Assessing osteoporosis in the young adult

Osteoporosis in the young adult is a relatively rare phenomenon, and its diagnosis needs careful assessment of the affected person. The emphasis in the assessment of bone health is gradually shifting from a simple quantitative assessment of bone mineral density to one that includes bone quality. This may be particularly important in the young adult, where the aetiological cause of osteoporosis may be a primary genetic condition or secondary to another chronic condition

Assessing osteoporosis in the young adult

Osteoporosis in the young adult is a relatively rare phenomenon, and its diagnosis needs careful assessment of the affected person. The emphasis in the assessment of bone health is gradually shifting from a simple quantitative assessment of bone mineral density to one that includes bone quality. This may be particularly important in the young adult, where the aetiological cause of osteoporosis may be a primary genetic condition or secondary to another chronic condition

Use of Currently Available Diagnostic and Therapeutic Tools in the Investigation and Treatment of Disorders of Bone and Calcium Metabolism

In the past decade considerable advances have been made in both the investigation and treatment of various disorders of bone and calcium metabolism. The progress in investigative techniques has taken place in many different directions including biochemical evaluation, parathyroid imaging and bone densitometric measurement. Advances have also taken place in therapeutics with, in particular, the introduction into clinical practice of the bisphosphonates. These drugs are potent inhibitors of bone resorption and are therefore potentially useful in conditions where bone resorption is increased such as in most cases of hypercalcaemia, Paget's disease of bone and some cases of osteoporosis. Accurate evaluation of serum parathyroid hormone (PTH) concentrations and parathyroid hormone-like activity by use of indirect biochemical indices such as nephrogenous cyclic adenosine monophosphate (NcAMP) and renal tubular threshold for phosphate reabsorption (TmPO4), led to the discovery that in many instances cancer-associated hypercalcaemia is due to the production by the tumour of a factor with PTH-like activity. This, in turn, led to the identification of this factor as PTH-related protein (PTHrP), a peptide with significant structural homology to PTH itself. It has generally become apparent that PTHrP driven hypercalcaemia is more common in the presence of squamous cancer whereas hypercalcaemia due to direct invasion of bone by lytic metastases is more common in conditions such as myeloma. Traditionally breast cancer-associated hypercalcaemia has been considered to be due to direct metastatic invasion of bone, though more recent evidence suggests that humoral factors, such as PTHrP, may also play a significant role. A retrospective analysis of 20 patients with breast cancer-associated hypercalcaemia was carried out (chapter 3.1). This study indicated that on the basis of elevated levels of urinary cAMP (UcAMP) excretion and/or depressed TmP04 (in the presence of undetectable serum PTH), hypercalcaemia associated with the presence of a PTH-like factor was present in between 45- 60% patients. Recent evidence has suggested a number of potential physiological roles for PTHrP. One such example is in the active transfer of calcium into milk in the breast and the active transfer of calcium from mother to fetus in pregnancy by an action at the placenta. In the physiological situation, where PTHrP and PTH concentrations are likely to be within the normal reference range, it is unlikely that measurement of UcAMP, NcAMP or TmPO4 will give accurate indication of plasma PTHrP concentrations. In this context direct measurement of PTHrP is essential. A prospective study of 10 normal women through pregnancy (chapter 3.2) showed that plasma PTHrP concentrations rise throughout pregnancy reaching their highest concentration around term. Thereafter levels continue to rise into the puerperium. PTHrP levels during pregnancy correlated closely with serum alkaline phosphatase (ALP) concentrations suggesting a placental source to this PTHrP. Post-partum, however, it is likely that the continued rise in PTHrP was due to the onset of lactation and production of PTHrP by the breast. As expected, concentrations of NcAMP did not change significantly during the period of study. The importance of the vitamin D/PTH axis has been known for a number of years. The availability of precise and accurate biochemical assays for 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) (the principal active metabolite of vitamin D3 in man) and intact PTH(l-84) has allowed detailed investigation of their inter-relationship in vivo. 1,25(OH)2D3 and other active metabolites of vitamin D3 such as 1alpha-hydroxycholecalciferol (alfacalcidol) have recently been used therapeutically in the treatment of hypocalcaemia (including that associated with hypoparathyroidism), osteoporosis and renal osteodystrophy. Recent evidence has suggested an advantage in using these drugs by intravenous routes such that significant PTH suppression may be achieved though not at the expense of the development of hypercalcaemia. The acute (first 24hours) effect of intravenous administration of alfacalcidol upon serum concentrations of 1,25(OH)2D3, PTH and osteocalcin was studied prospectively in 6 normal males, 6 patients with primary hyperparathyroidism (PHPT) and 6 women with osteoporosis (chapter 3.3). Significant increases in serum concentrations of l,25(OH)2D3 were seen in each group 2-3 hours after administration of alfacalcidol. The increase in 1,25(OH)2D3 observed was greatest in those patients with PHPT. In the first 24 hours after administration, suppression of PTH concentrations or elevations in serum concentration of osteocalcin were not observed. This would suggest that changes normally seen in the longer term with these parameters are effected via changes in hormone synthesis rather than secretion. (Abstract shortened by ProQuest.)

Neighbourhood green space, physical function and participation in physical activities among elderly men: the Caerphilly Prospective study

Background: The built environment in which older people live plays an important role in promoting or inhibiting physical activity. Most work on this complex relationship between physical activity and the environment has excluded people with reduced physical function or ignored the difference between groups with different levels of physical function. This study aims to explore the role of neighbourhood green space in determining levels of participation in physical activity among elderly men with different levels of lower extremity physical function. Method: Using data collected from the Caerphilly Prospective Study (CaPS) and green space data collected from high resolution Landmap true colour aerial photography, we first investigated the effect of the quantity of neighbourhood green space and the variation in neighbourhood vegetation on participation in physical activity for 1,010 men aged 66 and over in Caerphilly county borough, Wales, UK. Second, we explored whether neighbourhood green space affects groups with different levels of lower extremity physical function in different ways. Results: Increasing percentage of green space within a 400 meters radius buffer around the home was significantly associated with more participation in physical activity after adjusting for lower extremity physical function, psychological distress, general health, car ownership, age group, marital status, social class, education level and other environmental factors (OR = 1.21, 95% CI 1.05, 1.41). A statistically significant interaction between the variation in neighbourhood vegetation and lower extremity physical function was observed (OR = 1.92, 95% CI 1.12, 3.28). Conclusion: Elderly men living in neighbourhoods with more green space have higher levels of participation in regular physical activity. The association between variation in neighbourhood vegetation and regular physical activity varied according to lower extremity physical function. Subjects reporting poor lower extremity physical function living in neighbourhoods with more homogeneous vegetation (i.e. low variation) were more likely to participate in regular physical activity than those living in neighbourhoods with less homogeneous vegetation (i.e. high variation). Good lower extremity physical function reduced the adverse effect of high variation vegetation on participation in regular physical activity. This provides a basis for the future development of novel interventions that aim to increase levels of physical activity in later life, and has implications for planning policy to design, preserve, facilitate and encourage the use of green space near home

Neighbourhood green space, physical function and participation in physical activities among elderly men: the Caerphilly Prospective study

Background: The built environment in which older people live plays an important role in promoting or inhibiting physical activity. Most work on this complex relationship between physical activity and the environment has excluded people with reduced physical function or ignored the difference between groups with different levels of physical function. This study aims to explore the role of neighbourhood green space in determining levels of participation in physical activity among elderly men with different levels of lower extremity physical function. Method: Using data collected from the Caerphilly Prospective Study (CaPS) and green space data collected from high resolution Landmap true colour aerial photography, we first investigated the effect of the quantity of neighbourhood green space and the variation in neighbourhood vegetation on participation in physical activity for 1,010 men aged 66 and over in Caerphilly county borough, Wales, UK. Second, we explored whether neighbourhood green space affects groups with different levels of lower extremity physical function in different ways. Results: Increasing percentage of green space within a 400 meters radius buffer around the home was significantly associated with more participation in physical activity after adjusting for lower extremity physical function, psychological distress, general health, car ownership, age group, marital status, social class, education level and other environmental factors (OR = 1.21, 95% CI 1.05, 1.41). A statistically significant interaction between the variation in neighbourhood vegetation and lower extremity physical function was observed (OR = 1.92, 95% CI 1.12, 3.28). Conclusion: Elderly men living in neighbourhoods with more green space have higher levels of participation in regular physical activity. The association between variation in neighbourhood vegetation and regular physical activity varied according to lower extremity physical function. Subjects reporting poor lower extremity physical function living in neighbourhoods with more homogeneous vegetation (i.e. low variation) were more likely to participate in regular physical activity than those living in neighbourhoods with less homogeneous vegetation (i.e. high variation). Good lower extremity physical function reduced the adverse effect of high variation vegetation on participation in regular physical activity. This provides a basis for the future development of novel interventions that aim to increase levels of physical activity in later life, and has implications for planning policy to design, preserve, facilitate and encourage the use of green space near home

Metabolic, inflammatory and haemostatic effects of a low-dose continuous combined HRT in women with type 2 diabetes: potentially safer with respect to vascular risk?

BACKGROUND Conventional hormone replacement therapy (HRT) containing conjugated equine oestrogen (CEE) and medroxyprogesterone acetate (MPA) increases triglyceride, C- reactive protein (CRP) and coagulation Factor VII concentrations, potentially explaining their increased coronary heart disease (CHD) and stroke risk. OBJECTIVE To assess the metabolic effects of a continuous combined HRT containing 1 mg oestradiol and 0.5 mg norethisterone or matching placebo. DESIGN Double-blind, randomized placebo-controlled trial. PATIENTS Fifty women with type 2 diabetes. MEASUREMENTS Classical and novel risk factors for vascular disease. RESULTS Triglyceride concentration was not altered (P = 0.31, change in active arm relative to placebo) and low-density lipoprotein (LDL) cholesterol concentration declined 13% (P = 0.018). IL-6 concentration (mean difference -1.42 pg/ml, 95% CI: -2.55 to - 0.29 IU/dl, P = 0.015), Factor VII (-32 IU/dl, -43 to -21 IU/l, P lt 0.001) and tissue plasminogen activator antigen (by 13%, P = 0.005) concentrations fell, but CRP was not significantly altered (P = 0.62). Fasting glucose (P = 0.026) also declined significantly, but there are no significant effects on HBA1c, Factor IX or APC resistance. CONCLUSIONS HRT containing 1 mg oestradiol and 0.5 mg norethisterone may avoid the adverse metabolic effects potentially implicated in the elevated CHD and stroke risk induced by conventional higher dose HRT. This type of preparation may therefore be more suitable than conventional HRT for women at elevated CHD risk such as those with type 2 diabetes. Large randomized controlled trials of such low dose preparations, powered for cardiovascular end points, are now needed

Clinical and health economic evaluation of a post-stroke arrhythmia monitoring service

Atrial fibrillation (AF) is a major cause of recurrent stroke and transient ischaemic attack (TIA) in the UK. As many patients can have asymptomatic paroxysmal AF, prolonged arrhythmia monitoring is advised in selected patients following a stroke or TIA. This service evaluation assessed the clinical and potential health economic impact of prolonged arrhythmia monitoring post-stroke using R-TEST monitoring devices.This was a prospective, case-controlled, service evaluation in a single health board in the North of Scotland. Patients were included if they had a recent stroke or TIA, were in sinus rhythm, and did not have another indication for, or contraindication to, oral anticoagulation. A health economic model was developed to estimate the clinical and economic value delivered by the R-TEST monitoring. Approval to use anonymised patient data in this service evaluation was obtained.During the evaluation period, 100 consecutive patients were included. The average age was 70 ± 11 years, 46% were female. Stroke was the presenting complaint in 83% of patients with the other 17% having had a TIA. AF was detected in seven of 83 (8.4%) patients who had had a stroke and one of 17 (5.9%) patients with a TIA. Health economic modelling predicted that adoption of R-TEST monitoring has a high probability of demonstrating both clinical and economic benefits.In conclusion, developing a post-stroke arrhythmia monitoring service using R-TEST devices is feasible, effective at detecting AF, and represents a probable clinical and economic benefi

Associations with photoreceptor thickness measures in the UK Biobank.

Spectral-domain OCT (SD-OCT) provides high resolution images enabling identification of individual retinal layers. We included 32,923 participants aged 40-69 years old from UK Biobank. Questionnaires, physical examination, and eye examination including SD-OCT imaging were performed. SD OCT measured photoreceptor layer thickness includes photoreceptor layer thickness: inner nuclear layer-retinal pigment epithelium (INL-RPE) and the specific sublayers of the photoreceptor: inner nuclear layer-external limiting membrane (INL-ELM); external limiting membrane-inner segment outer segment (ELM-ISOS); and inner segment outer segment-retinal pigment epithelium (ISOS-RPE). In multivariate regression models, the total average INL-RPE was observed to be thinner in older aged, females, Black ethnicity, smokers, participants with higher systolic blood pressure, more negative refractive error, lower IOPcc and lower corneal hysteresis. The overall INL-ELM, ELM-ISOS and ISOS-RPE thickness was significantly associated with sex and race. Total average of INL-ELM thickness was additionally associated with age and refractive error, while ELM-ISOS was additionally associated with age, smoking status, SBP and refractive error; and ISOS-RPE was additionally associated with smoking status, IOPcc and corneal hysteresis. Hence, we found novel associations of ethnicity, smoking, systolic blood pressure, refraction, IOPcc and corneal hysteresis with photoreceptor thickness

Precompetitive data sharing as a catalyst to address unmet needs in Parkinson's disease

Parkinson's disease is a complex heterogeneous disorder with urgent need for disease-modifying therapies. Progress in successful therapeutic approaches for PD will require an unprecedented level of collaboration. At a workshop hosted by Parkinson's UK and co-organized by Critical Path Institute's (C-Path) Coalition Against Major Diseases (CAMD) Consortiums, investigators from industry, academia, government and regulatory agencies agreed on the need for sharing of data to enable future success. Government agencies included EMA, FDA, NINDS/NIH and IMI (Innovative Medicines Initiative). Emerging discoveries in new biomarkers and genetic endophenotypes are contributing to our understanding of the underlying pathophysiology of PD. In parallel there is growing recognition that early intervention will be key for successful treatments aimed at disease modification. At present, there is a lack of a comprehensive understanding of disease progression and the many factors that contribute to disease progression heterogeneity. Novel therapeutic targets and trial designs that incorporate existing and new biomarkers to evaluate drug effects independently and in combination are required. The integration of robust clinical data sets is viewed as a powerful approach to hasten medical discovery and therapies, as is being realized across diverse disease conditions employing big data analytics for healthcare. The application of lessons learned from parallel efforts is critical to identify barriers and enable a viable path forward. A roadmap is presented for a regulatory, academic, industry and advocacy driven integrated initiative that aims to facilitate and streamline new drug trials and registrations in Parkinson's disease

Automated retinal image quality assessment on the UK Biobank dataset for epidemiological studies.

Morphological changes in the retinal vascular network are associated with future risk of many systemic and vascular diseases. However, uncertainty over the presence and nature of some of these associations exists. Analysis of data from large population based studies will help to resolve these uncertainties. The QUARTZ (QUantitative Analysis of Retinal vessel Topology and siZe) retinal image analysis system allows automated processing of large numbers of retinal images. However, an image quality assessment module is needed to achieve full automation. In this paper, we propose such an algorithm, which uses the segmented vessel map to determine the suitability of retinal images for use in the creation of vessel morphometric data suitable for epidemiological studies. This includes an effective 3-dimensional feature set and support vector machine classification. A random subset of 800 retinal images from UK Biobank (a large prospective study of 500,000 middle aged adults; where 68,151 underwent retinal imaging) was used to examine the performance of the image quality algorithm. The algorithm achieved a sensitivity of 95.33% and a specificity of 91.13% for the detection of inadequate images. The strong performance of this image quality algorithm will make rapid automated analysis of vascular morphometry feasible on the entire UK Biobank dataset (and other large retinal datasets), with minimal operator involvement, and at low cost