Sydney Lou Bonnick | PubMed Health

PubMed2006

Monitoring osteoporosis therapy: bone mineral density, bone turnover markers, or both?

Monitoring the efficacy associated with antiresorptive therapy is an intuitive yet integral part of successful osteoporosis management. Although response rates to bisphosphonates in clinical trials--as judged by changes in bone mineral density (BMD)--are generally high, a small percentage of compliant patients do not respond. Accordingly, monitoring may help identify noncompliant patients and allow for other, possibly more successful, therapeutic interventions. Dual energy x-ray absorptiometry is the accepted method of assessing BMD to determine the need for treatment and to monitor its effects. Change in BMD is considered a valid intermediate end point for efficacy of fracture risk reduction. However, clinical trials have shown that the reduction in fracture risk associated with antiresorptive therapy may occur before changes in BMD become apparent. Vertebral fracture benefit is observed even among women who maintain rather than gain BMD during antiresorptive therapy. Clinical trials show that suppression of bone turnover markers after as little as 3 months of therapy is strongly associated with reductions in risk for fracture. Although formal guidelines for monitoring bone turnover markers do not yet exist, there are data to suggest that changes in these markers are valid intermediate endpoints for efficacy of fracture risk reduction that may provide valuable additional data on therapeutic success, particularly early in treatment and before changes in BMD become apparent.

Aged↗

PubMed2004

Response to therapy with once-weekly alendronate 70 mg compared to once-weekly risedronate 35 mg in the treatment of postmenopausal osteoporosis.

OBJECTIVE: The FACT study (Fosamax Actonel Comparison Trial) was a 1-year-head-to-head trial comparing the efficacy and tolerability of once weekly (DW) alendronate 70 mg and OW risedronate 35 mg for the treatment of postmenopausal osteoporosis. The present analysis was performed to determine the percentage of patients who had changes during the study in BMD and biochemical markers (BCMs) of bone turnover above or below specific cut-off points. A subgroup analysis of upper gastrointestinal (UGI) tolerability was also performed. RESEARCH DESIGN AND METHODS: 1053 postmenopausal women with low BMD were randomized to alendronate 70 mg OW (N = 520) or risedronate 35 mg OW (N = 533). The percentage of patients who had measured BMD gains > or = 3%, and > or = 5% after 12 months at the hip trochanter, total hip, femoral neck, and lumbar spine (LS) was analyzed. The percentage of patients who experienced any bone loss, and those with measured losses of 3% or more at these sites after 12 months, was determined. The percentage of patients achieving reductions in urinary N-telopeptide of type 1 human collagen (NTX) > or = 40%, and serum C-telopeptide of type 1 collagen (CTx) > or = 60%, bone-specific phosphatase (BSAP) > or = 30%, and N terminal propeptide of type 1 procollagen (P1NP) > or = 50% at 3 months and 12 months was also determined. Tolerability, based on adverse experience reporting, was evaluated in a subgroup of patients with history of UGI disorders at baseline. RESULTS: A greater percentage of alendronate- than risedronate-treated patients had measured BMD gains (> or = 0%) (p < 0.05) at all sites at 12 months. Significantly more (p < 0.01) alendronate- than risedronate-treated patients had measured gains in BMD > or = 3% and > or = 5% at the hip trochanter, total hip, and LS spine. Significantly more (p < 0.05) risedronate- than alendronate-treated patients had an apparent loss of BMD (> 0% and > or = 3% loss) at the same sites. After 3 months, significantly (p < 0.001) more alendronate- than risedronate- treated patients achieved predefined reductions in all BCMs. Similar tolerability was demonstrated in both treatment groups, regardless of whether or not patients had a history of UGI disorders at baseline. CONCLUSIONS: Significantly more alendronate- than risedronate-treated patients achieved predefined increases in BMD at 12 months and reductions in BCMs at 3 months. Significantly more risedronate- than alendronate-treated patients were classified as apparent 'non-responders' (i.e. experienced any bone loss) after 12 months of therapy. The tolerability profiles of the two medications were similar.

Administration, Oral↗

PubMed2002

Current controversies in bone densitometry.

In the face of increasing use of all types of bone densitometry in the diagnosis and management of osteoporosis, the limitations of the World Health Organization criteria for the diagnosis of osteoporosis based on bone density measurements have become apparent. Controversy has arisen about whether these criteria should be used for the diagnosis of osteoporosis. Using densitometry to monitor changes in bone density as a measure of therapeutic efficacy has been criticized. It has been suggested that changes in bone density are not surrogates for reduction in fracture risk and that regression to the mean invalidates serial testing. There is both truth and fallacy in these controversies. The resolutions are critical to the role of densitometry in clinical practice.

Absorptiometry, Photon↗