[Differential diagnosis between osteoporosis and asymptomatic primary hyperparathyroidism].

Recently, patients with asymptomatic primary hyperparathyroidism (aPHPT) are on the increase. When serum Ca, P and intact PTH are determined frequently, it is not difficult to diagnose of aPHPT, even when serum alkaline phosphatase activity is increased in some postmenopausal women. However, the criteria for operation for aPHPT is difficult, because the natural course of aPHPT is unknown, particularly in terms of bone mineral density. Since bone mineral density is genetically regulated by polymorphism of vitamin D receptor (Nature 1994), the analysis of restriction fragment length polymorphism of the vitamin D receptor may be useful as one of criteria for operation in patients with aPHPT in the near future.