Low urinary iodine postpartum is associated with hypothyroid postpartum thyroid dysfunction and predicts long-term hypothyroidism.
Clin Endocrinol (Oxf)
; 74(5): 631-5, 2011 May.
Article
em En
| MEDLINE
| ID: mdl-21470286
ABSTRACT
BACKGROUND:
Postpartum thyroid dysfunction (PPTD) is characterized by an early hyperthyroid phase followed, with peak prevalence at 6 months, by a hypothyroid phase which carries a risk of long-term hypothyroidism. Iodine has a major effect on thyroid function. Western Australia has previously been shown to be iodine replete.OBJECTIVE:
To examine the iodine status of women with and without PPTD and the relationship of iodine status postpartum with long-term hypothyroidism.DESIGN:
Case-control with follow-up. PATIENTS A total of 149 women at 6 months postpartum (74 PPTD, 75 controls) with 98 (46 PPTD, 52 controls) followed up at 12 years. MEASUREMENTS Urinary iodine concentration (UIC) and thyroid function at 6 months postpartum; thyroid function at 12-year follow-up.RESULTS:
At 6 months postpartum, median UIC (quartiles) for observed TSH ranges were for TSH < 0·4 mU/l 130·0 µg/l (82·0, 170·0); for TSH 0·4-4·0 mU/l 123·0 µg/l (80·5, 168·0); for TSH > 4·0 mU/l 85·0 µg/l (40·0, 141·5), P = 0·018. The odds ratio (OR) of hypothyroid PPTD with each unit of decreasing log iodine was 2·54, (95%CI 1·47, 4·35), and with UIC < 50 µg/l, OR 4·22, (95%CI 1·54, 11·55). In the long term, decreased log UIC significantly predicted hypothyroidism at 12-year follow-up (P = 0·002); as did UIC < 100 µg/l (P = 0·03) and UIC < 50 µg/l (P = 0·02). The association was independent of antibody status.CONCLUSION:
Low UIC measured at 6 months postpartum is associated with hypothyroid PPTD and independently predicts long-term hypothyroidism. We believe that it results from more severe preceding destructive thyroiditis, with discharge of thyroidal iodine, and thereby predicts a greater risk of long-term hypothyroidism.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Transtornos Puerperais
/
Valor Preditivo dos Testes
/
Período Pós-Parto
/
Hipotireoidismo
/
Iodo
Tipo de estudo:
Observational_studies
/
Prognostic_studies
/
Risk_factors_studies
Limite:
Female
/
Humans
País/Região como assunto:
Oceania
Idioma:
En
Revista:
Clin Endocrinol (Oxf)
Ano de publicação:
2011
Tipo de documento:
Article
País de afiliação:
Austrália