Three-Year Survey of Effects of Iodized Oil Injection in Schoolchildren With Iodine Deficiency Disorders

Abstract

High prevalence of goiter, other IDD such as impaired physical and intellectual growth and hearing deficit have been reported previously in Kiga. In order to evaluate the effect of iodized oil injection, this study was conducted in schoolchildren of Kiga village from 1989 to 1992. One ml of iodized oil solution containing 480 mg of iodine was injected into 198 schoolgirls and boys aged 8-14 years. Serum thyroid hormones, RT 3 U, TSH and thyroglobulin, before and 12, 24 and 36 months after the intra-muscular injection of iodized oil were measured. Assessment of urinary iodine was performed at the same periods by Foss method. Prior to the injection, all schoolchildren had goiters larger than grade 1 A (48% were grade 3); 3 years after intervention 20% had grades zero and 1 A and 8% grade 3 (P < 0.001). Urinary iodine was 11.4 +/- 19.8 before and increased to 113 +/- 63 and 83 +/- 66 microg/g creatinine 2 and 3 years after intervention. Mean serum T 4 was 5.0 +/- 2.1, 10.8 +/- 2.8, 9.8 +/- 2.5 and 9.5 +/- 2.1 microg/dl before and 12, 24 and 36 months after the injection, respectively (P < 0.001). Mean serum TSH was 20.3 +/- 22.8, 1.2 +/- 1.6, 0.8 +/- 1.2 and 2.2 +/- 0.9 mU/L in the same intervals, respectively (P < 0.001). Mean serum thyroglobulin was 132 +/- 107, 10 +/- 12 and 23 +/- 20 ng/ml before and at 2 and 3 years after injection, respectively (P < 0.001). Slight but significant increases in serum TSH and thyroglobulin occurred at 3 years after the injection. Findings show benefits of iodized oil administration in decreasing goiter size and in resuming normal thyroid function up to 3 years after the intervention. An increase in TSH and or thyroglobulin could be considered as the first sign of a fall in effectiveness of iodized oil injection.

Environmental, Urinary Iodine Status and Prevalence of Goitre among Schoolchildren in a High Altitude Area of Saudi Arabia

“…2 Iodine deficiency in children can be assessed by determination of urinary iodine concentration (UIC), the assessment of size of the thyroid gland 6 and the determination of T3, T4 and TSH concentration in blood. 7 In Saudi Arabia; a cross-sectional national epidemiological survey was conducted in 1997 to study the iodine status among schoolchildren. The southern province had the highest percentage of subjects with low UIC.…”

Urinary iodine and other iodine deficiency indicators in a sample of school-age children in Egypt

“…Following iodine supplementation, thyroglobulin normalizes before thyroid volume has decreased. Therefore, an increase in TSH and/or thyroglobulin could be considered the first sign of a fall in effectiveness of iodized oil injection [7].…”

“…Serum thyroglobulin has been reported to change inversely with iodine intake in all age groups [6]. On the other hand, the pattern of circulating thyroid hormones in clinically euthyroid children in areas of severe iodine deficiency has been characterized by low serum tetraiodothyronine (T 4 ), elevated thyroid stimulating hormone (TSH) and normal or supernormal triiodothyronine (T 3 ) [7].…”

Urinary iodine, thyroid function, and thyroglobulin as biomarkers of iodine status

“…In moderately to severely iodine-deficient regions, serum TSH concentrations may be elevated compared with those seen in iodine-sufficient regions, serum T4 concentrations may be slightly low, and serum T3 concentrations may be slightly high (19). After successful iodine fortification programs in severely deficient regions, these changes may reverse (20)(21)(22). However, even in severely iodine-deficient regions, there is a great deal of intraindividual variation in the ability of the thyroid to adapt (23); therefore, thyroid function tests (including serum TSH, T3, and T4) are not considered sensitive indicators of population iodine status in most settings (4).…”