Bone quality determined by Fourier transform infrared imaging analysis in mild primary hyperparathyroidism.
BACKGROUND
Mild primary hyperparathyroidism (PHPT) is characterized by asymptomatic hypercalcemia, most commonly in the absence of classical signs and symptoms. Hence, there is need to characterize this disorder with particular attention to the skeleton.


METHODS
We determined the ratio of pyridinium and dehydrodihydroxylysinonorleucine collagen cross-links in 46 iliac crest bone biopsies from patients with PHPT (14 men, aged 28-68 yr; 32 women, aged 26-74 yr) by Fourier transform infrared imaging. The results were compared with previously reported collagen cross-links ratio determined in iliac crest biopsies from normal subjects.


RESULTS
PHPT patients exhibited significantly lower pyridinium to dehydrodihydroxylysinonorleucine collagen cross-links ratio, compared with normal controls. Parathyroidectomy restored values to those comparable with normal controls. Moreover, the differences among PHPT subjects were gender dependent, with female PHPT patients having a statistically significant lower ratio, compared with either male PHPT patients or normal controls. Comparison of the obtained outcomes with histomorphometry showed that the collagen cross-link ratio was strongly correlated with rate of bone formation, and mineralizing surface, in individual patients. This ratio was also correlated with bone mineralization density distribution parameters obtained in the same patients. The strongest correlations were with bone mineralization density distribution variables reflecting heterogeneity of mineralization and primary mineralization parameters.


CONCLUSIONS
The results are consistent with the high turnover state manifested in PHPT patients. Reduced collagen cross-link ratio in patients with PHPT would be expected to reduce the stiffness of bone tissue. These observations provide a more complete assessment of bone material properties in this disorder.
Zoehrer
Ruth
R
Ludwig Boltzmann Institute of Osteology, Hanusch Hospital of WGKK (Social Health Insurance Vienna), Vienna, Austria.
Dempster
David W
DW
Bilezikian
John P
JP
Zhou
Hua
H
Silverberg
Shonni J
SJ
Shane
Elizabeth
E
Roschger
Paul
P
Paschalis
Eleftherios P
EP
Klaushofer
Klaus
K
D000328:Adult; D000368:Aged; D001706:Biopsy; D016723:Bone Remodeling / Q000502:physiology; D001842:Bone and Bones / Q000737:chemistry / Q000000981:diagnostic imaging* / Q000473:pathology; D002113:Calcification, Physiologic / Q000502:physiology; D015331:Cohort Studies; D003094:Collagen / Q000737:chemistry; D003952:Diagnostic Imaging / Q000379:methods; D004151:Dipeptides / Q000032:analysis; D018450:Disease Progression; D005260:Female; D006801:Humans; D049950:Hyperparathyroidism, Primary / Q000000981:diagnostic imaging* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D011726:Pyridinium Compounds / Q000032:analysis; D011786:Quality Control; D011859:Radiography; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods
D004151:Dipeptides; D011726:Pyridinium Compounds; C007235:delta-6-dehydro-5,5'-dihydroxylysylnorleucine; D003094:Collagen