Neonatal thyrotropin (TSH) screening as a tool for monitoring iodine nutrition in Armenia

Hutchings, Nicholas J.; Tovmasyan, Irina; Hovsepyan, Marine; Qefoyan, Mushegh; Baghdasaryan, Sisak; Bilezikian, John P.

doi:10.1038/s41430-018-0298-4

Cited by 7 publications

(8 citation statements)

References 8 publications

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“…This indicates the success of both the mandatory iodine fortification of bread and the recommendation for routine iodine supplementation in pregnancy in Australia to lower the risk of iodine deficiency. This finding is consistent with studies in Ireland (36) , Armenia (38) and Switzerland (39) that showed a declining trend in the percentage of newborn TSH > 5 mlU/l after the introduction of iodine fortification or salt iodisation. However, an exploratory analysis controlling for timing of blood sample collection, birth weight, season at birth and the underlying time trend resulted in a reversing of the effect estimate and a loss of precision.…”

Section: Discussionsupporting

confidence: 91%

Comparison of iodine status pre- and post-mandatory iodine fortification of bread in South Australia: a population study using newborn thyroid-stimulating hormone concentration as a marker

Wassie¹,

Yelland²,

Smithers³

et al. 2019

Public Health Nutr.

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Objective:The present study aimed to evaluate the effect of mandatory iodine fortification of bread on the iodine status of South Australian populations using newborn thyroid-stimulating hormone (TSH) concentration as a marker.Design:The study used an interrupted time-series design.Setting:TSH data collected between 2005 and 2016 (n 211 033) were extracted from the routine newborn screening programme in South Australia for analysis. Iodine deficiency is indicated when more than 3 % of newborns have TSH > 5 mIU/l.Participants:Newborns were classified into three groups: the pre-fortification group (those born before October 2009); the transition group (born between October 2009 and June 2010); and the post-fortification group (born after June 2010).Results:The percentage of newborns with TSH > 5 mIU/l was 5·1, 6·2 and 4·6 % in the pre-fortification, transition and post-fortification groups, respectively. Based on a segmented regression model, newborns in the post-fortification period had a 10 % lower risk of having TSH > 5 mIU/l than newborns in the pre-fortification group (incidence rate ratio (IRR) = 0·90; 95 % CI 0·87, 0·94), while newborns in the transitional period had a 22 % higher risk of having TSH > 5 mIU/l compared with newborns in the pre-fortification period (IRR = 1·22; 95 % CI 1·13, 1·31).Conclusions:Using TSH as a marker, South Australia would be classified as mild iodine deficiency post-fortification in contrast to iodine sufficiency using median urinary iodine concentration as a population marker. Re-evaluation of the current TSH criteria to define iodine status in populations is warranted in this context.

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Section: Discussionsupporting

confidence: 91%

Comparison of iodine status pre- and post-mandatory iodine fortification of bread in South Australia: a population study using newborn thyroid-stimulating hormone concentration as a marker

Wassie¹,

Yelland²,

Smithers³

et al. 2019

Public Health Nutr.

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“…The severity, (mild, moderate and severe) is further defined by the proportion of neonates with TSH concentrations greater than 5 mIU/L. There has been a large body of literature reporting iodine deficiency status or outcomes of iodine prophylaxis programs using nTSH results, with reference to the WHO criteria [32], and in more recent literature [33,34,35,36,37,38]. Most published reports have employed dried capillary blood spots from heel-prick as recommended.…”

Section: Methods For Measuring and Assessing Iodine Nutritionmentioning

confidence: 99%

Optimal Assessment and Quantification of Iodine Nutrition in Pregnancy and Lactation: Laboratory and Clinical Methods, Controversies and Future Directions

Eastman

2019

Nutrients

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Iodine intake must be boosted during pregnancy to meet the demands for increased production and placental transfer of thyroid hormone essential for optimal foetal development. Failure to meet this challenge results in irreversible brain damage, manifested in severity from neurological cretinism to minor or subtle deficits of intelligence and behavioural disorders. Attention is now being focused on explaining observational studies of an association between insufficient iodine intake during pregnancy and mild degrees of intellectual impairment in the offspring and confirming a cause and effect relationship with impaired maternal thyroid function. The current qualitative categorisation of iodine deficiency into mild, moderate and severe by the measurement of the median urinary iodine concentration (MUIC) in a population of school-age children, as a proxy measure of dietary iodine intake, is inappropriate for defining the degree or severity of gestational iodine deficiency and needs to be replaced. This review examines progress in analytical techniques for the measurement of urinary iodine concentration and the application of this technology to epidemiological studies of iodine deficiency with a focus on gestational iodine deficiency. We recommend that more precise definitions and measurements of gestational iodine deficiency, beyond a spot UIC, need to be developed. We review the evidence for hypothyroxinaemia as the cause of intrauterine foetal brain damage in gestational iodine deficiency and discuss the many unanswered questions, from which we propose that further clinical studies need to be designed to address the pathogenesis of neurodevelopmental impairments in the foetus and infant. Agreement on the testing instruments and standardization of processes and procedures for Intelligence Quotient (IQ) and psychomotor tests needs to be reached by investigators, so that valid comparisons can be made among studies of gestational iodine deficiency and neurocognitive outcomes. Finally, the timing, safety and the efficacy of prophylactic iodine supplementation for pregnant and lactating women needs to be established and confirmation that excess intake of iodine during pregnancy is to be avoided.

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“…Поэтому частота повышенного уровня ТТГ у новорожденных является ценным показателем йодного статуса в данной популяции. Считается, что при адекватном йодном статусе частота уровней ТТГ в крови более 5 мМЕ/л не должна превышать 3% [8]. Важным достоинством этого подхода являются низкие затраты -фактически только на статистический анализ баз данных.…”

Section: совершенствование системы мониторинга йодного статуса населенияunclassified

“…3), ни по отдельным ее регионам. Однако если частота повышения ТТГ более 5 мМЕ/л в 2012 г. была 2,86%, то при включении в анализ данных детей, у которых кровь была взята ранее 2-го или позднее 5-го дня жизни, частота возрастала до 3,23%, а при включении данных потенциально недоношенных -до 3,44% [8], что могло быть неправильно расценено как наличие йодного дефицита.…”

Section: совершенствование системы мониторинга йодного статуса населенияunclassified

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Armenia's experience in achieving an adequate iodine status of the population

Gerasimov

Hutchings

Aslanyan³

et al. 2021

Clin Exp Thyroid

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Armenia was one of the first post-Soviet countries, that after a relatively short break has restored the production of iodized salt at the beginning of the 2000s, and in 2004 adopted a decree that made the production and import of iodized salt mandatory, as well as its use in the food industry. A 2016 national survey showed high sustainability of the iodine prophylaxis program in Armenia – median urinary iodine concentration (UIC) in schoolchildren and pregnant women (PW) was in the optimal range (242 and 226 μg/l, respectively), and coverage of households with quality iodized salt was 95%. In addition to iodized salt used in households, more than 50% of iodine was consumed with processed foods, primarily bakery products. An essential advantage of the iodine prophylaxis program in Armenia is that it provides adequate iodine status not only for the general population, but also for PW. At the same time about 37% of PW used iodine supplements, which were not necessary. The experience of Armenia shows that the analysis of screening datasets for neonatal hypothyroidism screening makes it possible to efficiently and at minimal cost annually evaluate the iodine status of the population. And if the frequency of TSH levels > 5 mIU/L exceeds 3%, the health authorities should consider this as an alarm and conduct a more detailed assessment to find out the cause of the iodine status insufficiency and take appropriate measures

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Neonatal thyrotropin (TSH) screening as a tool for monitoring iodine nutrition in Armenia

Abstract: From all years and from all regions, values were consistently and uniformly below the cut point of 5 mIU/L. These results show no evidence of iodine deficiency in Armenia, and suggest that neonatal TSH may be a useful tool for monitoring iodine nutrition in Armenia.

Cited by 7 publications

References 8 publications

Comparison of iodine status pre- and post-mandatory iodine fortification of bread in South Australia: a population study using newborn thyroid-stimulating hormone concentration as a marker

Comparison of iodine status pre- and post-mandatory iodine fortification of bread in South Australia: a population study using newborn thyroid-stimulating hormone concentration as a marker

Optimal Assessment and Quantification of Iodine Nutrition in Pregnancy and Lactation: Laboratory and Clinical Methods, Controversies and Future Directions

Armenia's experience in achieving an adequate iodine status of the population

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