Higher serum levels of a cathepsin K-generated periostin fragment are associated with fractures in postmenopausal women with primary hyperparathyroidism: a pilot study

The only difference between fractured and non-fractured postmenopausal women with PHPT of same sex, age, and BMI was a significantly mean higher serum k-periostin level. K-periostin value was associated with fracture at any site (odds ratio 1.044, 95% CI 1.005-1.091, p = 0.03). Introduction To assess serum k-periostin fragment levels in patients with primary hyperparathyroidism (PHPT), fractured and non-fractured matched for sex, age, and body mass index. Methods Twenty-five Caucasian fractured postmenopausal women with PHPT (group Fx) and 25 PHPT non-fractured (group NFx) were enrolled. Each patient underwent DXA scan at lumbar, hip, and forearm, spine X-ray, and biochemical evaluation of calcium metabolism. For k-periostin analyses, we utilized a specific ELISA test that detects CatK-generated fragment levels in the bloodstream. Results We found no difference in mean BMD and bone turnover marker values between Fx and NFx groups. Prevalence of osteoporosis was not significantly different in Fx vs NFx (72% vs 60%, p = 0.55). Among Fx, 16% reported multiple fractures, 28% morphometric vertebral fractures, 4% femoral fractures, 28% non-vertebral non-femoral fractures, and 8% wrist fractures. The only detectable difference between Fx and NFx group was a significantly mean higher k-periostin serum level (46.2 +/- 21.4 vs 34.7 +/- 13.5 ng/ml, p = 0.02). K-periostin was associated with fracture at any site (odds ratio 1.044, 95% CI 1.005-1.091, p = 0.03). No difference in mean k-periostin values was found between patients with vertebral fracture vs those with non-vertebral fracture, and between those with multiple fractures vs those with single fracture. Conclusion Serum k-periostin is significantly associated with fracture in PHPT. If confirmed by further studies, k-periostin could be considered a new marker of bone fragility in PHPT, independently of BMD.

Automated summary

The study revealed a significant association between serum k-periostin levels and fractures in patients with primary hyperparathyroidism (PHPT), indicating potential for k-periostin to be a new marker of bone fragility in PHPT, independent of bone mineral density (BMD).