Iodine status as determined by urinary iodine excretion in Lesotho two years after introducing legislation on universal salt iodization

Objective Mildto severe iodine deficiency has been documented in Lesotho since 1960.To eliminate the persisting iodine deficiency, legislation on universalsalt iodization was introduced in 2000 as a long-term public healthintervention strategy. We assessed the urinary iodine status of schoolchildren and women of child-bearing age in Lesotho 2 y afterthe introduction of legislation on universal saltiodization. Methods A31-cluster national survey was conducted in 2002 by using theproportion to population size method. In each cluster, 30 women ages 15to 30 y and 30 primary school children ages 8 to 12y were randomly selected to provide urine samples for urinary iodineanalysis. Data were interpreted according to criteria of the WorldHealth Organization, United Nations Childrenʹs Fund, andInternational Council for Control of Iodine Deficiency Disorders(2001). Statistical analysis was performed usingSAS. Results Weanalyzed 912 urine samples from children and 924 from women. The medianurinary iodine concentrations were 214.7 μg/L for children and280.1 μg/L for women, indicating more than adequate iodineintake. Median iodine concentration was higher in the lowlands (256.0μg/L in children and 329.9 μg/L in women) than in themountains (99.30 μg/L in children and 182.6 μg/L inwomen). Analysis of the distribution of the data showed values below 50μg/L in 10.1% of children and in 9.8% of women. Inaddition, 21.5% of children and 17.9% of women hadurinary iodine excretion values below 100 μg/L. In contrast,36% of children and 47.2% of women had urinary iodineconcentrations in excess of 300μg/L. Conclusion Results of urinary iodineexcretion measurements indicated that iodine deficiency has beeneliminated as a public health problem in Lesotho. However, the highmedian urinary iodine concentration of women in the lowlands indicatedthe possibility of a risk of iodine-induced hyperthyroidism invulnerablepeople.