Iodine Deficiency Disorder and Goitre among School Children in Sarawak -A Nationwide Study

ABSTRACT

Iodine deficiency disorders (IDD), is one of the most important micronutrient deficiencies which has multiple adverse effects on growth and development. The aim of this study was to determine the prevalence of IDD among school children and to elucidate the distribution of iodized salt at household level in Sarawak, East Malaysia. This cross-sectional study was conducted among school children aged 8 to 10 years in 2008. A multi-stage probability proportionate to population size (PPS) cluster sampling method was used to obtain a representative state sample of 1200 school children. Spot urine samples were collected for the determination of urinary iodine concentration while the iodine content in salt was determined using field rapid test kits. The thyroid status was determined by palpation. Response rate was 92.0% (n=1104/1200). The prevalence of goitre among school children in Sarawak was 2.9% (5.2% in urban, 0.7% in rural). The median urinary iodine concentration (UIC) among the school children was 102.1 µg/L (IQR, 62.3-146.5 µg/L). Urban children had significantly higher median UIC of 109.3 µg/L (IQR, 72.4-159.0 µg/L) than their rural counterparts [91.9 µg/L (IQR, 55.7-140.2 µg/L)]. The salt samples tested by rapid test kit (RTK) showed only 46.0% of household salt contained iodine. The present study revealed that the population in Sarawak were of borderline iodine sufficient with mild IDD seen in rural areas. Hence, the state IDD control programmes need to encourage and advocate the consumption of iodized salt in order to eliminate IDD-related health problems in Sarawak.