C Cooper

University of Oxford, Oxford, England, United Kingdom

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Publications (652)3144.69 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Although a number of reports suggest very low persistence with oral bisphosphonates, there is limited data on persistence with other anti-osteoporosis medications. We compare rates of early discontinuation (in the first year) with all available outpatient anti-osteoporosis drugs in Catalonia, Spain. We conducted a population-based retrospective cohort study using data from the SIDIAP database. SIDIAP contains computerized primary care records and pharmacy dispensing data for >80 % of the population of Catalonia (>5 million people). All SIDIAP participants starting an anti-osteoporosis drug between 1/1/2007 and 30/06/2011 (with 2 years wash-out) were included. We modelled persistence as the time between first prescription and therapy discontinuation (refill gap of at least 6 months) using Fine and Gray survival models with competing risk for death. We identified 127,722 patients who started any anti-osteoporosis drug in the study period. The most commonly prescribed drug was weekly alendronate (N = 55,399). 1-Year persistence ranges from 40 % with monthly risedronate to 7.7 % with daily risedronate, and discontinuation was very common [from 49.5 % (monthly risedronate) to 84.4 % (daily risedronate)] as was also switching in the first year of therapy [from 2.8 % (weekly alendronate) to 10 % (daily alendronate)]. Multivariable-adjusted models showed that only monthly risedronate had better one-year persistence than weekly alendronate and teriparatide equivalent, whilst all other therapies had worse persistence. Early discontinuation with available anti-osteoporosis oral drugs is very common. Monthly risedronate, weekly alendronate, and daily teriparatide are the drugs with the best persistence, whilst daily oral drugs have 40-60 % higher first-year discontinuation rates compared to weekly alendronate.
    Calcified Tissue International 07/2015; DOI:10.1007/s00223-015-0040-3 · 2.75 Impact Factor
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    ABSTRACT: Under current guidelines, based on prior fracture probability thresholds, inequalities in access to therapy arise especially at older ages (≥70 years) depending on the presence or absence of a prior fracture. An alternative threshold (a fixed threshold from the age of 70 years) reduces this disparity, increases treatment access and decreases the need for bone densitometry. Several international guidelines set age-specific intervention thresholds at the 10-year probability of fracture equivalent to a woman of average BMI with a prior fracture. At older ages (≥70 years), women with prior fracture selected for treatment are at lower average absolute risk than those selected for treatment in the absence of prior fracture, prompting consideration of alternative thresholds in this age group. Using a simulated population of 50,633 women aged 50-90 years in the UK, with a distribution of risk factors similar to that in the European FRAX derivation cohorts and a UK-matched age distribution, the current NOGG intervention and assessment thresholds were compared to one where the thresholds remained constant from 70 years upwards. Under current thresholds, 45.1 % of women aged ≥70 years would be eligible for therapy, comprising 37.5 % with prior fracture, 2.2 % with high risk but no prior fracture and 5.4 % selected for treatment after bone mineral density (BMD) measurement. Mean hip fracture probability was 11.3, 23.3 and 17.6 %, respectively, in these groups. Under the alternative thresholds, the overall proportion of women treated increased from 45.1 to 52.9 %, with 8.4 % at high risk but no prior fracture and 7.0 % selected for treatment after BMD measurement. In the latter group, the mean probability of hip fracture was identical to that observed in women with prior fracture (11.3 %). The alternative threshold also reduced the need for BMD measurement, particularly at older ages (>80 years). The alternative thresholds equilibrate fracture risk, particularly hip fracture risk, in those with or without prior fracture selected for treatment and reduce BMD usage at older ages.
    Osteoporosis International 06/2015; DOI:10.1007/s00198-015-3176-0 · 4.17 Impact Factor
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    ABSTRACT: Fracture Liaison Services are the best model to prevent secondary fractures. The International Osteoporosis Foundation developed a Best Practice Framework to provide a quality benchmark. After a year of implementation, we confirmed that a single framework with set criteria is able to benchmark services across healthcare systems worldwide. Despite evidence for the clinical effectiveness of secondary fracture prevention, translation in the real-world setting remains disappointing. Where implemented, a wide variety of service models are used to deliver effective secondary fracture prevention. To support use of effective models of care across the globe, the International Osteoporosis Foundation's Capture the Fracture® programme developed a Best Practice Framework (BPF) tool of criteria and standards to provide a quality benchmark. We now report findings after the first 12 months of implementation. A questionnaire for the BPF was created and made available to institutions on the Capture the Fracture website. Responses from institutions were used to assign gold, silver, bronze or black (insufficient) level of achievements mapped across five domains. Through an interactive process with the institution, a final score was determined and published on the Capture the Fracture website Fracture Liaison Service (FLS) map. Sixty hospitals across six continents submitted their questionnaires. The hospitals served populations from 20,000 to 15 million and were a mix of private and publicly funded. Each FLS managed 146 to 6200 fragility fracture patients per year with a total of 55,160 patients across all sites. Overall, 27 hospitals scored gold, 23 silver and 10 bronze. The pathway for the hip fracture patients had the highest proportion of gold grading while vertebral fracture the lowest. In the first 12 months, we have successfully tested the BPF tool in a range of health settings across the globe. Initial findings confirm a significant heterogeneity in service provision and highlight the importance of a global approach to ensure high quality secondary fracture prevention services.
    Osteoporosis International 06/2015; DOI:10.1007/s00198-015-3192-0 · 4.17 Impact Factor
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    ABSTRACT: Symptomatic knee osteoarthritis (OA) can be viewed as the end result of a molecular cascade which ensues after certain triggers occur and ultimately results in irreversible damage to the articular cartilage. The clinical phenotype that knee OA can produce is variable and often difficult to accurately predict. This is further complicated by the often poor relationship between radiographic OA and knee pain. As a consequence, it can be difficult to compare studies that use different definitions of OA. However, the literature suggests that while there are multiple causes of knee OA, two have attracted particular attention over recent years; occupation related knee OA and OA subsequent to previous knee injury. The evidence of a relationship, and the strength of this association, is discussed in this chapter.
    Bailli&egrave re s Best Practice and Research in Clinical Rheumatology 06/2015; DOI:10.1016/j.berh.2015.05.005 · 3.06 Impact Factor
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    ABSTRACT: In 27 centres across Europe, the prevalence of deforming spinal Scheuermann's disease in age-stratified population-based samples of over 10,000 men and women aged 50+ averaged 8 % in each sex, but was highly variable between centres. Low DXA BMD was un-associated with Scheuermann's, helping the differential diagnosis from osteoporosis. This study aims to assess the prevalence of Scheuermann's disease of the spine across Europe in men and women over 50 years of age, to quantitate its association with bone mineral density (BMD) and to assess its role as a confounder for the radiographic diagnosis of osteoporotic fracture. In 27 centres participating in the population-based European Vertebral Osteoporosis Study (EVOS), standardised lateral radiographs of the lumbar and of the thoracic spine from T4 to L4 were assessed in all those of adequate quality. The presence of Scheuermann's disease, a confounder for prevalent fracture in later life, was defined by the presence of at least one Schmorl's node or irregular endplate together with kyphosis (sagittal Cobb angle >40° between T4 and T12) or a wedged-shaped vertebral body. Alternatively, the (rare) Edgren-Vaino sign was taken as diagnostic. The 6-point-per-vertebral-body (13 vertebrae) method was used to assess osteoporotic vertebral shape and fracture caseness. DXA BMD of the L2-L4 and femoral neck regions was measured in subsets. We also assessed the presence of Scheuermann's by alternative published algorithms when these used the radiographic signs we assessed. Vertebral radiographic images from 4486 men and 5655 women passed all quality checks. Prevalence of Scheuermann's varied considerably between centres, and based on random effect modelling, the overall European prevalence using our method was 8 % with no significant difference between sexes. The highest prevalences were seen in Germany, Sweden, the UK and France and low prevalences were seen in Hungary, Poland and Slovakia. Centre-level prevalences in men and women were highly correlated. Scheuermann's was not associated with BMD of the spine or hip. Since most of the variation in population impact of Scheuermann's was unaccounted for by the radiological and anthropometric data, the search for new genetic and environmental determinants of this disease is encouraged.
    Osteoporosis International 05/2015; DOI:10.1007/s00198-015-3170-6 · 4.17 Impact Factor
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    ABSTRACT: Poor diet quality in early childhood is inconsistently linked to obesity risk. Understanding may be limited by the use of cross-sectional data and the use of body mass index (BMI) to define adiposity in childhood. The objective of this study is to examine the effects of continued exposure to diets of varying quality across early childhood in relation to adiposity at 6 years. One thousand and eighteen children from a prospective UK birth cohort were studied. Diet was assessed using food frequency questionnaires when the children were aged 6 and 12 months, and 3 and 6 years; diet quality was determined according to scores for a principal component analysis-defined dietary pattern at each age (characterized by frequent consumption of fruits, vegetables and fish). At each age, children were allocated a value of 0/1/2 according to third of the distribution (bottom/middle/top) their diet quality score was in; values were summed to calculate an overall diet quality index (DQI) for early childhood (range 0-8). Obesity outcomes considered at 6 years were dual-energy X-ray absorptiometry-assessed fat mass and BMI. One hundred and seven (11%) children had a DQI=0, indicating a consistently low diet quality, 339 (33%) had a DQI=1-3, 378 (37%) had a DQI=4-6 and 194 (19%) had a DQI=7-8. There was a strong association between lower DQI and higher fat mass z-score at 6 years that was robust to adjustment for confounders (fat mass s.d. per 1-unit DQI increase: β=-0.05 (95% confidence interval (CI): -0.09, -0.01), P=0.01). In comparison with children who had the highest diet quality (DQI=7-8), this amounted to a difference in fat mass of 14% (95% CI: 2%, 28%) at 6 years for children with the poorest diets (DQI=0). In contrast, no independent associations were observed between DQI and BMI. Continued exposure to diets of low quality across early childhood is linked to adiposity at the age of 6 years.International Journal of Obesity advance online publication, 30 June 2015; doi:10.1038/ijo.2015.97.
    International journal of obesity (2005) 05/2015; DOI:10.1038/ijo.2015.97 · 5.39 Impact Factor
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    ABSTRACT: Trabecular bone score (TBS) is a recently-developed analytical tool that performs novel grey-level texture measurements on lumbar spine dual X-ray absorptiometry (DXA) images, and thereby captures information relating to trabecular microarchitecture. In order for TBS to usefully add to bone mineral density (BMD) and clinical risk factors in osteoporosis risk stratification, it must be independently associated with fracture risk, readily obtainable, and ideally, present a risk which is amenable to osteoporosis treatment. This paper summarizes a review of the scientific literature performed by a Working Group of the European Society for Clinical and Economic Aspects of Osteoporosis and Osteoarthritis. Low TBS is consistently associated with an increase in both prevalent and incident fractures that is partly independent of both clinical risk factors and areal BMD (aBMD) at the lumbar spine and proximal femur. More recently, TBS has been shown to have predictive value for fracture independent of fracture probabilities using the FRAX® algorithm. Although TBS changes with osteoporosis treatment, the magnitude is less than that of aBMD of the spine, and it is not clear how change in TBS relates to fracture risk reduction. TBS may also have a role in the assessment of fracture risk in some causes of secondary osteoporosis (e.g. diabetes, hyperparathyroidism and glucocorticoid-induced osteoporosis). In conclusion, there is a role for TBS in fracture risk assessment in combination with both aBMD and FRAX. Copyright © 2015. Published by Elsevier Inc.
    Bone 05/2015; 78. DOI:10.1016/j.bone.2015.05.016 · 4.46 Impact Factor
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    ABSTRACT: Objectives Poor appetite is commonly reported by older people but is rarely measured. The Simplified Nutritional Appetite Questionnaire (SNAQ) was validated to predict weight loss in community dwelling older adults but has been little used in hospitals. We evaluated it in older women on admission to hospital and examined associations with healthcare outcomes. Design Longitudinal observational with follow-up at six months. Setting Female acute Medicine for Older People wards at a University hospital in England. Participants 179 female inpatients. Measurements Age, weight, Body Mass Index (BMI), grip strength, SNAQ, Barthel Index Score, Mini Mental State Examination (MMSE), Geriatric Depression Scale: Short Form (GDS-SF), Malnutrition Universal Screening Tool (MUST), category of domicile and receipt of care were measured soon after admission and repeated at six month follow-up. The length of hospital stay (LOS), hospital acquired infection, readmissions and deaths by follow-up were recorded. Results 179 female participants mean age 87 (SD 4.7) years were recruited. 42% of participants had a low SNAQ score ( Conclusion Poor appetite was common among the older hospitalised women studied, and was associated with higher risk of poor healthcare outcomes.
    The Journal of Nutrition Health and Aging 05/2015; DOI:10.1007/s12603-015-0533-9 · 2.66 Impact Factor
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    ABSTRACT: Both maternal 25-hydroxyvitamin D (25(OH)D) concentrations during pregnancy and placental amino acid transporter gene expression have been associated with development of the offspring in terms of body composition and bone structure. Several amino acid transporter genes have vitamin D response elements in their promoters suggesting the possible linkage of these two mechanisms. We aimed to establish whether maternal 25(OH)D and vitamin D-binding protein (VDBP) levels relate to expression of placental amino acid transporters. RNA was extracted from 102 placental samples collected in the Southampton Women's Survey, and gene expression was analysed using quantitative real-time PCR. Gene expression data were normalised to the geometric mean of three housekeeping genes, and related to maternal factors and childhood body composition. Maternal serum 25(OH)D and VDBP levels were measured by radioimmunoassay. Maternal 25(OH)D and VDBP levels were positively associated with placental expression of specific genes involved in amino acid transport. Maternal 25(OH)D and VDBP concentrations were correlated with the expression of specific placental amino acid transporters, and thus may be involved in the regulation of amino acid transfer to the fetus. The positive correlation of VDBP levels and placental transporter expression suggests that delivery of vitamin D to the placenta may be important. This exploratory study identifies placental amino acid transporters which may be altered in response to modifiable maternal factors and provides a basis for further studies.
    The British journal of nutrition 05/2015; DOI:10.1017/S0007114515001178 · 3.34 Impact Factor
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    ABSTRACT: Various environmental factors have been associated with the timing of eruption of primary dentition, but the evidence to date comes from small studies with limited information on potential risk factors. We aimed to investigate associations between tooth emergence patterns and pre-conception, pregnancy and postnatal influences. Dentition patterns were recorded at ages 1 and 2 years in 2915 children born to women in the Southampton Women's Survey from whom information had been collected on maternal factors before conception and during pregnancy. In mutually adjusted regression models we found that: children were more dentally advanced at ages 1 and 2 years if their mothers had smoked during pregnancy or they were longer at birth; mothers of children whose dental development was advanced at age 2 years tended to have poorer socioeconomic circumstances, and to have reported a slower walking speed pre-pregnancy; and children of mothers of Asian ethnicity had later tooth development than those of white mothers. The findings add to the evidence of environmental impacts on the timing of the eruption of primary dentition in indicating that maternal smoking during pregnancy, socio-economic status and physical activity (assessed by reported walking speed) may influence the child's primary dentition. Early life factors, including size at birth are also associated with dentition patterns, as is maternal ethnicity.
    05/2015; DOI:10.1017/S2040174415001130
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    ABSTRACT: In this study, high-resolution peripheral quantitative computed tomography (HR-pQCT) was used to investigate geometric, volumetric and microstructural parameters at the distal radius and at the distal tibia in participants with ischaemic heart disease. We found that, compared with participants without ischaemic heart disease, they had substantially lower cortical volumetric bone mineral density (BMD) at the distal radius. HR-pQCT captures novel aspects of bone geometry and volumetric bone mineral density (vBMD) and offers the ability to measure bone microarchitecture, but data relating measures obtained from this technique in patients with ischemic heart disease (IHD) are lacking. Here, we report an analysis from the Hertfordshire Cohort Study, where we were able to study associations between measures obtained from HR-pQCT of distal radius and distal tibia in 350 participants (184 men and 166 women) aged 71.5-80.5 years with or without IHD (e.g. heart attack, angina or heart failure; n = 75 and n = 275, respectively). Analyses for all participants (men and women together) revealed that cortical vBMD (Ct.vBMD) was lower (p < 0.001) and cortical thickness (Ct.th) was not different (p = 0.519), whereas cortical porosity (Ct.Po) was higher (p = 0.016) in participants with IHD at the distal radius. Moreover, trabecular microarchitectural parameters were not significantly different in patients with IHD (p > 0.05 for all). Adjustment for a priori confounders (age, gender, body mass index, smoking status, alcohol consumption, high blood pressure and diabetes mellitus) did not materially affect the relationship described for Ct.vBMD (p = 0.002), but differences in Ct.Po were attenuated. Analyses in men alone revealed that only Ct.vBMD was lower at the distal radius in participants with IHD with and without adjustment for a priori confounders (p = 0.0002 and p = 0.004, respectively), whereas no statistical differences were found in women, although patterns of differences were similar in both sexes. Moreover, no association was found between IHD and bone parameters at the distal tibia either in men or women. We have demonstrated that IHD is associated with lower Ct.vBMD of the distal radius.
    Osteoporosis International 04/2015; DOI:10.1007/s00198-015-3132-z · 4.17 Impact Factor
  • Age and Ageing 04/2015; 44(suppl 1):i10-i10. DOI:10.1093/ageing/afv030.02 · 3.11 Impact Factor
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    ABSTRACT: Osteoporosis and sarcopenia are common in older age and associated with significant morbidity and mortality. Consequently, they are both attended by a considerable socioeconomic burden. Osteoporosis was defined by the World Health Organisation (WHO) in 1994 as a bone mineral density of less than 2.5 standard deviations below the sex-specific young adult mean and this characterisation has been adopted globally. Subsequently, a further step forward was taken when bone mineral density was incorporated into fracture risk prediction algorithms, such as the Fracture Risk Assessment Tool (FRAX®) also developed by the WHO. In contrast, for sarcopenia there have been several diagnostic criteria suggested, initially relating to low muscle mass alone and more recently low muscle mass and muscle function. However, none of these have been universally accepted. This has led to difficulties in accurately delineating the burden of disease, exploring geographic differences, and recruiting appropriate subjects to clinical trials. There is also uncertainty about how improvement in sarcopenia should be measured in pharmaceutical trials. Reasons for these difficulties including the number of facets of muscle health available, e.g. mass, strength, function, and performance, and the various clinical outcomes to which sarcopenia can be related such as falls, fracture, disability and premature mortality. It is imperative that a universal definition of sarcopenia is reached soon to facilitate greater progress in research into this debilitating condition. Copyright © 2015. Published by Elsevier Inc.
    Bone 04/2015; DOI:10.1016/j.bone.2015.04.016 · 4.46 Impact Factor
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    ABSTRACT: Osteoporosis accounts for about 3 % of total European health-care spending. The low proportion of costs for the pharmacological prevention of osteoporotic fracture means that it is highly cost saving, especially in patient with severe osteoporosis or patients who cannot take certain osteoporosis medications due to issues of contraindications or tolerability. Following recent regulatory changes, strontium ranelate is now indicated in patients with severe osteoporosis for whom treatment with other osteoporosis treatments is not possible, and without contraindications including uncontrolled hypertension, established, current or past history of ischaemic heart disease, peripheral arterial disease, and/or cerebrovascular disease. We review here today's evidence for the safety and efficacy of strontium ranelate. The efficacy of strontium ranelate in patients complying with the new prescribing information (i.e. severe osteoporosis without contraindications) has been explored in a multivariate analysis of clinical trial data, which concluded that the antifracture efficacy of strontium ranelate is maintained in patients with severe osteoporosis without contraindications and also demonstrated how the new target population mitigates risk. Strontium ranelate is therefore an important alternative in today's management of osteoporosis, with a positive benefit-risk balance, provided that the revised indication and contraindications are followed and cardiovascular risk is monitored. The bone community should be reassured that there remain viable alternatives in patients in whom treatment with other agents is not possible and protection against the debilitating effects of fracture is still feasible in patients with severe osteoporosis.
    Osteoporosis International 04/2015; DOI:10.1007/s00198-015-3109-y · 4.17 Impact Factor
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    ABSTRACT: Osteoporosis is a common condition which mainly affects older individuals and is more common in women than in men. Rates vary significantly across the world with higher rates in Northern Europe, North America, and Australasia. There are also differences by country and sometimes on a more local level. This review describes the variation and explores how secular trends in fracture rates have changes over recent years and may alter in the future. Although overall rates tend to be increasing, due largely to an ageing population, age-specific rates appear to be declining in some areas. This has considerable importance for the socioeconomic burden of the disease in years to come. Osteoporotic fractures are associated with significant morbidity and in some cases mortality. Consequently, they often require hospital treatment and may lead to long-term institutional care. This leads not only to effects on the individual’s quality of life but also to major health care and social costs.
    Clinical Reviews in Bone and Mineral Metabolism 04/2015; DOI:10.1007/s12018-015-9181-1
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    ABSTRACT: http://www.sciencedaily.com/releases/2015/03/150327120550.htm http://www.iofbonehealth.org/news/painful-knee-and-hand-osteoarthritis-middle-aged-women-associated-excess-mortality
    WCO-IOF-ESCEO MILAN 2015, Milan; 03/2015
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    ABSTRACT: To determine the association between socio-economic status (SES) and risk of hand, hip or knee osteoarthritis at a population level. Retrospective ecological study using the SIDIAP database (primary care anonymized records for > 5 million people in Catalonia (Spain)). Urban residents > 15 years old (2009-2012) were eligible. Validated area-based SES deprivation index MEDEA (proportion of unemployed, temporary workers, manual workers, low educational attainment and low educational attainment among youngsters) was estimated for each area based on census data as well as incident diagnoses (ICD-10 codes) of hand, hip or knee osteoarthritis (2009-2012). Zero-inflated Poisson models were fitted to study the association between MEDEA quintiles and the outcomes. Compared to the least deprived, the most deprived areas were younger (43.29 (17.59) versus 46.83 (18.49), years (Mean SD), had fewer women (49.1% versus 54.8 %), a higher percentage of obese (16.2 % versus 8.4 %), smokers (16.9 % versus 11.9%) and high-risk alcohol consumption subjects (1.5% versus 1.3 %). Compared to the least deprived, the most deprived areas had an excess risk of osteoarthritis: age-sex-adjusted IRR 1.26 (1.11-1.42) for hand, 1.23 (1.17-1.29) hip, and 1.51 (1.45-1.57) knee. Adjustment for obesity attenuated this association: 1.06 (0.93 -1.20), 1.04 (0.99-1.09), and 1.23 (1.19-1.28) respectively. Deprived areas have higher rates osteoarthritis (hand, hip, knee). Their increased prevalence of obesity accounts for a 50% of the excess risk of knee osteoarthritis observed. Public health interventions to reduce the prevalence of obesity in this population could reduce health inequalities. Copyright © 2015. Published by Elsevier Ltd.
    Osteoarthritis and Cartilage 03/2015; DOI:10.1016/j.joca.2015.03.020 · 4.66 Impact Factor
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    ABSTRACT: Loss of bone and muscle with advancing age represent a huge threat to loss of independence in later life. "Osteoporosis represents a major public health problem through its association with fragility fractures, primarily of the hip, spine and distal forearm" (Moselhy et al., 2012). Sarcopenia, the age related loss of muscle mass and function, may add to fracture risk by increasing falls risk. In the context of muscle aging, it is important to remember that it is not just a decline in muscle mass which contributes to the deterioration of muscle function. Other factors underpinning muscle quality come into play, including muscle composition, aerobic capacity and metabolism, fatty infiltration, insulin resistance, fibrosis and neural activation. Genetic, developmental, endocrine and lifestyle factors, such as physical activity, smoking and poor diet have dual effects on both muscle and bone mass in later life and these will be reviewed here. These include poor nutrition, lack of physical activity and cigarette smoking, comorbidities or medication use. Recent work has highlighted a possible role for the early environment. Inflammaging is an exciting emerging research field that is likely to prove relevant to future work, including interventions designed to retard to reverse bone and muscle loss with age. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
    Journal of Cellular Physiology 03/2015; DOI:10.1002/jcp.25001 · 3.87 Impact Factor
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    ABSTRACT: Vitamin D can be synthesized following exposure to ultraviolet radiation (UVR), ingested in the diet or provided through oral supplementation. The medical literature frequently states that humans obtain most of their vitamin D from sunshine and that UVR exposure is essential to maintain vitamin D levels. A systematic review was conducted to determine the requirement for UVR in maintaining adequate (> 50 nmol L−1) serum 25-hydroxyvitamin D [25(OH)D] levels. Studies reporting serum 25(OH)D during situations of negligible UVR exposure were sought. Forty-one studies (from a search yielding 42 698 articles) with a total of 4211 healthy adults met the inclusion criteria, providing 56 datasets from different population groups. Over 50% of subjects had > 50 nmol L−1 25(OH)D in 10 of 19 datasets reporting winter levels in areas with limited UVR. In addition, > 50% of subjects had adequate 25(OH)D levels in four of 12 datasets from polar regions during periods of negligible UVR, one of nine datasets documenting clothing-related minimal UVR and two of eight datasets detailing employment-related minimal UVR. The data demonstrate that many adults maintain adequate serum vitamin D levels despite negligible UVR exposure for several months. However, we acknowledge that preceding UVR exposure leading to vitamin D storage and delayed release may account for this maintenance of adequate serum vitamin D levels. There remains a need for further research on whether UVR exposure is required for longer-term maintenance of adequate vitamin D levels.
    British Journal of Dermatology 02/2015; 172(3). DOI:10.1111/bjd.13575 · 4.10 Impact Factor
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    ABSTRACT: Reference Point Indentation (RPI) has been proposed as a new clinical tool to aid the diagnosis of Osteoporosis. This study has examined the performance of the tool within entire femurs to improve the understanding of the mechanical properties of bone and also to guide future RPI testing to optimize repeatability of results obtained using the technique. Human, bovine, porcine and rat femurs were indented along three longitudinal axes: anterior and posterior: medial and lateral as well as around the circumference of the femoral head and neck. Cortical and subchondral bone thickness was measured using CT and radiography. The study shows that in some samples, bone is too thin to support the high loads applied with the technique and in these cases, RPI values are highly influenced by thickness. The technique will be useful in the mid-shaft region where cortical thickness is greatest, providing previously established guidelines are followed to optimize measurement repeatability, including performing multiple measurements per sample and investigating multiple samples. The study has also provided evidence that RPI values vary significantly with test site, hence mechanical properties should not be inferred from RPI findings alone away from the test site, even within the same bone. In conclusion, RPI appears to be a useful tool for scientific investigation; however further work is required to examine the feasibility of using RPI for assessing differences between healthy and diseased bone in a clinical setting. Copyright © 2015 Elsevier Ltd. All rights reserved.
    Journal of the Mechanical Behavior of Biomedical Materials 02/2015; 46. DOI:10.1016/j.jmbbm.2015.02.004 · 3.42 Impact Factor

Publication Stats

30k Citations
3,144.69 Total Impact Points

Institutions

  • 2008–2015
    • University of Oxford
      • • Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences (NDORMS)
      • • Botnar Research Centre Institute of Musculoskeletal Sciences
      Oxford, England, United Kingdom
    • Circumcision Resource Center
      Boston, Massachusetts, United States
  • 1986–2015
    • University of Southampton
      • • MRC Lifecourse Epidemiology Unit
      • • Developmental Origins of Health and Disease
      • • Institute of Sound and Vibration Research (ISVR)
      Southampton, England, United Kingdom
  • 2010–2014
    • NIHR Oxford Biomedical Research
      Oxford, England, United Kingdom
  • 2000–2013
    • University Hospital Southampton NHS Foundation Trust
      • Department of Medical Physics and Bioengineering
      Southampton, England, United Kingdom
  • 2001–2012
    • Universiteit Utrecht
      • • Utrecht Institute for Pharmaceutical Sciences
      • • Division of Pharmacoepidemiology and Pharmacotherapy
      Utrecht, Provincie Utrecht, Netherlands
  • 1995–2009
    • University of Cambridge
      • Department of Medicine
      Cambridge, England, United Kingdom
  • 1995–2008
    • Medical Research Council (UK)
      Londinium, England, United Kingdom
  • 2005
    • University of Nottingham
      Nottigham, England, United Kingdom
    • University of Brighton
      • Brighton and Sussex Medical School
      Brighton, ENG, United Kingdom
  • 2004
    • Netherlands Institute for Space Research, Utrecht
      Utrecht, Utrecht, Netherlands
    • CUNY Graduate Center
      New York City, New York, United States
  • 2000–2002
    • Keele University
      Newcastle-under-Lyme, England, United Kingdom
  • 1992–2000
    • The University of Manchester
      • School of Nursing, Midwifery and Social Work
      Manchester, England, United Kingdom
  • 1999
    • University College London
      • Institute of Child Health
      Londinium, England, United Kingdom
  • 1998
    • Procter & Gamble
      Cincinnati, Ohio, United States
    • VU University Amsterdam
      Amsterdamo, North Holland, Netherlands
  • 1995–1998
    • Newcastle University
      Newcastle-on-Tyne, England, United Kingdom
  • 1996
    • University of Amsterdam
      • Department of Endocrinology
      Amsterdamo, North Holland, Netherlands
  • 1994–1995
    • Mayo Clinic - Rochester
      • Department of Health Science Research
      Rochester, MN, United States
    • Royal National Hospital For Rheumatic Diseases NHS Foundation Trust
      Bath, England, United Kingdom
  • 1991
    • The Chinese University of Hong Kong
      Hong Kong, Hong Kong