Monitoring of treatment for hypothyroidism with L-thyroxine]

The study was aimed at the evaluation of treatment of hypothyroidism with L-thyroxine administration monitored by the determination of T3 and T4 concentrations. The investigations were carried out in a group of 57 patients with hypothyroidism including 37 patients with autoimmune etiology of hypothyroidism, 12 patients after strumectomy and 8 patients after treatment with 131J. The administration of L-thyroxine at a dose of 2 micrograms/kg/day effectively eradicated all symptoms of the disease and led to the normalization of blood serum T3 and T4 values in the majority of patients with autoimmune hypothyroidism. So the majority of women required the daily dose of L-thyroxine of 100-150 micrograms, and the majority of men 125-175 micrograms. Lower dosage of L-thyroxine (50-100 micrograms daily) was required to attain euthyroid state in some patients with postoperative or postradiation hypothyroidism. Monitoring of the therapy by the determination of blood serum T3 and T4 concentrations greatly facilitated the proper choice of the therapeutic dose of L-thyroxine as the return of the thyroid hormone concentrations to normal usually brought about the complete remission of symptoms of the disease. The exception from this rule was only in the case of patients with arterial hypertension and coronary disease in whom, because of the side-effects, lower dosage of L-thyroxine (usually 50 micrograms daily) must have been applied to attain the optimal improvement. The treatment with L-thyroxine caused much less side-effects as compared to the therapy using the dessicated thyroid preparations (Thyroideum).     

Maintenance requirements of L-thyroxine in the treatment of hypothyroidism

By analyzing data from 68 hypothyroid patients ranging in age from 15 to 75 years who had been maintained in a euthyroid state for at least a year with oral levothyroxine sodium therapy, we attempted to determine whether there was a correlation between L-thyroxine dose and body weight or patient age. The mean replacement dose of L-thyroxine was 186 mug a day +/-69.6 or 2.76 mug per kg of body weight a day +/-0.82. There was a significant correlation between L-thyroxine dose and body weight (P<.001), but due to the small number of patients studied who were older than 65 years of age, no correlation was noted between L-thyroxine dose and age.     

Prevalence of minor musculoskeletal anomalies in children with congenital hypothyroidism

In the last decade a high frequency of extrathyroidal congenital anomalies has been reported in infants with congenital hypothyroidism (CH) detected by neonatal screening. In the present study the occurrence of additional congenital malformations (CM) in a cohort of children with confirmed primary CH due to thyroid dysgenesis was investigated. A high prevalence of extrathyroidal major congenital anomalies (15.9%), more than 5-fold higher than that reported in the Egyptian population (2.7%), was found. The cardiac and musculoskeletal systems were the most commonly involved, comprising 9.09 and 47.72% of all anomalies, respectively. The high prevalence of musculoskeletal anomalies in this study was mostly due to minor anomalies as brachydactyly and digitalization of thumbs. The type of dysgenesis (i.e. aplastic, ectopic or hypoplastic) as well as the severity of hypothyroidism, as assessed by TSH and T(4) levels at diagnosis, had no relation with the occurrence of extrathyroidal abnormalities.     

Thyroid hypoplasia as a cause of congenital hypothyroidism in Williams syndrome

In the Williams-Beuren syndrome (WBS), disorders of the thyroid function and morphology have been reported and programs of thyroid screening and surveillance are recommended. However, the frequency of biochemical thyroid assessment, particularly in the first year of life, is being debated. In this report we describe an infant with WBS and congenital hypothyroidism, due to an important thyroid hypoplasia. The patient, a 1-month-old female, negative at primary neonatal thyroid screening, was referred to our hospital for dyspnea. Thyroid function tests showed a raised TSH (42 mIU/l; normal range 0.5-4 mIU/l) with a low FT(4) concentration (10.21 pmol/l; normal range: 10.29-24.45 pmol/l). Ultrasound examination of the neck showed a significant thyroid hypoplasia, whereas (99m)Tc-pertechnetate thyroid scintigraphy evidenced a thyroid gland in normal position, with reduced shape and overall weak fixation. Therefore, treatment with L-thyroxinewas started. Thyroid hypoplasia is a frequent characteristic of WBS and abnormalities of thyroid function are common in patients with this feature. Therefore, the possibility of congenital hypothyroidism should always be taken into consideration too and, even if congenital hypothyroidism neonatal screening is negative, thyroid (morphology and function) evaluation should be regularly assessed when the diagnosis is made and, thereafter, every year in the first years of life.     

Effects of early high-dose levothyroxine treatment on auditory brain event-related potentials at school entry in children with congenital hypothyroidism

AIMS: We tested whether brain event-related potentials (ERPs) are normal in children with congenital hypothyroidism (CH) after early high-dose levothyroxine treatment. METHODS: Auditory ERPs were recorded in 33 normal controls and in 15 children with CH at 5 years 9/12. Based on bone maturation at diagnosis, the CH group was divided into severe (n = 8) and moderate (n = 7) subgroups. CH patients were treated at a median age of 14 days with a mean initial dose of levothyroxine of 11.6 microg/kgxday. Two ERP components (N100 and N200) were measured and clinical follow-up variables collected. RESULTS: The functional anatomical and cognitive organisation of the auditory system, as revealed by the analyses of ERP measures, did not differ between CH and controls, or between severe and moderate CH subjects. However, N200 latency was globally longer in the CH than in the control group (p = 0.01) and was positively correlated with the over-treatment index (r = 0.61; p < 0.05) and verbal IQ. N200 amplitude was negatively correlated with initial dose (r = -0.74; p < 0.005). CONCLUSION: These data suggest that sensitive tools such as ERPs can reveal differences between CH and controls and relate these differences to the adequacy of treatment of CH.     

Precocious puberty with congenital hypothyroidism

Precocious puberty associated with profound hypothyroidism is a rare condition. It is usually characterized by breast development, vaginal bleeding, lack of pubic hair and delayed bone age. Multicystic ovaries in profound hypothyroid patients with precocious puberty have been rarely described. Vaginal bleeding in adolescent girls should be considered as a clinical significance particularly when it is prolonged or heavy, whereas vaginal bleeding in younger girls, regardless of its duration and quantity is always of clinical importance. Bleeding in such patients could be caused by local causes such as vulvar or vaginal lesions, or it could be from the endometrium, which is usually a sign of systemic hormonal disturbance [1]. In this report a rare case of vaginal bleeding, large, multicystic ovaries, precocious puberty and delayed bone age in a 7 years old girl with profound hypothyroidism is described.     

Comparative effects of desiccated thyroid gland and sodium salt of L-thyroxine in the treatment of hypothyroidism

The studies comparing the actions of dried thyroid gland (Thyroideum-Polfa) with L-thyroxine sodium (L-T4) were carried out in 20 female patients with hypothyroidism, including 19 patients with the primary hypothyroidism and 1 patient with hypothyroidism secondary to pituitary deficiency. Administration of the dried thyroid gland did not normalize blood serum T4 an TSH in any patient. Normal serum T4 or even slightly increased was achieved in all patients treated with L-T4. Serum TSH was normalized in 17 patients with the primary hypothyroidism. The following conclusions have been drawn: 1. Dried thyroid gland (Thyroideum-Polfa) is ineffective in the treatment of hypothyroidism. 2. Serum TSH remains elevated despite normal serum T3 in cases of the primary hypothyroidism with decreased serum T4 levels. 3. Sodium salt of L-thyroxine should be used for the treatment of hypothyroidism. 1-Triiodothyronine sodium may be used as an adjuvant therapy.     

Congenital anomalies associated with congenital hypothyroidism

The French national neonatal screening program for congenital hypothyroidism (CH) was initiated in 1978. The purpose of this study was to ascertain the incidence of congenital extrathyroid anomalies (ETAs) among the infants with congenital hypothyroidism (CH) and to compare it with the Northeastern France Birth Defect Monitoring System data from 1979 to 1996. Among 129 CH infants on whom adequate data were available, 20 infants (15.5%) had associated congenital anomalies. Eight out of 76 infants with persistent CH had ETAs (10.5%) whereas 12 out of 53 children with transient hypothyroidism had ETAs (22.6%, p < 0.05). Some additional anomalies were considerably more common than in the general population. Nine infants had congenital cardiac anomalies (6.9%). This rises the question if teratogenic effects active during organogenesis may affect simultaneously many organs, including the developing thyroid, causing a relatively high percentage of CH infants with congenital ETAs.     

Long term treatment of congenital hypothyroidism with L-triiodothyronine: 24 year follow-up

A congenital hypothyroidism complicated by ventricular septal defects which was treated with L-triiodothyronine (L-T3) alone from 1 5/12 to 25 years, is described. The patient's growth and development was satisfactory and without side effects. It suggests that L-T3 may be a safe drug for long term treatment of congenital hypothyroidism.     

Thyroid function and obesity in children and adolescents

The aim of this retrospective study was to investigate the frequency of thyroid dysfunction as assessed by TSH, T3 and T4 in a large cohort of 290 obese and 280 healthy children. In addition, thyroid autoantibodies were measured in random subgroups of 123 obese and 80 control children, iodine excretion in 50 and thyroid volume in 23 of the obese children. Elevated TSH levels (>4 U/l) were found in 22 obese children (7.5%), but only in one control (0.3%). The medians of TSH and T3 concentrations were normal, but significantly higher in the obese group than in the controls, while T4 levels did not differ. The prevalence of positive thyroid autoantibodies was increased in the obese children, for the most part in those with elevated TSH. There was no evidence for iodine deficiency as a cause of the average increase of TSH. We conclude that in childhood obesity TSH and T3 levels are significantly increased; in most cases, however, these increases are not accounted for by thyroid autoimmunity or iodine deficiency. As a consequence, TSH elevations with normal thyroid hormone levels in obese children don't need any thyroxine treatment, if thyroid disorders were definitely excluded beforehand.     

Thyroid function in patients during long-term treatment with amiodarone]

Thyroid function was evaluated in 31 patients with disturbances of heart rhythm both before and after 13 months of treatment with amiodarone. An increase in blood serum T4 concentration and transient increase (only during the first three months of treatment) in TSH concentration have been observed in almost all the patients studied. Clinically evident form of hyperthyroidism was found only in one female patient. In two patients the changes in hormone concentrations suggesting hyperthyroidism were not accompanied by clinical manifestations, and in four patients there was no clinical hypothyroidism despite hormone levels suggesting such a state. In addition to the determinations of T3, T4 and TSH also the results of TRH-TSH test played an important role in diagnosing both hypo- and hyperthyroidism.     

Differential effect of fetal, neonatal and treatment variables on neurodevelopment in infants with congenital hypothyroidism

OBJECTIVES: To identify the influence of fetal, neonatal and treatment variables on neurodevelopment in children with congenital hypothyroidism. METHODS: A multiple regression analysis was performed in the neurodevelopmental scores of 26 children with CH who were assessed at 3, 6, 12 and 18 months for postural control, fine eye-hand coordination and language. The independent variables were: duration of fetal hypothyroidism, initial biochemical severity, days at starting treatment, initial dose, and efficiency of treatment. RESULTS: Postural control was predicted by duration of fetal hypothyroidism and language by the biochemical severity of the disease at birth. Fine eye-hand coordination was not predicted by any variable. CONCLUSION: This pattern of influences suggests that fetal and neonatal hypothyroidism have different effects on brain maturation sites during the first 2 years of life and that some subtle neurocognitive deficits are probably unavoidable.     

Management of patients with congenital hypothyroidism.

The biochemical state and treatment of 73 children and 44 adults up to the age of 40 with proved congenital hypothyroidism were assessed in a regional study in the north of England. The findings showed that a substantial proportion of the patients were having inappropriate treatment or were not taking their treatment regularly and that in some of these there were clinical effects.     

Thyroid function following radiation therapy in breast cancer patients: risk of radiation-induced hypothyroidism

BackgroundRadiation exposure to the thyroid gland seems unavoidable in breast cancer (BC) patients receiving radiation therapy (RT) to the supraclavicular (SC) region. Hence, this study aimed to evaluate the effects of SC region RT on thyroid function and the prevalence of radiation-induced hypothyroidism (RIHT) in BC patients at regular intervals post-treatment.Materials and methodsTwenty-one patients with BC were enrolled in this analytical cross-sectional study by simple and convenient sampling, from March 2019 to March 2020. Thyroid function and the prevalence of RIHT were evaluated and compared by measuring the serum of thyroid-stimulating hormone (TSH) and free thyroxine hormone (fT4) levels before radiation therapy (pre-RT) and 3 and 6 months after radiation therapy (post-RT). The patients underwent 3 dimensional conformal. radiation therapy (3D CRT) of breast/chest wall, axillary, and supraclavicular lymph nodes with 50 Gy/25 fractions/5 weeks. The collected data were analyzed using SPSS software (version 20).ResultsSerum levels of TSH increased at 3 and 6 months post-RT, this increase was not statistically significant (p > 0.05). Nevertheless, serum levels of fT4 were significantly elevated at 3 and 6 months post-RT (p < 0.01). A correlation was observed between the follow-up period and the incidence of RIHT, where it was 0% at 3 months and 9.5% at 6 months post-RT. RIHT was not significantly associated with any factors, including patient’s age, type of surgery, thyroid gland dose, and thyroid gland volume.ConclusionsIt seems that SC region RT does not have a significant adverse effect on the thyroid function among BC patients at 3 and 6 months post-treatment. Hence, a long-term follow-up with a larger sample size is suggested.     

Adult height in congenital hypothyroidism: prognostic factors and the importance of compliance with treatment

OBJECTIVE: To study the growth, puberty and compliance of 66 hypothyroid children and to determine prognostic factors for adult height. PATIENTS: 66 children were included (12 boys, 54 girls). Aetiologies were 43 ectopic glands, 14 thyroid agenesis, 9 dyshormonogenesis. RESULTS: In girls the mean adult height was 164.7 +/- 6.5 cm for a target height (TH) of 162.8 +/- 5.4 cm. In boys the mean adult height was 178.2 +/- 6.4 cm for a TH of 175.7 +/- 4.7 cm. Puberty development was normal. Children who exceeded their TH had an earlier start of treatment versus children who failed to reach their TH: 24.8 +/- 13.5 vs. 42.0 +/- 47.3 days, p = 0.004. Delayed normalisation of TSH is a risk factor for bad compliance. Adequate correlations between treatment variables appeared only in children who exceeded their TH. CONCLUSIONS: TH, day of start of treatment and compliance with treatment are the main prognostic factors for adult height. Early detection of bad compliance is possible.