Introduction Following the reveal of borderline iodine sufficiency among the Sarawakians
from the 2008 National Iodine Deficiency Disorders (IDDs) survey, a
mandatory universal salt iodization (USI) was implemented in Sarawak
thereafter. This study aimed to determine the current status of USI in
Sarawak after a 3-year implementation of USI from 2008 to 2011.
Methods The IDD survey was conducted between Jun 2011 to July 2011 involving six
districts in Sarawak (Sarikei, Mukah, Kapit, Sibu, Bintulu and Miri). The
schools were selected via multistage proportionate-to-population size
sampling technique and the children were randomly selected via systematic
sampling. A total of 19 schools and 661 children were recruited into the
survey. Thyroid size was determined by palpation and was and graded
according to the classification of the World Health Organization (grade 0-2).
The iodine excretion level in spot morning urine was measured using inhouse
microplate method. The urinary iodine concentration (UIC) values
were compared by Kruskal-Wallis test and Chi-square tests were used to
compare categorical variables.
Results A total of 610 school children were participated in the study (92.3%). The
TGR of grade 1 and 2 was found to be 0.3% (n = 2). Overall the median UIC
level was 154.2 (IQR, 92.7 - 229.8) μg/L, with the highest median UIC been
observed in Sarikei [178.0 (IQR, 117.6 - 308.9) μg/L], followed by Mukah
[174.8 (IQR, 99.0 - 224.3) μg/L)], Miri [158.6 (IQR, 92.3 - 235.4) μg/L],
Sibu [147.0 (IQR, 89.8 - 221.4) μg/L], Bintulu [142.3 (IQR, 52.8 - 245.1)
μg/L] and Kapit [131.0 (IQR, 88.6 - 201.9) μg/L]. One in every ten child was
of iodine deficient (UIC < 50μg/L) while a third of the child (32%) were of
adequate level of UIC.
Conclusion The present findings indicate that the mandatory USI successfully improves
the iodine level of children in Sarawak. However, regular and proper
monitoring of the UIC level in the communities is needed to prevent
excessive iodine intake.