Iodine nutritional status and risk factors for goitre among schoolchildren in South Tajikistan.

Barbara Matthys,Gulzira Karimova,Michael B Zimmermann,Mohbegim Davlatmamadova,Kaspar Wyss,Vreni Jean-Richard

doi:10.1186/1472-6823-13-50

Abstract

BackgroundIodine deficiency affects nearly 1.9 billion people worldwide, but it can be prevented by salt iodization. This cross-sectional survey assessed current iodine status, iodized salt coverage and risk factors for goitre among schoolchildren in South Tajikistan.MethodsTen primary schools in four districts in South Tajikistan were randomly selected. In schoolchildren aged 7 to 11 years, a spot urine sample was collected for measurement of urinary iodine, dried blood spots were collected for measurement of thyroglobulin, and goitre was assessed by palpation. Iodine content of salt samples and local selling points was determined by coloration using rapid test kits and titration method.ResultsOf 623 schoolchildren enrolled, complete data was obtained from 589. The overall median urinary iodine concentration (UIC) was 51.2 μg/L indicating mild-to-moderate iodine deficiency. Among all children, 46.6% (95% Confidence Interval (CI) = 42.4%-50.6%) of children were found to be goitrous (grade 1 goitre: 30.6%, 95% CI = 26.9%-34.5%; grade 2 goitre: 16.0%, 95% CI = 13.1%-19.2%). The risk factor for goitre remaining significant in the multivariable logistic regression model was 'buying salt once a month’ (OR = 2.89, 95% CI = 1.01-8.22) and 'buying salt once every six months’ (OR = 2.26, 95% CI = 1.01-5.04) compared to 'buying salt every one or two weeks’. The overall median thyroglobulin concentration was elevated at 13.9 μg/L. Of the salt samples from households and selling points, one third were adequately iodised, one third insufficiently and one third were not iodised.ConclusionIodine deficiency remains a serious health issue among children in southern Tajikistan. There is a persisting high prevalence of goitre, elevated thyroglobulin and low UIC despite interventions implemented by Tajikistan and international partners. Quality control of salt iodine content needs to be improved. Continued efforts to raise awareness of the health effects of iodine deficiency are needed to increase consumer demand for iodised salt.

Highlights

Iodine deficiency affects nearly 1.9 billion people worldwide, but it can be prevented by salt iodization
Iodine deficiency in children is assessed and monitored by three recommended methods that are complementary: 1) urinary iodine concentration (UIC) is an indicator of recent iodine intake over the previous 1–2 days, as up to 90% of iodine is absorbed and excreted in the urine; 2) thyroglobulin, a thyroid-specific protein that is secreted into the bloodstream during iodine deficiency and reflects iodine status over weeks to months; and 3) changes in the goitre rate over months to years are assessed by the size of the thyroid gland [4,5]
623 schoolchildren from grades two and three were registered and 602 students participated in the crosssectional survey resulting in a compliance of 96.6%

Summary

Introduction

Iodine deficiency affects nearly 1.9 billion people worldwide, but it can be prevented by salt iodization. This cross-sectional survey assessed current iodine status, iodized salt coverage and risk factors for goitre among schoolchildren in South Tajikistan. 1.88 billion people worldwide have inadequate iodine intake, including one third of all schoolaged children [1,2]. An effective strategy to prevent iodine deficiency disorders (IDD) is salt iodisation. Iodine deficiency in children is assessed and monitored by three recommended methods that are complementary: 1) urinary iodine concentration (UIC) is an indicator of recent iodine intake over the previous 1–2 days, as up to 90% of iodine is absorbed and excreted in the urine; 2) thyroglobulin, a thyroid-specific protein that is secreted into the bloodstream during iodine deficiency and reflects iodine status over weeks to months; and 3) changes in the goitre rate over months to years are assessed by the size of the thyroid gland [4,5].

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