Thyroid function and pubertal development in malnutrition

Thyroid function and pubertal development of aborigines (Orang Asli) and Malays at different socioeconomic strata were assessed among 1136 subjects aged 7 years and above. Anthropometric measurements, goitre and pubertal staging were done. Serum thyroxine (T4), triiodothyronine (T3) and growth hormone were measured using radioimmunoassays (RIA) and serum thyroid stimulating hormone (TSH) by immunoradiometric assays (IRMA). It was found that serum T3 in children was significantly higher in Malays from rural areas, girls and children aged less than 13 years. However, in adults, T3 was significantly associated with anthropometric indices. On the contrary, serum T4 levels were higher among children from urban areas. In adults, serum T4 levels were significantly related to nutritional status and they increased according to the levels of social development, being lowest in remote areas and highest in urban areas. However, serum TSH levels were significantly higher in Orang Asli at all ages and among malnourished children. By using multiple regression, apart from age, gender and ethnicity, nutritional status was a significant predictor for T3 levels in children and adults. Presence of goitre was an important factor which determined the T4 levels in children and adults after controlling for other factors. It was also a predictor for TSH levels in children but not in adults. Fasting serum growth hormone (GH) levels were significantly higher among less privileged groups and decreased according to social development. Serum growth hormone was negatively correlated with anthropometric indices and had a significant association with malnutrition.(ABSTRACT TRUNCATED AT 250 WORDS)

Lung function, CT-scan and X-ray in upper airway obstruction due to thyroid goitre

The purpose of this study was to assess the clinical reliability and to compare routine lung function tests (maximal flows and resistance) and radiological images (computed tomography (CT)-scan and X-ray) in upper airway obstruction. We, therefore, performed these examinations prospectively in 28 female patients (aged 68 +/- 13 yrs) with a goitre and without pulmonary disorders. Lung function measurements consisted of maximum expiratory and inspiratory flow-volume curves and of airway resistance. CT-scans and X-rays were performed during apnoea at functional residual capacity (FRC). Peak expiratory flow was 3.6 +/- 1.3 l.s-1 (i.e. 62 +/- 21% predicted); airway resistance was 0.38 +/- 0.14 kPa (i.e. 149 +/- 58% pred); and specific conductance was 1.0 +/- 0.3 kPa (i.e. 70 +/- 24% pred). Almost all lung function tests were significantly correlated with each other. On CT-scan the tracheal cross-sectional area at the zone of tracheal narrowing could be evaluated in 26 patients and was 58 +/- 17% (CT1/2) of the control area 2 cm above the carina (CT2). On X-ray the sagittal and coronal tracheal diameters at the zone of narrowing could only be measured in 16 subjects and were 60 +/- 17% (X-dia1/2) of the diameter at the control level. CT1/2 and X-dia1/2 were significantly correlated to each other. No correlation was found between the lung function tests and the radiological indices except airway resistance and CT2. Routine lung function and CT-scan do not provide comparable information on the degree of airway obstruction due to a goitre.(ABSTRACT TRUNCATED AT 250 WORDS)

Simultaneous assay for three types of thyrotropin receptor antibody activities using FRTL-5 cells in patients with autoimmune thyroid diseases

The relationships between the different circulating thyrotropin receptor antibodies (TSH-R-abs) in autoimmune thyroid disease (AITD) are complex. In order to investigate them, we have developed an assay for the simultaneous measurement of three types of TSH-R-abs: TSH-binding inhibiting immunoglobulin (TBII): thyroid-stimulating antibody (TS-ab) and TSH-stimulation blocking antibody (TSB-ab). A large number of patients with Graves' disease (GD)--untreated and treated--Hashimoto's thyroiditis (HT), primary myxedema (PM) and non-immune goiter (NIG) were investigated. In untreated Graves' patients the frequency of positive TS-ab and TBII sera was found to be 90 and 69%, respectively, the presence of TS-ab and/or TBII being detected in 98%. After long-term antithyroid treatment administered to GD patients, the frequency of positivity of both TBII and TS-ab was decreased, whether hyperthyroidism was cured or not. The TSB-ab was detected in the serum of 8% of patients with GD, and the frequency of TSB-ab did not increase following treatment and alteration in thyroid function. No significant correlation was found between TSB-ab and thyroid function in Graves' patients. Besides, we found that all the GD patients presenting positive TSB-ab were also TBII positive. A follow-up study of the three TSH-R-abs was performed in 35 patients with GD during a mean of 14.3 +/- 8.5 months (4-34 months) of antithyroid drug treatment. Ten out of 24 patients (42%) with positive TBII and 16 out of 32 (50%) with positive TS-ab turned from positive to negative during the time of follow-up. Regarding relapse in hyperthyroid GD, we found that TS-ab was positive in 80% and TBII was positive in 40% of the patients with Graves' relapse, indicating that the presence of TS-ab is a better index for relapse prediction in Graves' hyperthyroidism than TBII. The TSB-ab was found with higher frequency in HT and PM than in GD, i.e. 21%, 18% and 8%, respectively., The TSB-ab positivity was correlated significantly with TBII in our patients with AITD when TSB-ab was positive. This new simultaneous assay of the three TSH-R-abs should be very helpful for further investigation of the autoimmune aspects of AITD and it should help us to progress in a better understanding of the pathogeny of the different AITDs.

Endemic goiter and thyroid function in central-southern Sardinia. Report on an extensive epidemiological survey

Although the existence of endemic goiter and cretinism in Sardinia is known since to ancient time, scanty information collected according to WHO criteria is available. In the present paper the results of an extensive epidemiological survey carried out in juvenile population living in some rural and/or hilly villages in the provinces of Nuoro and Oristano in Central-Southern Sardinia and in urban area of Cagliari, are reported. In the majority of the villages the mean urinary iodine excretion was lower than 60 micrograms/L; the goiter prevalence ranged between 39% and 61% in the district of Nuoro and between 21% and 56% in the district of Oristano. In the control area the urinary iodine excretion was 105 micrograms/L with a goiter prevalence of 12%. Goiter prevalence was not always inversely related to urinary iodine excretion. No relevant thyroid function alterations were found.

IN CONCLUSION

1) in extraurban areas of Central-Southern Sardinia mild to moderate iodine deficiency and endemic goiter are still a widespread problems; 2) also in urban area endemic goiter prevalence is still higher than 10%; 3) extemporary urinary samples are inadequate for assessing the severity of goiter endemia in mild to moderate iodine deficiency; 4) in mildly affected districts palpation is inaccurate for assessing the prevalence of goiter; 5) no relevant alterations of thyroid function were documented in juvenile population.

[A rapid morphometric method for determining thyroid gland function]

The incidence of postoperative hypothyrosis after subtotal resection of the thyroid for diffuse toxic goiter is rather high, 40-50% according to many authors. A method is suggested permitting assessment of the share of "active zones" during surgery. A certain amount of thyroid tissue is left with due consideration for this share, this amount being sufficient to attain an euthyroid state in the postoperative period.

Cytoplasmic calcium regulation and the electrocardiogram in patients with primary hyperparathyroidism

Primary hyperparathyroidism (HPT) is a disease caused by an abnormal cytosolic regulation of calcium concentration [Ca++]i leading to an increased secretion of parathyroid hormone and thereby increased levels of extracellular calcium. It is well known that the QT-interval measured at electrocardiography (ECG) is shortened in HPT subjects. Whether this is due to an abnormal intracellular handling of calcium also in the heart or to the raised extracellular calcium levels is not known. In order to study the extent to which the deranged extra- and intracellular levels of calcium in HPT patients were related to ECG characteristics, [Ca++]i was determined in vitro by microfluorometry in surgery-removed parathyroid cells at extracellular calcium concentrations of 0.5 mM and 30.0 mM and ECG was recorded preoperatively in 42 HPT patients and in 15 subjects operated on for atoxic goitre. Serum calcium and plasma-ionized calcium also were measured preoperatively. The QT-interval and ST-segment duration were both shortened in the HPT patients compared to controls (P < 0.001). [Ca++]i at 3.0 mM extracellular calcium divided by that at 0.5 mM was correlated to the QT-interval, when measured at the onset of the T-wave (QoT, r = 0.39, P < 0.03) and early diastolic phase (end of T-wave to onset of p-wave, r = -0.34, P = 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Thyroid volume and morphology and urinary iodine excretion in a Danish municipality

In order to throw light upon the eventual need for iodine supplementation in Denmark, four age groups of women (15, 30, 45 and 60 years) from the Holbaek municipality were invited for a clinical and ultrasound study of thyroid volume, structure and function. Of the 570 women invited, 391 accepted and were divided into the following groups: group I: 15 years, N = 113; group II: 30 years, N = 100; group III: 45 years, N = 98; group IV: 60 years, N = 80. The results were as follows the thyroid gland was palpable in 39% and visible in 16% of the entire group; 19% had a family history of thyroid disorders and 7.6% had a previous thyroid disorder. Thyroid volumes (median (range)) as measured by ultrasound were 12 ml (4-29 ml), 18 ml (5-47 ml), 18 ml (7-64 ml) and 18 ml (9-51 ml) in groups I-IV, respectively. The calculated 24-h iodine excretion was 65 micrograms (19-365 micrograms), 88 micrograms (15-274 micrograms), 97 micrograms (40-737 micrograms) and 83 micrograms (50-999 micrograms) in groups I-IV, respectively. An abnormal echo structure was present in 3, 10, 21 and 30%, respectively. Defining a goitre as a thyroid volume above 28 ml indicated a goitre prevalence of 17% in females aged 30-60 years in the Holbaek area of Denmark. Among the 60-year-old women, 3% had a clinically significant goitre (WHO grade III). Thyroid volume did not correlate with iodine excretion. The benefit of iodine supplementation is discussed.

[Frequency and temporal occurrence of a functional autonomy in recurring goiter]

In 168 patients who underwent thyroid surgery due to a goitre the frequency and the temporal occurrence of functional autonomy in recurrent goitres were determined retrospectively. The diagnosis of functional autonomy was established by quantitative suppression scintigraphy with 99mTc. In the region examined the limiting value for functional autonomy is 1.0% 99mTcU after suppression. In 41% (n = 69) of the patients a recurrent goitre was found in the clinical examination. The postoperative observation period in this patient group ranged from 2 months to 42 years with an average of 13.8 years. Whereas the prevalence of functional autonomy in the early postoperative years was low, a continuous increase of thyroid autonomy with values of about 4% per year could be found until the 20th postoperative year, the rate of patients with functional autonomy was then about 70%. Thereafter the prevalence of thyroid autonomy increased only marginally and reached about 90% in the 40th postoperative year. The results demonstrate that functional autonomies in recurrent goitres are frequent. The majority of examined patients had recurrent and not residual autonomies.

Oxalate in the human thyroid gland

Ninety-seven fixed surgical thyroid specimens and 63 unfixed and 40 fixed thyroid specimens from autopsies were examined for their oxalate content. Proteases were used to process the tissue, and the oxalate was determined with an enzymatic assay. The fixed samples were grouped into seven diagnostic categories (diffuse colloid goitre; partially diffuse, partially nodular colloid goitre; nodular colloid goitre; goitre with multifocal functional autonomy; non-functioning adenoma; unifocal functional autonomy; Graves' disease). The oxalate concentrations of the samples were mainly dependent on age and gender, which were distributed unequally among the seven diagnostic groups. In thyroid tissue from cases of Graves' disease, however, the concentration of oxalate was remarkably low and statistically different from those of four of the six other groups.

Goiter in adolescents

Enlargement of the thyroid gland during adolescence should be considered a pathologic rather than physiologic process. With diffuse enlargement in an asymptomatic patient, thyroid function tests and thyroid antibodies usually are the only tests needed to define the diagnosis of euthyroid autoimmune thyroiditis. Patients with lobular or nodular thyroid enlargement may require additional tests if the diagnosis of Hashimoto's thyroiditis cannot be established by the presence of thyroid antibodies in serum. The tests to define the anatomic and functional status of nodular thyroid disease include ultrasonography and radionuclide scintigraphy of the thyroid, but rarely fine needle biopsy. The only indications for surgical therapy of the thyroid are hyperfunctioning thyroid adenomas, the suspicion of thyroid carcinoma and Graves' disease in patients who are not responsive to antithyroid drug therapy and who are poor candidates for radioiodine ablative therapy. The prognosis of thyroid disease during c adolescence is usually excellent.

Menstrual irregularities and lactation failure may precede thyroid dysfunction or goitre

Menstrual and reproductive history of 178 women referred to the thyroid clinic was compared with 49 healthy controls. Cases were classified as euthyroid, hypothyroid or hyperthyroid after clinical examination and after serum T3, T4, TSH measurements. Reproductive history was related chronologically to symptoms and signs of thyroid dysfunction. Only 31.8% of hypothyroid and 35.3% of hyperthyroid women had normal menstrual pattern in contrast with 56.3% of Euthyroid and 87.8% of healthy controls (p < 0.001). Reproductive failure (infertility, pregnancy wastage, failure of lactation) occurred in 37.5% of hypothyroid and 36.5% of hyperthyroid cases against 16.3% of euthyroid and 16.7% of healthy controls (p < 0.05). Interestingly, in 45% of cases with menstrual abnormality, the anomaly was antecedent to other clinical features by a variable period of two months to ten years. Reproductive failure and lactation failure also preceded thyroid dysfunction or goitre. Reproductive dysfunction may therefore be considered as one of the presenting symptoms of thyroid disorders in women, keeping in mind both menstrual irregularities and lactation failure may also arise from other common or idiopathic origins. Especially in women with menstrual irregularities in the perimenopausal age if thyroid dysfunction is detected, pharmacotherapy may be a superior alternative to surgical interventions like hysterectomy.

Multiple genetic factors in the heterogeneity of thyroid hormone resistance

Generalized resistance to thyroid hormone (GRTH), a syndrome of inherited tissue hyposensitivity to thyroid hormone, is linked to thyroid hormone receptor (TR) mutations. A typical feature of GRTH is variable severity of organ involvement among families that, surprisingly, does not correlate with the degree of T3-binding impairment of the corresponding in vitro synthesized mutant TRs. Furthermore, variations in the clinical severity among family members harboring identical TR beta mutations have been reported. We compared serum levels of thyroid hormones that maintained a normal TSH in members of a large family with GRTH divided in three groups: Group A, 8 affected subjects with a mutation replacing arginine-320 with a histidine in the T3-binding domain of TR beta; Group B, 11 first degree relatives (sibs and children of affected subjects) with no TR beta mutation; Group C, 16 controls related by marriage. TSH values were not different among the three groups. As expected, total and free T4 and T3, and rT3 levels were significantly higher in Group A vs Groups B and C. However, with the exception of T3, the same tests were also significantly higher in Group B vs Group C. The latter differences are not due to thyroid hormone transport in serum since TBG concentrations were not different. It is postulated that genetic variability of factors that contribute to the action of thyroid hormone modulate the phenotype of GRTH associated with TR beta mutations.

Microcephalic cerebrum with hypomyelination in the congenital goiter mouse (cog)

2',3'-Cyclic nucleotide 3'-phosphohydrolase activity in the cerebrum of the congenital goiter mouse (cog/cog) is reduced in comparison with the normal heterozygote (cog/+). The weight of the cog/cog cerebrum and cerebellum were significantly less than those of the normal controls, 89.0% less for the cerebrum, and 81.1% less for the cerebellum. However, no differences were observed with regard to DNA and RNA content and the RNA/DNA ratio. The results of this study indicate that hypomyelination in the congenital goiter mouse is restricted to the cerebrum, and is not related to arrested glial proliferation.

Thyroid cell lines in research on goitrogenesis

Thyroid cell lines have contributed a lot to the understanding of goitrogenesis. The cell lines mostly used in thyroid research are briefly discussed, namely the rat thyroid cell lines FRTL and FRTL-5, the porcine thyroid cell lines PORTHOS and ARTHOS, The sheep thyroid cell lines OVNIS 5H and 6H, the cat thyroid cell lines PETCAT 1 to 4 and ROMCAT, and the human thyroid cell lines FTC-133 and HTh 74. Chinese hamster ovary (CHO) cells and COS-7 cells, stably transfected with TSH receptor cDNA and expressing a functional TSH receptor, are discussed as examples for non-thyroidal cells, transfected with thyroid genes.

Interrelationships between age, thyroid volume, thyroid nodularity, and thyroid function in patients with sporadic nontoxic goiter

PURPOSE

To test the hypothesis that during the natural history of sporadic nontoxic goiter (SNG), a diffuse goiter precedes a multinodular goiter with gradual development of autonomous thyroid function.

PATIENTS AND METHODS

A cross-sectional survey of 102 consecutive patients with SNG (seven male, 95 female) was performed. Thyroid volume was measured by ultrasonography, and plasma thyroid-stimulating hormone (TSH) by a sensitive assay (TSH immunoradiometric assay).

RESULTS

Patients with a multinodular goiter were older and had a larger thyroid volume than patients with a diffuse or uninodular goiter. Plasma free thyroxine (T4) and total triiodothyronine (T3) were higher and plasma TSH was lower in patients than in normal subjects. Free T4 was higher in the subgroup of patients with a multinodular goiter and a decreased TSH response to thyrotropin-releasing hormone. Plasma TSH (y, in mU/L) was negatively related to thyroid volume (x, in mL): y = 8.2x-0.667 (r = 0.578, p less than 0.001). Thyroid volume (y, in mL) was positively related to age (x, in years): y = -21.8 + 2.0x (r = 0.455, p less than 0.001); and to duration of goiter (x, in years): y = 40.6 + 2.1x (r = 0.505, p less than 0.001). The annual increase in thyroid volume was calculated at 4.5%.

CONCLUSION

The data suggest a continuous growth of SNG and provide support for the concept of increasing thyroid nodularity and autonomy of thyroid function--related to increasing thyroid volume--during the natural history of this disorder.

[Changes in serum thyroglobulin levels during the TRH test in euthyroid female patients with diffuse and nodular goiters]

Concentrations of thyroglobulin (Tg) in the sera of 48 euthyroid females of different ages suffering from diffuse and nodular goitre during TRH test, were determined. The aim of this study was to examine the correlation between the increased TSH levels and Tg, and thyroid hormones in the serum in dependence of pathomorphological thyroid status and the patients' ages. TSH maximal level reached (+314%) compared with the basal level 25 minutes after TRH injection, while max Tg level was found 60 minutes after TRH in 15 female patients, medium age 41 (range:33-48), with diffusely enlarged thyroid gland. Concentrations of Tg and T4 in the serum of patients increased at the same time, although no statistical difference for T4 was noted. In 23 females, aged over 60 years (range: 65-80), suffering from euthyroid diffuse goitre, maximal TSH level was achieved later, i.e. 60 minutes after TRH injection, while max Tg was found 90 min after TRH. If we compare Tg serum levels in geriatric females with the data obtained in the younger group, we will note that the increase of Tg concentrations was significantly lower and delayed in elderly subjects (p less than 0.001). Data on TSH-and Tg-increase during TRH test in 10 females suffering from solitary, functioning nodular goitre, were very similar to findings obtained in 15 female patients with diffusely enlarged thyroid (25 minutes after TRH max TSH + 205%, and max Tg level + 198%). The obtained results indicate that Tg serum levels were increased after TRH injection in 48 euthyroid females.(ABSTRACT TRUNCATED AT 250 WORDS)

Vascular compression from goiter as an unusual cause of cerebrovascular accident

The unusual case of a patient with goiter and left faciobrachiocrural paresis due to right temporoparietal infarction is reported. Cerebral angioscintigram and arteriography showed a brachiocephalic and right subclavian stenosis secondary to compression by an extended thyroid nodule.

Upper airway obstruction due to goitre: detection, prevalence and results of surgical management

A group of 132 women and 12 men with goitre were studied to determine the prevalence of upper airway obstruction caused by the goitre. Inspection of flow-volume loops was used to detect upper airway obstruction and this suggested that 44 subjects (31 per cent) had the condition. Of these 44 subjects 19 per cent were men, which was a greater proportion than could be accounted for by chance. Flow-volume loops after surgery were recorded on 43 patients of whom 29 were from the group thought to have had upper airway obstruction. Comparison of measurements before and after surgery showed no important change in the 14 without, and improvement in 27 of those with, upper airway obstruction. Analysis indicated two failures of treatment and four probable false-positives among the group with upper airway obstruction. Inspection of the flow-volume loop had a 78 per cent specificity and 100 per cent sensitivity in detecting upper airway obstruction whereas an FEV:PEF ratio above 8 had a specificity of 94 per cent and a sensitivity of 64 per cent in this respect. Ultrasonography and plain radiography of the upper airway accurately predicted retrosternal extension of the goitre but did not predict upper airway obstruction. It is recommended that all patients with symptomatic goitre should have a flow volume loop recorded.

Syndrome of generalized (peripheral tissue and pituitary) resistance to thyroid hormone

Generalized resistance to thyroid hormone (GRTH), or Refetoff syndrome, is a disease in which peripheral tissues show resistance to thyroid hormone. Three patients with this disease were investigated. Cases 1 and 2 involved identical 7-year-old female twins and case 3, a 5-year-old girl. All three patients had goiters, and cases 1 and 2 had sensorineural deafness. In all three, the blood levels of T4, free T4, and T3 were high, while the blood levels of TSH were normal or slightly elevated. The responses shown by blood levels of the thyroid hormone and TSH to administration of propylthiouracil and T3 suggest that the regulating mechanism in the hypothalamic-pituitary-thyroid system was functional. Upon administration of T3, no sign of hyperthyroidism was observed.

[A case report of Refetoff's syndrome]

An 11-year-old girl with diffuse goiter is presented. She had no clinical evidence of thyrotoxic symptoms or signs of palpitation, excessive sweating, tachycardia or finger tremor. Both the serum T4 (24.0 micrograms/dl) and T3 (282ng/dl) were high, and thyroid 131I uptake rate (63.2%) was significantly elevated, but T3/T4 ratio was not elevated (11.8). BMR was measured three times and remained within normal limits. Her serum TSH was 1.9 microU/ml, and a TRH stimulation test resulted in a normal rise of serum TSH (13.4 microU/ml). The TSH secretion was not suppressed by medication (p.o.) of 75 micrograms of L-triiodothyronine given for 8 days. The autoantibodies of T4, T3 and TSH were negative. No sign of pituitary tumor was observed by plain X-ray film. No defect in her sight-field was found. From these clinical figures and data, Refetoff's syndrome was suspected. She was eumetabolic without any treatment, but the goiter gradually enlarged and dysphagia developed. A large dose of L-thyroxine (450 micrograms/day) was given for a period of one year and four months. She has been eumetabolic. Her goiter disappeared and the dysphagia completely subsided. After she was given large doses of L-T4, her serum TSH was reduced to 0.07 microU/ml and was slightly elevated to 0.24 microU/ml at 30 min after i.v. infusion of 500 micrograms TRH. Thyroid 123I uptake rate was suppressed to 8.3%. According to Refetoff's papers, this case was classified as being in the group with generalized resistance to thyroid hormone.