Prevalence of iodine deficiency among school children in Cairo

Abstract

Background and objective. A neonatal screening program for hypothyroidism began in Egypt in 2000. A high percentage of transient congenital hypothyroidism in different governorates was reported. In addition, a high prevalence of iodine deficiency was detected recently in some rural cities. This study was conducted to determine the prevalence of iodine deficiency among school children in Cairo in order to evaluate the severity of the problem in our area. Also, we hoped to assess the consumption of household iodized salt. Methods. The study was conducted on a sample of 2167 primary school children (aged 6-12 years) chosen by multi-stage random sampling. Assessment of goiter prevalence (TGR) clinically and measurement of urinary iodine concentration were carried out on the entire sample. Children found to have a urinary iodine level less than 10μg/dl were subjected to thyroid ultrasonography and measurement of serum concentrations of TSH, FT4 and FT3. Results. The prevalence of goiter by clinical indicator was 11.8%. The prevalence of Iodine Deficiency Disorders (IDD) by urinary iodine estimation was 31.0%; 90% of the cases were considered to have mild deficiency. Higher mean TSH levels were found among goitrous subjects. The prevalence of hypothyroidism among IDD children was 6.1 %, with 3.9% being compensated. A negative correlation (p<0.01) was detected between the severity of iodine deficiency and the degree of salt iodization. On the other hand, iodine deficiency was detected in 9.7% of children who consumed iodized salt, and normal urinary iodine levels were detected in 50.6% of children in spite of use of non-iodized salt. There was an increase in the prevalence of IDD among lower socioeconomic groups, while the prevalence was least among children who had been breast fed in infancy. Conclusion. Iodine deficiency continues to be a major health problem. The campaign of salt iodization, already established, must be reinforced. A recent survey has shown that 78% of households consume iodized salt and the median urinary iodine is normal.