Schoolchildren thyroid volume in North Macedonia: data from a national survey in an iodine-sufficient country.

PURPOSE: North Macedonia is historically iodine deficient, but due to the longstanding and effective preventive measures, it has been considered iodine replete since 2003. The aim of the recent national survey was to re-evaluate iodine status and to measure thyroid volume (TVol) by ultrasound in schoolchildren as a representative of the general population. METHODS: A stratified probability proportionate to size cluster sampling was used to obtain a representative national sample of school children aged 7-10 years between the 28th of March and 4th of October 2016. Thyroid volume (TVol) was measured using ultrasonography in 1188 children. All TVol measurements were done by a single operator and their medians were compared with an international reference standard. RESULTS: Significant positive correlation was found between Tvol and age, height, weight, body surface area (BSA), body mass index (BMI) in both girls and boys (p < 0.001), but not between TVol and urinary ioidine concentration (UIC). The most important predictors for Tvol in all children were age, height, weight, BMI, and BSA ( all p < 0.001). In multivariate regression, independent predictors for TVol were only BSA (p < 0.001) and age (p = 0.004) after being adjusted for sex, BMI, and UIC (R2 = 0.291). The 97th percentile of Tvol in our survey was generally higher than in the reference study and goiter prevalence of 18.3% in boys and 15.6% in girls was found compared to the international standard. CONCLUSION: In our survey, Tvol of schoolchildren was larger than in the international reference study, although iodine nutritional status of the country has been considered sufficient for many years. In countries and regions with long and effective, well-documented iodine prophylaxis, the optimal way to have realistic normative TVol would be to create their TVol reference limits. Therefore, the provided data for TVol measured in our survey could be proposed as the national reference TVol for schoolchildren aged 7-10 years.

Correction of iodine deficiency in Macedonia.

A national survey conducted in 1995-96 showed that mild to moderate iodine deficiency existed in Macedonia (median urinary iodine [UI] concentration 117 microg/l). It was concluded that a new legal regulation should be introduced concerning the iodination of table salt for human consumption. The iodine level was recommended to be 20-30 mg/kg salt, exclusively in the form of the more stable potassium iodate. The new regulations were instituted and became effective in October, 1999. National surveys performed in 2000 and 2001 showed increased median UI concentrations (154.1 microg/l in 2000 and 164.5 microg/l in 2001). In 2001, UI excretion was assessed in 490 pregnant and lactating women (median UI concentration 140 microg/l). During the last three surveys, household salt specimens were assessed for iodine content. The findings showed an increase of the percentage of the optimal iodine content in household salt (42-69%), which correlated with the higher IU excretion results. The new regime of salt iodination was proved to be highly effective in correcting the iodine deficiency in Macedonia.

Reevaluation of the results of iodine prophylaxis in eradication of endemic goiter in Macedonia.

In order to reevaluate effectiveness of iodine prophylaxis in Macedonia, epidemiological, ultrasonographic studies and estimation of urine excretion were performed. The results from the epidemiological survey in nongoitrogenic regions demonstrated goiter between 12.8% and 18%. Much higher prevalence of goiter was found in goitrogenic regions, between 20.8% and 60.8%. The incidence of goiter increased with age, and its prevalence is higher in girls when compared with the boys of the same age group. The thyroid volume estimated by ultrasonography was higher in children from goitrogenic regions when compared to nongoitrogenic. There was a good correlation between ultrasonographic volumetry data and size of the thyroid estimated by palpation. Urinary iodine excretion demonstrated low values in children from goitrogenic regions as indicator of iodine deficiency.

Extended long-term drug monotherapy of Graves' disease.

The results are presented of a 3-17 years' prolongation of the usual one-year "long-term" drug treatment applied to patients with Graves' disease. Most of the 87 patients with an average age of 34.3 years were on the maintenance dose of 10 mg methimazole daily. This mono-drug therapy was well tolerated and accepted by the patients, the toxic state disappeared, glandular consistency and the size remained almost unchanged. Thirty-six patients of this group (41.4%) were in a "permanent" remission lasting over three years. The remaining 51 patients continued their maintenance dose which kept a balanced euthyroid state. The authors support the convenience of a considerable extension of the traditional long-term methimazole treatment of Graves' disease. This extended scheme of the drug suppression of euthyroid functions is reversible in contrast to radical surgical or radioiodine treatments which increase the cumulative rate of irreversible hypothyroidism over decades.

Early diagnosis and detection of clinically non-suspected thyroid neoplasia by the cytologic method: a critical review of 1536 aspiration biopsies.

Aspiration biopsies were performed on 1536 patients with goiter who showed scintigraphically "cold" nodules. Twelve among them had clinical and cytological positive diagnosis. The remaining 1524 patients had aspiration biopsies without suspicion of the malignant nature of their goiters. Among them, 45 patients had a positive or suspect cytological diagnosis. Fourteen had not been yet operated on. Thirty-one were operated on and 28 malignancies were confirmed histologically. In three patients, cytological diagnosis was false positive. The remaining patients were cytologically negative. Thirty-seven were operated on and four false negative cases were found. The application of aspiration biopsy on every patient with a cold thyroid nodule resulted in the detection and very early diagnosis of clinically unsuspected thyroid neoplasms, the great majority of which were confined to the gland itself without metastasic spread. This fact makes the prognosis better. In addition, it is probable that the early detection of differentiated thyroid neoplasms and their surgical ablation interrupt their natural course towards anaplastic carcinoma, with its grim prognosis.