RESUMEN
Objective@#To observe the association between puberty development and thyroid function among school-aged girls in Minhang District of Shanghai, in order to explore the effect of puberty development on thyroid function. @*Methods@#The study was based on a cohort of adolescent girls recruited in iodine-suitable areas of Minhang District, and the baseline and follow-up survey have been carried out from January to March 2019. The method of phased cluster sampling was used to select one junior high school in the east, south, north and middle of Minhang District, Shanghai, respectively. Finally, 464 new junior high school girls were included in the Cohort study for physical examination, and girls were followed up from January to March 2021. The Puberty Development Scale (PDS) was used to assess the stage of puberty. Serum thyroid stimulating hormone (TSH), free triiodothyronine (FT3), and free thyroxine (FT4) were determined for each participant. Thyroid homeostasis structure parameters (THSPs) was calculated. Changes of Thyroid hormones at baseline and follow-up were compared by Wilcoxon signed rank sum test. Multiple linear regression analyses were used to evaluate the associations of thyroid hormones (THs) and THSPs changes with pubertal develepment.@*Results@#Serum TSH levels of female studentds decreased significantly, while their FT3 and FT4 levels increased significantly during the study period ( Z=-10.53, -4.71, -12.46, P <0.01). In multiple linear regression analysis after adjustment for co-variables (including baseline age, change of BMI and waist circumference), FT4 and thyroid feedback quantile-based index (TFQI) in the higher puberty category scores changes (△PCS) group were further reduced compared with those in the low △PCS group ( β =-0.66, -0.55 ). Compared to the late puberty at baseline and follow-up (BLFL) group, FT4 and TFQI showed higher decline in the pre-puberty at baseline and late puberty at follow-up (BPFL) group with the pre-puberty at baseline and end of puberty at follow-up (BPFT) group ( β =-0.55, -0.44)( P <0.05). There were no association of △TSH, △FT3, △FT4/FT3 and TSH index changes (△TSHI) with △PCS or the puberty pattern.@*Conclusion@#Serum TSH decreases while serum FT3 and FT4 increase among girls during puberty. Both the initial stage and the velocity of pubertal development are related to thyroid hormone fluctuations.
RESUMEN
Objective@#To investigate thyroid hormone concentration and associated factors among pubertal girls in Minhang District of Shanghai.@*Methods@#From January to March 2019, a stratified sampling method was used to select junior high schools from the east, south, north, and middle areas in Minhang district. A total of 386 girls of grade 6 in selected schools were included in the study. Physical examination was conducted, and their urine and blood samples were collected to determine urinary iodine concentration (UIC) and thyroid function. Puberty Development Self-rating Scale (PDS) was used to define the pubertal stage. Logistic regression models were conducted to analyze the associations between pubertal stage and thyroid function.@*Results@#The median urinary iodine concentration was 163.57(106.57, 232.96) μg/L. The geometric mean values of TSH, TT3, FT3 and FT4 were 0.29 mU/L, 0.26 nmol/L, 0.68 pmol/L and 1.18 pmol/L.The mean value of TT4 was 91.64 nmol / L. The abnormal rates of TGAb and TPOAb were 6.22% and 4.15%. The rate of abnormal TGAb combined with abnormal TPOAb was 3.68%. Girls in puberty and post-puberty had the lower level of TT4 (OR=0.47,0.43) as compared with girls in pre-puberty stage. Obese girls had higher level of TT3(OR=9.08, 95%CI=1.52-54.07). With the increase of exercise time(0.5-1, >1 h/d), FT4 level was increased (OR=2.45, 2.19). TSH levels were significantly higher in girls with higher TGAb and TPOAb. Girls had higher TT4 or FT4 levels if their TGAb levels were higher and TPOAb levels were normal.@*Conclusion@#There is an association between pubertal stage, obesity, exercise and thyroid function in school-aged girls during puberty in iodine sufficient areas. TSH, FT4 and TT4 levels are correlated with TGAb and TPOAb levels.