What predicts early fracture or bone loss on bisphosphonate therapy?

Radiological Factors Associated with Bisphosphonate Treatment Failure and Their Impact on Fracture Healing in Postmenopausal Women with Osteoporotic Vertebral Fractures

(1) Background: Bisphosphonate treatment failure is one of the most difficult clinical problems for patients with osteoporosis. This study aimed to analyze the incidence of bisphosphonate treatment failure, associated radiological factors, and effect of fracture healing in postmenopausal women with osteoporotic vertebral fractures (OVFs). (2) Methods: A total of 300 postmenopausal patients with OVFs who were prescribed bisphosphonate were retrospectively analyzed and divided into two groups according to the treatment response: response (n = 116) and non-response (n = 184) groups. The radiological factors and the morphological patterns of OVFs were included in this study. (3) Results: The initial BMD values of the spine and femur in the non-response group were significantly lower than those in the response group (all Ps < 0.001). The initial BMD value of the spine (odd ratio = 1.962) and the fracture risk assessment tool (FRAX) hip (odd ratio = 1.32) showed statistical significance in logistic regression analysis, respectively (all Ps < 0.001). (4) Conclusions: The bisphosphonate non-responder group showed a greater decrease in BMD over time than the responder group. The initial BMD value of the spine and the FRAX hip could be considered radiological factors influencing bisphosphonate non-response in the postmenopausal patients with OVFs. The failure of bisphosphonate treatment for osteoporosis has a possible negative on the fracture healing process in OVFs.

Factors associated with inadequate responses to risedronate in Japanese patients with osteoporosis

Factors associated with an inadequate response (IR) to bisphosphonates have been reported in many countries, but not in Japan, where the approved dose is half the global dose. We analyzed factors associated with IR to risedronate in Japanese patients with osteoporosis. This was a post hoc analysis of 1261 Japanese osteoporosis patients who received risedronate for 1 year in phase III trials. IR was defined as more than one new vertebral fracture (VF) and/or negative change in lumbar spine bone mineral density (BMD) at 1 year. Various baseline and follow-up variables were examined for potential contribution to IR. Of the 1261 subjects, 118 exhibited an IR. At baseline, IR was associated with a higher BMD, lower levels of bone turnover markers (BTM) (serum bone-specific alkaline phosphatase, urinary N-terminal telopeptide of type 1 collagen and C-terminal telopeptide of type 1 collagen), and serum 25-hydroxyvitamin D [25(OH)D] below 16 ng/mL. BTM changes were blunted at 6 months in subjects with IR. On simple regression analysis, all the above variables and poor drug adherence were associated with an IR. On multivariate regression analysis, factors associated with IR were high BMD, vitamin D deficiency at baseline and low BTM at baseline, or a decreased BTM response at 6 months. Low serum 25(OH)D and BTM as well as high BMD at baseline were independent predictors of an IR to risedronate in Japan. These results emphasize the importance of the assessment of serum 25(OH)D and BTM in the management of osteoporosis with bisphosphonates.

Relationship between baseline characteristics and response to risedronate treatment for osteoporosis: data from three Japanese phase III trials

We evaluated the influence of baseline age, bone mineral density (BMD), and serum levels of vitamin D on the response to risedronate treatment. Risedronate consistently increased BMD, but our results suggest vitamin D supplementation may be necessary to achieve optimal treatment effect. Furthermore, early intervention may help prevent bone fractures.

INTRODUCTION

We aimed to investigate the influence of baseline age, BMD, and vitamin D insufficiency on the response to risedronate treatment.

METHODS

Data regarding 1447 patients was obtained from the registries of three phase III clinical trials of risedronate. The response to treatment was expressed in terms of BMD increase and occurrence of new vertebral fractures. The patients were stratified by baseline values for age (<65, 65-72, and ≥72 years), lumbar spine BMD T-score (osteoporotic, <-2.5; and non-osteoporotic, ≥- 2.5), and serum levels of 25-hydroxyvitamin D (deficient, <21 ng/mL; and non-deficient, ≥21 ng/mL).

RESULTS

Risedronate consistently increased lumbar spine BMD in all the groups, with similar percentage and absolute increments in all the age tertiles. The percentage, but not absolute, increment in BMD was significantly higher (p = 0.0003) in the osteoporotic than that in the non-osteoporotic patients (baseline). Of the 1330 patients whose baseline serum levels of 25-hydroxyvitamin D were available, 44.7% had vitamin D deficiency (<20 ng/mL), while 89.2% had insufficiency (<30 ng/mL). The percentage and absolute increments in BMD were lower (p < 0.05 and p < 0.01, respectively) in the vitamin D-deficient than those in the non-deficient patients. New vertebral fractures occurred in 1.5 and 0.8% of the osteoporotic and non-osteoporotic patients, respectively (end of the treatment).

CONCLUSIONS

Therapeutic response in elderly patients is consistent, but early initiation of risedronate treatment may help prevent fractures. Risedronate-induced increase in BMD is lower in patients with vitamin D deficiency, suggesting that vitamin D supplementation is important to achieve optimal treatment response.

Proportion and Characteristics of Patients in Sweden Remaining at High Risk of Fracture Despite Prior Treatment

PURPOSE

Fragility fractures are a clinical consequence of osteoporosis (OP). Evidence suggests however, current OP treatments may be inadequate in reducing fracture risk. The purpose of this study was to estimate the proportion and characteristics of Swedish patients who remain at high risk of fracture after 2 years of treatment, as evidenced by osteoporotic bone mineral density (BMD), a decrease in BMD, or the occurrence of new fractures.

METHODS

This was a retrospective, descriptive analysis of a subset of participants obtained from a Swedish osteoporosis patient registry from 1991 to 2009. Patients were required to be osteoporotic, to be treatment naive at baseline, to have returned for at least 1 follow-up visit, and to have reported osteoporosis treatment use for ≥2 years after the baseline visit with a BMD T score. Two overlapping cohorts remaining at high risk of fracture were defined using the BMD T score measured after 2 years of treatment from baseline. The osteoporosis cohort comprised patients who remained osteoporotic, whereas the BMD decrease cohort included patients whose total hip or lumbar spine T score decreased by ≥3%.

FINDINGS

A total of 3292 osteoporotic patients were identified in the registry, of whom 392 met the study inclusion criteria. The mean (SD) patient age was 68.3 (8.5) years, with most patients being female (92.3%). Among all patients, 297 (75.8%) remained osteoporotic after at least 2 years of treatment, 90 (23.0%) experienced a BMD decrease of ≥3%, and 23 (5.9%) reported an incident fracture between the baseline and first follow-up visit. More than three-quarters (76.8%) of all patients reported taking bisphosphonates, whereas only 72.4% and 47.8% reported this in the osteoporosis and BMD decrease cohorts, respectively. Raloxifene was the only nonbisphosphonate used, with 24.2% of all patients reportedly taking it.

IMPLICATIONS

This study highlighted that despite 2 years of osteoporosis treatment, a high percentage of patients remain at high risk of fracture. There is a need for improved treatment strategies that reduce fracture risk and improve patient outcomes in the real-world setting.

Incidence and Predictors of Multiple Fractures Despite High Adherence to Oral Bisphosphonates: A Binational Population-Based Cohort Study

Oral bisphosphonates (BPs) are highly effective in preventing fractures and are recommended first-line therapies for patients with osteoporosis. We identified the incidence and predictors of oral BP treatment failure, defined as the incidence of two or more fractures while on treatment (≥2 FWOT) among users with high adherence. Fractures were considered from 6 months after treatment initiation and up to 6 months after discontinuation. Data from computerized records and pharmacy invoices were obtained from Sistema d'Informació per al Desenvolupament de l'Investigació en Atenció Primària (SIDIAP; Catalonia, Spain) and Danish Health Registries (Denmark) for all incident users of oral BPs in 2006-2007 and 2000-2001, respectively. Fine and Gray survival models using backward-stepwise selection (p-entry 0.049; p- exit 0.10) and accounting for the competing risk of therapy cessation were used to identify predictors of ≥2 FWOT among patients having persisted with treatment ≥6 months with overall medication possession ratio (MPR) ≥80%. Incidence of ≥2 FWOT was 2.4 (95% confidence interval [CI], 1.8 to 3.2) and 1.7 (95% CI, 1.2 to 2.2) per 1000 patient-years (PYs) within Catalonia and Denmark, respectively. Older age was predictive of ≥2 FWOT in both Catalonian and Danish cohorts: subhazard ratio (SHR) = 2.28 (95% CI, 1.11 to 4.68) and SHR = 2.61 (95% CI, 0.98 to 6.95), respectively, for 65 to <80 years; and SHR = 3.19 (95% CI, 1.33 to 7.69) and SHR = 4.88 (95% CI, 1.74 to 13.7), respectively, for ≥80 years. Further significant predictors of ≥2 FWOT identified within only one cohort were dementia, SHR = 4.46 (95% CI, 1.02 to 19.4) (SIDIAP); and history of recent or older fracture, SHR = 3.40 (95% CI, 1.50 to 7.68) and SHR = 2.08 (95% CI: 1.04-4.15), respectively (Denmark). Even among highly adherent users of oral BP therapy, a minority sustain multiple fractures while on treatment. Older age was predictive of increased risk within both study populations, as was history of recent/old fracture and dementia within one but not both populations. Additional and/or alternative strategies should be investigated for these patients.

Factors associated with bisphosphonate treatment failure in postmenopausal women with primary osteoporosis

Among 97 postmenopausal women with primary osteoporosis, adequate calcium and vitamin D supplementation, and good compliance to a 36-month bisphosphonate treatment, the 25.8% of patients are inadequate responders. Current smoking and a bone turnover in the upper part of the normal range increase the risk of treatment failure.

INTRODUCTION

To evaluate the prevalence of the bisphosphonate treatment failure and its possible associated factors in women with primary osteoporosis (PO).

METHODS

We studied 97 previously untreated postmenopausal women with PO and fragility fractures and/or a FRAX® 10-year probability of a major osteoporotic fracture ≥ 7.5%, before and after a 36-month treatment with alendronate or risedronate and adequate vitamin D supplementation with good compliance. At baseline and after 36 months, lumbar spine (LS) and femoral bone mineral density (BMD) were assessed by Dual X-ray absorptiometry and vertebral fractures by spinal radiographs. Spinal deformity index (SDI) was calculated. Treatment failure was defined by the presence of ≥ 2 incident fragility fractures and/or a BMD decrease greater than the least significant change.

RESULTS

Bisphosphonate treatment failure was observed in 25.8% of patients. Age, body mass index, years since menopause, familiar history of hip fracture, number of falls, type of bisphosphonate used, 25-hydroxyvitamin D levels (25OHVitD), BMD, SDI, and FRAX® score at baseline were not different between responders and inadequate responders. Treatment failure was associated with current smoking (OR 3.22, 95% CI 1.10-9.50, P = 0.034) and baseline alkaline phosphatase total activity levels ≥ 66.5 U/L (OR 4.22, 95% CI 1.48-12.01, P = 0.007), regardless of age, number of falls, LS BMD, and baseline SDI.

CONCLUSIONS

The 25.8 % of PO postmenopausal women inadequately responds to bisphosphonates, despite a good compliance to therapy and normal 25OHVitD levels. The current smoking and bone turnover in the upper part of the normal range are associated with the inadequate response to bisphosphonates.

Risk factors for prediction of inadequate response to antiresorptives

Some patients sustain fractures while on antiresorptives. Whether this represents an inadequate response (IR) to treatment or a chance event has not been elucidated. We performed a study to identify which patients are more likely to fracture while on treatment. This is a multicentric, cross-sectional study of postmenopausal women on antiresorptives for osteoporosis in 12 Spanish hospitals, classified as adequate responders (ARs) if on treatment with antiresorptives for 5 years with no incident fractures or inadequate responders (IRs) if an incident fracture occurred between 1 and 5 years on treatment. Poor compliance, secondary osteoporosis, and previous anti-osteoporosis treatment other than the assessed were exclusion criteria. Clinical, demographic, analytical, dual-energy X-ray absorptiometry (DXA) variables, and proximal femur structure analysis (ImaTx™) and structural/fractal analyses of distal radius were performed. A total of 179 women (76 IRs; mean (SD): age 68.2 (9.0) years; 103 ARs, age 68.5 (7.9) years) were included. History of prior fracture (p = 0.005), two or more falls in the previous year (p = 0.032), low lumbar spine bone mineral density (BMD) (p = 0.02), 25 hydroxyvitamin D (p = 0.017), and hip ImaTx fracture load index (p = 0.004) were associated with IR. In the logistic regression models a fracture before treatment (odds ratio [OR], 3.60; 95% confidence interval [CI], 1.47-8.82; p = 0.005) and levels of 25 hydroxyvitamin D below 20 ng/mL (OR, 3.89; 95% CI, 1.55-9.77; p = 0.004) significantly increased risk for IR, while increased ImaTx fracture load (OR, 0.96; 95% CI, 0.93-0.99; p = 0.006; per every 100 units) was protective, although the latter became not significant when all three variables were fitted into the model. Therefore, we can infer that severity of the disease, with microarchitectural and structure deterioration, as shown by previous fracture and hip analysis, and low levels of 25 hydroxy vitamin D carry higher risk of inadequate response to antiresorptives. More potent regimes should be developed and adequate supplementation implemented to solve this problem.

Risk factors for hip fracture in older home care clients

BACKGROUND

Little information is available on hip fracture risks among community-dwelling persons receiving home care. Our aim was to identify risk factors for hip fracture from health information routinely collected for older home care clients.

METHODS

This was a cohort study involving secondary analysis of data on 40,279 long-stay (>60 days) home care clients aged 65 and older in Ontario, Canada; occurrence of hip fracture as well as potential risk factor information were measured using the Resident Assessment Instrument (RAI)/Minimum Data Set-Home Care assessment instrument.

RESULTS

In all, 1,003 clients (2.5%) had hip fracture on follow-up assessment. Older (85+ vs 65-74, relative risk [95% confidence interval]: 0.52 [0.43-0.64]) clients are at increased risk; males are at reduced risk [0.60 (0.51-0.70)]. Other risk factors include osteoporosis (1.19 [1.03-1.36]), falls (1.31 [1.15-1.49]), unsteady gait (1.18 [1.03-1.36]), use of ambulation aide (1.39 [1.21-1.59]), tobacco use (1.42, [1.13-1.80]), severe malnutrition (2.61 [1.67-4.08]), and cognitive impairment (1.30 [1.12-1.51]). Arthritis (0.86 [0.76-0.98]) and morbid obesity (0.34 [0.16-0.72]) were associated with reduced risk. Males and females demonstrated different risk profiles.

CONCLUSIONS

Important risk factors for hip fracture can be identified from routinely collected data; these could be used to identify at-risk clients for further investigation and prevention strategies.

Inadequate responders to osteoporosis treatment: proposal for an operational definition

The concept of inadequate response to osteoporosis treatment is not clear. In the literature several criteria have been used. We propose an operational definition of an inadequate responder based on the changes observed in bone mineral density and incident fractures while on therapy.

INTRODUCTION

Fractures may occur in compliant patients even while on active treatment. These cases have been defined as inadequate responders (IR).

METHODS

We reviewed the basis for this concept and propose an operational definition for IR.

RESULTS

Good compliance and adequate calcium and vitamin D supplementation are the first requirement. The second requirement is a treatment period of at least 1 year, since before that time treatment may not have been fully effective. Fractures are the gold standard for measuring efficacy and changes in bone density and turnover markers may be surrogates. We propose classifying patient response as: Inadequate--incident fracture and a decrease in BMD greater than a significant change (Trend Assessment Margin or TAM); Possibly inadequate--incident fracture or a decrease in BMD greater than a significant change (TAM); and Appropriate--no fracture and no decrease in BMD greater than a significant change (TAM). Additional criteria (biochemical markers, bone quality parameters) may be taken into account.

CONCLUSION

A wide consensus on the IR concept is required given its clinical, regulatory, and reimbursement implications.

Assessing response to osteoporosis therapy

Patients treated with pharmacological agents to improve bone strength and reduce fracture risk may not achieve optimal skeletal benefit for reasons that include poor compliance and persistence, inadequate calcium and vitamin D intake, malabsorption, and medications or co-morbidities with adverse skeletal effects. Monitoring the effects of therapy can inform the patient and physician that the drug is having its expected skeletal response. Treatment is often monitored with serial bone mineral density (BMD) measurements using dual-energy X-ray absorptiometry or bone turnover markers (BTMs). Stable or increasing BMD is associated with reduced fracture risk in clinical trials, and is considered an indication of good response to therapy in individual patients outside of clinical trials. There are many differences between subjects in clinical trials and patients being treated in clinical practice. Thus, although defining a clinical practice patient as a "nonresponder" or "suboptimal responder" to treatment is problematic, a pragmatic approach would be to consider evaluation for contributing factors and possible changes in therapy in patients who have a statistically significant decrease in BMD, do not have the expected change in BTMs, or have a fracture.

Alendronate for the primary and secondary prevention of osteoporotic fractures in postmenopausal women

BACKGROUND

Osteoporosis is an abnormal reduction in bone mass and bone deterioration leading to increased fracture risk. Alendronate belongs to the bisphosphonate class of drugs, which act to inhibit bone resorption by interfering with the activity of osteoclasts.

OBJECTIVES

To assess the efficacy of alendronate in the primary and secondary prevention of osteoporotic fractures in postmenopausal women.

SEARCH STRATEGY

We searched CENTRAL, MEDLINE and EMBASE for relevant randomized controlled trials published between 1966 to 2007.

SELECTION CRITERIA

Women receiving at least one year of alendronate, for postmenopausal osteoporosis, were compared to those receiving placebo and/or concurrent calcium/vitamin D. The outcome was fracture incidence.

DATA COLLECTION AND ANALYSIS

We undertook study selection and data abstraction in duplicate. We performed meta-analysis of fracture outcomes using relative risks and a > 15% relative change was considered clinically important. We assessed study quality through reporting of allocation concealment, blinding and withdrawals.

MAIN RESULTS

Eleven trials representing 12,068 women were included in the review. Relative (RRR) and absolute (ARR) risk reductions for the 10 mg dose were as follows. For vertebral fractures, a significant 45% RRR was found (RR 0.55, 95% CI 0.45 to 0.67). This was significant for both primary prevention, with 45% RRR (RR 0.55, 95% CI 0.38 to 0.80) and 2% ARR, and secondary prevention with 45% RRR (RR 0.55, 95% CI 0.43 to 0.69) and 6% ARR. For non-vertebral fractures, a significant 16% RRR was found (RR 0.84, 95% CI 0.74 to 0.94). This was significant for secondary prevention, with 23% RRR (RR 0.77, 95% CI 0.64 to 0.92) and 2% ARR, but not for primary prevention (RR 0.89, 95% CI 0.76 to 1.04). There was a significant 40% RRR in hip fractures (RR 0.60, 95% CI 0.40 to 0.92), but only secondary prevention was significant with 53% RRR (RR 0.47, 95% CI 0.26 to 0.85) and 1% ARR. The only significance found for wrist was in secondary prevention, with a 50% RRR (RR 0.50 95% CI 0.34 to 0.73) and 2% ARR. For adverse events, we found no statistically significant differences in any included study. However, observational data raise concerns regarding potential risk for upper gastrointestinal injury and, less commonly, osteonecrosis of the jaw.

AUTHORS' CONCLUSIONS

At 10 mg per day, both clinically important and statistically significant reductions in vertebral, non-vertebral, hip and wrist fractures were observed for secondary prevention ('gold' level evidence, www.cochranemsk.org). We found no statistically significant results for primary prevention, with the exception of vertebral fractures, for which the reduction was clinically important ('gold' level evidence).