Iodine nutrition status among schoolchildren after salt iodisation

Abstract

Earlier studies done in Sri Lanka have indicated the importance of iodine deficiency as a public health problem. The universal salt iodisation programme has been implemented since 1995. The goals of salt iodisation are reduction of the goitre rate to <5% in school-aged children, to maintain the median urinary iodine level in the population between 100-200 µg/L and >90% of households using iodised salt. Objective To estimate the goitre prevalence, the urinary iodine level, and measure the household iodised salt consumption pattern by Province. Method A school-based study of 6574 randomly selected children in the age group 8-10 years, from 263 schools was assessed for goitre by palpation. The concentration of urinary iodine levels was measured in 2630 of these children. Estimation of iodine in the 6181 samples of salt used in households of the schoolchildren was also assessed by test kits. Results The prevalence of goitre in the Provinces varied from 16.3% to 26.2%. The median urinary iodine levels were above the cutoff point of 100 µg/L in all Provinces except in Uva. The highest median urinary iodine level was reported in North Central Province (231.3 µg/L). Overall, 35.4% of the children had urine iodine levels in the 'ideal' range (100-199.9 µg/L); 30.6% with lower values (<100 µg/L) indicated iodine deficiency and 16.3% with higher values (< 300 µg/L) indicated excessive iodine intake. Only 49.5% of households had used adequately iodised salt. Conclusions This study showed that iodine deficiency still exists in Uva Province, and that more than adequate iodine levels were found in the North Central Province. The level of permitted salt iodine at household level needs to be revised.

The prevalence of autoimmune thyroiditis after universal salt iodisation in Sri Lanka

“…There is no data on prevalence AIT in Sri Lanka. In the early post iodisation period, the median urinary iodine levels were above the cut-off point of 100 µg/l in all provinces except in the Uva Province [5]. The highest median urinary iodine level was reported in North Central Province (231.3 µg/l).…”

“…Some propose that thyroid injury occurs through the generation of reactive oxygen species when both these elements are present [9]. Evidence from the United States and China showing an increase in AIT with high iodine intake suggests a similar phenomenon in humans [4][5][6][7][8][9][10]. Some authors have suggested that AIT is caused by high iodine intake coupled with goitrogens and not by iodine alone [11][12].…”

“…Some authors have suggested that AIT is caused by high iodine intake coupled with goitrogens and not by iodine alone [11][12]. Universal iodisation programme is aimed at eradicating iodine deficiency disorders and has shown satisfactory outcome in many regions [3][4][5]. Yet if the deleterious effects are not taken note of, the benefits of the programme will be negated.…”

Epidemiology of goitre in Sri Lanka in the post-iodization era

“…A previous study showed that prevalence of goitre was 18.8% among school children in 17 districts out of 24 in the country and refuted the presence of a goitre belt and suggested pockets of high prevalence [2]. More recently a study done across the country among school children aged 8-10 years showed a low prevalence of goitre [8].…”

“…Goitre was a public health issue in Sri Lanka. Universal iodization of salt was implemented in Sri Lanka in 1995 as iodine deficiency was considered the main aetiological factor for goitre [7]. Varying prevalence rates have been noted in previous studies.…”