Effect of co-morbidities on fracture risk: findings from the Global Longitudinal Study of Osteoporosis in Women (GLOW)

Five-year fracture risk estimation in patients with Parkinson's disease

BACKGROUND

Previous studies have shown that patients with Parkinson's disease (PD) are at increased risk of fractures. However, no specific prediction model for fracture estimation among PD patients is currently available. Therefore, the aim of this study was to develop a simple score for estimating the 5-year osteoporotic and hip fracture risks among patients with PD.

METHODS

The U.K. Clinical Practice Research Datalink (1987-2011) was used to identify incident PD patients. Cox proportional-hazards models were used to calculate the 5-year risks of osteoporotic and hip fracture among PD patients. The regression model was fitted with various risk factors for fracture and the final Cox model was converted into integer risk scores.

RESULTS

We identified 4411 incident PD patients without a history of osteoporotic treatment. The 5-year risks of osteoporotic and hip fracture were plotted in relation to the risk score. Risk scores increased with age, female gender, history of renal disease and history of dementia. The C-statistic, which is a parameter to test the internal validity of the model, was reasonable for the prediction of osteoporotic fracture (0.69) and hip fracture (0.73).

CONCLUSION

In this study, we developed a simple model to estimate 5-year fracture risk among incident PD patients. It may be useful in daily practice after external validation.

Randomized, double-blind, placebo-controlled trial of vitamin D supplementation in Parkinson disease

BACKGROUND

In our previous study, higher serum 25-hydroxyvitamin D [25(OH)D] concentrations and the vitamin D receptor (VDR) FokI CC genotype were associated with milder Parkinson disease (PD).

OBJECTIVE

We evaluated whether vitamin D3 supplementation inhibits the progression of PD on the basis of patient VDR subgroups.

DESIGN

Patients with PD (n = 114) were randomly assigned to receive vitamin D3 supplements (n = 56; 1200 IU/d) or a placebo (n = 58) for 12 mo in a double-blind setting. Outcomes were clinical changes from baseline and the percentage of patients who showed no worsening of the modified Hoehn and Yahr (HY) stage and Unified Parkinson's Disease Rating Scale (UPDRS).

RESULTS

Compared with the placebo, vitamin D3 significantly prevented the deterioration of the HY stage in patients [difference between groups: P = 0.005; mean ± SD change within vitamin D3 group: +0.02 ± 0.62 (P = 0.79); change within placebo group: +0.33 ± 0.70 (P = 0.0006)]. Interaction analyses showed that VDR FokI genotypes modified the effect of vitamin D3 on changes in the HY stage (P-interaction = 0.045), UPDRS total (P-interaction = 0.039), and UPDRS part II (P-interaction = 0.021). Compared with the placebo, vitamin D3 significantly prevented deterioration of the HY stage in patients with FokI TT [difference between groups: P = 0.009; change within vitamin D3 group: -0.38 ± 0.48 (P = 0.91); change within placebo group, +0.63 ± 0.77 (P = 0.009)] and FokI CT [difference between groups: P = 0.020; change within vitamin D3 group: ±0.00 ± 0.60 (P = 0.78); change within placebo group: +0.37 ± 0.74 (P = 0.014)] but not FokI CC. Similar trends were observed in UPDRS total and part II.

CONCLUSION

Vitamin D3 supplementation may stabilize PD for a short period in patients with FokI TT or CT genotypes without triggering hypercalcemia, although this effect may be nonspecific for PD. This trial was registered at UMIN Clinical Trials Registry as UMIN000001841.

Multiple sclerosis and fracture

Multiple sclerosis (MS) is a chronic, inflammatory, demyelinating central nervous system disease with time and space disseminated lesions that usually occurs in young adults, typically aged between 20 and 45 years. Recently, researches have indicated MS may be associated with increased risk of fracture and osteoporosis. In this review, we aim to identify the fracture risk in MS patients, also address the pathogenic mechanisms and interventions of fracture in those patients.

Clinical and economic characteristics of hip fracture patients with and without muscle atrophy/weakness in the United States

This retrospective analysis of hip fracture patients with and without muscle atrophy/weakness (MAW) revealed that those with MAW had significantly higher healthcare utilization and costs compared with hip fracture patients without MAW.

PURPOSE

Examine the demographics, clinical characteristics, and healthcare resource utilization and costs of hip fracture patients with and without MAW.

METHODS

Using a large US claims database, individuals who were newly hospitalized for hip fracture between 1 Jan 2006 and 30 September 2009 were identified. Patients aged 50-64 years with commercial insurance (Commercial) or 65+ years with Medicare supplemental insurance (Medicare) were included. The first hospitalization for hip fracture was defined as the index stay. Patients were categorized into three cohorts: patients with medical claims associated with MAW over the 12 months before the index stay (pre-MAW), patients whose first MAW claim occurred during or over the 12 months after the index stay (post-MAW), and patients without any MAW claim (no-MAW). Multivariate regressions were performed to assess the association between MAW and healthcare costs over the 12-month post-index period, as well as the probability of re-hospitalization.

RESULTS

There were 26,122 Medicare (pre-MAW, 839; post-MAW, 2,761; no-MAW, 22,522) and 5,100 Commercial (pre-MAW, 132; post-MAW, 394; no-MAW, 4,574) hip fracture patients included in this study. Controlling for cross-cohort differences, both the pre-MAW and post-MAW cohorts had significantly higher total healthcare costs (Medicare, $7,308 and $18,753 higher; Commercial, $18,679 and $25,495 higher) than the no-MAW cohort (all p < 0.05) over the 12-month post-index period. The post-MAW cohort in both populations was also more likely to have any all-cause or fracture-related re-hospitalization during the 12-month post-index period.

CONCLUSIONS

Among US patients with hip fractures, those with MAW had higher healthcare utilization and costs than patients without MAW.

Assessing fracture risk in people with MS: a service development study comparing three fracture risk scoring systems

OBJECTIVES

Suboptimal bone health is increasingly recognised as an important cause of morbidity. Multiple sclerosis (MS) has been consistently associated with an increased risk of osteoporosis and fracture. Various fracture risk screening tools have been developed, two of which are in routine use and a further one is MS-specific. We set out to compare the results obtained by these in the MS clinic population.

DESIGN

This was a service development study. The 10-year risk estimates of any fracture and hip fracture generated by each of the algorithms were compared.

SETTING

The MS clinic at the Royal London Hospital.

PARTICIPANTS

88 patients with a confirmed diagnosis of MS.

OUTCOME MEASURES

Mean 10-year overall fracture risk and hip fracture risk were calculated using each of the three fracture risk calculators. The number of interventions that would be required as a result of using each of these tools was also compared.

RESULTS

Mean 10-year fracture risk was 4.7%, 2.3% and 7.6% using FRAX, QFracture and the MS-specific calculator, respectively (p<0.0001 for difference). The agreement between risk scoring tools was poor at all levels of fracture risk.

CONCLUSIONS

The agreement between these three fracture risk scoring tools is poor in the MS population. Further work is required to develop and validate an accurate fracture risk scoring system for use in MS.

TRIAL REGISTRATION

This service development study was approved by the Clinical Effectiveness Department at Barts Health NHS Trust (project registration number 156/12).

Association between cardiovascular diseases and osteoporosis-reappraisal

Positive association between cardiovascular diseases and osteoporosis is important because it concerns two major public health problems. Men and women with cardiovascular diseases (including severe abdominal aortic calcification (AAC) and peripheral arterial disease) tend to have lower areal and volumetric bone mineral density (BMD) as well as faster bone loss, although findings vary according to skeletal site. On one hand, severe forms of cardiovascular diseases (heart failure, myocardial infarction, hypertension, severe AAC) are associated with higher risk of osteoporotic fracture, especially hip fracture. This link was found in the studies based on healthcare databases and the cohort studies. On the other hand, low BMD, history of fragility fracture, vitamin D deficit and increased bone resorption are associated with higher risk of major cardiovascular events (myocardial infraction, stroke, cardiovascular mortality). Moreover, osteocalcin secreted by osteoblasts may be involved in the regulation of energetic and cardiovascular metabolism. The association between both pathologies depends partially on the shared risk factors, and also on the mechanisms that are involved in the regulation of bone and cardiovascular metabolism. Interpretation of the data should take into account methodological limitations: representativeness of the cohorts, quality of the registers and the information obtained from questionnaires, severity of diseases, number of events (statistical power) and their temporal closeness, availability of the information on potential confounders. It seems that patients with severe form of osteoporosis would benefit from assessment of the cardiovascular status and vice versa. However, official guidelines for the clinical practice are still lacking.

Potential Extensions of the US FRAX Algorithm

To determine if the revised US FRAX can identify those at high risk for fractures at any skeletal site, we studied 250 women and 249 men ≥40 years old from an age-stratified random sample of Rochester, MN residents. At baseline, femoral neck (FN) bone density was assessed, as were the clinical risk factors included in FRAX, along with additional fracture risk factors such as bone turnover markers and fall history. Fracture ascertainment through periodic interviews and comprehensive medical record review was performed over 10 years of followup. In both women and men, a higher FRAX probability at baseline was associated with greater subsequent likelihood of a major osteoporotic fracture. However, a relative 10% increase in the FRAX 10-year fracture probability was also associated with a 1.4-fold increase (95% confidence interval (CI) 1.1-1.7) in other fractures in women and a 1.7-fold increase (95% CI 0.8-3.1) in men. Furthermore, FRAX predicted asymptomatic vertebral fractures and fractures generally in both sexes. The addition of risk factors not currently included in FRAX did not appear to improve the accuracy of fracture risk prediction. FRAX may provide a conservative estimate of risk for major osteoporotic fractures, but it also predicts fractures generally.