Introduction: In primary hyperparathyroidism (PHPT) bone involvement is frequent. In women with PHPT it has been previously reported that menopausal status together with PTH, calcium levels and renal function are independent predictors of bone density. In male subjects, the impact of PHPT on bone status is less defined.
Aim of the study: To investigate this study was possible predictors of bone mineral density (BMD) in a series of male subjects affected by PHPT.
Subjects and methods: Sixty male patients with PHPT were consecutively studied (age, mean±S.D.: 57.9±14.1 years; Symptomatic/Asymptomatic 32/28; PTH, median and interquartile levels: 119 and 95.0228 pg/ml, calcium 11.1±1.0 mg/dl). In all subjects BMI, levels of calcium, PTH, 25 hydroxy-vitamin D, creatinine and creatinine clearance and bone mineral density (BMD) at lumbar spine, femur and distal radius by DXA were evaluated.
Results: A positive association between BMI and DXA measurement at femoral levels was found (BMI-BMD: R=0.52, P<0.004; BMI-T score: R=0.53, P<0.002; BMI-Z score: R=0.55, P<0.002). On the contrary, neither PTH, calcium, renal function nor 25-hydroxy-vitamin D showed significative correlation with BMD levels.
Conclusions: BMI resulted a good predictor of BMD in male patients with PHPT as found in women with PHPT, confirming the important role of BMI as risk factor for bone damage in osteoporosis of both primary and secondary origin. On the contrary, biochemical indices of PHPT as well as renal function did not associate with DXA measures in male patients, differently from female. These findings could indicate gender-dependent differences in the clinical expression of PHPT, particularly at bone level. A peculiar resistance of male bone to PTH excess in PHPT could be also hypothesized. These findings suggest that the clinical management of the modern form of PHPT should be differently by gender.