High bone turnover is associated with low bone mass and spinal fracture in postmenopausal women.

Abstract

A group of 366 healthy, white postmenopausal women, aged 50-81 years, mean age 66 years, were selected from the screened population of Scandinavians who were part of a multicenter study of the efficacy of tiludronate, a new bisphosphonate, in established postmenopausal osteoporosis. Eighty-eight women had a lumbar spine bone mineral density (BMD) above 0.860 g/cm2, and 278 women had a BMD below 0.860 g/cm2. Spinal fracture was diagnosed from lateral spine X-ray studies and defined as at least 20% height reduction (wedge, compression, or endplate fracture) in at least one vertebra (T4-L4). Bone resorption was assessed by measurement of the urinary excretion of type I collagen degradation products by the CrossLaps enzyme-linked immunoassay (ELISA). Bone formation was assessed by ELISA measurement of the N-terminal-midfragment as well as the intact serum osteocalcin (OCN-MID), thus omitting the influence of the instability of osteocalcin caused by the labile 6 amino acid C-terminal sequence. The women were divided into groups with high or low bone turnover according to the concentrations of urinary Cross-Laps or OCN-MID. Women in the quartiles with the highest concentrations of CrossLaps [519 +/- 119 micrograms/mmol (SD)] or OCN-MID [44.6 +/- 7.5 ng/ml (SD)] had 10-16% lower spinal BMD compared with women in the lowest quartiles (CrossLaps 170 +/- 48 micrograms/mmol (SD), and OCN-MID [22.1 +/- 3.0 ng/ml (SD)] (P < 0.0004). The prevalences of spinal fracture were 25 to 29% in the lowest quartiles, whereas the prevalences in the highest quartiles were almost double-53-54% (P < 0.006). If the women were subgrouped according to spinal BMD and prevalence of spinal fracture, corresponding results were found. Women with a BMD less than 0.860 g/cm2, without or with spinal fracture (n = 136 and n = 142), had 36-43% higher concentration of Cross-Laps (P = 0.0001) and 11-15% higher concentration of OCN-MID (P < 0.02), as compared with women with a BMD above 0.860 g/cm2 and no spinal fracture (n = 84). In conclusion, the results indicate a strong association among high bone turnover, low bone mass, and prevalence of spinal fracture, which supports the theory that high bone turnover is a risk factor for spinal fracture and osteoporosis.

• Authors: P Ravn, M Rix, H Andreassen, B Clemmesen, M Bidstrup, M Gunnes
• Journal: Calcified tissue international (Calcif Tissue Int) Vol. 60 Issue 3 Pg. 255-60 (Mar 1997) ISSN: 0171-967X [Print] United States
• PMID: 9069162 (Publication Type: Clinical Trial, Journal Article, Multicenter Study)

Chemical References

• Biomarkers
• Diphosphonates
• Reagent Kits, Diagnostic
• Osteocalcin
• tiludronic acid

Topics

• Aged
• Aged, 80 and over
• Biomarkers (analysis)
• Bone Density (drug effects, physiology)
• Bone Development (drug effects)
• Bone Resorption (physiopathology)
• Bone and Bones (drug effects, metabolism)
• Cross-Sectional Studies
• Diphosphonates (pharmacology, therapeutic use)
• Enzyme-Linked Immunosorbent Assay
• Female
• Humans
• Immunoassay
• Lumbar Vertebrae (injuries)
• Middle Aged
• Osteocalcin (blood, immunology)
• Osteoporosis, Postmenopausal (complications, drug therapy, physiopathology)
• Reagent Kits, Diagnostic
• Spinal Fractures (etiology, prevention & control)
• Thoracic Vertebrae (injuries)