birth (as measured in cord blood) is associated with fetal growth. We also aimed to study whether fetal thyroid hormone at birth is associated with maternal thyroid hormone in the third trimester. Methods: In 616 healthy mother-child pairs, TSH, free T4 (FT4), and free T3 (FT3) were measured in mothers at 28 wk gestation and in umbilical cord blood at birth. Birth weight, length, head circumference, and tricep and bicep skinfold thicknesses were measured on the babies. Results: Cord FT4 was associated with birth weight (r = 0.25; P &lt; 0.001), length (r = 0.17; P &lt; 0.001), and sum of skinfolds (r = 0.19; P &lt; 0.001). There were no associations between birth measurements and either cord TSH or cord FT3. Maternal FT4 and cord FT4 were correlated (r = 0.14; P = 0.0004), and there were weaker negative associations between maternal TSH and cord FT4 (r = −0.08; P = 0.04) and FT3 (r = −0.10; P = 0.01). Conclusion: Associations between cord FT4 and birth size suggest that fetal thyroid function may be important in regulating fetal growth, both of skeletal size and fat. The correlation between third-trimester maternal FT4 and cord FT4 supports the belief that maternal T4 crosses the placenta even in late gestation.


1994 ◽  
Vol 266 (6) ◽  
pp. E905-E913
Author(s):  
M. Michalkiewicz ◽  
L. J. Huffman ◽  
M. Dey ◽  
G. A. Hedge

Vasoactive intestinal peptide (VIP) is present in thyroid parasympathetic nerves. To assess the involvement of endogenous VIP in the regulation of thyroid function, blood levels of thyroid hormones and thyroid blood flows (TBF) were measured after systemic immunization against VIP or after transection of the superior laryngeal nerves in male rats, which reduced the thyroid content of VIP but did not affect blood levels of thyroid hormones or TBF. Anti-VIP monoclonal antibody or anti-VIP serum was used for immunization against VIP in normal rats. In addition, VIP antibody was given to rats fed an iodine-deficient diet for 5 days to examine the involvement of this peptide in iodine deficiency-induced increases in TBF. Effects were measured at different times (90 s, 30 min, 1 h, and 5 days) after immunoneutralization, but none of these treatments changed blood levels of thyroid hormones or TBF in normal or iodine-deficient rats. However, passive immunization against VIP was associated with a high binding capacity of rat plasma to VIP, and this treatment reduced blood levels of prolactin as well as blood flows to the duodenum, stomach, and lung. These findings suggest that the VIP present in thyroid nerves is not involved in maintaining basal thyroid hormone secretion or TBF and that this neuropeptide does not mediate thyroid vascular adjustments to dietary iodine deficiency.


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