Serum calcium was measured in 12,339 men and 13,394 women ages 25 to 75. Pr
imary hyperparathyroidism, defined as a combination of serum calcium and pa
rathyroid hormone (PTH) levels within the extreme or upper normal range, wa
s diagnosed in 17 men and 47 women. The prevalence in both sexes increased
with age. When 42 subjects with asymptomatic primary hyperparathyroidism we
re followed for 3 years, no significant increase in serum calcium or PTH wa
s seen. In a subgroup of 473 men and 517 women ages 50 to 75, serum PTH was
measured along with serum calcium. Depending on the criteria used to defin
e primary hyperparathyroidism, the prevalence in older women within this su
bgroup ranged from 3.6% to 13.9%. The study concluded that a high prevalenc
e of primary hyperparathyroidism exists in older women, although the progre
ssion of the disease, judging by serum calcium and PTH measurements, appear
s to be very slow. (C) 2000 Elsevier Science Inc. All rights reserved.