Primary Hyperparathyroidism - Aspects on skeletal Involvemnt and PTH levels after Surgery.

The aim of this thesis was to evaluate risk factors for fractures in patients with primary hyperparathyroidism (pHPT), to study the association between preoperative variables and postoperative changes in bone density and to investigate long-term changes and peripheral PTH sensitivity in patients with elevated PTH levels after surgery. 203 pHPT patients were investigated with regard to clinical and biochemical variables and bone density. Serum levels of 25(OH)D3 and PTH, were the only variables independently associated with a risk of bone fracture. Thirteen patients with pHPT were investigated with a PTH infusion test six weeks after surgery. During the PTH-infusion test we found that patients with raised PTH had signs of decreased peripheral sensitivity to PTH with attenuated calcemic response. 99 pHPT patients were followed five years after surgery. 16% of the patients had elevated PTH levels. One group of patients that demonstrated fluctuation between normal and elevated PTH levels showed signs of renal insufficiency. In this group of patients, an increased risk for recurrent disease is postulated and long time surveillance could be suggested. Bone mass was investigated before and one year after surgery in 126 pHPT patients. Postmenopausal women had lower bone density compared to premenopausal women. 40-50% of all patients improved in bone density after surgery. It was not possible to predict the increase in bone mass. Considering that 18 % respectively 61% of patients had signs of vitamin D and calcium deficiency, we suggest that pHPT patients could be considered for calcium and vitamin D supplement postoperatively