High-fluoride and Low-iodine Environment and Subclinical Cretinism in Xinjiang
Lin Fa-fu , Aihaiti , Zhao Hong-xin , Lin Jin , Jiang Ji-yong, Maimaiti, and Aiken (Xinjiang Institute for Endemic Disease Control and Research, Urumqi; Endemic Disease Controlling Office of Hetian District; Sanitary and Antiepidemic Station of Yutian County , Xinjiang)
One hundred and thirty schoolchildren aged 7-14 years were tested by random stratified sampling method with Combined Raven's test—The Rural in China (CRT-RC) in different types of iodine-deficient areas in Hetian District, and their hearing, 4 psychomotilities and thyroid function were examined in the mean time. In affected areas with high-fluoride and low-iodine levels, the average IQ was 71.09±6.84, the average auditory threshold 24.08±13.18dB, the detection rate of bone age retardation 28.5%, the thyroid 131I uptake 59.87±14.63%, the TSH level 21.09±9.43/μU/ml, and the prevalence rate of subclinical cretinism 15.71; in those areas with low-iodine level, the corresponding figures were 77.32±11.54, 19.91±7.23dB, 13.5%, 50.26±19.25%, 11.05±11.49μU/ml and 9.36%, respectively; and in control areas with iodine supplementation, the corresponding figures were 95.76±17.52, 16.08±3.21dB, 3.88%, 23.61±,11.71%, 6.26±2.08/μU/ml and 3.20%, respectively. Statistically significant differences existed between these areas, suggesting that in low-iodine environment with concurrent high-fluoride intake, the fluoride could exacerbate central nervous lesions and somatic developmental disturbance of iodinfe deficiency origin. The detection rate of subclinical cretinism in 104 children with mild mental retardation was found to be 69.23%.