Evaluation of Goiter Prevalence and Iodine to Creatinine Ratio among School-aged Girls in Urmia County

Introduction: Clinical evaluation of iodine deficiency disorders (IDDs) is often accomplished by assessment of urinary iodine excretion (UIE) in random samples; however, the utilization of 24 hour urine samples is a more reliable biomarker of nutritional iodine status. This study was designed to evaluate total goiter prevalence (TGP) and iodine/creatinine ratio among school-aged children in Urmia County. Methods: Schoolchildren (n=500) were recruited by cluster sampling from different educational areas in Urmia County. Goiter prevalence was assessed by thyroid palpation, UIE was determined by Sandell-Koltoff reaction, and Urinary creatinine was measured by the Jaffe-method. Results: In general, TGP was 12.2%. Among these, there were 48 individuals (9.6%) with grade I goiter and 13 subjects (2.6%) with grade II goiter. Mean urinary creatinine, median UIE and median I/Cr ratio were respectively 1.36±0.76 mg/dL, 14.3μg/dL, and 11.5μg/mg. Prevalence of iodine deficiency according to UIE criteria was 22.8% and that of I/Cr ratio was 41.2%. There was a correlation between age and UIE (P=001; r=0.163). UIE and urinary creatinine were correlated as well (P<0.003; r= 0.133). A correlation was also detected between I/Cr ratios and UIE (P=0.003; r=0.133) whilst a negative association was seen between age and I/Cr ratios (P=0.001; and r=–0.263). Conclusion: This investigation reconfirms that there is slight-to-mild iodine deficiency in Urmia County. The utilization of I/Cr ratio in conjugation with UIE and palpation may provide a better assessment in investigating nutritional iodine status.