Iodine deficiency affects people of all age groups and yields detrimental health effects known as Iodine Deficiency Disorders (IDD). Universal Salt Iodization (USI) where above 90% household use iodized salt became the main program to optimized population iodine status. This study aimed to analyze iodine in salt, iodine status and thyroid functions from three different IDD endemic regions.
Methods: This was a cross-sectional study, with women of reproductive age (15 to 45 y old) as subjects, conducted in plain area (Yogyakarta) city (n=250), mountainous area (Bukit Tinggi city) (n=249), and combination of mountaneous and plain area (Purworejo regency) (n=249). Urinary iodine (UIE), prevalence of hyperthyroidism, and hypothyroidism (diagnostic based on combination of TSH and fT4 level), also the presence or absence and level of iodine in salt were assessed.
Result: Iodized salt coverage have reached >90% household in all three region, while titration found 75.6% with adequate level of iodine in salt (>30 ppm), with wide range of iodine level in salt (0.00-218.2 ppm). With that condition, population in plain and combination of plain and mountainous area have more than adequate iodine status (218 μg/L and 224 μg/L), while population in mountaneous area still in mild iodine deficiency status (UIE median of 88 μg/L). Most population is in euthyroid condition. Hyperthyroidism, subclinical hyperthyroidism, secondary hyperthyroidism, subclinical hypothyroidism, and hypothyroidism were found in 0.7%, 4.8%, 0.4%, 8.9%, and 0.9% population consecutively. There were no relationship between iodine status and prevalence of hyperthyroidism and hypothyroidism, but subclinical hypothyroidism most prevalent in excess UIE population (12.5% vs 8.3%).
Conclusion: All three regions have achieved USI target. But the risk of iodine deficiency still found in mountaneous area. Household iodized salt coverage discrepancy between rapid test and titration strengthen the need of more accurate but efficient test of iodine level in salt.
Keywords: geographical risk; iodine intake; iodized salt; thyroid dysfunction.