Primary hyperparathyroidism: Whole-body bone mineral density in surgicallytreated Danish patients: A three-year follow-up study

Whole-body bone mineral density (BMD) and body composition were measured be fore surgery in 25 patients (20 women and 5 men, aged 53 +/- 13 years, rang e 26-73 years) with mild to moderate primary hyperparathyroidism (PHPT) and compared with 25 controls exactly matched with respect to age, gender, and menopausal status. Fifteen pairs of matched patients and controls were ree xamined 3 years later (5 men and 10 women, aged 53 +/- 12 years in both gro ups), In the untreated PHPT patients, whole-body BMD was 95.4% +/- 10.5% (S D) of control BMD (p < 0.05), Body weight and height, body mass index, whol e-body fat mass, and lean body mass did not differ significantly between th e groups. Relative to values in matched controls, whole-body bone mineral c ontent (BMC) and BMD increased by 4.4% and 3.0%, respectively, in PHPT pati ents (p < 0.005) during the 3-year follow-up. Neither whole-body BMC nor BM D differed between patients and controls after the 3-year follow-up. A posi tive correlation was observed between initial serum calcium levels and the 3-year increase in whole-body BMD (r(s) = 0.645, p < 0.01). Baseline serum osteocalcin, serum pyridinoline crosslinked telopeptide of Type I collagen and several histomorphometric indices of trabecular bone turnover (eroded a nd labeled surfaces, bone formation rate, and activation frequency) also co rrelated positively with the subsequent increase in whole-body BMD, Six pat ients disclosed transient postoperative secondary hyperparathyroidism, prob ably due to hungry bones. Four of these patients completed 3 years of follo w-up and had higher increases in whole-body BMD than the remaining normo-pa rathyroid patients (7.9% +/- 4.5%, range 4.3-14.3% versus 1.9% +/- 2.1%, p < 0.01). It is concluded that Danish patients with mild to moderate PHPT on ly reveal small reductions in whole-body mineral density. Furthermore, with in 3 years after parathyroid surgery, most of the lost bone mineral is rega ined even in patients with initial high bone turnover. Finally, PHPT in the se patients is not associated with substantial changes in body compositions . (C) 1999 by Elsevier Science Inc. All rights reserved.