Randomized controlled clinical trial of surgery versus no surgery in patients with mild asymptomatic primary hyperparathyroidism.

Parathyroidectomy is the definitive therapy for patients with symptomatic primary hyperparathyroidism. However, the role of surgery in mild asymptomatic primary hyperparathyroidism remains controversial. Accordingly, we conducted a prospective, randomized, controlled clinical trial of parathyroidectomy to determine the benefits of surgery vs. adverse effects of no surgery. Fifty-three patients were randomly assigned to either parathyroidectomy (n = 25) or regular follow-up (n = 28). Bone mineral density (BMD), biochemical indices of the disease, quality of life, and psychological function were measured at 6- or 12-month intervals for at least 24 months. Twenty-three of the 25 patients randomized to parathyroidectomy had surgery within the specified time of the protocol and three of the 28 patients randomized to regular follow-up had parathyroidectomy during follow-up. After parathyroidectomy, there was an increase in BMD of the spine (1.2%/yr, P < 0.001), femoral neck (0.4%/yr, P = 0.031), total hip (0.3%/yr, P = 0.07), and forearm (0.4%/yr, P < 0.001) and an expected fall in serum total and ionized calcium, serum PTH, and urine calcium (P < 0.001 for all). In contrast, patients followed up without surgery lost BMD at the femoral neck (-0.4%/yr, P = 0.117) and total hip (-0.6%/yr, P = 0.007) but gained at the spine (0.5%/yr; P = ns) and forearm (0.2%/yr, P = 0.047), with no significant changes in biochemical indices of disease. Consequently, a significant effect of parathyroidectomy on BMD was evident only at the femoral neck (a group difference of 0.8%/yr; P = 0.01) and total hip (a group difference of 1.0%/yr; P = 0.001) but not at the spine (a group difference of 0.6%/yr) or forearm (a group difference of 0.2%/yr). Quality-of-life scores as measured by a 36-item short-form health survey showed significant declines in five of the nine domains (social functioning, physical problem, emotional problem, energy, and health perception) in patients followed up without surgery but in only one of the nine domains (physical function) in the patients who had parathyroidectomy. Consequently, a modest measurable benefit of parathyroidectomy was evident in social and emotional role function (P = 0.007 and 0.012, respectively). Psychological function as assessed by the symptom checklist revised did not change significantly in either group, except for a significant decline in anxiety (P = 0.003) and phobia (P = 0.024) in patients who had surgery in comparison with those who did not. We conclude that it is feasible to conduct a randomized, controlled clinical trial of parathyroidectomy in patients with mild asymptomatic primary hyperparathyroidism, and measurable benefits of surgery on BMD, quality of life, and psychological function can be demonstrated. However, the small but significant benefits of parathyroidectomy must be weighed against the risks of surgery in these otherwise healthy individuals.

Role of vitamin D and calcium nutrition in disease expression and parathyroid tumor growth in primary hyperparathyroidism: a global perspective.

Since the classic description by Fuller Albright in the 1940s, primary hyperparathyroidism has evolved from a disease with classic signs and symptoms to a disease in search of symptoms! Since that time, two major events have occurred. First, in the United States, United Kingdom, and in most European countries, there has been a steady rise in the apparent incidence of the disease. Second, there has been a dramatic shift in the pattern of presentation. A majority of patients with primary hyperparathyroidism in countries with multichannel screening panels are asymptomatic. Skeletal and renal complications are uncommon, and osteitis fibrosa is rare. In contrast, the clinical presentation of primary hyperparathyroidism has changed very little in other regions such as the East, the Middle East, and some parts of the southern hemisphere over the same period of observation. Accordingly, we assessed the influence of vitamin D and calcium nutrition on the disease expression and parathyroid tumor growth in patients with primary hyperparathyroidism from different parts of the world. Between 1945 and 1950, both the prevalence of osteitis fibrosa and parathyroid tumor weight declined dramatically in the United States, coinciding with fortification of milk with vitamin D. In contrast, osteitis fibrosa and parathyroid tumor weight changed very little in parts of the world where vitamin D depletion is endemic. Furthermore, for a comparable degree of vitamin D depletion, Asian Indians have significantly larger tumors compared with Americans (3.95 +/- 2.23 vs. 0.66 +/- 2.84 g; p < 0.001). Within the United States, blacks have larger tumors compared with whites (0.78 +/- 2.87 vs. 0.58 +/- 2.78 g; p < 0.01). However, the slopes of regression between serum 25-hydroxyvitamin D, the best index of vitamin D nutrition, and parathyroid tumor weight, the best available index of parathyroid growth, were not significantly different between Asian Indians, whites, and blacks. We conclude that vitamin D and calcium nutrition of the population affect both the clinical expression and parathyroid tumor growth in patients with primary hyperparathyroidism. It will be of interest to see if the pattern of presentation of primary hyperparathyroidism changes when better nutritional policies are implemented in developing countries.