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Changes in Skeletal Microstructure Through Four Continuous Years of rhPTH(1–84) Therapy in Hypoparathyroidism
Author(s) -
Cusano Natalie E,
Rubin Mishaela R,
Williams John M,
Agarwal Sanchita,
Tabacco Gaia,
Tay Donovan,
Majeed Rukshana,
Omeragic Beatriz,
Bilezikian John P
Publication year - 2020
Publication title -
journal of bone and mineral research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.882
H-Index - 241
eISSN - 1523-4681
pISSN - 0884-0431
DOI - 10.1002/jbmr.4005
Subject(s) - medicine , quantitative computed tomography , hypoparathyroidism , bone mineral , femoral neck , urology , bone density , vitamin d and neurology , parathyroid hormone , nuclear medicine , osteoporosis , tibia , endocrinology , surgery , calcium
Bone remodeling is reduced in hypoparathyroidism, resulting in increased areal bone mineral density (BMD) by dual‐energy X‐ray absorptiometry (DXA) and abnormal skeletal indices by transiliac bone biopsy. We have now studied skeletal microstructure by high‐resolution peripheral quantitative computed tomography (HR‐pQCT) through 4 years of treatment with recombinant human PTH(1–84) (rhPTH[1–84]) in 33 patients with hypoparathyroidism (19 with postsurgical disease, 14 idiopathic). We calculated Z ‐scores for our cohort compared with previously published normative values. We report results at baseline and 1, 2, and 4 years of continuous therapy with rhPTH(1–84). The majority of patients (62%) took rhPTH(1–84) 100 μg every other day for the majority of the 4 years. At 48 months, areal bone density increased at the lumbar spine (+4.9% ± 0.9%) and femoral neck (+2.4% ± 0.9%), with declines at the total hip (−2.3% ± 0.8%) and ultradistal radius (−2.1% ± 0.7%) ( p < .05 for all). By HR‐pQCT, at the radius site, very similar to the ultradistal DXA site, total volumetric BMD declined from baseline but remained above normative values at 48 months ( Z ‐score + 0.56). Cortical volumetric BMD was lower than normative controls at baseline at the radius and tibia ( Z ‐scores −1.28 and − 1.69, respectively) and further declined at 48 months (−2.13 and − 2.56, respectively). Cortical porosity was higher than normative controls at baseline at the tibia ( Z ‐score + 0.72) and increased through 48 months of therapy at both sites ( Z ‐scores +1.80 and + 1.40, respectively). Failure load declined from baseline at both the radius and tibia, although remained higher than normative controls at 48 months ( Z ‐scores +1.71 and + 1.17, respectively). This is the first report of noninvasive high‐resolution imaging in a cohort of hypoparathyroid patients treated with any PTH therapy for this length of time. The results give insights into the effects of long‐term rhPTH(1–84) in hypoparathyroidism. © 2020 American Society for Bone and Mineral Research.