title: Severe hyponatremia in association with I(131) therapy in a patient with metastatic thyroid cancer.
abstract: Hyponatremia is a common clinical problem that results from various causes. Hypothyroidism is known to be one of the causes of this disorder. We report a case of metastatic thyroid cancer presenting with severe hyponatremia in association with hypothyroidism induced by pretreatment of I(131) therapy, such as a low-iodine diet and withdrawal of thyroid hormone. Serum arginine vasopressin (AVP) was elevated and urine osmolality was higher than that of serum. Saline infusion and thyroid hormone replacement normalized serum sodium and AVP. Inappropriate secretion of AVP in hypothyroid state was thought to be one of the causes of this hyponatremia.
authors.affiliation: Department of Regional Medicine and Education, Asahikawa Medical University, Japan. tnozu@sea.plala.or.jp
authors.forename: Tsukasa
authors.initials: T
authors.lastname: Nozu
authors.forename: Yuri
authors.initials: Y
authors.lastname: Yoshida
authors.forename: Masumi
authors.initials: M
authors.lastname: Ohira
authors.forename: Toshikatsu
authors.initials: T
authors.lastname: Okumura
mesh_terms: D000368:Aged; D001127:Arginine Vasopressin / Q000097:blood; D002291:Carcinoma, Papillary / Q000150:complications / Q000532:radiotherapy / Q000556:secondary / Q000601:surgery; D005260:Female; D006801:Humans; D007010:Hyponatremia / Q000209:etiology* / Q000628:therapy; D007037:Hypothyroidism / Q000150:complications; D007177:Inappropriate ADH Syndrome / Q000150:complications; D007457:Iodine Radioisotopes / Q000009:adverse effects*; D008207:Lymphatic Metastasis / Q000532:radiotherapy; D013964:Thyroid Neoplasms / Q000150:complications / Q000532:radiotherapy* / Q000601:surgery; D013965:Thyroidectomy
chemical_list: D007457:Iodine Radioisotopes; D001127:Arginine Vasopressin