Optimal initial dose of levothyroxine replacement therapyin children with congenital hypothyroidism
Objective:To analyze the incidence and treatment of congenital hypothyroidism(CH)to explore an optimal initial replacement therapy dose of levothyroxine(LT4)for CH.Methods:231 children with CH,who were followed-up and treated with LT4 at the Neonatal Screening Center in Children's Hospital of Shanghai during 1987 to 2018,were enrolled and divided into three groups according to the initial level of free thyroxine(FT4):mild CH group(n =60),moderate CH group(n =97)and severe CH group(n =74).The dose-effect curves were performed in different groups,after which Poisson regression was used to analyze the adjustments of LT4 within 2 years under different initial doses in each group.Results:(1)The effects of neonatal screening TSH concentrations,the first serum free thyroxine(fT4)concentrations and thyroid ultrasonography on TSH level after treatment were statistically significant(P＜0.05).(2)For the children in the mild CH group and the moderate CH group who received an ini-tial therapeutic doseof about 6-8 μg·(kg·d)-1 and 8-10 μg·(kg·d)-1 respectively,the proportion of res-toration of TSH to normal level was high(70.37%and 70.00%,respectively)after treatment for 2 weeks to 1 month,and fT4 could be within or higher than the age-specific reference range,and the adjustments of LT4 were less during the first 2 years(22.30%in mild CH and 20.09%in moderate CH).The difference was statistically significant(P＜0.05).Conclusion:LT4 is effective in treating CH.According to the severity of CH,6-8 μg·(kg·d)-1 for mild CH and＞8-10 μg·(kg·d)-1 for moderate CH is an optimal initial dose.Infants with se-vere CH may be treated with a higher initial dose[＞10 μg·(kg·d)-1]to maintain TSH and fT4 concentration in the age-specific reference range as soon as possible.
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万方数据
维普
