Biochemical markers of bone turnover are influenced by recently sustained fracture.
ABSTRACT In striving to refine the clinical utility of different markers of bone metabolism, we should take into account numerous confounders, many of which are well known, such as sampling time, fasting status, and bone density. One further confounder may be ongoing fracture healing and/or post-fracture immobilization, which at least theoretically should impose an increased bone formation and resorption. Since both recent fracture and high bone turnover are independent predictors for new fracture, we thought it of importance to define the potential influence of such fracture on markers of bone turnover. From a population-based cohort of 1604 women, all 75 years old (the OPRA-study), 1024 women attended a clinical examination. The bone metabolism was assessed in serum, by three markers of bone formation [bone-specific alkaline phosphatase (S-Bone ALP), intact and N-Mid osteocalcin (S-Total OC), and total carboxylated osteocalcin (S-cOC)], two markers of bone resorption [C-terminal cross-linked telopeptides of type I collagen (S-CTX) and tartrate-resistant acid phosphatase type 5b (S-TRACP5b)], and in urine by one marker of bone resorption [deoxypyridinoline/creatinine (U-DPD/crea)] and two putative markers of bone resorption [urinary osteocalcins (U-OC/crea)]. Current physical activity and retrospective fracture data were recorded by questionnaires. The fracture data, for the entire cohort of 1604 women, were validated with radiographic referrals and reports, saved since the beginning of the last century. All data provided, except date of occurrence of retrospectively sustained fracture, were thus obtained cross-sectionally and in all women at the age of 75. Fracture had ever been sustained by 727 of the entire cohort (n = 1604), and by 523 of the attending women (n = 1024). All markers were marginally higher (significant only for U-DPD/crea, P = 0.027) in women who had ever sustained fracture, compared to women without fracture. In women with recent retrospective fracture (since 2 years) (n = 100), the levels of all markers, except the two S-OCs, were significantly higher (r = 0.20-0.33, P = 0.049-0.001) the more recently the fracture had been sustained. Women with low current physical activity had elevated levels of U-DPD/crea (P < 0.001) and one U-OC (P = 0.014), while the other markers were unaffected.
Full-textDOI: · Available from: Kaisa Ivaska, Dec 04, 2014
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ABSTRACT: Purpose The activity and metabolism of fracture healing can be monitored quantitatively by measuring bone turnover markers (BTMs) in serum or urine. However, in osteoporotic bone, the exact metabolism processes during the healing of metaphyseal fractures remain unknown. There is no diagnostic approach which currently allows dynamic insight into the fracture healing processes in order to monitor the progression of healing and to assist in therapeutic decision making. Methods Between March 2007 and February 2009, 30 patients over 50 years of age who suffered a metaphyseal fracture were included in our study. The levels of the osteoanabolic marker BAP (bone-specific alkaline phosphatase) and osteocatabolic marker β-CTX [crosslinked C-(CTX)-telopeptide-of-type-I-collagen] were monitored during the fracture healing of osteoporotic and nonosteoporotic fractures for a duration of 8 weeks. Results After an initial decrease of BAP in the first week, the BAP level steadily increased through the fourth week in both groups. The levels of BAP in the osteoporotic group surpassed the healthy group. β-CTX steadily increased in healthy bone up to the fourth week; in osteoporotic bone, β-CTX first increased and, thereafter, decreased from the first week onwards. Conclusions In this work, the first molecular biological aspects of osteoporotic fracture healing have been uncovered, helping to explain the mechanisms of delayed fracture healing in osteoporotic bone. The early decrease of reduced β-CTX as well as elevated BAP during the healing process may be the first aspects within the delayed healing of osteoporotic bone. Further studies are necessary in order to achieve more detailed insight to fracture healing and to ascertain the progression of fracture healing as being essential (criteria) for therapeutic decision making.European Journal of Trauma and Emergency Surgery 08/2012; 38(4). DOI:10.1007/s00068-012-0190-1 · 0.38 Impact Factor
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ABSTRACT: The incidence of osteoporotic fractures increases as our population ages. Until now, the exact biochemical processes that occur during the healing of metaphyseal fractures remain unclear. Diagnostic instruments that allow a dynamic insight into the fracture healing process are as yet unavailable. In the present matched pair analysis, we study the time course of the osteoanabolic markers bone specific alkaline phosphatase (BAP) and transforming growth factor β1 (TGFβ1), as well as the osteocatabolic markers crosslinked C-telopeptide of type-I-collagen (β-CTX) and serum band 5 tartrate-resistant acid phosphatase (TRAP5b), during the healing of fractures that have a low level of bone mineral density (BMD) compared with fractures that have a normal BMD. Between March 2007 and February 2009, 30 patients aged older than 50 years who suffered a metaphyseal fracture were included in our study. BMDs were verified by dual energy Xray absorptiometry (DXEA) scans. The levels of BTMs were examined over an 8-week period. Osteoanabolic BAP levels in those with low levels of BMD were significantly different from the BAP levels in those with normal BMD. BAP levels in the former group increased constantly, whereas the latter group showed an initial strong decrease in BAP followed by slowly rising values. Osteocatabolic β-CTX increased in the bone of the normal BMD group constantly, whereas these levels decreased significantly in the bone of the group with low BMD from the first week. TRAP5b was significantly reduced in the low level BMD group. With this work, we conduct first insights into the molecular biology of the fracture healing process in patients with low levels of BMD that explains the mechanism of its fracture healing. The results may be one reason for the reduced healing qualities in bones with low BMD.PLoS ONE 05/2014; 9(5):e96058. DOI:10.1371/journal.pone.0096058 · 3.53 Impact Factor