Natural history of primary hyperparathyroidism.

Primary hyperparathyroidism has evolved into a disorder that is largely asymptomatic. Nevertheless, there is ample evidence of target organ effects even in asymptomatic patients. Recent data suggest that the disease is stable in most asymptomatic patients. Little change is observed in biochemical parameters or bone mineral density over time. A subgroup of asymptomatic patients shows biochemical evidence of disease progression, although, in the author's series, no overt clinical complications developed. Surgical cure is associated with biochemical normalization and increased bone density. Several important questions remain: What are the neuropsychiatric and cardiovascular features of the disease? Are these features progressive over time, and do they regress with cure? What implications do any cardiovascular manifestations have on mortality? Is there an increase in fractures associated with mild asymptomatic disease? Is there an increase in fractures at more cortical sites, with a decrease in vertebral fractures in affected postmenopausal women? Although ongoing targeted research should answer some of these questions, a large multicenter trial is necessary to provide the data needed concerning the natural history of primary hyperparathyroidism.