Hyperparathyroidism: the limits of surgery in cases of bone or cardiovascular involvement

In primary hyperparathyroidism (PHPT), asymptomatic bone disease can be detected by bone densitometry. The bone mineral density is about 10% lower than normal control values, especially in the cortical radius. Without parathyroidectomy, bone mineral density is frequently stable, but a few patients, mostly postmenopausal women, have a significant decrease. Histology shows maintenance of trabecular connectivity but with an increase in cortical porosity. After parathyroidectomy, bone mineral density increases, particularly at the lumbar spine and femoral neck, and the benefit persists after 10 years. The fracture risk is controversial but risk of trabecular bone fracture may be higher than that for controls. The impact of PHPT on survival is also controversial, but highest quartile of serum calcium, osteoporosis, old age, and low lean mass are each associated with a death risk. There is also a debate about the criteria for distinguishing between asymptomatic and symptomatic PHPT and about the bone mineral density threshold that should be used as a basis to recommend surgery. The rate of progression of PHPT is slow but in some cases bone loss progresses, justifying bone mineral density follow-up. The frequency of inadequate follow-up and the cost of nonoperative follow-up are in favor of recommending surgery. With broader indications for surgery, it is mandatory to improve the biochemical diagnosis of PHPT.