Abstract:

Objective

To investigate the application value of serum Irisin，thyroid-stimulating hormone （TSH） and homocysteine （Hcy） in diagnosing gestational hypothyroidism.

Methods

From September 2021 to September 2023，one hundred cases of hypothyroidism during pregnancy admitted to the First Affiliated Hospital of Xi′an Jiaotong University Yulin Hospital were classified into hypothyroidism group.During the same period，normal physical examinees （100 cases） were classified into control group.Clinical data of the 2 groups were collected，and serum Irisin，TSH and Hcy levels were detected.The correlations among serum Irisin，TSH，Hcy levels and thyroid function indexes were analyzed by Pearson correlation analysis.The diagnostic value of the 3 biomarkers on hypothyroidism in pregnancy was analyzed by receiver operating characteristic （ROC） curve.

Results

The levels of serum Irisin ［（7.71±0.84）μg/L，（4.01±0.92）μg/L］，TSH［（8.01±1.23）mU/L，（2.81±0.45）mU/L］，Hcy［（9.89±2.44）μmol/L，（6.82±2.04）μmol/L］ and thyroid peroxidase antibody （TPO-Ab） ［（388.45±33.71）U/mL，（18.56±4.01）U/mL］ in hypothyroidism group were higher than those in the control group （t= 29.70，39.70，9.65，108.96，all P ＜0.01）.While the levels of free triiodothyronine （FT₃） ［（3.31±0.34）pmol/L，（3.92±0.28）pmol/L］ and free thyroid hormone （FT₄） ［（9.89±1.88）pmol/L，（13.04±0.65）pmol/L］were lower than those in the control group （t=13.85，15.84，all P ＜0.01）.Pearson correlation analysis showed that serum Irisin was positively correlated with TSH （r=0.411，P ＜0.01），and negatively correlated with FT₃ and FT₄ （r=-0.368，-0.391，all P ＜0.01），but had no significant correlation with TPO-Ab （r=0.201，P ＞0.05）.Serum Hcy was positively correlated with TSH and TPO-Ab （r=0.432，0.359，all P ＜0.01），and negatively correlated with FT₃ and FT₄ （r=-0.387，-0.374，all P ＜0.01）.ROC results showed that the areas under the curve （AUC） of serum Irisin，TSH and Hcy in diagnosing gestational hypothyroidism were 0.755，0.675 and 0.664，and the sensitivity and specificity were 76.00%，64.00%，60.00%，and 76.00%，66.00%，68.00%，respectively.The AUC for the combined diagnosis was 0.761，and the sensitivity and specificity were 71.00% and 76.00%，respectively.

Conclusions

Serum Irisin，TSH and Hcy of patients with hypothyroidism during pregnancy are at high levels，and serum Irisin and Hcy are positively correlated with TSH，and negatively correlated with FT₃ and FT₄.Serum Irisin exhibits high diagnostic efficiency，and the combined use of the 3 biomarkers can enhance the accuracy of diagnosis.

Key words: Irisin, Thyroid stimulating hormone, Homocysteine, Period of pregnancy, Hypothyroidism