Bisfosfonatos podem minimizar a fome óssea após paratireoidectomia em pacientes com hiperparatireoidismo primário e osteíte fibrosa cística

Abstract

To assess the effect of bisphosphonates on post-parathyroidectomy hypocalcemia in patients with osteitis fibrosa cystica. Review of the medical records of six patients using bisphosphonates preoperatively. Mean age was 35.6 ± 10.5 years; serum calcium = 13.51 + 0.87 mg/dL; iPTH = 1,389 + 609 pg/mL. The mean value of urine deoxypyridinoline (UDPD) of three patients was 131 ± 183 nmol/mmol Cr, and of C-telopeptide (CTX), 2,253 ± 1,587 pg/mL. The mean values of bone densitometry (T score) were as follows: 0.673 ± 0.150 g/cm(2) (-4.42 ± 1.23) in lumbar spine (L2-L4); 0.456 ± 0.149 g/cm(2) (-5.58 ± 1.79) in the femoral neck; and 0.316 ± 0.055 g/cm(2) (-5.85 ± 0.53) in radius 33. Patient 1 received oral alendronate, 30 mg/day for four weeks; his calcium decreased from 14 to 11.6 mg/dL, and his UDPD from 342 to 160 nmol/mmol Cr. Patient 2 received oral alendronate, 20 mg/day for six weeks; his calcium decreased from 14 to 11.0 mg/dL and his UDPD from 28.8 to 14 nmol/mmol Cr. Patient 3 received intravenous pamidronate, 90 mg prior to surgery. Patient 4 received oral alendronate, 140 mg/week for six weeks; her calcium decreased from 13.7 to 12.3 mg/dL and her CTX from 2,160 to 1,340 pg/mL. Patient 5 received oral alendronate, 140 mg/ week for six weeks; her calcium levels dropped from 14.3 to 14.1 mg/dL; her CTX did not change. Patient 6 received ibandronate, 150 mg, ten days prior to surgery; his CTX reduced by 62%. No patient developed severe hypocalcemia in the first postoperative week. One year after surgery, the mean gain in bone mineral density was 40% ± 29% in L2-L4, 86 ± 39% in the femoral neck, and 22% ± 11% in radius 33. The preoperative use of bisphosphonates seems to attenuate bone hunger without preventing a significant increase in bone mass in the follow-up of parathyroidectomy.