Primary hyperparathyroidism in a New Zealand community: a review of 40 cases.

Forty cases of primary hyperparathyroidism presenting over a 15 year period, have been reviewed. The disease was equally prevalent in both sexes with highest incidence in the sixth decade. Most patients presented with renal colic or calculi (73 percent) and skeletal disease was found in only 13 percent. A single parathyroid adenoma was found in 32 cases and hyperplasia was diagnosed in only two cases. Follow-up questionnaires were sent to 32 patients, and in 27 of these a full clinical and laboratory assessment was undertaken. Of 26 patients with renal colic preoperatively only six continued to experience colic one year after parathyroid surgery. Thirty percent of all patients were hypertensive preoperatively, and in only two patients did blood pressure normalise after surgery. Fourteen of 27 patients followed-up were found to be hypertensive. A highly significant fall was noted in serum calcium, chloride, alkaline phosphatase and urine calcium excretion postoperatively. Recurrence of the disease was low and less than 8 percent in this series. The low incidence (1 per 10 000 population per year) suggests that primary hyperparathyroidism is under diagnosed in the Christchurch community.