[Multifactor analysis of relationship between the biological exposure to iodine and hypothyroidism].
OBJECTIVE
To assess the relationship between the biological exposure to iodine and hypothyroidism.


METHODS
Logistic regression model was used to analyze the risk factors of hypothyroidism, according to the epidemiologic data of 3761 adults in 3 kinds of rural communities: mild iodine deficiency area (4 natural villages in Panshan County, Liaoning Province), more than adequate iodine (7 natural villages of Zhangwu County, Liaoning Province), and excessive iodine area (2 natural villages of Huanghua City, Hebei Province).


RESULTS
More than adequate iodine and excessive iodine were independent risk factors of subclinical hypothyroidism (OR = 3.172 and 6.391, P < 0.05) and overt hypothyroidism (OR = 3.696 and 9.213, P < 0.05). When interactions of iodine exposure and thyroid peroxidase antibody (TPOAb) or thyroglobulin antibody (TgAb) were included, more than adequate iodine was still a risk factor of subclinical hypothyroidism (OR = 2.788, P < 0.01), but had no such effect on overt hypothyroidism. Interaction of more than adequate iodine and positive TgAb significantly affected subclinical hypothyroidism and overt hypothyroidism (OR = 2.656 and 3.347, P < 0.05).


CONCLUSIONS
More than adequate and excessive iodine exposure are independent risk factors of hypothyroidism. The risk of hypothyroidism grows up and thyroid dysfunction becomes more serious with the increasing of the biological exposure to iodine.
Chong
Wei
W
Department of Endocrinology, NO.1 Hospital of China Medical University, Shenyang 110001, China.
Shi
Xiao-guang
XG
Teng
Wei-ping
WP
Sun
Wei
W
Jin
Ying
Y
Shan
Zhong-yan
ZY
Guan
Hai-xia
HX
Li
Yu-shu
YS
Gao
Tian-shu
TS
Wang
Wei-bo
WB
Chen
Wei
W
Tong
Ya-jie
YJ
D000328:Adult; D001324:Autoantigens / Q000276:immunology; D015984:Causality; D002681:China / Q000453:epidemiology; D005260:Female; D006801:Humans; D007037:Hypothyroidism / Q000139:chemically induced / Q000453:epidemiology*; D007453:Iodide Peroxidase / Q000276:immunology; D007455:Iodine / Q000009:adverse effects* / Q000172:deficiency; D033862:Iron-Binding Proteins / Q000276:immunology; D016015:Logistic Models; D008297:Male; D015995:Prevalence; D012307:Risk Factors; D014881:Water Supply / Q000032:analysis*
D001324:Autoantigens; D033862:Iron-Binding Proteins; D007455:Iodine; C056658:TPO protein, human; D007453:Iodide Peroxidase