A five-year follow-up study of hypothyroidism in areas with different iodine intakes
- VernacularTitle:不同碘摄入量社区甲状腺功能减退症的五年随访研究
- Author:
Hong DAI
;
Zhong-Yan SHAN
;
Xiao-Chun TENG
;
Di TENG
;
Hai-Xia GUAN
;
Yu-Shu LI
;
Xiao-Hui YU
;
Chen-ling FAN
;
Wei CONG
;
Fan YANG
;
Hua LIU
;
Song-chen WEN
;
Xiao-lan GU
;
Jin-yuan MAO
;
Yang YU
;
Jia LI
;
Yan-yan CHEN
;
Dong ZHAO
;
Rong YANG
;
Ya-qiu JIANG
;
Wei-ping TENG
- Publication Type:Journal Article
- Keywords:
Iodine;
Hypothyroidism;
Hypothyroidism;
subclinical;
Epidemiologic studies
- From:
Chinese Journal of Endocrinology and Metabolism
2000;0(06):-
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate epidemiologieal characteristics of hypothyroidism and factors influencing its outcome in the areas with different iodine intakes.Methods An epidemiologic follow-up study of thyroid diseases was performed in Panshan (iodine deficient),Zhangwu [mild iodine deficiency before universal salt iodination (USI) and more than adequate iodine intakes after USI ] and Huanghua ( iodine excessive) in China.A total of 3 761 subjects were investigated in 1999,and 3 018 (80.2% ) of them were followed up in 2004.FT_4,FT_3,TSH,thyroid autoantibodies and urinary iodine concentration were determined and thyroid B ultrasound was performed in all participants.Results Five-year cumulative incidence of overt hypothyroidism was 0.23%,0.47% and 0.35% in Panshan,Zhangwu and Huanghua,respectively.Twenty patients with autoimmune- induced overt hypothyroidism did not comply with the physician's orders to take thyroxine.Thyroid function spontaneously turned to normal in 55% of them,turned to subclinical hypothyroidism in 20% and maintained overt hypothyroidism in 25%.Five-year cumulative incidence of subclinical hypothyroidism in Zhangwu (2.60%) and Huanghua (2.89%) were significantly higher than that in Panshan(0.23% ) (both P＜0.01 ).One hundred patients with subclinical hypothyroidism were followed up,and 5% of them developed overt hypothyroidism,66% turned to euthyroidism and 29% maintained subclinical hypothyroidism.Raised serum TSH (＞6 mU/L) in the original survey ( OR = 3.4),positive thyroid autoantibodies in the follow-up study ( OR = 5.3 ) and more than adequate iodine supplementation in the mild iodine-deficient population ( OR = 8.0) were risk factors influencing outcome of subclinical hypothyroidism.Conclusion More than adequate iodine supplementation among a population in the mildly iodine-deficient area may increase the incidence of overt and subolinical hypothyroidism, and also influence outcome of subclinical hypothyroidism.
