Socioeconomic correlates of iodine status among school children in Sarawak, Malaysia

Iodine deficiency is recognized as a public health problem. This paper assesses iodine status by socioeconomic factors in school children in Sarawak, East Malaysia. Kuching, Bau and Simunjan districts were chosen based on advice from the Sarawak's Medical and Health Authority. 803 school children, aged eight years, were selected from 19 schools via proportionate systematic sampling. About half the proportion of the school children were from Kuching, 24% from Simunjan and 22% from Bau. Almost all were equally distributed by sex. By mother's race, almost half were Malays, followed by Bidayuh, Iban, Chinese and other races. Mean urinary iodine concentration was 3.36 microg/ 100ml, mean creatinine level was 111.10 mg/100ml and mean creatinine/iodine ratio was 39.45 microg/ gram. Four female children (0.5%) were found to have enlarged thyroid. Urinary iodine levels were significantly different by district, mother's race and household income. It was highest in Kuching, among children with Malay mothers, and with household incomes more than RM500 per month. Conversely, it was lowest in Bau, among children of Iban/Dayak and Chinese mothers, and incomes of RM500 or less per month. Based on the WHO/UNICEF/ICCIDD classification, the Sarawak school children in the present study fall into the moderate IDD category. The low prevalence of goitre is a positive finding indicating that iodine deficiency is corrected over time.