Prevalence of iodine intake inadequacy in elderly Brazilian women. A cross-sectional study

Abstract

Background/objectives: Inadequate iodine intake is still a problem in various regions of the world, and limited data exist regarding the ingestion of iodine in elderly people. We investigated the prevalence of iodine intake inadequacy in a group of elderly women living in a region of Brazil considered to be iodine-sufficient.

Design and setting: Cross-sectional study conducted in the public healthcare system of Bauru, São Paulo, Brazil.

Methods: We evaluated 135 elderly women (average age of 68.2 years) who participated in a program of assistance to the elderly with respect to iodine intake through two 24-hour recalls using a nutritional computer program. The women were also evaluated with respect to serum levels of free thyroxin (FT4) and thyrotropin (TSH) and were classified as euthyroid, hypothyroid or hyperthyroid.

Results: The average iodine intake of the group was 100.7 ± 39.2 μg. Twenty-nine patients (21.5%) presented thyroid dysfunction: 27 (20%) had hypothyroidism, and two (1.5%) had hyperthyroidism. The average iodine intake of the patients with hypothyroidism and euthyroidism was 92.7 μg and 101.7 μg, respectively. The prevalence of iodine intake inadequacy, considering the co-variables of age, race, income, body mass index, TSH, FT4 and arterial hypertension, was 51%, 48% and 66% in the general, euthyroid and hypothyroid patients, respectively.

Conclusion: We concluded that high prevalence of iodine intake inadequacy was present in this group of elderly women living in a region of Brazil considered to be iodine-sufficient.