Endemic goiter with iodine sufficiency: a possible role for the consumption of pearl millet in the etiology of endemic goiter.

BACKGROUND

Deficiencies of iodine, iron, and vitamin A are the 3 most common micronutrient deficiencies in developing countries, although control programs, when properly implemented, can be effective.

OBJECTIVE

We investigated these deficiencies and their possible interaction in preschool children in the southern Blue Nile area of Sudan.

DESIGN

Goiter, signs of vitamin A deficiency, and biochemical markers of thyroid, vitamin A, and iron status were assessed in 984 children aged 1-6 y.

RESULTS

The goiter rate was 22. 3%. The median urinary iodine concentration was 0.79 micromol/L and 19.3% of the children had a concentration >1.57 micromol/L. Although serum thyroxine and triiodothyronine concentrations were within reference ranges, the median thyrotropin concentration was 3.78 mIU/L and 44% of the children had thyrotropin concentrations above normal. The mean urinary thiocyanate concentration was high (259 +/- 121 micromol/L). The prevalences of Bitot spots and night blindness were 2.94% and 2.64%, respectively, and 32% of the subjects had serum retinol binding protein concentrations <15 mg/L. A significant positive correlation was observed between thyrotropin and retinol binding protein. Whereas 88% of the children had hemoglobin concentrations <1.86 mmol/L, only 13.5% had serum ferritin concentrations below the cutoff of 12 microg/L and 95% had serum transferrin concentrations above the cutoff of 2.50 g/L.

CONCLUSIONS

Our results indicate that goiter is endemic in this region of Sudan despite iodine sufficiency and that both anemia and vitamin A deficiency are health problems in the area. Moreover, consumption of millet, vitamin A deficiency, and protein-energy malnutrition are possible etiologic factors in this endemic area.