Title: Incidence of hypercalcaemia and primary hyperparathyroidism in relation to the biochemical profile.
Abstract: Over a period of one year, 24 500 patients underwent a biochemical profile investigation.Seven hundred and thirty-eight (3 %) patients had a plasma calcium concentration of greater than 2-60 mmol/l, and hypercalcaemia was confirmed in 49-8 % of those subjects from whom a second fasting sample was received.Primary hyperparathyroidism and malignant disease were the two commonest causes of hypercalcaemia, occurring with equal frequency.The overall incidence of primary hyperparathyroidism in our population was 1:680.Over 75 % of the patients with primary hyperparathyroidism appeared to have asymptomatic disease.The merits of including a plasma calcium determination in a biochemical profile would seem to depend particularly on the natural history of asymptomatic primary hyperparathyroidism.In 1976 a multichannel analyser was commissioned in our Department and a plasma calcium deter- mination has been included as one of the 14 tests performed on each blood sample submitted for a biochemical profile.In view of several reports describing increased recognition of hypercalcaemia following the introduction ofbiochemical screeningl-4 we conducted over a period of one year a study of patients whose biochemical profile indicated hyper- calcaemia.We have looked in particular at the causes of hypercalcaemia and the occurrence of primary hyperparathyroidism.