[Reference Intervals of Thyroid Hormones in Normal Pregnant Women and Effects of Thyroid Autoantibodies on Thyroid Hormone Levels in Pregnant Women in Chengdu Area].

OBJECTIVES: To establish the reference intervals of thyroid hormones in normal pregnant women in Chengdu area of China, and to investigate the effects of thyroid autoantibodies on thyroid function in pregnant women. METHODS: We included 696 pregnant women who had gestation data from June 2013 to March 2014 in Chengdu Women & Children's Central Hospital. Every subject under went questionnaire survey, physical examination, thyroid ultrasound and measurement of thyroid hormone and thyroid autoantibodies. The normal reference intervals were established according to the percentiles (P2.5-P97.5) of the healthy pregnant women in the same trimester. Another 50 non-pregnant women were selected as the control group. RESULTS: Of the 696 pregnant women, 579 subjects had negative thyroid autoantibodies and 117 subjects had positive thyroid autoantibodies. The positive rate of thyroid autoantibodies was 16.81%. Of the 579 subjects with negative thyroid autoantibodies, 257 were in the first trimester, 202 in the second trimester and 120 in the third trimester. In the first trimester of normal pregnancy, the reference intervals of serum thyrotropin (TSH) , free triiodothyronine (FT3) and free thyroxine (FT4) were 0.02-4.03 mIU/L, 3.85-6.27 pmol/L and 11.93-21.04 pmol/L respectively. In the second trimester, the reference intervals of serum TSH, FT3 and FT4 were 0.02-4.05 mIU/L, 3.51-5.82 pmol/L and 11.23-19.22 pmol/L respectively. In the thirdtrimester, the reference intervals for serum TSH, FT3 and FT4 were 0.24-5.41 mIU/L, 3.18-4.97 pmol/L and 11.10-17.00 pmol/L, respectively. When compared with non-pregnant women, the median TSH value was increasingly consisted with the progress of pregnancy period, while the median FT4 and FT3 values were decreasing accordingly. The similar tendencies of TSH, FT3, and FT4 were found in pregnant women with positive thyroid autoantibodies, but the trends were more remarkable when compared with those with negative thyroid autoantibodies. In pregnant women with positive thyroid autoantibodies, the incidences of clinical hypothyroidism, subclinical hypothyroidism and clinical hyperthyroidism were 0.85%, 15.38% and 0.85%, respectively. CONCLUSIONS: The thyroid hormone reference ranges of pregnant women is quite different from those of non-pregnant women. It is necessary to establish the reference intervals of thyroid hormones in normal pregnant women. Thyroid function of pregnant women with positive thyroid autoantibodies should be monitored during the pregnant period.

[Influence Factors on Serum Thyroid Hormone Level in Healthy People].

OBJECTIVE: To explore the influences of age, gender and season on serum thyroid stimulating hormone level and thyroid hormone level in healthy people. METHODS: There were 2 564 healthy volunteers enrolled in this study, whom were divided into different groups according to gender, age and the season. The levels of serum TSH, T3, T4, FT3, FT4 were measured and the data were statistically analyzed. RESULTS: The level of serum TSH in both young and middle-age groups of female was higher than that in the same age groups of male. The serum levels of T3, FT3, FT4 in both young and middle-age groups of female were lower than those in the same age groups of male (P < 0.05). In female, the serum level of TSH was increasing with age. However, the serum levels of FT3, FT4 had the opposite tendency. The level of serum FT3 in young group was higher than that in elderly group of, but T4 were lower. Lower levels of TSH, T3, FT4 were found in summer instead of winter (P < 0.05) and there was no significant difference of FT3 between that two seasons. The levels of serum TSH, T3, T4 and FT4 were correlated with seasons (r = 0.079, 0.092,-0.137, 0.140). CONCLUSION: The levels of serum TSH and thyroid hormones are influenced by age, gender and seasons, which needs to be considered for the diagnosis of thyroid diseases and evaluation of thyroid function.

The association between thyroid autoantibodies in serum and abnormal function and structure of the thyroid.

OBJECTIVES: To evaluate the association between thyroid autoantibodies and abnormalities in thyroid function and structure, and to investigate any risk factors. METHODS: A cross-sectional survey was undertaken in Chengdu residents ≥ 18 years with no previous thyroid disease. The study participants provided demographic and clinical data. Thyroid function and serum concentrations of the thyroid autoantibodies antithyroperoxidase antibody (TPOAb) and antithyroglobulin antibody (TgAb) were measured. RESULTS: A total of 1334 subjects were included in this study. The prevalence of TPOAb and TgAb positivity was significantly higher in female than in male subjects. The prevalence of thyroid autoantibodies in those with subclinical hypothyroidism and clinical hyper- and hypothyroidism was significantly greater than in euthyroid subjects. The concentration of TPOAb and TgAb in subjects with both TPOAb and TgAb was significantly higher than in those who exhibited only one type of thyroid autoantibody. Using multivariate logistic regression analysis, female sex, thyroid volume, thyroid hypo- and heteroechogenicity were found to be risk factors for the presence of autoantibodies. CONCLUSIONS: Thyroid autoantibodies were common in the general population. Women with thyroid enlargement, hypoechogenicity and heteroechogenicity might benefit from routine screening for thyroid autoantibodies and thyroid function.

[Relationship between depression and thyroid hormone levels in patients with Graves disease].

OBJECTIVE: To explore the relationship between depression and thyroid hormone levels in Graves disease patients. METHODS: A total of 188 out-patients with Graves disease were enrolled in this study. All patients received the measurements of Zung Self-Rating Depression Scale (SDS) and serum thyroid stimulating hormone (TSH), free thyroxine (FT4), free triiodothyronine (FT3) and TSH receptor antibodies (TRAb). RESULTS: All the patients were divided into 3 groups: high FT4 level group (n=65), normal FT4 level group (n=113) and low FT4 level group (n=19). There were statistically significant difference of SDS scores (P < 0.05) in 3 groups, but no significant difference in the occurrence of depression (P > 0. 05). In Pearson correlation analysis, SDS score was positively correlated with serum FT3 (r = 0.372, P < 0.001) and FT4 level (r = 0.288, P < 0.001), negatively correlated to serum TSH level but no statistically significant (r = -0.028, P = 0.614). logistic regression analysis showed that TSH (P = 0.131), FT4 (P = 0.637), and FT3 (P = 0.208) were not the independent risk factors for the occurrence of depression. CONCLUSION: Although the prevalence of depression is high in Graves disease patients, there is no close correlation between depression and the level of thyroid hormone.