The risk of fractures in postmenopausal women with primary hyperparathyroidism

To evaluate the prevalence of vertebral (vFr) and non-vertebral (nvFr) fractures in postmenopausal women with primary hyperparathyroidism (PHPT).

We studied 98 patients with PHPT, divided into 'mild' (M, n = 25) and 'non-mild' (NM, n = 73) sub-groups, according to recently published guidelines (2002), and 89 healthy women (C) matched for age, years since menopause and body mass index. vFr was evaluated according to a visual semiquantitative method; bone mineral density (BMD) at the lumbar spine (LS), and femoral sites (femoral neck, FN and total femur, FT) was measured by dual energy X-ray absorptiometry. Volumetric BMD of the third lumbar vertebra (vBMDL3) was also calculated.

The prevalence of vFr was significantly higher (P < 0.001) in both M and NM PHPT patients compared with C; this prevalence did not differ between M and NM patients. BMD was significantly lower (P < 0.05) in NM patients compared with both C and M patients. BMD at LS in M patients was also significantly higher with respect to C. Similar results were also obtained for vBMDL3; in M patients, vBMDL3 was also significantly higher compared to C. When M and NM patients were subdivided according to the presence or lack of vFr, no difference was found between fractured and unfractured patients for either BMD or vBMDL3 values.

The risk of vFr is higher in postmenopausal patients with mild PHPT even if BMD appears well preserved. This finding suggests that other factors, such as bone quality, seem to be relevant in determining fracture risk, especially when gonadal function is lacking.