Iodine status as determined by urinary iodine excretion in Lesotho two years after introducing legislation on universal salt iodization
Received 13 April 2004; accepted 27 July 2004.
Abstract
Objective
Mild
to severe iodine deficiency has been documented in Lesotho since 1960.
To eliminate the persisting iodine deficiency, legislation on universal
salt iodization was introduced in 2000 as a long-term public health
intervention strategy. We assessed the urinary iodine status of school
children and women of child-bearing age in Lesotho 2 y after
the introduction of legislation on universal salt
iodization.
Methods
A
31-cluster national survey was conducted in 2002 by using the
proportion to population size method. In each cluster, 30 women ages 15
to 30 y and 30 primary school children ages 8 to 12
y were randomly selected to provide urine samples for urinary iodine
analysis. Data were interpreted according to criteria of the World
Health Organization, United Nations Children's Fund, and
International Council for Control of Iodine Deficiency Disorders
(2001). Statistical analysis was performed using
SAS.
Results
We
analyzed 912 urine samples from children and 924 from women. The median
urinary iodine concentrations were 214.7 μg/L for children and
280.1 μg/L for women, indicating more than adequate iodine
intake. Median iodine concentration was higher in the lowlands (256.0
μg/L in children and 329.9 μg/L in women) than in the
mountains (99.30 μg/L in children and 182.6 μg/L in
women). Analysis of the distribution of the data showed values below 50
μg/L in 10.1% of children and in 9.8% of women. In
addition, 21.5% of children and 17.9% of women had
urinary iodine excretion values below 100 μg/L. In contrast,
36% of children and 47.2% of women had urinary iodine
concentrations in excess of 300
μg/L.
Conclusion
Results of urinary iodine
excretion measurements indicated that iodine deficiency has been
eliminated as a public health problem in Lesotho. However, the high
median urinary iodine concentration of women in the lowlands indicated
the possibility of a risk of iodine-induced hyperthyroidism in
vulnerable
people.
ABSTRACT