Endocrine Abstracts

A 47-year-old male farmer presented to our endocrinology clinic in 2001 with progressive polyuria for half a year. He had a past history of left intracranial hemorrhage with right hemiparesis due to traumatic injury in November 1998 but recovered thereafter. He complained of urine output more than 10 000 c.c. per day. Routine urine check with SP. GRAVITY < 1.005 was noted ( Normal range: 1.005–1.030 ). Serum osmolality was 299 mosm/KgH₂O (Normal range: 275–295) while urine osmolality was 86 mosm/KgH₂O (Normal range: 50–1400). We also checked his serum ADH level which was 0.13 pg/ml (Normal range: 0.4–2.4), and therefore central diabetes insipidus (DI) was impressed. In addition, serum level of pituitary hormones, including luteinizing hormone (LH), follicle-stimulating hormone (FSH), prolactin, growth hormone (GH), adrenocorticotropic hormone (ACTH) were normal. However, elevated serum FT4 level (FT4: 2.22 ng/dl) (Normal range: 0.85–1.86 ng/dl) with higher serum TSH level (TSH 13.7 ulU/ml) (Normal range: 0.25–4 ulU/ml) was noted. Serum TBII level was 4.45% (Normal < 15%). Repeated thyroid function test revealed similar results with slightly higher serum FT4 level and normal to higher serum TSH level. Brain magnetic resonance imaging (MRI) was performed and revealed no pituitary mass. The patient did not have any symptoms and signs of hyperthyroidism, such as weight loss, heat intolerance, hand tremor and tachycardia. Thyroid ultrasonography was performed and showed a normal thyroid. Thus, thyroid hormone resistance syndrome was suspected. Except a large amount of DDAVP (nasal spray) (10 mg/ds, 25 ds/bot) 5 bottles per months, he did not receive any treatment for abnormal thyroid function. Serum FT4 level has been continued to be higher than normal with a normal to higher serum TSH level. In conclusion, our patient had been diagnosed with central diabetes insipitus and thyroid hormone resistance syndrome.