RESUMO
Objective To evaluate the effect of iodine supplementation on improvement of developmental quotient (DQ) at the critical period of infant brain development.Methods Pregnant,lactating women and infants less than 3 years old were supplemented with iodized oil in Linxia Hui Autonomous Prefecture(Linxia Prefecture) Gansu Province in 2006-2010.Before and after the intervention(2006,2007-2010),five townships were randomly selected in the north,the south,the east,the west and the center of eight counties(cities) of Linxia.One village was chosen from each of those townships and 20 infants,20 pregnant women and 20 lactating women were randomly selected in each village(insufficient was made up from the neighboring villages).Urinary iodine(UI) level of the infants,pregnant and lactating women were determined by arsenic cerium catalytic spectrophotometry.DQ value of infants was measured before and after supplementation of iodized oil in 2006 and 2010.UI value of pregnant,lactating women and infants was monitored every year after iodine supplementation.Results Before iodine supplementation(2006),the median UI level of pregnant,lactating women and infants was 89.28,84.85,107.3 μg/L,respectively.After iodine supplementation,the medians UI level in 2007,2008,2009 and 2010 were,respectively,pregnant women:136.0,187.8,118.2,175.8 μg/L; lactating women:135.2,159.8,187.5,163.5 μ g/L; infants:139.6,174.7,190.7,168.4 μg/L.Before iodine supplementation,the DQ value of infants was 92.8 ± 16.3,and the average score of gross motor,fine motor,adaptive capacity,language and social behavior was 93.7 ± 20.0,91.4 ± 20.0,92.4 ± 19.0,90.3 ± 20.0,96.4 ± 22.1,respectively.After iodine supplementation,the DQ value of infants was 104.3 ± 13.8,and the average score of gross motor,fine motor,adaptive capacity,language and social behavior was 104.8 ± 21.5,104.1 ± 17.2,104.8 ± 16.1,99.9 ± 19.1,108.0 ± 22.7,respectively,which were higher than that before iodine supplementation (t =-10.43,-10.77,-13.78,-14.28,-9.96,-15.33,all P ＜ 0.01).Conclusions Iodine deficiency at the critical period of brain development can affect the intellectual development of infants and young children at all functional areas of intelligence.Iodine supplementation at the critical period of brain development can prevent mental retardation caused by iodine deficiency disorders.
RESUMO
Objective To investigate the relationship between iodine nutrition and growth/ development in infants at the key period of brain development.Methods All women from pregnancy to the end of lactation and the weaning infants within 3 years in the Linxia Hui Autonomous Prefecture (Linxia Prefecture) were added iodized oil in 2006-2010.In 2006,2010 one town was randomly selected from each of the five directions (east,south,west,north,central) of each county in Linxia Prefecture.One village was chosen from every town and 20 infants,20 pregnant women and 20 lactating women were randomly selected in each town.Urinary iodine (UI) of the infants,pregnant and lactating women were determined.DQ value,height and weight of part of infants were measured.According to the above sampling plan,UI of pregnant women,lactating women and infants had been monitored every year after intervention.0-3 infants were choosing to be control before intervention.Results UI of 1056 and 2989 0-3 infants were investigated before and after the iodine oil intervention.After the ‘iodine oil' intervention,the median UI of infants increased from 107.3 μg/L to 139.6-190.7 μg/L,the percentage of UI level that lower than 50 μg/L,decreased from 23.9％ to 6.7％-12.9％.DQ value increased from 92.8 to 104.3,the percentage of normal height and above increased from 65.0％ to 82.1％ and the percentage of the normal weight and above,increased from 59.3％ to 81.4％.The outcomes of DQ value,height and weight showed statistically significant differences,compared to the pre- intervention outcomes (P＜0.05).The median UI of pregnant and lactating women increased from 89.3 μg/L to 118.2-187.8 μg/L and from 84.9 μg/L to 135.2-187.5 μg/Lrespectively.Conclusion Infant' s growth and development were retarded when iodine deficiency existed at the key period of brain development.Intake of oral iodine oil at key period of brain development could provide adequate nutrition thus improve growth and development on infants.