PREDICTION OF BONE LOSS IN PATIENTS WITH PRIMARY HYPERPARATHYROIDISM USING QUANTITATIVE BONE SPECT

Bone loss is a major complication of primary hyperparathyroidism (PHPT ), and it has significant implications in the treatment of this diseas e. Bone turnover was measured in patients with PHPT, using quantitativ e bone SPECT (QBS), to determine if the rate of bone loss could be pre dicted before a significant decrease in bone mass occurs. Methods: For ty-six patients were included in the study. QBS and bone mineral densi ty (BMD) of the lumbar spine (LS) and femoral neck (FN) were done at b aseline. The percent deviation of QBS in patients with PHPT from the v alues in normal matched controls was calculated. BMD was measured agai n after a mean of 17.5 mo in 38 patients, and in 29 patients a repeat BMD study was done after a mean of 41.4 mo. The change in BMD in patie nts with high and normal QBS values was compared using the nonparametr ic Mann-Whitney test. Regression analysis tested the correlation betwe en baseline QBS values and BMD changes over time. Results: For the FN, there was a statistically significant difference in the BMD change be tween patients with high and normal QBS values for short-term follow-u p (-2.82% +/- 4.80% versus 1.45% +/- 4.67%, p < 0.05) and for long-ter m follow-up (-3.53% +/- 5.34% versus 0.92% +/- 2.40, p < 0.02). There was a negative correlation in the FN, r = -0.48 between QBS values and the percentage of change in BMD. There was no significant difference between the percentage of change in BMD in the LS in patients with hig h and normal QBS values for either short- or long-term follow-up. Conc lusion: The results of this study show that QBS can predict bone loss in the FN in patients with PHPT. QBS can thus indicate the need for su rgery at an early stage of the disease to prevent bone loss.