The Change Of Serum Ghrelin Level In Children With Autoimmune Thyroid Disease And Its Related Factors

Objective:To investigate serum ghrelin level in the patients with AITD, including Graves disease (GD) and Hashimoto thyroiditis (HT). To study the relationship between the level of serum ghrelin and age, body mass index and the relationship between the level of serum ghrelin and the level of function of thyroid (FT3, FT4 and TSH), and then explore the role of ghrelin in children with AITD when they were in inatial stage and different course.Methods:The subjects which come from Tianjin Medical University General Hospital pediatric endocrine clinic were divided into three groups by the thyroid function stage. The first group was hyperthyroidism group including 6 boys and 19 girls. The second group was hypothyroidism including 4 boys and 19 girls.The third group was normal control group including 9 boys and 22 girls. All patients were measured FT3, FT4, TSH, ghrelin, TGAb, TRAb, TPOAb. To determinate their serum level of ghrelin by ELISA method. Hyperthyroidism group were given methimazole(MMI) therapy and hypothyroidism were given levothyroxine sodium (L-T4) therapy. After treament the hyperthyroidism group and the hypothyroidism group were measured FT3, FT4, TSH, ghrelin. Make relationship analysis between the level of ghrelin and the level of FT3, FT4, TSH.Results:1 The level of serum ghrelin in hyperthyroidism group were significant lower than the normal control group (P<0.001). The level of serum ghrelin in hypothyroidism group were significant higher than the normal control group (P<0.001). The level of serum Ghrelin in hyperthyroidism group were lower than the hypothyroidism group (P<0.001).2 The level of serum ghrelin in hyperthyroidism group before they therapied were significant lower than that they were therapied by MMI after one month or when thyroid hormone normalized after treatment (P<0.05); The level of serum ghrelin in hypothyroidism group before they therapied were significant higher than that they were therapied by L-T4 after one month or when thyroid hormone normalized after treatment (P<0.05). The level of serum ghrelin of hyperthyroidism group and hypothyroidism group after treatment have no significant difference with that of normal control group (P>0.05).3 The correlation analysis showed that patients with hyperthyroidism ghrelin level was significantly negatively correlated with FT3, FT4 (r=-0.30 and r=-0.33, P <0.05) and positively correlated with TSH (r=0.27, P<0.05); Ghrelin level of hypothyroidism was significantly negatively correlated with FT4 (r=-0.23, P <0.05).Conclusion:1 The level of serum ghrelin in hyperthyroidism group were significant lower than controls. But the level of serum ghrelin in hyperthyroidism group were increased when the thyroid function was remission after they were therapied. The level of serum ghrelin in hypothyroidism group were significant higher than controls. But the level of serum ghrelin in hypothyroidism group were decreased when the thyroid function was remission after they were therapied. The ghrelin level of children with autoimmune thyroid disease are changed with the energy balance status and thyroid hormone level. These findings suggest that ghrelin level can be used as a reflection of changes in thyroid function of the autoimmune thyroid disease and a sensitive indicator of the disease prognosis.2 Patients with hyperthyroidism ghrelin level was significantly negatively correlated with FT3, FT4 and positively correlated with TSH; Ghrelin level of hypothyroidism was significantly negatively correlated with FT4. These suggested that FT3 and FT4 were two factors that can change the level of serum ghrelin.