Novel advances in the treatment of osteoporosis

INTRODUCTION

Osteoporosis is a significant public health issue affecting over half of women aged over 50. With an aging population, its importance is set to increase further over time. Prevention of fragility fractures avoids significant mortality and morbidity as well as saving significant direct and indirect costs to the economy. In this review, we discuss existing treatments to contextualize the treatment landscape, and demonstrate how our understanding of bone pathophysiology has led to novel therapies-in the form of combinations and altered durations of existing treatments, as well as newer drug therapies.

SOURCES OF DATA

PubMed and Embase were searched for randomized controlled trials of new therapies for osteoporosis. These searches were supplemented with material presented in abstract form at international meetings.

AREAS OF AGREEMENT

New drugs that appear promising in the treatment of osteoporosis include the cathepsin K inhibitor, monoclonal antibodies against sclerostin and parathyroid hormone-related protein analog.

AREAS OF CONTROVERSY

Separate to the development of novel drug therapies is the issue of how best to use agents that are currently available to us; specifically which agent to choose, alone or in combination; duration of therapy; how best to identify patients at highest risk of fracture, and to ensure the highest possible adherence to medication. Many of these issues have been addressed in other excellent review papers, and will not be considered in detail here.

GROWING POINTS

As with all new treatments, we await results of long-term use and experience in 'real life' patient populations.

AREAS TIMELY FOR DEVELOPING RESEARCH

As alluded to above, data are urgently required regarding the optimal duration of therapy; use of combination therapy; ordering of therapies for best therapeutic effect. As stratified medicine becomes more strongly considered in all areas of therapy, its merits in osteoporosis as in other musculoskeletal conditions, is timely and valuable.

Genetic and treatment-related risk factors associated with external apical root resorption (EARR) concurrent with orthodontia

OBJECTIVE

As genetic variation accounts for two-thirds of the variation in external apical root resorption (EARR) concurrent with orthodontic treatment, we analyzed the association of selected genetic and treatment-related factors with EARR concurrent with orthodontic treatment.

SETTING AND SAMPLE POPULATION

This case-control study of 134 unrelated, orthodontically treated Caucasian individuals was conducted in part at an Indiana Private Practice, Indiana University and the University of Kentucky.

METHODS

Utilizing a research data bank containing information from ~1450 orthodontically treated patients, pre- and post-treatment radiographs from 460 individuals were evaluated for EARR of the four permanent maxillary incisors. Sixty-seven unrelated Caucasians with moderate to severe EARR were identified and were age-/sex-matched with orthodontically treated Caucasian controls yielding 38 females and 29 males per group. Factors tested for an association with EARR included the following: 1) treatment duration, 2) extraction of maxillary premolars, 3) numerous cephalometric measurements, and 4) DNA polymorphisms within/near candidate genes in a pathway previously implicated in EARR such as the purinergic-receptor-P2X, ligand-gated ion channel 7 (P2RX7; rs208294, rs1718119, and rs2230912), caspase-1 (CASP1; rs530537, rs580253, and rs554344), interleukin-1 beta (IL1B; rs1143634), interleukin-1 alpha (IL1A; rs1800587), and interleukin-1 receptor antagonist (IL1RA; rs419598) genes. Stepwise logistic regression was utilized to identify the factors significantly associated (significance taken at or less than the layered Bonferroni correction alpha) with the occurrence of EARR.

RESULTS

A long length of treatment and the presence of specific genotypes for P2RX7 SNP rs208294 were significantly associated with EARR.

CONCLUSION

EARR occurrence was associated with both genetic and treatment-related variables, which together explained 25% of the total variation associated with EARR in the sample tested.

An audit of the management of childhood-onset growth hormone deficiency during young adulthood in Scotland

Background

Adolescents with childhood onset growth hormone deficiency (CO-GHD) require re-evaluation of their growth hormone (GH) axis on attainment of final height to determine eligibility for adult GH therapy (rhGH).

Aim

Retrospective multicentre review of management of young adults with CO-GHD in four paediatric centres in Scotland during transition.

Patients

Medical records of 130 eligible CO-GHD adolescents (78 males), who attained final height between 2005 and 2013 were reviewed. Median (range) age at initial diagnosis of CO-GHD was 10.7 years (0.1–16.4) with a stimulated GH peak of 2.3 μg/l (0.1–6.5). Median age at initiation of rhGH was 10.8 years (0.4–17.0).

Results

Of the 130 CO-GHD adolescents, 74/130(57 %) had GH axis re-evaluation by stimulation tests /IGF-1 measurements. Of those, 61/74 (82 %) remained GHD with 51/74 (69 %) restarting adult rhGH. Predictors of persistent GHD included an organic hypothalamic-pituitary disorder and multiple pituitary hormone deficiencies (MPHD). Of the remaining 56/130 (43 %) patients who were not re-tested, 34/56 (61 %) were transferred to adult services on rhGH without biochemical retesting and 32/34 of these had MPHD. The proportion of adults who were offered rhGH without biochemical re-testing in the four centres ranged between 10 and 50 % of their total cohort.

Conclusions

A substantial proportion of adults with CO-GHD remain GHD, particularly those with MPHD and most opt for treatment with rhGH. Despite clinical guidelines, there is significant variation in the management of CO-GHD in young adulthood across Scotland.

Are there dangers in biologic dose reduction strategies?

Biologic dose reduction strategies, for patients with inflammatory rheumatic diseases, have been assessed in multiple studies to assess outcomes compared to ongoing maintenance dosing. Whilst cessation in established disease usually leads to disease flare, dose tapering approaches for those achieving low disease activity often appear to be successful in the short term. However, tapering can be associated with a higher risk of losing disease control and rates of recapture of disease control using the original biologic dose vary between studies. Over relatively short periods of follow-up, a number of studies have shown no statistical difference in radiographic progression in patients tapering or discontinuing biologics. However, a Cochrane review found that radiographic and functional outcomes may be worse after TNF inhibitor discontinuation, and over long-term disease follow-up flares have been associated with radiographic progression and worse patient reported outcomes. To date, no studies of biological therapy dose reduction have specifically investigated the risk of increased immunogenicity or the effects on cardiovascular risk and other co-morbidities, although these remain important potential risks. In addition, whether there are greater dangers in certain dose reduction approaches such as a reduction in dose at the same frequency or a spacing of doses is not established.

Gamification of Learning Deactivates the Default Mode Network

We hypothesized that embedding educational learning in a game would improve learning outcomes, with increased engagement and recruitment of cognitive resources evidenced by increased activation of working memory network (WMN) and deactivation of default mode network (DMN) regions. In an fMRI study, we compared activity during periods of learning in three conditions that were increasingly game-like: Study-only (when periods of learning were followed by an exemplar question together with its correct answer), Self-quizzing (when periods of learning were followed by a multiple choice question in return for a fixed number of points) and Game-based (when, following each period of learning, participants competed with a peer to answer the question for escalating, uncertain rewards). DMN hubs deactivated as conditions became more game-like, alongside greater self-reported engagement and, in the Game-based condition, higher learning scores. These changes did not occur with any detectable increase in WMN activity. Additionally, ventral striatal activation was associated with responding to questions and receiving positive question feedback. Results support the significance of DMN deactivation for educational learning, and are aligned with recent evidence suggesting DMN and WMN activity may not always be anti-correlated.

Prioritizing investment in public health and health equity: what can commissioners do?

OBJECTIVES

To explore commissioners' views on prioritizing for investment in health. This study reviewed: methods for decision support; their relevance for prioritizing health and health equity in principle; and their adoption by decision makers in practice.

METHODS

Decision makers' views were sought through semi-structured interviews and an online survey, and prioritization tools were reviewed. Interviews were held in 2008-2009 with a subsample followed up in 2009-2010. In late 2009, a national online survey was sent to 508 individuals across 146 primary care trusts (PCTs). The two phases of the interviews comprised 52 and 17 participants, respectively. Responses to the national survey were received from 138 decision makers in 95 (65%) PCTs. Prioritization tools were identified through interviews and the survey as above, a rapid review of literature and in consultation with health economists. A grounded theory approach was adopted for the qualitative interview analysis.

RESULTS

Although most PCTs used a prioritization framework, few of the tools identified in this review were used by public health commissioners. This was partly a consequence of limitations of priority-setting tools in the context of public health investment, and partly a lack of relevant skills and data. Tensions in relation to developing strategies for disinvestment and in prioritizing a long-term public health agenda in a context of economic austerity were evident.

CONCLUSIONS

The context for decision making appears to be more important than the deployment of specific tools and techniques. Commissioners need to recognize the limitations of priority-setting tools, but also know how to apply them to help maximize health gain and health equity over the longer term. Decision-support tools should be developed in collaboration with public health commissioners to ensure relevance and practicality of use.

Impact of inflammatory bowel disease on pubertal growth

BACKGROUND

Puberty is thought to be commonly affected in adolescents with inflammatory bowel disease (IBD).

AIMS

To determine the impact of Crohn's disease (CD) and ulcerative colitis (UC) on the pubertal growth spurt.

METHODS

Retrospective study of 30 boys with CD (CD-M), 11 girls with CD (CD-F), 14 boys with UC (UC-M) and 12 girls with UC (UC-F). Pubertal growth was assessed by calculating peak height velocity SDS (PHV SDS), height SDS at diagnosis (Ht(Diag)) and height SDS at PHV (Ht(PHV)) and age at PHV (Age(PHV)). Systemic markers of disease activity were also collected.

RESULTS

Altered parameters of pubertal growth were observed in the CD groups compared to the normal population: in the CD-M group, median Ht(Diag) was -0.56 (p = 0.001) and median Age(PHV) was 14.45 years (p = 0.004), and in the CD-F group, median Ht(Diag) was -1.14 (p = 0.007) and Ht(PHV) was -0.79 (p = 0.039). Individually, 8/30 CD-M cases had one or more parameter affected: 2 boys had Ht(Diag )<-2, 3 boys had Ht(PHV) <-2, 2 boys had an Age(PHV) >2 years above population mean, and 2 boys had a PHV SDS <-2. In the whole group, Age(PHV) showed an association with erythrocyte sedimentation rate (r = 0.4; p = 0.005) and an inverse association with BMI (r = 0.4; p = 0.001).

CONCLUSION

Disorders of pubertal growth are more likely to occur in CD and, particularly, in boys.

Effect of testosterone therapy for delayed growth and puberty in boys with inflammatory bowel disease

BACKGROUND

pubertal delay and growth retardation are common in children with inflammatory bowel disease (IBD).

AIMS

To assess pubertal status and growth in a group of boys with IBD undergoing testosterone therapy for pubertal induction.

METHODS

retrospective study of height, weight and pubertal status in 8 boys with IBD before and after testosterone therapy. Height velocity (HV) over the 6 months before each assessment was converted to standard deviation score. Markers of disease activity and concomitant medication were recorded. Response was based on an advance in pubertal status and a greater than 50% increase in HV.

RESULTS

eight boys with IBD, median age 14.8 years, had pubertal induction using either monthly injections of 50 mg Sustanon or daily 2.5/5 mg Andropatch. Seven boys showed an advance of pubertal status. Six boys had a greater than 50% increase in HV; median HV at T0 was 1.6 cm/year (0, 5) compared with 6.9 cm/year (1, 11.7) at T6 (p = 0.005). C-reactive protein during testosterone therapy had a significant association with HV at T6 (r = -0.786; p = 0.021).

CONCLUSION

in most cases, testosterone therapy in boys with IBD and delayed growth and puberty is associated with an advance in pubertal status and an improvement in growth.

Oesophageal xanthalasma with Barrett's Oesophagus and Menetrier's Disease

This case report describes three conditions; oesophageal xanthalasma, Menetrier’s disease and Barrett’s oesophagus, none of which have ever been seen together, diagnosed in one patient. Further to the details of the case the endoscopic, radiological and histological findings are discussed. Any links between these three conditions are currently unclear.

The Influence of W Filament Alloying on the Electronic Properties of Hwcvd Deposited a-Si:H Films

In depositing a-Si:H by HWCVD using W filaments, one issue common to this technique is that of filament lifetime. When using undiluted silane as the source gas, a buildup of silicon at the colder ends of the filament is routinely observed (thickening), and it is here that filament breakage usually occurs. Less well understood is the effect of filament alloy formation on a-Si:H electronic properties. In this work we combine ambipolar diffusion length (SSPG) measurements on consecutively deposited a-Si:H films with SEM surface topography and sputter (SP) Auger depth profiling of the filament Si/(W+Si) composition to track film electronic properties as a function of the Si buildup on short filaments entirely exposed to the growing film surface. We find that with increasing exposure time of the filament to silane, appreciable Si exists everywhere along the filament length, even in the non-thickened central regions. We discuss the effect of this alloying on the film deposition rate and electronic properties, and suggest that the nature of the filament surface must be carefully considered when optimizing a- Si:H film electronic properties. Finally, we discuss possible ways to minimize this alloying by post deposition treatments, which include different filament ‘run’ temperatures.

Hydrogenated Amorphous Silicon Germanium Alloys Grown by the Hot-Wire Chemical Vapor Deposition Technique

We successfully grow high-quality hydrogenated amorphous-silicon-germanium alloys (a-SiGe:H) by the hot-wire chemical-vapor deposition (HWCVD) technique using silane and germane gas mixtures. These alloys display electronic properties as good as those grown by the plasma-enhanced chemical-vapor deposition (PECVD) technique, when comparing materials with the same optical bandgaps. However, we grow materials with good electrical properties at high deposition rates—up to 40 Å/s, compared to 1–4 Å/s for PECVD materials. Our alloys exhibit similar trends with increasing Ge content to alloys grown by PECVD. The defect density, the dark conductivity, and the degree of nanostructural heterogeneity (as measured by small-angle X-ray scattering) all increase with increasing germanium content in the alloy. The nanostructural heterogeneity displays a sharp transition between 9 at.% and 14 at.% germanium. PECVD- grown a-SiGe:H alloys exhibit a similar transition at 20 at.% Ge. The photoconductivity and the ambipolar diffusion length of the alloys decrease with increasing germanium content. For a fixed silane-to-germane gas ratio, all material properties improve substantially when increasing substrate temperature (Tsub) from 220°C to 375°C. Increasing Tsub also narrows the optical bandgap and lowers the hydrogen content in the alloys for the same germane-to-silane gas ratio.

Factors affecting the uptake of new medicines in secondary care - a literature review

BACKGROUND AND OBJECTIVE

The rate of uptake of new medicines in the UK is slower than in many other OECD countries. The majority of new medicines are introduced initially in secondary care and prescribed by specialists. However, the reasons for relatively low precribing levels are poorly understood. This review explores the determinants of uptake of new medicines in secondary care.

METHODS

Nine electronic databases were searched covering the period 1992-2006. Once the searches had been run, records were downloaded and those which evaluated uptake of new medicines in secondary care were identified. UK studies were of primary interest, although research conducted in other countries was also reviewed if relevant. With the exception of 'think pieces', eligibility was not limited by study design. Studies published in languages other than English were excluded from the review. Determinants of uptake in secondary care were classified using Bonair and Persson's typology for determinants of the diffusion of innovation.

RESULTS

Almost 1400 records were screened for eligibility, and 29 studies were included in the review. Prescribing of new medicines in secondary care was found to be subject to a number of interacting influences. The support structures which exist within secondary care facilitate access to other colleagues and shape prescribing practices. Clinical trial investigators and physicians who sit on decision-making bodies such as Drug and Therapeutic Committees (DTCs) appear to have a special influence due to their proximity to their research and understanding of evidence base. Pharmaceutical representatives may also influence prescribing decisions through funding of meetings and academic detailing, but clinicians are wary of potential bias. Little evidence on the influence of patients upon prescribing decisions was identified. The impact of clinical guidelines has been variable. Some guidelines have significantly increased the uptake of new medicines, but others have had little discernible impact despite extensive dissemination. However given the increasing influence of the National Institute for Health and Clinical Excellence, guidelines may become more important. The impact of financial prescribing incentives on secondary care prescribing is unclear. Although cost and budget may influence hospital prescribing of new drugs, they are of secondary importance to the safety and effectiveness profile of the medicine. If a drug has a novel mechanism of action, or belongs to a class with few alternatives, clinicians are more likely to consider it favourably as a prescribing option.

CONCLUSIONS

Although price does not appear to be a primary factor behind prescribing decision-making, in secondary care there has long been a historical need for formal purchasing decisions through the DTC, which differentiates it from primary care. This, in addition to increasing pressures for cost-effectiveness within the NHS means that cost will appear more frequently on clinician consciousness. As a result, guidelines are more likely to be implemented using the strong professional networks in existence within secondary care, and although the influence of patients has not been addressed by the literature, they are likely to have an increasing input into the prescribing decision, given the importance of patient involvement in current UK policy.