Endocrine Abstracts

Background and aims: Primary hyperparathyroidism (PHPT) often presents without classical symptoms such as overt skeletal disease or nephrolithiasis. Treatment strategies have been widely discussed. The objective of our research was to study the effect of parathyroidectomy (PTX) compared to observation (OBS) on skeletal outcomes such as bone mineral density (BMD).

Subjects and methods: A retrospective observational study was conducted between 1991 and 2014. 170 patients with PHPT who had baseline dual energy x-ray absorptiometry (DXA) and at least another one after 2 years of follow-up were included. Mean follow-up time was 6 years. PHPT was diagnosed when persistent hypercalcemia occurred with the presence of elevated or inappropriately normal parathyroid hormone levels. Clinical features were registered. Area based BMD was measured by at the lumbar (L2–L4) spine (LS), femoral neck (FN), total hip, and forearm at the radius 33% (Rad33).

Results: 112 patients were treated with PTX and 58 patients were under OBS. Patients under OBS were older than PTX group, mean age 68.8±12.1 years and 62.5±11.3 years respectively (P<0.005). More than 85% of patients in both groups were women. DXA after two years of surgical intervention showed a mean BMD change of 4.37% in LS, 3.9% in FN, and 2.72% in the total hip. Significantly higher than those presented at 2 years in the observation group (1.59% in LS, −0.19% FN, 0.14% CT) (P<0.005). In Rad33, BMD remained stable in the PTX group and decreased in OBS group (P=0.583). At 4 and 6 years, a positive effect of PTX was still observed with statistically significant improvements in the LS and FN (P<0.05). In total hip and Rad33, improvement was observed with PTX and worsening in the OBS group, but these differences were not statistically significant. It is important to note that 58% of patients in PTX group and 63.8% of patients in OBS group received treatment with drugs with bone activity, mainly bisphosphonates according to the criteria of their physician. Anyway it may have reduced, but not increased, the difference between groups.

Conclusions: In conclusion, PTX improves BMD and OBS leads to a small, but statistically significant decrease in BMD in FN. The surgical intervention does not involve significant changes in Rad33 BMD. Thus, bone health appears to be a clinical concern with long-term observation in patients with mild PHPT.