A 50-year-old man was admitted to our hospital for the evaluation of hypocalcemia and the treatment of diabetes mellitus. Seven months before admission, he sometimes felt thirst and polyuria, and 4 months before admission, he went to a doctor to check his blood glucose and was diagnosed as having diabetes mellitus which had suddenly developed. At that time he was treated with sulfonylurea, but his diabetic control was very poor.
At the time of admission to our hospital, the patient's serum calcium (Ca) level was 5.7mg/dl, phosphorus (P) 5.0mg/dl, and fasting blood glucose 308mg/dl, but urinary ketone bodies were not detected. High sensitive assay of parathyroid hormone (HS-PTH), intact PTH, and C-terminus PTH concentrations were under the level of detection. TSH level was slightly high (6.1μU/ml) with positive antimicrosomal and antithyroglobulin anti-bodies but thyroid hormone levels were within normal limits. TRH test showed over-response of TSH. Based on Ellsworth-Howard test, we made the diagnosis of idiopathic hypoparathyroidism associated with primary hypothyroidism and diabetes mellitus. He was treated with insulin twice a day and reached good control, and he was also administered 1α-OH-D3 and calcium lactate resulting in an increase of serum Ca level after 2 weeks.
These findings suggest that this case may be a polyglandular autoimmune (PGA) syndrome type 1 reported by Neufeld, which is very rare in Japan. The type of diabetes mellitus of this case is controversial. It is, however, necessary to pay attention to the decrease of the patient's insulin-secreting activity because autoimmune disorders are accompanied by this case.
