辽宁省碘缺乏病病区不同补碘时期出生儿童智力水平调查

An analysis of the intelligence level of children born in different time periods after iodized salt was supplied in regions with iodine deficiency in Liaoning province

目的 了解和比较辽宁省碘缺乏病病区不同补碘时期出生儿童智力水平.方法 1900-2007年,在辽宁省的6个碘缺乏病病区县（市、区）各选出1个乡,其中轻中重病区乡各2个.在6个乡的10所学校中,以病区供应碘盐初期（1978-1980年）、非碘盐充销期（1981-1990年）、恢复普及碘盐期（1991-1995年）、全民食盐加碘期（1996-2000年）出生的7～14岁儿童为凋查对象,用中国联合型瑞文测验（CRT-C）和第二版农村儿童智商（intelligence quotient,IQ）常模测试（CRT-RC2）检查儿童IQ.结果 病区儿童IQ在非碘盐充销期（91.9±14.3）明显低于供应碘盐初期（95.8±14.6,q=8.60,P〈0.01）,恢复普及碘盐期（99.7 ±14.7）明显高于供应碘盐初期、非碘盐充销期（q值分别为9.53、18.13,P均〈0.01）,全民食盐加碘期（104.3±14.9）明显高于供应碘盐初期、非碘盐充销期、恢复普及碘盐期（q值分别为20.00、28.00、10.46,P均〈0.01）.儿童智力落后率（IQ≤69）在非碘盐充销期（6.7%,88/1314）高于供应碘盐初期（4.4%,21/471,χ^2=3.85,P〈0.05）,恢复普及碘盐期（3.3%,48/1470）明显低于非碘盐充销期（χ^2=15.37,P〈0.01）,全民食盐加碘期（2.7%,36/1344）低于供应碘盐初期（χ^2=4.41,P〈0.05）和非碘盐充销期（χ^2=26.34,P〈0.01）.供应碘盐初期各年度出生儿童IQ及智力落后率未有明显变化;非碘盐充销期的10年间,出生儿童IQ呈＂∪＂形降升,智力落后率则呈＂∩＂形升降;恢复普及碘盐时期出生儿童IQ逐年提高,智力落后率逐年降低;全民食盐加碘期各年度儿童IQ继续上升,智力落后率降到历史最低程度.结论 碘缺乏病病区非碘盐充销时期出生儿童智力水平明显低于供应碘盐初期儿童,全民食盐加碘期病区出生儿童智力水平较供应碘盐初期和恢复普及碘盐时期出生儿童有明显提高.

Objecfive To know and compare the intelligence level of children born in different time periods in regions with iodine deficiency disorders（IDD）in Liaoning province.Methods All 7-14 year-old children from ten schools were chosen as the subjects respectively from six villages in each of the six counties and in regions with iodine deficiency,who were respectively born at the initialization of iodinated salt supplying period（1978-1980）;non-iodinated salt supplying period（1981-1990）;recovery of supplied iodized salt period（1991-1995）;universal iodized salt period（1996-2000）,respectively.Intelligence quotient（IQ）was measured by Combined Ravens Test in China（CRT-C）and Combined Ravens Test-the Rural,in China,2nd edition（CRT-RC2）.Results IQ of children during the non-iodized salt period（91.9±14.3）was significantly lower than the initial supply of iodized salt period（95.8±14.6,q=8.60,P〈0.01）,recovery of supplied iodized salt period（99.7±14.7）was significantly higher than the initial supply of iodized salt period, non-iodized salt sales period（q = 9.53, 18.13, all P 〈 0.01 ）,universal salt iodization（ 104.3 ± 14.9） was significantly higher than the initial supply of iodized salt period, non-iodized salt sales period, recovery of supplied salt iodization（q = 20.00,28.00,10.46, all P 〈 0.01）. Children＇s rate of mental retardation （IQ≤69） was higher in non-iodinated salt supplying period （6.7%, 88/1314 ） than the initial supply of iodized salt （4.4%, 21/471, χ^2= 3.85, P 〈 0.05）, recovery of supplied iodized salt period（3.3%,48/1470） was significantly lower than non-iodinzed salt supplying period （χ^2= 15.37, P 〈 0.01）, universal salt iodization period（2.7%, 36/1344） was lower than the initial supply of iodized salt period（χ^2= 4.41, P 〈 0.05） and non-iodinzed salt supplying period（χ^2= 26.34, P 〈 0.01 ）. The IQ and intelligent retarded rates in children born during the initial years of iodinated salt supplying period were not different. The IQ of the children during ten years of non-iodized salt supplying period fluctuated in a ＂∪＂ curve, while the intelligent retardation rates in a ＂∩＂ curve.The children born during the period of recovery supplied iodized salt increased their IQ and lowered the retardation rates year after year. The IQ of the children in universal iodized salt period kept on increasing while intelligent retarded rates reduced to the lowest level. Conclusions The intelligence level of children born in regions with IDD during non-iodized salt supplying period is remarkably lower than that of the beginning years of iodinated salt supplying period. The intelligence level of children born after universal iodized salt period is remarkably higher than that of the initial iodinated salt supplying period and recovery of supplied iodized salt period, respectively.