Asymptomatic primary hyperparathyroidism: preliminary results of a prospetive randomized study on the effect of parathyroidectomy
E Ambrogini1, L Cianferotti1, E Vignali1, F Cetani1, G Viccica1, A Picone1, P Miccoli2, A Pinchera1 & C Marcocci1
Aim of this 2-year, prospective, randomized study is to compare the effect of parathyroidectomy (PTX) vs no treatment in patients with asymptomatic primary hyperparathyroidism (PHPT), who didnt meet the 1991 NIH criteria for surgery. The study was approved by our local Ethical Committee. The primary endpoint was the change in lumbar spine bone mineral density (BMD); secondary endpoints were BMD changes at femur and distal radius, markers of bone turnover, quality of life and psychosocial well-being evaluation, echocardiographic parameters, complications of surgery and progression of the disesase in the untreated group. Forty-nine patients (45 women and 4 men) have been enrolled so far: 24 underwent PTX and 25 were not treated. We report the results in the 39 patients who completed the 1-year follow-up (18 trated with PTX and 21 untreatred). At baseline the 2 groups were similiar for age, biochemical parameters and BMD. PHPT persisted after surgery in one patient (excluded from the analysis). In the PTX-treated group lumbar spine and total femur BMD increased after one year by 4.3% and 2.5%, respectively, whereas in the untreated group they decreased by 1.3% and 2.3% respectively. The % changes were significantly different between the two groups (P<0.005 at both sites). No clinically meaningful changes in quality of life, psychosocial well-being and echocardiografic parameters were observed in the two groups. Seven of the 21 untreated patients (33%) had de novo appearance of at least one of the NIH criteria for surgery: worsening of hypercalcemia in 1, hypercalciuria in 4, worsening of cortical BMD in 2, kidney stone in 1 and clinical vertebral fracture in 1. Non-complications of surgery were observed. In conclusion our preliminary results suggest that PTX is advantageous in patients with asymptomatic PHPT since treated patients had significantly improved BMD at lumbar spine and femur compared to untreated ones and conservative follow-up was associated with progression of the disease in about one third of patients.