Decreased parathyroid function in hyperthyroidism: interrelationships between serum parathyroid hormone, calcium-phosphorus metabolism and thyroid function.
Serum immunoreactive parathyroid hormone (S-iPTH) was measured together with serum and urinary calcium and phosphorus in 45 hyperthyroid patients in order to assess parathyroid fe of hyperthyroidism. The prevalence of hypercalcaemia was 51.1% using serum calcium values corrected for individual variations in serum albumin concentration compared to 15.6% using the uncorrected calcium values. S-iPTH was decreased and inversely correlated to serum calcium values. S-iPTH was decreased and inversely correlated to serum calcium (corrected). Subnormal levels of S-iPTH were found in 28.9% of the patients. The urinary excretion of calcium and phosphorus was increased and positively correlated to the degree of hyperthyroidism. The tubular reabsorption of calcium (TRCa%) was decreased, positively correlated to S-iPTH and inversely correlated to serum calcium. Increased mobilisation of bone mineral in hyperthyroidism is suggested mainly to be responsible for the elevated serarathyroid function.
D000293:Adolescent; D000328:Adult; D000368:Aged; D002118:Calcium / Q000097:blood / Q000378:metabolism* / Q000652:urine; D005260:Female; D006044:Goiter, Nodular / Q000503:physiopathology; D006801:Humans; D006980:Hyperthyroidism / Q000378:metabolism / Q000503:physiopathology*; D007455:Iodine / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D010280:Parathyroid Glands / Q000503:physiopathology*; D010281:Parathyroid Hormone / Q000097:blood*; D010758:Phosphorus / Q000097:blood / Q000378:metabolism* / Q000652:urine; D013961:Thyroid Gland / Q000503:physiopathology*; D013974:Thyroxine / Q000097:blood; D014284:Triiodothyronine
D010281:Parathyroid Hormone; D014284:Triiodothyronine; D010758:Phosphorus; D007455:Iodine; D013974:Thyroxine; D002118:Calcium