Background: Hypothyroidsim is known to be associated with liver function, cholesterol and some hormone levels including GH. But, there are fewer reports about the gonadotropin levels in thyroid dysfunction.
Objectives and hypotheses: We report here some interesting laboratory findings in a 19.24-year-old severe short stature female case of ectopic thyroid.
Methods: Laboratory investigations including the combined anterior pituitary function (Cocktail) study were done before and after thyroid hormone replacement.
Results: A 19.24-year-old female presented with short stature; height 141 cm (mid-parental height. 167 cm), weight 52 kg and bone age 13 years. Since 15 years of age, she had periods every 3 months until last year, but this year every 2 months. Laboratory investigations showed free T4<0.40 ng/dl, TSH>100 IU/ml, ALT/AST 92/63 IU/l, cholesterol 459 mg/dl, total protein/albumin 7.7/5.1 g/dl, and prolactin 94.4 ng/ml. In the 1st day of GH stimulation, successive l-dopa and clonidine tests resulted in 1.4 and 1.5 ng/ml of GH peaks, respectively. In the 2nd day of Cocktail study, insulin stimulation test (Humalog 0.1 u/kg, 52 units) resulted in 3.5 ng/ml of GH peak with the lowest blood glucose of 59mg/dl. And, LH basal/peak were 0.5/6.4 mIU/ml and FSH basal/peak were 7.8/11.7 mIU/ml, respectively. Thyroid scan showed ectopic thyroid. In abdominal ultrasonography, fatty liver was suspected and 2 cm-sized echogenic mass was found in uterine cervix. After 6 weeks of thyroxine replacement, her thyroid function was 1.84 ng/dl of free T4 and 0.281 IU/ml of TSH. She lost 6 kg and menstruation was normalized. Laboratory findings of ALT/AST, cholesterol, and prolactin were also normalized; 22/23 IU/l, 140 mg/dl and 16.7 ng/ml, respectively. But, total protein/albumin decreased to 5.7/3.6 g/dl. In the rechecked 1st day of GH stimulation, l-dopa and clonidine tests showed 2.40 and 3.13 ng/ml of GH peaks, respectively. The 2nd day Cocktail test (Humalog 0.1 u/kg, 46 units) showed 7.31 ng/ml of GH peak with the lowest blood glucose of 33mg/dL. And, LH basal/peak were 25.6/43.7 mIU/ml and FSH basal/peak were 11.2/15.0 mIU/ml, respectively. In follow-up abdominal ultrasonography, the findings of suspicious fatty liver and echogenic mass in uterine cervix disappeared.
Conclusion: In GH stimulation after thyroxine replacement, we found an interesting finding of about two-fold increases of GH peaks using the three stimulating agents of l-dopa, clonidine and insulin. In GnRH study, LH levels were markedly increased, but just with a little increase in FSH. And, levels of total protein/albumin decreased and the echogenic mass in uterine cervix disappeared after thyroid hormone replacement.
20 - 22 Sep 2014
European Society for Paediatric Endocrinology