Factors associated with permanent hypothyroidism in infants with congenital hypothyroidism

Abstract

BackgroundCongenital hypothyroidism (CH) is one of the most common endocrine diseases in childhood. A significant proportion of CH cases are transient, but the risk factors for permanent CH (PCH) are not yet well established. The current guidelines suggest using levothyroxine until the age of 3 years, but some studies suggest the possibility of earlier discontinuation. However, few, if any, studies have followed up on the results of early discontinuation. This study aimed to identify predictive factors of transient CH among infants with CH. We also investigated the results in patients who underwent a trial of early discontinuation.MethodsWe gathered data regarding infants diagnosed with CH between July 2005 and July 2015 by retrospective chart review. Those with aplastic, hypoplastic or ectopic glands on thyroid ultrasonography or scan were excluded. Among them, early discontinuation subgroup was defined as those who discontinued levothyroxine before 30 months of age.ResultsFrom the 80 infants (40 males, 40 females) enrolled in this study, 51 were preterm. Nine (11.3%) were diagnosed with PCH. Compared with transient cases, those with PCH were on higher levothyroxine dose at discontinuation (4.3 vs 2.9 μg/kg, P < 0.001). There was no difference in the proportion of permanent cases between preterm and full-term groups. In preterm group,infants with PCH required higher levothyroxine dose at discontinuation than those with transient CH (3.8 vs 2.5 μg/kg, P = 0.018). Levothyroxine discontinuation at a dose of 2.86 μg/kg could suggest PCH (sensitivity, 88.9%; specificity, 71.0%). Among the 9 patients who underwent a trial of early discontinuation, 8 successfully discontinued levothyroxine.ConclusionThe majority of CH patients discontinued levothyroxine successfully, including those who underwent a trial of early discontinuation. Higher levothyroxine dose at the time of discontinuation was found to be a predictive factor for PCH.

Analysis of Mutation Spectra of 28 Pathogenic Genes Associated With Congenital Hypothyroidism in the Chinese Han Population

“…Current guidelines recommend that if the serum free T4 (fT4) concentration is reduced and thyroidstimulating hormone (TSH) is significantly increased, levothyroxine (LT4) treatment should be started immediately (7). However, for CH with elevated serum TSH and normal fT4, the requirement for LT4 treatment remains controversial (8,9). Currently, better methods to identify such42 conditions do not exist; thus, genetic screening may be helpful (10).…”

Pediatric Quality of Life in Congenital Hypothyroidism: an Indonesian Study

“…Some studies supported this finding. 21,22) As shown in Nonetheless, other authors have shown a dual effect of an initial high dose. A higher starting dose level of LT4 also contributed to more behavior problems in spite of better learning ability.…”

“…Unlike our results, the findings of other studies indicated a correlation between serum TSH and fT4 levels and PedsQL. 21,22) The improvement of TSH and fT4…”

Prevalence and predictive factors of transient and permanent congenital hypothyroidism in Fars province, Iran

“…Several cutoffs have been proposed for better predicting permanent or transient CH, using levothyroxine dose at the third year including cutoffs of > 2.86 µg/kg by Park ES et al, (Sensitivity: 88.9 %, Specificity: 71 %) [ 38 ] and > 3.96 µg/kg by Itonaga et al, (Specificity: 100 %) [ 39 ] for permanent CH and cutoffs of < 1.3 µg/kg by Higuchi et al, (Sensitivity: 80 %, Specificity: 84 %) [ 36 ] and < 2.76 µg/kg by Park IS et al, (Sensitivity: 87.3 %, Specificity: 67.6 %) [ 40 ] for transient CH. In our study, a cutoff point of > 2.25 µg/kg with a sensitivity of 76.11 % and specificity of 58.52 % at the third year of follow up was the predictor for permanent CH.…”