Site-Specific Difference of Bone Geometry Indices in Hypoparathyroid Patients.
BACKGROUND
Hypoparathyroid patients often have a higher bone mineral density (BMD) than the general population. However, an increase in BMD does not necessarily correlate with a solid bone microstructure. This study aimed to evaluate the bone microstructure of hypoparathyroid patients by using hip structure analysis (HSA).


METHODS
Ninety-five hypoparathyroid patients >20 years old were enrolled and 31 of them had eligible data for analyzing bone geometry parameters using HSA. And among the control data, we extracted sex-, age-, and body mass index-matched three control subjects to each patient. The BMD data were reviewed retrospectively and the bone geometry parameters of the patients were analyzed by HSA.


RESULTS
The mean Z-scores of hypoparathyroid patients at the lumbar spine, femoral neck, and total hip were above zero (0.63±1.17, 0.48±1.13, and 0.62±1.10, respectively). The differences in bone geometric parameters were site specific. At the femoral neck and intertrochanter, the cross-sectional area (CSA) and cortical thickness (C.th) were higher, whereas the buckling ratio (BR) was lower than in controls. However, those trends were opposite at the femoral shaft; that is, the CSA and C.th were low and the BR was high.


CONCLUSIONS
Our study shows the site-specific effects of hypoparathyroidism on the bone. Differences in bone components, marrow composition, or modeling based bone formation may explain these findings. However, further studies are warranted to investigate the mechanism, and its relation to fracture risk.
Division of Endocrinology and Metabolism, Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea.
Hye Sun
HS
Park
Division of Endocrinology and Metabolism, Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea.
Da Hea
DH
Seo
Division of Endocrinology and Metabolism, Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea.
Yumie
Y
Rhee
Division of Endocrinology and Metabolism, Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea. lsk@yuhs.ac.
Sung Kil
http://orcid.org/0000-0002-2734-7341
SK
Lim
Bone density; Bone geometry; Hypoparathyroidism; Parathyroid hormone