Abstract. Population-based screening showed 2.1% prevalence of primary
hyperparathyroidism (pHPT) in postmenopausal women. Individuals
with total serum (s)-calcium levels of 2.55 mmol/L or more at screening
were diagnosed with pHPT when subsequent analysis supported inappropriately
elevated intact parathormone (PTH) levels in relation to even
normal s-calcium levels. The arbitrary diagnostic criteria were validated
by parathyroidectomy. Herein we reinvestigated biochemical signs of
pHPT in women not diagnosed with pHPT due to s-calcium 2.50 to 2.54
mmol/L (group A, n 160) at screening or due to appropriate PTH levels
on two occasions after screening (group B, n 70). Altogether, 99 women
in group A and 47 in group B underwent reinvestigation 8.8 years after
screening when they were 65 to 84 years old. The s-calcium levels averaged
2.56 mmol/L and had increased in group A (mean 0.04 mmol/L) and
decreased in group B (mean 0.05 mmol/L). A total of 48 and 18 females
(48%, 38%), respectively, met the previously validated criteria of pHPT.
Altogether 21% of them were hypercalcemic (range 2.60 –3.12 mmol/L).
Subgroup analysis showed that PTH had not increased with time (n 47)
and that atherogenic blood lipids, but not glucose levels, were similar in
pHPT patients and matched controls (n 37). Assuming the existence of
pHPT already at screening, the prevalence of pHPT could be adjusted to
3.4%. Even the most liberal diagnostic criteria utilized at pHPT screening
seemed to underdiagnose the disease by inefficient cutoff limits for scalcium
and PTH. Because one-fifth of the women with pHPT progressed
to hypercalcemia, long-term follow-up is advocated for those with scalcium
in the upper normal range.
2002. Vol. 26, no 8, 931-936 p.