Primary hyperparathyroidism: biochemical markers and bone mineral density at multiple skeletal sites in Danish patients.

Biochemical bone markers and bone mineral density (BMD) in spine, hip, and forearm were measured, before surgery, in 30 patients with mild to moderate primary hyperparathyroidism (PHP) (25 women and 5 men; mean age 54 +/- 12 years, range 26-73 years) and compared with normal controls. A group of 291 healthy adults (181 women and 110 men) served as controls for BMD. A smaller group of 30 normal individuals (25 women and 5 men; mean age 54 +/- 12 years; range 26-74 years) were used as matched normal controls. Parameters of bone formation (s-osteocalcin, s-alkaline phosphatase activity, and s-bone isoenzyme alkaline phosphatase activity) and bone resorption (s-type-1 collagen telopeptide) were considerably increased in patients with PHP compared with normal controls (p < 0.01 for all parameters). BMD was found to be reduced in the hip (trochanteric: 95.1 +/- 14.7% of expected, p < 0.05; intertrochanteric: 95.2 +/- 13.8% of expected, p < 0.05), and the forearm (proximal: 93.3 +/- 12.2% of expected, p < 0.05; mid: 91.8 +/- 11.6% of expected, p < 0.001; distal: 90.7 +/- 13.1% of expected, p < 0.001). Spine BMD was found significantly reduced in premenopausal (87.8 +/- 7.6% of expected, p < 0.05) but not in postmenopausal patients, and although normal women showed a decrease in spinal BMD with increasing age this was not found in the PHP women. Forearm BMD was reduced in both pre- and postmenopausal patients (distal forearm: 86.7 +/- 12.2% of expected, p < 0.05; 87.6 +/- 12.1% of expected, p < 0.01, respectively). It was concluded that Danish patients with mild or moderate PHP have only small reductions in BMD. The bone loss is mainly found in the appendicular skeleton.