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Prevalence of multivessel coronary artery disease in patients with diabetes mellitus plus hypothyroidism, in patients with diabetes mellitus without hypothyroidism, and in patients with no diabetes mellitus or hypothyroidism.

BACKGROUND: We report the prevalence of significant multivessel coronary artery disease (CAD) (>50% stenosis) in patients with diabetes plus hypothyroidism, in patients with diabetes without hypothyroidism, and in patients without diabetes or hypothyroidism who had significant CAD documented by coronary angiography. METHODS: We performed a retrospective analysis in 100 patients selected randomly with significant CAD documented by coronary angiography to investigate the prevalence of significant multivessel CAD in patients with diabetes, in patients with hypothyroidism, and in patients without diabetes or hypothyroidism. RESULTS: Significant 3-4-vessel CAD was present in 9 of 10 patients (90%), mean age 73 +/- 11 years, with diabetes plus hypothyroidism, in 10 of 25 patients (40%), mean age 63 +/- 9 years, with diabetes without hypothyroidism, and in 10 of 65 patients (15%), mean age 68 +/- 12 years, without diabetes or hypothyroidism (p <.001 comparing diabetes plus hypothyroidism with no diabetes or hypothyroidism; p <.01 comparing diabetes plus hypothyroidism with diabetes without hypothyroidism; and p <.02 comparing diabetes without hypothyroidism with no diabetes or hypothyroidism). Significant 2-4-vessel CAD was present in 10 of 10 patients (100%) with diabetes plus hypothyroidism, in 20 of 25 patients (80%) with diabetes without hypothyroidism, and in 37 of 65 patients (57%) with no diabetes or hypothyroidism (p <.01 comparing diabetes plus hypothyroidism with no diabetes or hypothyroidism; and p <.05 comparing diabetes without hypothyroidism with no diabetes or hypothyroidism). CONCLUSIONS: In patients with diabetes mellitus plus hypothyroidism, the prevalence of 3-vessel or 4-vessel CAD was significantly higher than in patients with diabetes mellitus without hypothyroidism or in patients with no diabetes mellitus or hypothyroidism. In patients with diabetes mellitus without hypothyroidism, the prevalence of 3-vessel or 4-vessel CAD was significantly higher than in patients without diabetes mellitus or hypothyroidism.

Age Distribution↗

Morphometric study on the uterine horn and thyroid gland in hypothyroid, and thyroxine treated hypothyroid rats.

A wide range of reproductive disorders such as irregular menstruation and frank infertility is found in women with hypothyroidism. Most research done on these patients has focused on steroid and gonadotropin hormone profiles, whilst there has been little work on uterine morphology. Studies on hypothyroid animals have also demonstrated increases in fetal wastage, but there have been few studies of uterine structure in the hypothyroid rat. The present study has used hypothyroid Wistar rats as a model for investigating the effects of hypothyroidism on uterine structure. Three groups of Wistar rats were studied. One was made hypothyroid with methimazole (MMI), the 2nd was also made hypothyroid with methimazole but in addition the rats were simultaneously given daily thyroxine intraperitoneally (MMI + T4), and the 3rd was an untreated euthyroid group (control). Daily vaginal smears were obtained from rats in all 3 groups. All rats were aged 6 wk at the start of treatment and were killed after a further 6 wk. Uterine horns were removed and studied. Systematic random transverse sections were obtained from the proximal, middle, and distal regions of the horn and subjected to morphometric analysis. Difference between regions was assessed using 2-way analysis of variance. Absolute volume of endometrium in the uteri of hypothyroid rats was reduced by 45.1% (P < 0.05), whilst that of the muscle layer was decreased by 33.6% (P < 0.05). The cross-sectional area and absolute volume of the uterine horns were also reduced in hypothyroid animals (P < 0.05). In hypothyroid rats given thyroxine (MMI + T4) all variables increased significantly above those of hypothyroid rats. These changes suggest that hypothyroidism has an effect on uterine structure, which demonstrably improves under exogenous thyroxine administration. The observed structural changes might well play a significant role in the reproductive difficulties observed during hypothyroidism.

Analysis of Variance↗

Increased arterial and venous plasma noradrenaline levels in patients with primary hypothyroidism during hypothyroid as compared to euthyroid state.

The use of venous plasma noradrenaline levels as a marker of general sympathetic tone has been questioned as changes in local sympathetic activity may influence the venous levels. To compare arterial and venous plasma noradrenaline levels in patients with primary hypothyroidism, arterial and venous blood were sampled during strictly standardized conditions during hypothyroid and euthyroid states. The patients were hospitalized for 5 days at a metabolic ward on a standardized sodium and potassium intake. On the fourth day catheters were positioned in the axillary artery and vein. Blood samples were drawn simultaneously for noradrenaline and adrenaline determinations during resting conditions. The arterial and venous plasma noradrenaline levels did not differ significantly, neither during hypothyroidism nor during euthyroidism. The arteriovenous difference in plasma adrenaline was similar during hypothyroidism compared to euthyroidism, indicating similar peripheral extraction rate of catecholamines during hypothyroidism as compared to euthyroidism. During hypothyroidism venous and arterial noradrenaline were significantly higher as compared to euthyroidism. In conclusion, there is no difference between arterial and venous noradrenaline levels either in the hypothyroid or the euthyroid state, and the peripheral extraction rate of plasma noradrenaline seems to be similar in hypothyroidism and euthyroidism. The local contribution of noradrenaline from the arm, reflecting local sympathetic nervous activity, is limited during resting conditions. In hypothyroid patients plasma noradrenaline levels are increased as compared to the euthyroid state, indicating increased general sympathetic activity in hypothyroidism.

Adult↗

Secretion of nascent lipoproteins by isolated hepatocytes from hypothyroid and hypothyroid, hypercholesterolemic rats.

The induction of hypothyroidism in the rat is necessary for the development of pronounced dietary-induced hypercholesterolemia. The nature of nascent lipoproteins secreted by isolated hepatocytes from euthyroid, hypothyroid and hypothyroid, cholesterol-fed rats was investigated to distinguish between these hormonal and dietary effects. Serum total lipids, apolipoproteins, B, E and A-I, were greatly elevated in hypercholesterolemia. In hypothyroidism, serum apolipoproteins B and E were elevated, triacylglycerols were reduced by 65% and free cholesterol was increased by 50%. The total lipid, apolipoprotein B and E, secreted by hypercholesterolemic rat hepatocytes was markedly elevated when compared to normal. Triacylglycerol and phospholipid secretion was slightly increased by hypothyroid rat hepatocytes; however, apolipoprotein B, E and A-I secretion rates were unaffected. Gel filtration of the nascent lipoproteins demonstrated that compared to normal, proportionately more apolipoprotein B and E from hypercholesterolemic rat hepatocytes and apolipoprotein E from hypothyroid rat hepatocytes was secreted as larger lipoproteins. Hypercholesterolemic rat hepatocytes secreted abnormal cholesterol-rich particles even after 24 h of incubation in a lipid-deficient medium. Hypothyroidism alone cannot account for this observation, as hypothyroid rat hepatocytes secreted a triacylglycerol-rich, cholesterol-deficient lipoprotein having a normal nascent lipoprotein lipid composition. These observations are consistent with the hypothesis that in hypothyroidism the accumulation of beta-migrating lipoproteins results from impaired removal of lipoprotein catabolites from the serum, a condition which would only promote hypercholesterolemia in cholesterol feeding where direct synthesis of abnormal lipoproteins occurs.

Animals↗

Quantitative [3H]thymidine autoradiography of neurogenesis in the olfactory epithelium of developing normal, hypothyroid and hypothyroid-rehabilitated rats.

We recently reported that postnatal hypothyroidism results in marked reduction in surface area and cell number in the rat olfactory epithelium (OE) and recovery from this condition is accompanied by compensatory growth and restitution of these parameters. To explore the correlative changes in olfactory neurogenesis, i.e. mitotic activity of basal cells (BCs) and migration and survival of developing olfactory receptor neurons (ORNs), hypothyroid rats at postnatal (P) days of P10, P25 and P75 were injected with [3H]thymidine and OE was examined by quantitative autoradiography to determine the density of labeled nuclei at the BC and ORN zones at days 1, 5 and 15 post-injection. These data were compared with those of age-matched controls as well as young adult rats allowed to recover from hypothyroidism at the end of the suckling period (P25). Hypothyroidism was induced by administration of propylthiouracil (PTU) from birth in the drinking water (1 g/l) for 10, 25 and 90 days; recovery was induced by withdrawal of PTU at P25. The results indicated that the densities of labeled nuclei in the BC and ORN zones were not significantly altered in the suckling hypothyroid rats. In the P75 hypothyroid rats density of labeled BC nuclei was unaffected 1 day after injection but was significantly (36%) more than controls 5 days after injection; the density of neuronal nuclei in the ORN zone of P75 injected rats was markedly and significantly reduced (56% and 37% at 5- and 15-days post-injection). Data indicate that mitotic activity of BCs and their migration into the ORN zone is not affected in the hypothyroid infant rats but migration and/or survival of developing ORNs are markedly reduced in the postweaning growing rats made hypothyroid from birth. In rats allowed to recover from hypothyroidism at P25 and injected with labeled thymidine at P75, the density of labeled BC nuclei were significantly increased (48% and 43% at 1- and 5-days post-injection) compared to normal rats suggesting elevated levels of neurogenesis; density of ORN nuclei, however, were the same as controls. The results indicate critical regulatory influences of thyroid hormones on olfactory neurogenesis in the rat olfactory receptor sheet, in particular during the postweaning period.

Animals↗

Estimation of tissue hypothyroidism by a new clinical score: evaluation of patients with various grades of hypothyroidism and controls.

The classical signs and symptoms of hypothyroidism were reevaluated in the light of the modern laboratory tests for thyroid function. We analyzed 332 female subjects: 50 overt hypothyroid patients, 93 with subclinical hypothyroidism (SCH), 67 hypothyroid patients treated with T4, and 189 euthyroid subjects. The clinical score was defined as the sum of the 2 best discriminating signs and symptoms. Beside TSH and thyroid hormones, we measured parameters known to reflect tissue manifestations of hypothyroidism, such as ankle reflex relaxation time and total cholesterol. Classical signs of hypothyroidism were present only in patients with severe overt hypothyroidism with low T3, but were rare or absent in patients with normal T3 but low free T4 or in patients with SCH (normal thyroid hormones but elevated basal TSH; mean scores, 7.8 +/- 2.7 vs. 4.4 +/- 2.2 vs. 3.4 +/- 2.0; P < 0.001). Assessment of euthyroid subjects and T4-treated patients revealed very similar results (mean score, 1.6 +/- 1.6 vs. 2.1 +/- 1.5). In overt hypothyroid patients, the new score showed an excellent correlation with ankle reflex relaxation time and total cholesterol (r = 0.76 and r = 0.60; P < 0.0001), but no correlation with TSH (r = 0.01). The correlation with free T4 was r = -0.52 (P < 0.0004), and that with T3 was r = -0.56 (P < 0.0001). In SCH, the best correlation was found between the new score and free T4 (r = -0.41; P < 0.0001) and TSH (r = 0.35; P < 0.0005). Evaluation of symptoms and signs of hypothyroidism with the new score in addition to thyroid function testing is very useful for the individual assessment of thyroid failure and the monitoring of treatment.

Adult↗

Pituitary-thyroid function of fetuses of hypothyroid and growth hormone treated hypothyroid rats.

Maternal hypothyroidism induced by surgical thyroidectomy (Tx) of the rat resulted in significantly higher fetal serum levels of thyroid stimulating hormone (TSH) and thyroxine (T4) on day 22 of gestation. Surprisingly, administration of growth hormone (GH) to hypothyroid mothers increased further the fetal serum T4 and TSH. The in vitro uptake of 131I-T4 by erythrocytes was elevated significantly when incubated with serum from fetuses of both hypothyroid and hypothyroid GH-treated mothers. Although the plasma protein levels of hypothyroid mothers and their fetuses are decreased significantly as compared to controls this is not true of hypothyroid GH-treated mothers and their fetuses. The T4 levels of both groups of Tx mothers were significantly below that of controls. However, as in the case of their fetuses, the serum T4 of GH-treated hypothyroid mothers was elevated from that of Tx only animals. It is concluded that the pituitary-thyroid system of fetuses of hypothyroid mothers is activated excessively during late gestation, that considerable T4 can be transported from the fetus to the mother during this period and that these fetuses are in fact born in a hyperthyroid state which is aggravated by maternal treatment with GH.

Animals↗

Primary hypothyroidism manifested in childhood with special reference to various types of reversible hypothyroidism.

The clinical course of 15 patients with overt primary hypothyroidism manifested in childhood were studied. Nine female patients with goitrous hypothyroidism due to chronic thyroiditis showed almost normal height and became euthyroid spontaneously during iodine restriction. The other 6 nongoitrous patients (3M and 3F) (atrophic thyroiditis in 2, lingual goiter in 2 and probable hypoplastic thyroid in 2) showed physical growth retardation and remained irreversibly hypothyroid requiring replacement therapy. In the reversible group, the characteristic findings were high thyroidal radioactive iodine uptake (58 +/- 19%/24 h, N = 8) and positive perchlorate discharge test. Serum nonhormonal iodine levels were high in 4 of 6 patients measured. During the long-term follow-up period of 6 years in 6 patients, 2 patients remained euthyroid with normal growth and regular menstrual cycle and 4 patients became hypothyroid again (after eating seaweed in 1, despite iodine restriction in 2 and after the episode of painless thyroiditis in 1). Transient retardation of growth was observed during the second episode of hypothyroidism. In the irreversible group, one patient with blocking type TSH binding inhibitor immunoglobulin (TBII) became thyrotoxic 4 years later with the decrease in activity of blocking type TBII. These results suggested that reversible recovery of the thyroid function could be expected in patients with juvenile hypothyroidism due to chronic thyroiditis after (1) iodine restriction, (2) improvement of immunological perturbation, or (3) disappearance of blocking type TBII. However, careful follow-up is necessary, because hypothyroidism would recur again with transient retardation of growth in children.

Adolescent↗

Hypothyroidism and the heart. Examination of left ventricular function in subclinical hypothyroidism.

For revealing whether cardiac performance is changed in subclinical hypothyroidism, the left ventricular ejection fraction (LVEF), a value characterizing left ventricular function, was studied in this clinical state. The results were compared to those obtained in euthyroid subjects and patients with overt hypothyroidism. In a part of subclinical cases, there is a subnormal resting LVEF, which on isometric exercise, increases, but to a lesser extent than in euthyroid controls. In overt hypothyroidism resting LVEF is considerably lower than in euthyroid and subclinically hypothyroid subjects and its value does not respond to exercise. There has been evidence that heterogeneous subclinical hypothyroidism is an intermediate state between euthyroidism and overt hypothyroidism; the majority of patients are euthyroid, a part of them, however, based on systolic time intervals and LVEF studies, are suspect of developing 'tissue' hypothyroidism, although their serum thyroid hormone level is still within normal limits.

Adult↗

Hypothalamo-pituitary hypothyroidism detected by neonatal screening for congenital hypothyroidism using measurement of thyroid-stimulating hormone and thyroxine.

UNLABELLED: The optimal strategy in neonatal screening for congenital hypothyroidism is still a subject of controversy. In Kanagawa Prefecture in Japan, simultaneous thyroid-stimulating hormone (TSH) and T4/fT4 determination has been used, while the results of our program may provide valuable information. Cumulative findings were analysed to determine the type and frequency of thyroid disorders in infants detected by simultaneous TSH and T4/fT4 determination, and the TSH and T4/fT4 screening strategy was validated. A total of 1284130 neonates were screened between October 1979 and September 1997 and infants followed because of low T4/fT4 without elevated TSH (T4 < 51.5 nmol/L or fT4 < 9 pmol/L and TSH < 15 mU/L) were retrospectively analysed. The first survey was carried out within 6 mo of birth and the second in 1998; 258 infants were diagnosed with congenital hypothyroidism at the first medical evaluation, 15 of them with hypothalamo-pituitary hypothyroidism. However, in the second survey, only 8 children were confirmed as having hypothalamo-pituitary hypothyroidism, therefore the incidence detected by the present strategy was 1/160516. Of 8 children with hypothalamo-pituitary hypothyroidism, mental retardation was prevented in 3 owing to early treatment. CONCLUSIONS: Simultaneous measurement of TSH and T4/fT4 is a useful strategy for detecting hypothalamo-pituitary hypothyroidism, but more studies are needed to show the cost-benefits of using this strategy.

Congenital Hypothyroidism↗

Influence of hypothyroidism and the reversal of hypothyroidism on hemodynamics and cell size in the adult rat heart.

Hypothyroid-induced atrophy of cardiac myocytes was examined in adult female rats in an effort to correlate hemodynamic and cellular changes associated with this disorder. Additional rats were studied 6 weeks after discontinuing antithyroid treatment to determine if structural and functional changes were completely reversible. To induce hypothyroidism, rats were injected daily with propylthiouracil (PTU) for 4 weeks. Control animals were injected similarly with Tris buffer. At the end of the treatment period, hemodynamic measurements were made prior to obtaining isolated myocytes. Cell volume, length, and cross-sectional area were obtained from the septum, and left and right ventricles of treated and untreated rats. After four weeks treatment with PTU, body weight was unchanged but heart weight was significantly reduced by 24%. Characteristic hemodynamic changes associated with hypothyroidism in the rat were noted (eg. reduced heart rate, cardiac output, dP/dtmax, and ventricular pressure). Cell volume was significantly smaller in hypothyroid rats primarily due to a reduction in myocyte cross-sectional area. The hemodynamic and cellular response to hypothyroidism was similar in the right and left ventricle. Six weeks after discontinuing PTU treatment, cellular and hemodynamics changes had returned to normal. It was concluded that hypothyroidism caused a true cardiac atrophy which was reversible. Reduced myocyte cross-sectional area was responsible for most of the myocyte atrophy.

Animals↗

Difference in pituitary-thyroid feedback regulation in hypothyroid patients, depending on the severity of hypothyroidism.

In an attempt to study pituitary-thyroid interplay during replacement therapy for hypothyroidism, T4 (75-150 micrograms/day) was administered for at least 3 months. A small dose of T4 (75 micrograms/day) significantly depressed basal and TRH-stimulated TSH levels in normal subjects without significantly elevating serum T4 and T3 concentrations. In patients with severe hypothyroidism and marked enlargement of the sella turcica, T4 (2.53 micrograms/kg BW) normalized the serum T4 and slightly elevated the serum T3 but failed to normalize basal and TRH-stimulated TSH levels. In patients with moderate hypothyroidism and moderate enlargement of the sella turcica, T4 (2.0 micrograms/kg BW) normalized serum T4, T3, and basal TSH concentrations but failed to normalize TRH-stimulated TSH levels. In patients with slight hypothyroidism and slight enlargement of the sella turcica, T4 (1.84 micrograms/kg BW) normalized serum T4, T3, and TSH (both basal and TRH stimulated) concentrations. In five patients, an apparent paradoxical increase of basal serum TSH level was found shortly after starting thyroid hormone treatment. It is suggested that pituitary-thyroid interplay during the first 3-6 months of replacement therapy for hypothyroidism varies greatly depending on the severity of hypothyroidism.

Adult↗

Increased plasma thyroid stimulating hormone in treated congenital hypothyroidism: relation to severity of hypothyroidism, plasma thyroid hormone status, and daily dose of thyroxine.

Plasma thyroid stimulating hormone (TSH) concentrations obtained during the first four years of treatment in 418 children with congenital hypothyroidism, identified by neonatal screening, were examined in relation to paired measurements of plasma thyroxine (n = 1945), free thyroxine (n = 836), triiodothyronine (n = 480), and free triiodothyronine (n = 231), and estimated daily dose of thyroxine at the time of blood sampling. Overall, plasma TSH was above 7 mU/l in 1280 out of 2960 samples (43%); the percentage was not related to severity of hypothyroidism at diagnosis. Mean values for thyroxine and free thyroxine, and to a lesser extent free triiodothyronine, were consistently lower in samples with TSH concentrations over 7 mU/l and this was the case in patients with either severe or less severe hypothyroidism. Raised TSH concentrations were also associated with lower mean doses of thyroxine (micrograms/kg/day) but here the mean doses of thyroxine in children with severe hypothyroidism were higher than in the children with less severe hypothyroidism. The mean dose of thyroxine associated with low/normal TSH values was highest in the first 6 months and fell progressively. Thyroxine dose was significantly related to thyroxine and free thyroxine concentrations but not to triiodothyronine and free triiodothyronine and the latter appeared to be of limited value as measures of plasma thyroid hormone status during treatment.

Child, Preschool↗

Hypothyroidism and glaucoma. A study of 100 hypothyroid patients.

PURPOSE: To determine whether glaucoma is associated with hypothyroidism, as has previously been suggested. METHODS: This is a cross-sectional study and a noncomparative interventional case series. One hundred consecutive patients with newly diagnosed hypothyroidism were referred for complete ophthalmologic examination, including automated perimetry and examination of the optic disks, to identify the presence of glaucoma. After correction of the hypothyroidism, reexamination was performed. RESULTS: No patient had glaucoma and no correlation was found between intraocular pressure and either thyroid stimulating hormone or free tri-iodothyronine. No statistically significant difference was found between intraocular pressure levels before and after treatment of the hypothyroidism. CONCLUSION: This study does not demonstrate an association between hypothyroidism and glaucoma.

Adolescent↗

[Profile of autoimmune antibodies in idiopathic hypothyroidism and hypothyroidism following radio-iodine treatment in Basedow's disease: comparison with a group of normal subjects from the female population of Switzerland].

Prevalence of thyroid microsomal antibodies (MCHA) and thyroglobulin antibodies (TGHA), as well as frequency of other autoantibodies (parietal cell antibodies [PZA], adrenal antibodies [NNA], islet cell antibodies [IZA], smooth muscle antibodies [SMA], mitochondrial antibodies [MitA] and antibodies to nuclear antigens [ANF]), are reported for three different female groups in Switzerland in 91 euthyroid controls (group A), in 58 patients with idiopathic hypothyroidism (group B) and in 55 patients with hypothyroidism after administration of radioactive iodine for Graves' disease (group C). Prevalence of MCHA in the three groups was 14.5%, 90%, and 72%, respectively, and TGHA were positive in 6.5%, 56%, and 28%, respectively. Simultaneous occurrence of both thyroid antibodies and their appearance in higher titers were significantly more frequent in group B than in the other two groups. Goitrous forms of idiopathic hypothyroidism show higher MCHA titers than the atrophic forms. There was no association between thyroid antibodies and the presence of endocrine ophthalmopathy in group C. PZA were frequently found in groups B and C (26% and 13.6%, respectively; 4.7% in controls). The higher frequency of other autoantibodies was even more pronounced for ANF (52.1% in group B, 29.7% in group C, and 12.5% in controls). NNA and SMA were also more frequent, but not to a statistically significant degree. Two patients (both in group B) had positive islet cell antibodies. MitA were equally distributed in the three groups. These results suggest a relatively high proportion of asymptomatic autoimmune thyroiditis in the female population of Switzerland, with possible progression to overt hypothyroidism. Determinations of PZA and NNA are mandatory in both Graves' disease and idiopathic hypothyroidism. Cases with positive PZA must be closely monitored in view of the association with autoimmune atrophic gastritis and pernicious anemia.(ABSTRACT TRUNCATED AT 250 WORDS)

Autoantibodies↗

Intellectual, school and occupational performance in patients with idiopathic hypothalamo-pituitary hypothyroidism and primary hypothyroidism.

Intelligence quotient (IQ), school and professional performance were reviewed in 33 patients with idiopathic hypothalamo-pituitary hypothyroidism. Diagnosis was based on low T4 values and clinical signs. All were treated with growth hormone (HGH). In some, hypothyroidism became manifest only after HGH therapy. Birth history revealed breech delivery in 24 and perinatal asphyxia in 15 of them. Thyroid treatment was started at a mean age of 9.8 (range 4-18 years). The mean IQ was 103.4 +/- 16.7 (SD). 9 patients had IQs below 90, 8 of them were born by breech delivery, 3 had severe perinatal asphyxia, one recurrent symptomatic hypoglycemia, and one a micropenis. Of those patients who have reached the respective age, 7 attended college, 3 university, and 9 had skilled professions. Only 7 required special education. For comparison, 52 patients with primary hypothyroidism were studied. Their mean IQ was with 89.3 +/- 18.1 (SD) significantly lower (p < 0.001) than the mean IQ of patients with hypothalamo-pituitary hypothyroidism. The best IQ (96.8 +/- 16.9) was attained when thyroid treatment was started before the age of 4 months, the lowest IQ (78.2 +/- 19.2) was found in the group of patients in whom thyroid substitution was initiated between 5 and 12 months. Patients who were treated after one year of age, had a mean IQ of 90.0 +/- 15.7. This group includes patients with ectopic thyroid glands or acquired hypothyroidism such as Hashimoto's thyroiditis.

Adolescent↗

Transient hypothyroidism in infants born to mothers with chronic thyroiditis--a nationwide study of twenty-three cases. The Transient Hypothyroidism Study Group.

To define the difference in prognosis and the clinical features of transient neonatal hypothyroidism in infants born to mothers with chronic thyroiditis, we conducted a nationwide study of this condition. Sixteen mothers with chronic thyroiditis and twenty-three of their offspring with transient hypothyroidism were registered and reported in this paper. Five (group A) of twenty-two live infants showed physical, mental and/or psychomotor developmental delay (IQ below 80). No significant difference between TSH-binding inhibitor immunoglobulin (TBII) or thyroid-stimulation blocking antibody (TSBAb) activities in groups A and B (normal development) were noted. Moreover, there was no significant difference in thyroid function in the newborn period, ages at the start of thyroid medication or the dose and duration of treatment in the two groups. A striking difference observed between the two groups was the thyroid function of their mothers during pregnancy. In group A, four mothers were hypothyroid during pregnancy, and another mother discontinued thyroid medication in the last trimester and her baby was most delayed at the start thyroid medication. On the other hand, the mothers of only two of seventeen live cases in group B had mild hypothyroidism during pregnancy. There were two sets of siblings whose mother received inadequate treatment during the first pregnancy and adequate treatment during the second pregnancy. The psychomotor, physical and mental developmental delay were observed in their first babies. These findings suggested that maternal thyroid function during pregnancy might be an important factor in the prognosis of infants born to mothers with chronic thyroiditis.

Adolescent↗