Primary hyperparathyroidism of postmenopausal women : Prospective population-based case-control analysis on prevalence, clinical findings and treatment

Abstract: The need of prospective studies on prevalence, clinical features and treatment of mild primary hyperparathyroidism (HPT) has been emphasised. Population-based screening was performed in 5 202 women attending screening mammography at 55-75 years of age. HPT was diagnosed in 2.1% of the women, and almost one third of them were normocalcemic. The demonstration of parathyroid pathology in 60 of 61 cases treated surgically suggested underestimation of the prevalence of HPT. Examination of the operatively excised parathyroid tissue showed quantitative rather than qualitative discrepancies between normocaldemic and hypercalcemic HPT, and that the hypercalcemic phase of the disorder may be preceded by a period of normocalcemia.Cases and matched controls from the screened population underwent extensive biochemical analyses, bone mass determination, and questionnaires on symptoms, illnesses and medications, and background variables. Despite that the cases were unaware of their biochemically mild HPT and appeared to be asymptomatic, the disorder was coupled to significant psychic complaints, bone loss, and several risk factors for cardiovascular diseases. Case-control analysis on sick leave before the diagnosis of HPT revealed an increased requirement of sickness benefits due mainly to cardiovascular diseases. These findings contradict suggestions on the innocuous nature of mild,asymptomatic HPT, and the generally rare indication for active treatment of the disease in the elderly.Treatment with parathyroid surgery, hormone replacement therapy (HRT), HRT combined with surgery, and conservative surveillance was evaluated prospectively during five years. Surgery was found to be the only treatment that normalised the investigated indices of the calcium homeostasis and made the cases and controls indistinguishable in this respect. Further analysis on the recorded symptoms and signs of HPT will display any clinically relevant benefits from this normalisation.