Urinary iodine and sodium concentration and thyroid status in the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil).
J Trace Elem Med Biol
; 68: 126805, 2021 Dec.
Article
em En
| MEDLINE
| ID: mdl-34247033
ABSTRACT
OBJECTIVES:
To evaluate urinary iodine concentration (UIC) in civil servants aged 35-74 years of the Brazilian Study of Adults Health (ELSA-Brasil) to analyze its relationship with sociodemographic, clinical risk factors, lifestyle, urinary Na and thyroid status.DESIGN:
Cross-sectional study in six Brazilian cities.METHODS:
This analysis included 792 participants with information about urinary iodine concentration (UIC). Thyroid status was defined by serum levels of TSH/FT4 and the current use of antithyroid drugs for treatment of overt hyperthyroidism or levothyroxine to treat overt hypothyroidism. The determination of UIC was carried out with an inductively coupled plasma mass spectrometer (ICP-MS) and was expressed as median with Interquartile Range (IQR).RESULTS:
In 792 participants, thereof 52% women, mean age was 51.9 (9.0) years. The median UIC was 219 (IQR, 166-291) for all persons studied, thereof 211 (IQR, 157-276) for women and 231 (IQR, 178-304) for men. According to the WHO classification, for all persons studied, 60% had more than adequate iodine-supply (UIC ≥200⯵g/L), 37% were adequately supplied (UIC 100-199⯵g/L) and <3% had a deficient iodine status (<100⯵g/L). In the 35-44-year age strata, which includes women of childbearing age, 23.2% of women presented less than 150⯵g/L of UIC. No differences in UIC were detected according to thyroid status. (Pâ¯=â¯0.39) The correlation between Ur-Na and UIC showed a Spearman coefficient of 0.52 (Pâ¯<â¯0.0001) and it was also found an association of Ur-Na with UIC Beta of 1.76 (95% Confidence Interval (95% CI) 1.01 to 2.51. The urinary Na concentration showed a synergy with the UIC, that means medians of 57, 72, 107 and 141â¯mmol Na/L urine (Pâ¯<â¯0.001) in the groups with the four UIC classes according to the WHO grading mentioned above. The very low Na content in the persons exhibiting <100⯵g/L UIC seems to reflect also a higher urine volume due to the frequent use of diuretics. The strong relationship between the urinary Na concentration and the UIC points to a dependence of the UIC on the individual consumption of iodized salt, which should be more considered in future studies. The strong relationship between the urinary Na concentration and the UIC points to a dependence of the UIC on the individual consumption of iodized salt, which should be more considered in future studies.CONCLUSIONS:
Euthyroid persons were dominating by more than four fifths and no significant association was found between UIC and thyroid status. Although most of the persons studied present more than adequate iodine intake it was observed that nearly a quarter of women in childbearing age are iodine deficient.Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Glândula Tireoide
/
Iodo
Tipo de estudo:
Observational_studies
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Prevalence_studies
Limite:
Adult
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Female
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Humans
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Male
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Middle aged
País/Região como assunto:
America do sul
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Brasil
Idioma:
En
Ano de publicação:
2021
Tipo de documento:
Article