Changes in Bone Mineral Density After Parathyroidectomy and Their Relations With Biochemical Markers of Bone Metabolism

Background To measure total type 1 serum amino-terminal propeptide procollagen (t-P1NP), β- type 1 cross-linked C-terminal telopeptide collagen (β-CTX), N-terminal osteocalcin (OC), and 25-(OH)-VD3 levels before parathyroidectomy (PTX) in patients with PHPT, and correlate these measurements with bone mineral density (BMD) changes at 1-year post-PTX. Methods Patients with primary hyperparathyroidism (PHPT) were followed from diagnosis to 12 months after surgery. Serum levels of calcium, parathyroid hormone (PTH), vitamin 25-(OH)-VD3, OC, β-CTX, t-P1NP, and BMD were measured before and 1 year after surgery. Results One year after PTX, mean BMD increased by 25.7, 27.7, and 33.5% in the lumbar spine (L1-L4), femoral neck (FN), and greater trochanter (GT), respectively. Percent BMD change 1-year post-PTX was significant correlated with preoperative levels of β-CTX (L1-L4: r = 0.41 , P < 0.0001; FN: r = 0.54 , P = 0.0003; GT: r = 0.46 , P = 0.0029), t-P1NP (L1-L4: r = 0.58 , P < 0.0001; FN: r = 0.73 , P < 0.0001; GT: r = 0.65 , P < 0.0001), 25-(OH)-VD3 (L1-L4: r = −0.33 , P = 0.034; FN: r = −0.48 , P = 0.002; GT: r = −0.52 , P = 0.0007), and OC (L1-L4: r = 0.49 , P = 0.0013; FN: r = 0.55 , P = 0.0002; GT: r = 0.47 , P = 0.002). Conclusions Preoperative levels of turnover markers and BMD improvements were significantly correlated in patients with PHPT 1 year after PTX.