Abstract / Summary
Background: A substantial portion of surgically treated patients with primary hyperparathyroidism (pHPT) are older than 65 years. The indication for parathyroidectomy in older patients with pHPT and mild hypercalcaemia is unclear. Specifically, it is not known whether parathyroid surgery improves bone mineral density (BMD) in this age group.
Method: Patients 65 years or older with pHPT, ionized calcium not exceeding 1.50 mmol/l, and a BMD Z-score above -2.5 standard deviations who were referred to the Department of Surgery, Lund University Hospital, were included in the study. Follow-up was performed over 2 years. The random allocation sequence to surgery or observation was computer generated. There was no blinding. Primary outcome was BMD of the hip, with the primary endpoint being the change in total hip BMD from baseline to the end of follow-up. Secondary outcome was BMD of the lumbar spine. Continuous variables were analysed using Satterthwaite's t-test. Intention-to-treat analysis of change from baseline was performed using a mixed-model repeated-measures ANOVA (MMRM ANOVA).
Results: A total of 255 patients were screened and 102 were randomized: 50 to observation and 52 to surgery. The median age was 71 (range 65-85) years. For analysis of the primary endpoint, 41 patients in the surgery group and 40 in the observation group were available. Total hip BMD at 2 years increased by a mean of 1.3% (95% confidence interval -0.2% to 2.8%) in the surgery group and decreased by a mean of -1.4% (-2.6% to -0.2%) in the control group (P = 0.006). Analysis of total hip BMD at the end of follow-up by MMRM ANOVA showed a difference between the two groups of patients (P = 0.006). BMD of the lumbar spine increased by a mean of 4.6% (3.0% to 6.1%) in the surgery group versus 0.2% (-1.1% to 1.4%) in the observation group (P < 0.001). Analysis of lumbar spine BMD at the end of follow-up by MMRM ANOVA showed a difference between the two groups of patients (P < 0.001).
Conclusion: At the 2-year follow-up, patients 65 years or older with pHPT and mild hypercalcaemia demonstrated a slight increase in BMD after parathyroidectomy.
Registration number: NCT01087619 (http://www.clinicaltrials.gov).