Title: Thyroid size and goiter prevalence after introduction of iodized salt: a 5-y prospective study in schoolchildren in Côte d'Ivoire.

POPLINE Document Number: 299513

Author(s):

Zimmermann MB
Hess SY
Adou P
Toresanni T
Wegmuller R

Source citation:

American Journal of Clinical Nutrition, 2003 Mar;77(3):663-667.

Abstract:

The long-term goal of salt iodization is elimination of iodine deficiency and reduction of the goiter rate to < 5% in school-aged children. Normalization of the goiter rate probably indicates disappearance of iodine deficiency disorders as a public health problem. However, thyroid size may not return to normal for months or years after correction of iodine deficiency. We described the time course and pattern of changes in thyroid size and goiter rate in response to the introduction of iodized salt in an area of severe endemic goiter. In a 5-y prospective study, we measured thyroid size by ultrasonography and urinary iodine and thyroid hormone concentrations in schoolchildren 6 mo before the introduction of iodized salt and annually for 4 y thereafter. Four years after the introduction of iodized salt and normalization of the median urinary iodine concentration, mean thyroid size had decreased 56% (P < 0.0001). However, 29% of the children remained goitrous, with a significant age shift in the distribution of goiter. At baseline, the goiter rate was significantly higher in younger (age: 5-9 y) than in older (age: 10-14 y) children (P < 0.0001). At 2, 3, and 4 y after salt iodization, the goiter rate was significantly higher in the older than in the younger children (at 4 y: 52% compared with 19%), and the difference increased with time (P < 0.0001). The goiter rate in school-aged children may remain sharply elevated for up to 4 y after successful introduction of iodized salt, primarily because of persistent goiter in older children. (author's)

Keywords:

Cote d'Ivoire
Research Report
Prospective Studies
Children
Thyroid Effects
Deficiency Diseases
Goiter
Prevalence
Prevention and Control
Sodium
Diet
Africa, Western
Africa South of the Sahara
Africa
Developing Countries
Studies
Research Methodology
Youth
Age Factors
Population Characteristics
Demographic Factors
Population
Endocrine Effects
Endocrine System
Physiology
Biology
Nutrition Disorders
Diseases
Measurement
Metals
Vitamins and Minerals
Nutrition
Health