Bone turnover markers urinary hydroxyproline

A 2-year randomized controlled study in 90 women compared the effects of oral tibolone doses of 1.25 mg/day and 2.5 mg/day on bone loss in the early postmenopausal period all took calcium 1000 mg/day. Vertebral and femoral bone density rose in both treated groups but fell in the control group, and bone turnover markers (urinary excretion of hydroxyproline/creatinine and plasma osteocalcin concentrations) were similarly affected favorably in the treated groups, as was the incidence of hot flushes/ flashes (5). Studies such as this still leave open the question of the advisability of continuing tibolone treatment over a longer period. While tibolone has indeed been shown to benefit mineral bone density, few data are available to show whether it lowers fracture incidence nor is it clear whether there is a link between tibolone and breast cancer (6). 

Alkaline phosphatase is a marker for bone formation. Urinary hydroxyproline is a marker for bone resorption. Better markers for bone turnover are being evaiuated. Osteomaiacia due to vitamin D deficiency can be confirmed by finding a iow... 

The AHRQ Report summarized numerous studies that evaluated the effects of soy products, including both protein and isoflavones, on various markers of bone health, such as bone mineral density (BMD) and biomarkers related to bone formation (bone-specific alkaline phosphatase and osteocalcin) and resorption (urinary hydroxyproline, urinary pyridinoline, and urinary deoxypyridinoline). In general, no effect of soy consumption on BMD or on biomarkers of bone formation resulted. Although a number of studies observed reductions in markers of bone resorption, these were restricted to only two biomarkers urinary pyridinoline and deoxypyridinoline. Moreover, the effects were not consistent across studies. The AHRQ report found no consistent evidence of dose-response effects for either soy isoflavones or soy protein on markers of bone turnover (Balk et al., 2005). 

Paget s disease (Table 35.6) is characterized by excessive bone resorption, followed by replacement of the normally mineralized bone with soft, poorly mineralized tissue (20). It has been determined that the osteoclasts have an abnormal structure, are hyperactive, and are present at elevated levels (20). Patients afflicted with this painful condition often suffer from multiple compression fractures. Administration of calcitonin and oral calcium and phosphate supplements had been the treatment of choice until the bisphosphonate risedronate was approved by the U.S. Food and Drug Administration (FDA). Daily administration of risedronate results in a decreased rate of bone turnover and a decrease in the levels of serum alkaline phosphatase and urinary hydroxyproline, two biochemical markers of bone turnover (4,20). A significant advantage to treatment with the bisphosphonates is long-term suppression of the disease (20). Calcium supplementation, which often is necessary in these patients, must be dosed separately from risedronate, because calcium- and aluminum- or... 

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