原発性副甲状腺機能亢進症における尿酸代謝

- 高尿酸血症または正尿酸血症を呈した各1例における検討-

抄録

We investigated uric acid metabolism in two patients with primary hyperparathyroidism in relation to parathyroid function.
Patient 1 was a 56-year-old man, who visited our clinic for headache and insomnia in March,1987. Two years earlier he noticed right flank pain and red-colored urine. Urological examination revealed a right ureter stone. On examination, hypercalcemia (5.6mEq/l), hypophosphatemia (2.1 mg/dl) and reduced % tubular reabsorption of phosphate (%TRP) were found, and the serum uric acid level was 8.0-9.5mg/dl. Patient 2 was a 44-year-old woman, who visited our clinic because of epigastral discomfort. She also exhibited hypercalcemia(6.0mEq/l), hypophosphatemia (2.5mg/dl)and decreased %TRP (71.8%), although the serum uric acid level was normal. Surgery of the neck revealed adenoma of the parathyroid gland, which was confirmed by histological examination.
In these two patients, we investigated uric acid metabolism by urate clearance study and pyrazinamide (PZA) suppression test. Patient 1, who had hyperuricemia, showed reduced urate clearance, although the results of PZA suppression test were normal. On the other hand, Patient 2, whose serum urate level was normal, had almost normal results, although there was no difference in the serum level of PTH between the two. We also examined the changes of serum and urinary urate following calcium or EDTA loading. In Patient 1 there was a significant correlation between serum urate level and calcium and phosphate levels. On the other hand, there was no correlations in Patient 2 between these parameters. After successful parathyroidectomy, serum urate level did not show any significant changes in Patient 1.
These results indicate that PTH dose not affect human uric acid metabolism, especially in the renal tubular transport system.