LONGITUDINAL MEASUREMENTS OF BONE-DENSITY AND BIOCHEMICAL INDEXES IN UNTREATED PRIMARY HYPERPARATHYROIDISM

A large number of patients with primary hyperparathyroidism today do n ot undergo parathyroidectomy. In this prospective study, we evaluated the effect of untreated disease on biochemical and bone densitometric indices. In 66 patients, seven annual measurements showed no change in serum calcium, phosphorus, PTH, vitamin D, or alkaline phosphatase; i n urinary calcium, hydroxyproline or hydroxypyridinium cross-link excr etion; or lumbar spine, femoral neck, and radial bone mineral density. The subset of postmenopausal women also showed no change in biochemic al indices or bone density at any of the three sites. Twenty-four pati ents met guidelines for surgery as established by the NIH Consensus Co nference, 1990. They differed from those who did not meet these guidel ines only by being younger (50 +/- 3 us. 62 +/- 2 yr; P = 0.0005) and by having higher urinary calcium excretion [7.7 +/- 0.9 vs. 5.4 +/- 0. 3 mmol/L (310 +/- 37 vs. 215 +/- 14 mg/g creatinine); P < 0.01]. No lo ngitudinal changes in biochemical profile or bone mineral density at a ny site were noted in this subgroup. Conservative management of patien ts with mild primary hyperparathyroidism does not lead to progression of disease, as reflected by biochemical indices. Bone density is maint ained over 6 yr of observation at sites reflecting both cortical (radi us) and cancellous (lumbar spine) bone.