Hypercalcemia: long-term follow-up with matched controls.

Using laboratory tests and the presence of complaints thought to be associated with hyperparathyroidism, we retrospectively studied 160 patients found to have hypercalcemia on a routine multiphasic examination in two different calendar years. Each case was compared to a matched control, and mean follow-up was 8.5 yr. The diagnosis of presumptive hyperparathyroidism was made by attempting to eliminate any confounding causes of hypercalcemia and by performing parathyroid hormone assays in 41 unoperated patients. Fifteen patients had a parathyroid adenoma removed (12 during and 3 after the duration of the study). Except for an increase in the incidence of hypertension in black male patients, we noted no significant differences in symptomatology or renal function between patients and matched controls. We conclude that most patients with mild persistent (presumptive) hyperparathyroidism may be left untreated under surveillance for long periods of time without the development of significant complications.