Knowledge Attainment and Engagement Among Medical Students: A Comparison of Three Forms of Online Learning

OBJECTIVE

This study compared knowledge attainment and student enjoyment and engagement between clinical case vignette, patient-testimony videos and mixed reality (MR) teaching via the Microsoft HoloLens 2, all delivered remotely to third year medical students. The feasibility of conducting MR teaching on a large scale was also assessed.

SETTING & PARTICIPANTS

Medical students in Year 3 at Imperial College London participated in three online teaching sessions, one in each format. All students were expected to attend these scheduled teaching sessions and to complete the formative assessment. Inclusion of their data used as part of the research trial was optional.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome measure was performance on a formative assessment, which served to compare knowledge attainment between three forms of online learning. Moreover, we aimed to explore student engagement with each form of learning via a questionnaire, and also feasibility of applying MR as a teaching tool on a large scale. Comparisons between performances on the formative assessment between the three groups were investigated using a repeated measures two-way ANOVA. Engagement and enjoyment were also analysed in the same manner.

RESULTS

A total of 252 students participated in the study. Knowledge attainment of students using MR was comparable with the other two methods. Participants reported higher enjoyment and engagement (p<0.001) for the case vignette method, compared with MR and video-based teaching. There was no difference in enjoyment or engagement ratings between MR and the video-based methods.

CONCLUSION

This study demonstrated that the implementation of MR is an effective, acceptable, and feasible way of teaching clinical medicine to undergraduate students on a large scale. However, case-based tutorials were found to be favoured most by students. Future work could further explore the best uses for MR teaching within the medical curriculum.

Development of a Novel Tool to Demystify Drug Distribution at Tissue-Blood Barriers

Tissue endothelial cells express ABC-transporter enzymes that change the concentration of small molecule within different tissue-compartments. These "blood-tissue barriers" have been shown to directly affect the efficacy and toxicity of anti-cancer, anti-microbial, psychiatric, and anti-epileptic drugs. Currently this phenomenon is best studied for the blood-brain barrier but remains enigmatic for most other tissues. In addition, canonical pharmacokinetic theory specifically assumes an equal concentration of free drug within all tissue compartments. Inspired by Lipinski's "rule of 5," we here clarify current knowledge on drug-tissue distribution by: (1) curating the in vivo literature on 73 drugs across 23 tissues and (2) developing two graphical web-based applications to visually describe and interpret data. This curated in vivo dataset and visualization tools enabled us to achieve new insights into the logic of the barrier-tissues organization and showed remarkable correspondence to whole-body imaging of radiolabeled molecules.

Corrigendum to "Ferritin as a Risk Factor for Glucose Intolerance amongst Men and Women Originating from the Indian Subcontinent"

[This corrects the article DOI: 10.1155/2015/924387.].

Ferritin as a Risk Factor for Glucose Intolerance amongst Men and Women Originating from the Indian Subcontinent

Background. Serum ferritin predicts the onset of diabetes; however, this relationship is not clear amongst South Asians, a population susceptible to glucose intolerance and anaemia. Objective. This study tests whether ferritin levels reflect glucose tolerance in South Asians, independent of lifestyle exposures associated with Indian or British residence. Methods. We randomly sampled 227 Gujaratis in Britain (49.8 (14.4) years, 50% men) and 277 contemporaries living in Gujarati villages (47.6 (11.8) years, 41% men). Both groups underwent a 75 g oral-glucose-tolerance test. We evaluated lifestyle parameters with standardised questionnaires and conducted comprehensive clinical and lab measurements. Results. Across sites, the age-adjusted prevalence of diabetes was 9.8%. Serum ferritin was higher amongst diabetics (P = 0.005), irrespective of site, gender, and central obesity (P ≤ 0.02), and was associated with fasting and postchallenge glucose, anthropometry, blood pressure, triglycerides, and nonesterified fatty acids (P < 0.001). Diabetes was less in those with low ferritin (<20 mg/mL), P < 0.008, and risk estimate = 0.35 (95% CI 0.15-0.81), as were blood pressure and metabolic risk factors. On multivariate analysis, diabetes was independently associated with ferritin (P = 0.001) and age (P < 0.001). Conclusion. Ferritin levels are positively associated with glucose intolerance in our test groups, independent of gender and Indian or UK lifestyle factors.

CD36 expression and lipid metabolism following an oral glucose challenge in South Asians

AIM: To investigate lipid metabolism and the relationship with monocyte expression of the fatty acid translocase CD36 in South Asians.

METHODS: An observational study of South Asians whom as an ethnic group have - a higher risk of developing diabetes. The susceptibility to diabetes is coupled with an earlier and more rapid progression of micro-, and macro-vascular complications. Twenty-nine healthy South Asian participants [mean age 34.6 (8.9) years, 76.2% male, mean body-mass index 25.0 (5.2) kg/m²] were recruited from an urban residential area of central Birmingham (United Kingdom). The main outcomes measured were post prandial (30 min) and post absorptive (120 min) changes from fasting (0 min) in circulating lipoproteins, lipds and hormones, and monocyte expression of CD36 post injection of a 75 g oral glucose challenge. The inducements of variations of monocyte CD36 expression were analysed.

RESULTS: Our results showed evident changes in monocyte CD36 expression following the glucose challenge (P < 0.001). Non-esterified fatty acids (NEFA) levels decreased progressively during the challenge (P < 0.001), in contrast to increased cholesterol (but not triglyceride) concentrations within very low density lipoprotein (VLDL) and low density lipoprotein subfractions (P < 0.01). Levels of, glucose, serum triglycerides and high density lipoprotein cholesterol remained largely unchanged. Variations of monocyte CD36 were negatively (r = -0.47, P = 0.04) associated to fat from the diet and positively to carbohydrate from the diet (r = 0.65, P < 0.001).

CONCLUSION: These data suggest that the initiation of VLDL genesis follows the consumption of glucose within this population, inferring that the sequestration of NEFA from these particles happens due to the increased availability of CD36 receptors. While these are preliminary results, it would appear that lifestyle exposures have a role in moderating the expression of CD36.

Brain regional vulnerability to anaesthesia-induced neuroapoptosis shifts with age at exposure and extends into adulthood for some regions

BACKGROUND

General anaesthesia facilitates surgical operations and painful interventions in millions of patients every year. Recent observations of anaesthetic-induced neuronal cell death in newborn animals have raised substantial concerns for young children undergoing anaesthesia. However, it remains unclear why some brain regions are more affected than others, why certain neurones are eliminated while neighbouring cells are seemingly unaffected, and what renders the developing brain exquisitely vulnerable, while the adult brain apparently remains resistant to the phenomenon.

METHODS

Neonatal (P7), juvenile (P21), and young adult mice (P49) were anaesthetized with 1.5% isoflurane. At the conclusion of anaesthesia, activated cleaved caspase 3 (AC3), a marker of apoptotic cell death, was quantified in the neocortex (RSA), caudoputamen (CPu), hippocampal CA1 and dentate gyrus (DG), cerebellum (Cb), and olfactory bulb (GrO) and compared with that found in unanaesthetized littermates.

RESULTS

After anaesthetic exposure, increased AC3 was detected in neonatal mice in RSA (11-fold, compared with controls), CPu (10-fold), CA1 (three-fold), Cb (four-fold), and GrO (four-fold). Surprisingly, AC3 continued to be elevated in the DG and GrO of juvenile (15- and 12-fold, respectively) and young adult mice (two- and four-fold, respectively).

CONCLUSIONS

The present study confirms the findings of previous studies showing peak vulnerability to anaesthesia-induced neuronal cell death in the newborn forebrain. It also shows sustained susceptibility into adulthood in areas of continued neurogenesis, substantially expanding the previously observed age of vulnerability. The differential windows of vulnerability among brain regions, which closely follow regional peaks in neurogenesis, may explain the heightened vulnerability of the developing brain because of its increased number of immature neurones.

Cell age-specific vulnerability of neurons to anesthetic toxicity

OBJECTIVE

Anesthetics have been linked to widespread neuronal cell death in neonatal animals. Epidemiological human studies have associated early childhood anesthesia with long-term neurobehavioral abnormalities, raising substantial concerns that anesthetics may cause similar cell death in young children. However, key aspects of the phenomenon remain unclear, such as why certain neurons die, whereas immediately adjacent neurons are seemingly unaffected, and why the immature brain is exquisitely vulnerable, whereas the mature brain seems resistant. Elucidating these questions is critical for assessing the phenomenon's applicability to humans, defining the susceptible age, predicting vulnerable neuronal populations, and devising mitigating strategies.

METHODS

This study examines the effects of anesthetic exposure on late- and adult-generated neurons in newborn, juvenile, and adult mice, and characterizes vulnerable cells using birth-dating and immunohistochemical techniques.

RESULTS

We identify a critical period of cellular developmental during which neurons are susceptible to anesthesia-induced apoptosis. Importantly, we demonstrate that anesthetic neurotoxicity can extend into adulthood in brain regions with ongoing neurogenesis, such as dentate gyrus and olfactory bulb.

INTERPRETATION

Our findings suggest that anesthetic vulnerability reflects the age of the neuron, not the age of the organism, and therefore may potentially not only be relevant to children but also to adults undergoing anesthesia. This observation further predicts differential heightened regional vulnerability to anesthetic neuroapoptosis to closely follow the distinct regional peaks in neurogenesis. This knowledge may help guide neurocognitive testing of specific neurological domains in humans following exposure to anesthesia, dependent on the individual's age during exposure.

Sofosbuvir and daclatasvir combination therapy in a liver transplant recipient with severe recurrent cholestatic hepatitis C

Recurrent HCV infection following liver transplantation can lead to accelerated allograft injury that is difficult to treat with interferon. The aim of this study is to describe the first ever use of an interferon-free, all oral regimen in a liver transplant recipient with severe recurrent HCV. A 54-year-old male with HCV genotype 1b developed severe cholestatic HCV at 6 months posttransplant with ascites, AST 503 IU/mL, alkaline phosphatase of 298 IU/mL, HCV RNA of 12 000 000 IU/mL, and histological cholestasis with pericellular fibrosis. Sofosbuvir, an HCV polymerase inhibitor (400 mg/day), and daclatasvir, an HCV NS5A replication complex inhibitor (60 mg/day), were co-administered for 24 weeks. Within 4 weeks of initiating treatment, serum HCV RNA levels became undetectable and liver biochemistries normalized with concomitant resolution of ascites. The patient achieved a sustained virological response with undetectable HCV RNA at 9 months posttreatment. During and following treatment, the daily dose and blood level of tacrolimus remained stable and unchanged. The rapid and sustained suppression of HCV replication in this liver transplant recipient provides great promise for the use of combination oral antiviral regimens in other immunosuppressed and interferon refractory HCV patients.

Characterization and quantification of isoflurane-induced developmental apoptotic cell death in mouse cerebral cortex

BACKGROUND

Accumulating evidence indicates that isoflurane and other, similarly acting anesthetics exert neurotoxic effects in neonatal animals. However, neither the identity of dying cortical cells nor the extent of cortical cell loss has been sufficiently characterized. We conducted the present study to immunohistochemically identify the dying cells and to quantify the fraction of cells undergoing apoptotic death in neonatal mouse cortex, a substantially affected brain region.

METHODS

Seven-day-old littermates (n = 36) were randomly assigned to a 6-hour exposure to either 1.5% isoflurane or fasting in room air. Animals were euthanized immediately after exposure and brain sections were double-stained for activated caspase 3 and one of the following cellular markers: Neuronal Nuclei (NeuN) for neurons, glutamic acid decarboxylase (GAD)65 and GAD67 for GABAergic cells, as well as GFAP (glial fibrillary acidic protein) and S100β for astrocytes.

RESULTS

In 7-day-old mice, isoflurane exposure led to widespread increases in apoptotic cell death relative to controls, as measured by activated caspase 3 immunolabeling. Confocal analyses of caspase 3-labeled cells in cortical layers II and III revealed that the overwhelming majority of cells were postmitotic neurons, but some were astrocytes. We then quantified isoflurane-induced neuronal apoptosis in visual cortex, an area of substantial injury. In unanesthetized control animals, 0.08% ± 0.001% of NeuN-positive layer II/III cortical neurons were immunoreactive for caspase 3. By contrast, the rate of apoptotic NeuN-positive neurons increased at least 11-fold (lower end of the 95% confidence interval [CI]) to 2.0% ± 0.004% of neurons immediately after isoflurane exposure (P = 0.0017 isoflurane versus control). In isoflurane-treated animals, 2.9% ± 0.02% of all caspase 3-positive neurons in superficial cortex also coexpressed GAD67, indicating that inhibitory neurons may also be affected. Analysis of GABAergic neurons, however, proved unexpectedly complex. In addition to inducing apoptosis among some GAD67-immunoreactive neurons, anesthesia also coincided with a dramatic decrease in both GAD67 (0.98 vs 1.84 ng/mg protein, P < 0.00001, anesthesia versus control) and GAD65 (2.25 ± 0.74 vs 23.03 ± 8.47 ng/mg protein, P = 0.0008, anesthesia versus control) protein levels.

CONCLUSIONS

Prolonged exposure to isoflurane increased neuronal apoptotic cell death in 7-day-old mice, eliminating approximately 2% of cortical neurons, of which some were identified as GABAergic interneurons. Moreover, isoflurane exposure interfered with the inhibitory nervous system by downregulating the central enzymes GAD65 and GAD67. Conversely, at this age, only a minority of degenerating cells were identified as astrocytes. The clinical relevance of these findings in animals remains to be determined.

Cardiovascular Risk Profiles amongst Women in a Multiethnic Population in Inner City Britain: A Potential Impact of Anaemia

The risk of diabetes is markedly reduced in men with iron deficiency anaemia (IDA). The nature of this relationship in women is not clear, nor is there information about the influence of ethnicity, given the increased susceptibility of diabetes amongst South Asians and Afro-Caribbeans. We reviewed 3563 patients with a diagnosis of anaemia from 2000 to 2007. The age-adjusted prevalence of vitamin B12 deficiency and IDA was calculated, together with cardiovascular comorbidities amongst Caucasians, South Asians, and Afro-Caribbeans. The prevalence of vitamin B12 deficiency (women only) or IDA was markedly higher in South Asians compared to Caucasians and Afro-Caribbeans. Among women with IDA, diabetes was more prevalent among South Asians (45%, 95% CI 39.0-51.0) compared to Caucasians (3.0%, 2.1-4.0); P < 0.001. Among South Asian women with vitamin B12 deficiency, the prevalence of diabetes was reduced 8.5% (5.2-12.0). South Asian women with vitamin B12 deficiency had a higher prevalence of myocardial infarction (MI) and ischemic heart disease (IHD), but this relationship was reversed in IDA. IDA is associated with a greater prevalence of diabetes in South Asian women, but it is not coordinated by a greater risk of macrovascular complications. Given the cardiovascular impact of diabetes in South Asians, this association merits further study in relation to its pathophysiological implication.

Validation of a novel resin-porcine thorax model for chest drain insertion training

Chest drain insertion in inexperienced hands carries a significant morbidity and mortality. The royal colleges, recognising this, stipulated that chest drain insertion be included as one of the core competences for all core medical trainees. However, there is no formal training in chest drain insertion included in training programmes. Simulation training should, in theory, provide a safe and objective method to overcome the obstacles in chest drain insertion training. There have been a number of attempts to find the ideal simulator for chest drain insertion with varying success. This article describes a model which is practical and affordable in all clinical skills labs, using porcine ribs mounted on a resin cast of a human thorax, and the data about the validation of the porcine-thorax model for chest drain insertion presented.

Diabetes Health, Residence & Metabolism in Asians: the DHRMA study, research into foods from the Indian subcontinent - a blinded, randomised, placebo controlled trial

Background

Coronary heart disease (CHD) is highly prevalent amongst the South Asian communities in Britain. The reasons for this excess CHD risk are multifactorial, but in part relate to a susceptibility to diabetes mellitus - where the aberrant metabolism of non-esterified fatty acids (NEFA) and glucose are likely to underpin vascular disease in this population. Dietary intervention is an important and first line approach to manage increased CHD risk. However, there is limited information on the impact of the South Asian diet on CHD risk.

Methods/Design

The Diabetes Health, Residence & Metabolism in Asians (DHRMA) study is a blinded, randomised, placebo controlled trial that analyses the efficacy of reduced glycaemic index (GI) staples of the South Asian diet, in relation to cardio-metabolic risk factors that are commonly perturbed amongst South Asian populations - primarily glucose, fatty acid and lipoprotein metabolism and central adiposity. Using a 10-week dietary intervention study, 50 healthy South Asians will be randomised to receive either a DHRMA (reduced GI) supply of chapatti (bread), stone ground, high protein wheat flour and white basmati rice (high bran, unpolished) or commercially available (leading brand) versions chapatti wheat flour and basmati rice. Volunteers will be asked to complete a 75g oral glucose tolerance test at baseline and at 10-weeks follow-up, where blood metabolites and hormones, blood pressure and anthropometry will also be assessed in a standardised manner.

Discussion

It is anticipated that the information collected from this study help develop healthy diet options specific (but not exclusive) for South Asian ethnic communities.

Trial registration

Current Controlled Trials ISRCTN02839188

Short-term effects of screening for cardiovascular risk in the deaf community: a pilot study

There is limited information on the risk of cardiovascular disease amongst the Deaf community. Given that the access of Deaf people to mainstream health promotion is likely to be hindered by language barriers, we were interested to assess the short-term impact of cardiovascular health promotion within this group. Using a pilot study we investigated changes in cardiovascular risk factors amongst Deaf people identified to be at high cardiovascular risk, who received standard health promotion by a medical team specializing in cardiovascular health promotion. The short-term impact of cardiovascular health promotion in this group did not reduce estimates of cardiovascular risk. The reasons for this are likely to relate to the design and delivery of health promotion to Deaf people, which deserves further study.

Omega-3 polyunsaturated acids and cardiovascular disease: notable ethnic differences or unfulfilled promise?

The consumption of long chain omega-3 polyunsaturated acids (PUFA) is considered to protect against cardiovascular disease and promote longevity following a heart attack. Historically, research in this area was fuelled by compelling reports of the cardiovascular benefits of omega-3 PUFA in select populations and cultures. More recent studies, in wider populations, suggest discordant findings: differences that are difficult to reconcile as the mechanism of action of omega-3 PUFA are poorly understood. As such, the use of this 'natural treatment' for cardiovascular disease is increasingly controversial, and potentially one of unfulfilled promise. To what extent does ethnicity influence the impact that omega-3 PUFA have on cardiovascular disease and its associated complications? We were interested to review the benefits of omega-3 PUFA in the management of cardiovascular risk amongst diverse ethnic groups. Using a systematic review of literature relating to omega-3 PUFA and cardiovascular disease, we found ethnicity to be a factor that accounts for inconsistency between studies. Some of the effects of omega-3 PUFA are limited to cultures with a very high omega-3 intake, and in turn, ethnicity moderates the efficiency with which PUFA are derived from the diet. Moreover, omega-3 PUFA are an important health care intervention in the current climate of globalization, where supplementation is likely to give protection to cultural groups undergoing dietary transition. Future epidemiological research into the efficacy of omega-3 PUFA in cardiovascular disease should consider the influence of ethnicity.

Triglycerides and small dense low density lipoprotein in the discrimination of coronary heart disease risk in South Asian populations

INTRODUCTION

Coronary heart disease (CHD) is exceptionally prevalent amongst globally dispersed migrant groups originating from the Indian subcontinent, but the contribution of dyslipidaemia to their increased risk remains poorly defined.

METHODS

Fasting lipids and lipoproteins, apolipoproteins (Apo), low density lipoprotein (LDL) diameter and oxidised LDL were measured amongst rural Indians in India (n=294) and their migrant contemporaries in the UK (n=242). The performance of qualitative and quantitative measures of lipid metabolism were compared in the discrimination of WHO defined metabolic risk and raised Framingham CHD risk scores (>15%) using Receiver Operating Characteristic (ROC) curves.

RESULTS

LDL diameter was correlated with triglycerides (R(2)=0.12, P<0.001) and with high density lipoprotein (HDL) cholesterol levels (R(2)=0.15, P<0.001) in both groups. Migrants had less small dense LDL (95% CI: 12.5-14.2%) vs. rural Indians (15.7-17.2, P<0.05). On ROC analysis, triglycerides were the only consistent discriminators of metabolic and CHD risk scores (all P< or =0.001). Apo B was also a strong indicator of raised CHD risk scores. Irrespective of site, individuals with raised triglycerides also had higher total cholesterol and Apo B, denser LDL, lower HDL and more oxidised LDL (all P< or =0.01).

DISCUSSION

Fasting triglycerides reflect both qualitative and quantitative aspects of lipid metabolism, and are a comprehensive discriminator of CHD risk in this South Asian population.

Omega-3 polyunsaturated fatty acids: a necessity for a comprehensive secondary prevention strategy

Long-chain omega-3 polyunsaturated fatty acid (PUFA) supplementation has been used for the secondary prevention of fatal and nonfatal myocardial infarction (MI). However, the benefit of this therapy is frequently confused with other established treatments in the therapeutic strategy among such patients. We review the data on omega-3 PUFA use in secondary care and consider indications for its use which include post-MI and raised triglycerides. We suggest that the available evidence supports the use of omega-3 supplementation as part of the comprehensive secondary care package for post-MI patients.

Glycemic Status Underlies Increased Arterial Stiffness and Impaired Endothelial Function in Migrant South Asian Stroke Survivors Compared to European Caucasians

Background— The pathophysiology of an increased risk of cerebrovascular disease mortality among South Asians (SA) remains unclear. Indices of arterial stiffness and endothelial dysfunction are independent markers of vascular disease, having both prognostic and diagnostic implications. We hypothesized that there are ethnic variations in indices of arterial stiffness and endothelial dysfunction between SA and European Caucasian (EC) stroke patients, which may underline a poorer prognosis in the former, and further investigated promoters of vessel wall abnormalities.

Methods— Using a cross-sectional approach, a total of 100 SA stroke survivors were prospectively recruited from the ongoing West Birmingham Stroke Project. Indices of vessel wall characteristics (arterial stiffness and endothelial function [change in reflective index]) were measured noninvasively using the digital volume pulse analysis technique in a temperature-controlled environment, using a direct standardized approach. SA stroke subjects were compared to 60 EC stroke survivors, 60 SA with risk factors, and 73 healthy controls.

Results— Among stroke patients, both ethnic groups were comparable for cardiovascular risk profile, except for more diabetes mellitus in SA ( P =0.007) subjects and a higher prevalence of atrial fibrillation in EC ( P =0.04) subjects. According to the TOAST and Bamford classifications, SA subjects had more small vessel ( P =0.04) and lacunar infarctions ( P =0.01). SA subjects had higher measurements of arterial stiffness ( P <0.001) and impaired endothelial-dependent vascular function (change in reflective index %; P <0.001). On univariate analysis, endothelial function was negatively correlated with fasting plasma glucose ( r =−0.4; P <0.001) and total cholesterol level ( r =−0.2; P <0.001). On multivariate analysis, glycemic status was independently associated with impaired endothelial function ( P =0.008) and increased arterial stiffness ( P <0.001) among SA subjects.

Conclusion— SA stroke survivors had more small vessel disease-related cerebrovascular events compared to EC subjects. Underlying glycemic status in SA subjects had an adverse impact on the vascular system, leading to abnormal vessel wall characteristics.

Ischemic Stroke in South Asians

Background and Purpose— Within the United Kingdom, mortality from stroke is higher among South Asians compared to European whites. The reasons for this excess cerebrovascular risk in South Asians remain unclear. The aim of this review is to present a comprehensive and systematic overview of the available literature relating to ischemic stroke among South Asian populations identifying distinct features of stroke epidemiology in this group.

Summary of Review— A high frequency of lacunar strokes is a familiar pattern among South Asians, which suggests a greater prevalence of small-vessel disease in South Asians. This may be a consequence of abnormal metabolic and glycemic processes. In addition, stroke mortality among South Asians appears to be explained by glycemic status, which is an independent predictor of long-term stroke mortality. Within India, there is a perceptible rural–urban gradient in stroke prevalence, underlying the dangers of the rapid transition in socioeconomic circumstances seen across the Indian subcontinent.

Conclusions— This review emphasizes the importance of further research into ischemic stroke for South Asians given their higher cardiovascular disease burden and necessity for targeted healthcare approaches.

Circulating biomarkers of angiogenesis as indicators of left ventricular systolic dysfunction amongst patients with coronary artery disease

BACKGROUND

Patients with coronary artery disease (CAD) and left ventricular systolic dysfunction (LVSD) are often asymptomatic. Angiogenesis is implicated in the physiology of vascular repair and cardiac remodelling, and is one of many pathophysiological processes implicated in heart failure. We hypothesized that plasma indices associated with angiogenesis [angiogenin, vascular endothelial growth factor (VEGF), and angiopoietin (Ang)-1 and Ang-2] would be abnormal in CAD patients with LVSD, being correlated with EF and wall motion abnormalities (wall motion score) independently of underlying CAD (coronary atheroma score). We also evaluated the specificity of angiogenic 'biomarkers' in their detection of LVSD [ejection fraction (EF) <40%] amongst CAD patients.

METHODS

Using a cross sectional approach, we measured angiogenin, VEGF, Ang-1 and Ang-2 by ELISA in 194 CAD patients (aged 34-81 years) undergoing elective coronary angiography.

RESULTS

Levels of angiogenin were inversely related with EF (r = -0.17, P = 0.02) and positively with coronary atheroma scores (r = 0.15, P = 0.04, but not independently of EF). Other angiogenic markers were unrelated to objective measures of LVSD but VEGF (P = 0.008) and Ang-2 (P = 0.015) were lower amongst those patients with heart failure. Angiogenin levels were related to wall motion scores (r = 0.16, P = 0.024).

CONCLUSION

Heart failure has a modest impact on biomarkers of angiogenesis, in patients with CAD. Further research is warranted into the diagnostic and prognostic utility of biomarkers of angiogenesis, in this common cardiac condition.

Circulating levels of adiponectin, leptin, and tumour necrosis factor alpha in hypertension

BACKGROUND

Abnormal adipocyte function is implicated in the coalition of multiple cardiovascular risk factors, where aberrant circulating levels of the adipose-derived hormones adiponectin, leptin, and tumour necrosis factor (TNF) alpha may provide the putative link between hypertension and increased cardiovascular risk. The pragmatic utility of these 'adipocytokines' in the clinical setting of hypertension is unclear, and we hypothesized a relationship of circulating adipocytokines to hypertension, and associated cardiovascular morbidity.

METHOD

Using a cross-sectional approach, we measured plasma adipocytokines in 278 'high-risk' treated hypertensive participants of the Anglo-Scandinavian Cardiac Outcomes Trial (ASCOT) study (mean (SD) age 62.9 (7.7) years), who were compared to 54 newly diagnosed untreated hypertensives (61.3 (10.9) years) and 55 healthy controls (48.3 (12.3) years).

RESULTS

Levels of all three adipocytokines were lower amongst treated hypertensives compared to newly diagnosed hypertensives and healthy controls (P<0.001 for leptin and adiponectin), and varied with gender, co-morbidities (e.g. diabetes, cardiovascular disease (CVD), left ventricular hypertrophy) and by treatments (e.g. statins and beta-blockade). Levels of adiponectin (P<0.001) and leptin (P=0.02) rose in an ordinal fashion with increasing hypertension severity (grade). Levels of leptin were associated with diastolic blood pressure in a positive fashion (P<0.001).

CONCLUSIONS

While hypertension affects adipocytokine levels, the clinical interpretation of circulating levels in hypertension is confounded by a range of factors. The positive relation between leptin and adiponectin with hypertension severity may reflect an underlying adaptive response that is attenuated during pharmacological hypertension management.

Circulating serum adiponectin levels in patients with coronary artery disease: relationship to atherosclerotic burden and cardiac function

BACKGROUND

Abnormal adipocyte function is implicated in both the pathophysiology of coronary heart disease (CHD) and cardiac function, where adiponectin provides a putative link. However, the utility of adiponectin as a discriminator of CHD severity is unclear and may be confounded by cardiac function. We hypothesized that plasma adiponectin would relate to indices of coronary artery disease severity (coronary atheroma scores, CAS), ejection fraction (EF) and regional wall motion abnormalities (RWMA) therein.

METHOD

We measured adiponectin using a cross-sectional approach, we measured plasma adiponectin enzyme-linked immunosorbent assay in 204 consecutive patients (aged 34-81 years) undergoing elective coronary angiography.

RESULTS

Levels of adiponectin decreased in an ordinal fashion across tertiles of increasing CAS (P = 0.047), but were nonsignificantly correlated to absolute values of CAS (P = 0.06). Adiponectin levels were unrelated to left ventricular dysfunction related measures of RWMA or EF. On multivariate analysis, (including factors relating to CHD risk, history and medication) adiponectin levels were independently inversely associated with triglycerides (P = 0.001), CAS tertiles (P = 0.01) and positively with age (P < 0.001).

CONCLUSION

Levels of adiponectin decreased with coronary artery disease severity, without impact from systolic dysfunction, but levels may be moderated through established CHD risk factors such as smoking and triglycerides. Further work is warranted as to the clinical prognostic utility of this marker amongst CHD patients.

Ethnic differences in myocardial infarction in patients with hypertension: effects of diabetes mellitus

BACKGROUND

It has been reported that hypertension carries a greater risk of myocardial infarction (MI) in South Asians living in the UK than in the indigenous British population. This has been attributed to some specifically Asian susceptibility factor.

DESIGN

Using a longitudinal approach, we investigated the relationship between coronary heart disease (CHD) risk factors amongst hypertension patients attending Sandwell and City Hospitals, and the onset of cardiovascular events over a 5-year follow-up period.

RESULTS

A total of 350 Caucasian (83.7% male) and 104 South Asian (66.3% male) patients with hypertension [age 63.7 (7.6) years and 57.1 (11.1) years respectively, P < 0.001] were followed-up for a mean (SD) period of 64.7(12.1) months. There were 11 (6.4/1000 patient years) cases of MI in Caucasian patients vs. 11 (17.8/1000 patient years) in South Asians, with event-free survival times being significantly lower amongst South Asians (log-rank test P = 0.04). The prevalence of diabetes mellitus was 22.9% higher amongst South Asians (P < 0.001), whilst mean serum cholesterol and fasting triglyceride levels were higher amongst Caucasians (P = 0.001). There were no ethnic differences in HDL cholesterol concentrations, the use of tobacco, statin therapy or anti-platelet therapies (all P = NS), or in composite endpoint (MI, angina, peripheral vascular disease, stroke, revascularization or death; P = 0.74). On Cox regression analysis of all independent cardiovascular risk variables, associated treatments and ethnicity, MI risk was associated with diabetes mellitus (odds ratio 3.77, 95%CI 1.55-9.15, P = 0.003) but not ethnicity per se (P = 0.26).

CONCLUSION

Increased risk of MI in hypertensive South Asians in the United Kingdom appears to be the result of a higher prevalence of diabetes mellitus. Further work is required to understand the pathophysiological basis with which diabetes increases CHD risk in this ethnic group.

Increased 5-year mortality in the migrant South Asian stroke patients with diabetes mellitus in the United Kingdom: the West Birmingham Stroke Project

BACKGROUND

Stroke is a major cause of premature mortality in Britain, but its burden is markedly greater amongst South Asians. Because of the paucity of data in this area, we investigated the magnitude and impact of risk from cardiovascular comorbidities on survival amongst South Asian stroke patients.

METHODS

We reviewed hospital case records of consecutive first in life time ischaemic stroke patients [self reported ethnicity and International Classification of Disease (ICD) 10th revision, codes 430-438] admitted to an inner city hospital in the UK between 1997 and 2001. In-hospital mortality data and CVD risk factors were analysed. Five-year mortality data was obtained from the National Health Tracing Services.

RESULTS

Of 1474 ischaemic stroke patients, 242 (16%) were South Asian of whom, 143 (59.1%) were male. The prevalence of hypertension was 70.2%, followed by diabetes 56.2%, hyperlipidaemia 7% and myocardial infarction 10.3%. At 5 years follow-up, 40.5% had died. Cumulative event-free survival at 5 years was significantly poorer in patients with diabetes (log-rank test, p=0.009). On Cox regression analysis, incorporating age, gender and other CVD risk factors, diabetes mellitus was an independent predictor of mortality odds ratio=1.65 (1.02-2.6, p=0.039). Hypertension and dyslipidaemia did not discriminate survival amongst South Asian patients.

CONCLUSION

Stroke mortality in South Asians is associated with presence of diabetes mellitus. This highlights the significance of early and intensive CVD risk modification strategies in ethnic minorities particularly in patients with diabetes. Further research is warranted in South Asians to examine the underlying basis and related pathophysiological abnormalities.

Elevated angiogenin levels in chronic heart failure

BACKGROUND

Abnormal indices of angiogenesis have been reported in chronic heart failure (CHF). We tested the hypothesis that circulating angiogenin (a potent inducer of neovascularization in vivo) is higher in CHF patients compared with controls and associated with indices of CHF severity: brain natriuretic peptide (BNP), Simpson's left ventricular ejection fraction (EF), and New York Heart Association (NYHA) class.

METHODS

Using a cross-sectional approach, we measured serum angiogenin and BNP levels in 109 consecutive patients with CHF (85 males; mean age 60 (standard deviation (SD) 10 yrs) and 112 asymptomatic controls with normal cardiac function and related levels to echocardiographic parameters.

RESULTS

Angiogenin was significantly higher in CHF patients compared to controls (P < 0.001). On univariate analysis, angiogenin was positively associated with age, plasma glucose, insulin, and BNP (all P < 0.001); and negatively correlated with diastolic blood pressure (P = 0.04) and EF (P = 0.002). Angiogenin levels increased in an ordinal fashion with NYHA class, exaggerated by the presence of diabetes mellitus (pseudo R2 = 0.15, P < 0.001). In multivariate analysis, angiogenin levels were only associated with deteriorating NYHA classification (beta = 0.14 (95% confidence interval (CI) 0.09-0.19), P < 0.001). Angiogenin was also a modest discriminator for the presence of CHF (area under the curve 0.72; 95% CI 0.62-0.82), P < 0.001).

CONCLUSION

Angiogenin is related to worsening heart failure severity (NYHA classification), with the highest levels in NYHA class III. Further research is warranted to determine the validity of angiogenin in a diagnostic and prognostic capacity in CHF.

Angiopoietin-2 levels as a biomarker of cardiovascular risk in patients with hypertension

BACKGROUND

Abnormal angiogenesis is a pathophysiological component of cardiovascular disease (CVD), where circulating biomarkers of angiogenesis are associated with increased CVD risk in hypertension. We hypothesized that raised levels of angiopoietin (Ang)-1 and -2 would predict events in patients with hypertension treated for CVD.

METHODS

We measured angiopoietin levels by enzyme-linked immunosorbent assay (ELISA) in 251 hypertensive participants (85% male; mean age 63.5 years; 192 free of previous CVD events). Plasma angiopoietin levels were related to the subsequent CVD events over a mean follow-up period of 57.1 (SD 11) months.

RESULTS

There were 11 cases of myocardial infarction (MI) and 18 cases of stroke during follow-up. Ang-2 was a significant predictor of MI, stroke, and composite CVD events, with the greatest event-free survival amongst those in the lower tertile (all P<0.05). Ang-1 was not predictive of CVD outcomes. Of CVD risk factors at recruitment (blood pressure, body mass index, plasma glucose, serum and high-density lipoprotein (HDL)-cholesterol), Ang-2 was the only discriminator of incident MI (area under curve (AUC) = 73%, P = 0.013), where a value >4.3 ng/mL optimized specificity and sensitivity. On Cox regression analysis (CVD treatments and risk factors), raised Ang-2 was an independent predictor of MI, P<0.05, but not stroke or composite outcomes.

CONCLUSIONS

Among patients with hypertension, raised levels of Ang-2 were predictive of MI, and further study is warranted to evaluate the use of this biomarker in CVD management, risk stratification, and prevention.

Widening access to cardiovascular healthcare: community screening among ethnic minorities in inner-city Britain - the Healthy Hearts Project

BACKGROUND

The burden of cardiovascular disease (CVD) in Britain is concentrated in inner-city areas such as Sandwell, which is home to a diverse multi-ethnic population. Current guidance for CVD risk screening is not established, nor are there specific details for ethnic minorities. Given the disparity in equitable healthcare for these groups, we developed a 'tailored' and systematic approach to CVD risk screening within communities of the Sandwell locality. The key anticipated outcomes were the numbers of participants from various ethnic backgrounds attending the health screening events and the prevalence of known and undiagnosed CVD risk within ethnic groups.

METHODS

Data was collected during 10 health screening events (September 2005 and July 2006), which included an assessment of raised blood pressure, overweight, hyperlipidaemia, impaired fasting glucose, smoking habit and the 10 year CVD risk score. Specific features of our approach included (i) community involvement, (ii) a clinician who could deliver immediate attention to adverse findings, and (iii) the use of an interpreter.

RESULTS

A total of 824 people from the Sandwell were included in this study (47% men, mean age 47.7 years) from community groups such as the Gujarati Indian, Punjabi Indian, European Caucasian, Yemeni, Pakistani and Bangladeshi. A total of 470 (57%) individuals were referred to their General Practitioner with a report of an increased CVD score - undetected high blood pressure in 120 (15%), undetected abnormal blood glucose in 70 (8%), undetected raised total cholesterol in 149 (18%), and CVD risk management review in 131 (16%).

CONCLUSION

Using this systematic and targeted approach, there was a clear demand for this service from people of various ethnic backgrounds, of whom, one in two needed review from primary or secondary healthcare. Further work is required to assess the accuracy and clinical benefits of this community health screening approach.

Elevated lipoprotein (a) and apolipoprotein B to AI ratio in South Asian patients with ischaemic stroke

BACKGROUND

Stroke is a continuing cause of excess cardiovascular disease (CVD) mortality amongst migrants from the Indian subcontinent (South Asians) living in Britain. However, little is known about the dyslipidaemia associated with stroke in South Asians. In particular, the highly atherogenic lipoprotein (a) [Lp(a)] and high apolipoprotein (Apo) B to AI ratio are emerging risk factors for CVD.

METHODS

Using a case-control study, we investigated features of the dyslipidaemia in South Asian patients with stroke compared with South Asian subjects with no history of clinically detectable stroke. We studied 55 consecutive South Asian patients with ischaemic stroke (confirmed on computerised scan of the brain) and 85 controls.

RESULTS

The stroke patients were significantly older than controls (65.2 vs. 59.8 years, p = 0.001), but were similarly matched for male gender (63.6 vs. 61.2%), smoking habit (20.7 vs. 18.1%) and presence of type 2 diabetes (25.5 vs. 19.3%). There were no differences between serum total cholesterol (p = 0.07) and high-density lipoprotein cholesterol (p = 0.08) between the groups, but stroke patients had higher serum triglycerides (p = 0.005). Mean [95% confidence interval (CI)] Apo B to AI ratio was higher amongst stroke patients [1.0 (0.9-1.0) vs. 0.7 (0.7-0.75), p < 0.001]. Similarly, geometric mean serum Lp(a) was significantly higher (p = 0.037) in stroke patients [19.9 mg/dl (14.0-28.5)] vs. controls [15.1 mg/dl (11.4-20.1)]. On logistic regression, stroke was independently associated with age and Apo B to AI ratio (p < 0.01).

CONCLUSION

The present study suggests that Lp(a) and the Apo B to AI ratio are associated with ischaemic stroke in South Asians. A prospective analysis is needed to elucidate the role of Lp(a), Apo B and AI as risk factors for ischaemic stroke in this population, as well as the effects of intervention.

Raised leptin concentrations among South Asian patients with chronic heart failure

BACKGROUND

The disease presentation of chronic heart failure (CHF) is considered to progress with metabolic deterioration, underlined by changes in adipose associated hormones (adipocytokines). However, little is known about ethnic variations of adipocytokines amongst CHF patients, in particular South Asians, who are at an increased risk of CHF.

METHODS

Using a cross-sectional study, South Asians (n=106) and Caucasians (n=105) living in the UK were compared by CHF status. We investigated ethnic differences in adipocytokines (leptin, adiponectin, tumor necrosis factor (TNF)alpha), and their association with CHF. Patients with mild to moderate CHF were recruited from heart failure clinics (47 Caucasian, 54 South Asian), and compared to healthy controls. Metabolic parameters (including insulin resistance using HOMA modelling), echocardiography and brain natriuretic peptide (BNP) were measured amongst patients and healthy controls, and compared across and within ethnic groups.

RESULTS

Mean (log transformed) plasma leptin concentrations were highest amongst South Asian patients, being 5.25% (95%CI: 1.50-9.02) higher than Caucasian patients (P=0.007), and similarly raised with respect to controls (P< or =0.04). Indices of insulin resistance were higher amongst CHF patients compared with controls, with no ethnic variation. In addition to age, female gender and body-mass index, levels of leptin were also associated with South Asian ethnicity (P<0.001), insulin resistance (P=0.02), smoking habit (P=0.01) and HDL cholesterol (P=0.004). Levels of adiponectin showed no ethnic variation, but were associated with CHF and a previous history of myocardial infarction (P<0.001). On multivariate regression analysis of patients and healthy controls, CHF was independently associated with smoking habit, adiponectin and insulin resistance (all P<0.01).

CONCLUSION

Metabolic abnormalities are present in CHF, which in turn, are influenced by ethnicity. The role of adipocytokines in CHF pathophysiology and prognosis merits further study.

Sampling water from chemically cleaned dental units with detachable power scalers

Power toothbrushes (PTBs), in combination with abrasive dentifrices, may encourage wear of dental cements at crown margins.

PURPOSE

This study's purpose was to determine the effect chemical cleaning had on the microbial quality of water emitted from dental unit waterlines (DUWL), 3-way syringes, and power scalers.

METHODS

Ten randomly selected dental units with attached self-contained independent water reservoirs filled with deionized water were used. An ultrasonic scaler was paired with each of the ten units. This combination was retained for the duration of the study. Water samples were collected at the beginning of the fall semester and again after two weeks. Analysis indicated unacceptable levels of microorganisms and the need for a shock treatment, which included cleanings on 3 consecutive days. Water samples were collected following the initial shock treatment and for the following 4 weeks. Weekly cleanings were performed as part of routine equipment maintenance. Water specimens from the 3-way syringes and scaler handpieces were spiral plated on R2A agar plates. Incubation was at room temperature for 7 days. Plates were examined and the number of colony-forming units per milliliter (CFU/mL) was determined for each specimen.

RESULTS

The first sampling showed that none of the 3-way syringes and one of the power scalers produced potable water after sitting unused for 6 weeks and receiving only one chemical cleaning. Improvement was noted after the second cleaning with specimens from 8 units having bacterial levels <500 CFU/mL. Three power scalers emitted potable water. Improvements in the bacterial levels of the power scalers were noted following the shock treatment; all of the power scalers emitted potable water.

CONCLUSIONS

Practitioners should routinely treat dental units and power scalers with products that will maintain acceptable microbial water quality. Administration of a shock treatment may be necessary prior to beginning a weekly maintenance protocol. Shock treatments are beneficial if units or power scalers have not been used for an extended period of time.

Effects of white European, African Caribbean and South Asian ethnicity on homocysteine levels in patients with systolic heart failure

BACKGROUND

Patients with heart failure of any cause have elevated homocysteine compared to healthy controls. A number of studies in the UK and other western countries have documented higher levels of homocysteine among South Asian than among White European or African Caribbean subjects both in health and in disease, and have suggested that dietary deficiency of folate is the main cause for the difference.

METHODS

Plasma homocysteine, vitamin B(12), and folate levels were measured in a multiethnic UK heart failure clinic population (n=112), and compared to matched control subjects (n=131).

RESULTS

Plasma homocysteine levels were significantly higher in heart failure patients than controls (p<0.001), a result that was consistent across all ethnic groups. There was no difference in homocysteine levels by ethnic group in either patients (p=0.898) or controls (p=0.368). There was no significant difference in levels of folate or B(12) among patients or controls. Using a stepwise linear regression model, homocysteine levels in patients and controls were independently associated with age (p<0.001), vitamin B(12) (p<0.001), folate (p<0.001) and healthy control status (p<0.001), but not with gender, ethnicity, diabetes status, smoking status or BNP levels.

CONCLUSION

This study does not provide evidence of ethnic differences in homocysteine levels between White European, South Asian, and African Caribbean subjects with systolic heart failure. The lack of difference in levels of folate or B(12) among patients or controls, suggests that homocysteine levels - and differences previously seen between South Asians and other ethnic groups - may be driven by dietary factors.

Secular trends in the cardiovascular risk profile and mortality of stroke admissions in an inner city, multiethnic population in the United Kingdom (1997–2005)

Our objective was to study ethnic differences in the cardiovascular risk profile and mortality of stroke admissions to an inner city teaching hospital serving a multiethnic population in Birmingham, UK, over a 9-year period (1997-2005). Hospital case notes and registry data of 3083 patients admitted with a first onset stroke were reviewed. Secular trends in the prevalence of risk factors (hypertension, diabetes, hyperlipidaemia, atrial fibrillation and myocardial infarction), hospital admission rates and 30-day mortality among Afro-Caribbean, European Caucasian and South Asian ethnic groups were analysed. Between 1997 and 2005, there were 3083 first onset strokes, of whom 47.6% (1595) were men, 9.3% Afro-Caribbean, 57.8% European Caucasian and 15.1% South Asian. There was a significant trend towards a reduction in non-haemorrhagic stroke admissions over the study period (P<0.001), with no ethnic variation (P=0.07). Increases in hypertension and hyperlipidaemia were observed (P<0.001), whereas myocardial infarction showed a decline (P<0.001). Compared to other ethnic groups, South Asian patients were younger on admission (P<0.001), had more hyperlipidaemia (P<0.05) and poorer survival at 30 days (P=002). We conclude that cardiovascular risk profiles among patients admitted with non-haemorrhagic stroke have changed over the last decade. In particular, hyperlipidaemia has increased, especially among South Asians. The reduced decline in stroke admissions and 30-day survival of stroke in South Asians in recent years warrants further investigation and highlights the importance of a targeted health-care approach in the migrant ethnic minorities.

Prognostic value of plasma soluble P-selectin and von Willebrand factor as indices of platelet activation and endothelial damage/dysfunction in high-risk patients with hypertension: a sub-study of the Anglo-Scandinavian Cardiac Outcomes Trial

BACKGROUND

Abnormal levels of prothrombotic markers have been described in hypertension, but no such marker has yet been shown to reliably predict cardiovascular outcomes in hypertension. We hypothesized that raised circulating levels of soluble P-selectin (sP-sel, an index of platelet activation) and/or von Willebrand factor (vWF, an index of endothelial damage/dysfunction) would predict vascular events in patients treated for cardiovascular risk.

METHODS

We measured vWF and sP-sel levels by an ELISA in 234 hypertensive participants with no prior cardiovascular events who were participating in the Anglo-Scandinavian Cardiac Outcomes Trial (ASCOT). Plasma vWF and sP-sel levels were related to the subsequent cardiovascular events over a mean (SD) follow-up period of 59.6 (19) months.

RESULTS

Plasma sP-sel was a significant predictor of myocardial infarction (P = 0.03), with the greatest risk amongst those with the highest sP-sel levels. sP-sel did not predict cerebrovascular events (P = 0.53) or composite cardiovascular events (P = 0.06). No significant relationships were found between vWF levels and outcomes. There was no relationship to the presence or absence of diabetes mellitus (DM) at baseline or subsequent development of DM during the follow-up period.

CONCLUSIONS

Among 'high-risk' patients with hypertension, raised levels of sP-sel (platelet activation) were predictive of myocardial infarction. Levels of vWF (endothelial damage/dysfunction) were not associated with coronary events and neither marker predicted cerebrovascular or composite cardiovascular endpoints. Platelets (or P-selectin) might represent a target for novel therapies or an adjunctive aid to risk stratification in the setting of hypertension.

Effects of omega-3 polyunsaturated fatty acids on metabolically active hormones in patients post-myocardial infarction

BACKGROUND

Long-chain omega-3 polyunsaturated fatty acids (PUFA) supplementation is used as a therapeutic secondary prevention strategy among post-myocardial infarction (MI) patients. The effects of omega-3 PUFA on markers of energy homeostasis among post-MI patients are unclear.

METHODS

We investigated the effects of Omacor (a pharmaceutical capsule formulation of highly refined, concentrated omega-3 PUFA; Solvay Healthcare, Southampton, UK; 1 g/day) in addition to usual care (cardiovascular therapy) in a pilot randomised study of 35 post-MI men. Following randomisation to Omacor (n=16), or 'usual care' controls (n=19), fasting levels of insulin, non-esterified fatty acids (NEFA), triglycerides, glucose and adipocytokines (adiponectin, leptin and tumour necrosis factor (TNF)-alpha), as indices of markers of energy homeostasis, were measured at baseline and after 3-month treatment.

RESULTS

There were no baseline differences in age, body mass index, blood pressure, fasting triglycerides, plasma glucose, NEFA and adipocytokines between the two treatment arms (P=0.07). There were no significant changes in metabolically active hormones within groups after 3-month treatment. Across arms, the direction of baseline to follow-up changes in insulin levels were significantly different (P= 0.03), with a mean increase with Omacor (+3.39 mU/ml) and a decrease among controls (-17.6 mU/ml), without associated deteriorating changes in triglycerides, NEFA or plasma glucose.

CONCLUSION

This pilot study suggests that Omacor had little effect on glycaemic control among male post-MI patients. However, Omacor was associated with raised insulin levels, compared to usual care; thus, a metabolic basis for the cardioprotective action of Omacor, outside of its lipid lowering effects, merits further investigation.

Role of metabolically active hormones in the insulin resistance associated with short-term glucocorticoid treatment

BACKGROUND

The mechanisms by which glucocorticoid therapy promotes obesity and insulin resistance are incompletely characterized. Modulations of the metabolically active hormones, tumour necrosis factor alpha (TNF alpha), ghrelin, leptin and adiponectin are all implicated in the development of these cardiovascular risk factors. Little is known about the effects of short-term glucocorticoid treatment on levels of these hormones.

RESEARCH METHODS AND PROCEDURES

Using a blinded, placebo-controlled approach, we randomised 25 healthy men (mean (SD) age: 24.2 (5.4) years) to 5 days of treatment with either placebo or oral dexamethasone 3 mg twice daily. Fasting plasma TNFalpha, ghrelin, leptin and adiponectin were measured before and after treatment.

RESULTS

Mean changes in all hormones were no different between treatment arms, despite dexamethasone-related increases in body weight, blood pressure, HDL cholesterol and insulin. Changes in calculated indices of insulin sensitivity (HOMA-S, insulin sensitivity index) were strongly related to dexamethasone treatment (p < 0.001).

DISCUSSION

Our data do not support a role for TNF alpha, ghrelin, leptin or adiponectin in the insulin resistance associated with short-term glucocorticoid treatment.

Efficacy, safety and LDL-C goal attainment of ezetimibe 10 mg-simvastatin 20 mg vs. placebo-simvastatin 20 mg in UK-based adults with coronary heart disease and hypercholesterolaemia

It is increasingly accepted that more intensive lipid-lowering treatment is associated with greater cardiovascular risk reductions in patients with coronary heart disease (CHD), thus providing a rationale for more aggressive LDL-cholesterol (LDL-C) targets. Ezetimibe in combination with statin therapy provides an additional approach to lipid management by utilising the additive action of two different mechanisms of LDL-C reduction. In this multicentre, randomised, double-blind, placebo-controlled study, a total of 98 men and 55 women with CHD and primary hypercholesterolaemia, naïve to statin therapy, were randomised to receive treatment for 6 weeks with either ezetimibe 10 mg-simvastatin 20 mg (n = 77) or placebo-simvastatin 20 mg (n = 75). At 6 weeks, ezetimibe 10 mg-simvastatin 20 mg provided a mean additional LDL-C reduction of 14.6% (95% CI 10.1-19.1) compared with simvastatin monotherapy (p < 0.0001). Moreover, a higher proportion of patients on ezetimibe/simvastatin achieved the National Standard Framework LDL-C standard (<3.0 mmol/l; 93% vs. 75%, p < 0.001) or the new Joint British Societies (JBS 2) goal of LDL-C < 2.0 mmol/l (49.3% vs. 11.1%, p < 0.001). On logistic regression analysis, the odds ratio of achieving target LDL-C with ezetimibe 10 mg-simvastatin 20 mg was 5.1 (95% CI 1.8-15.0) times higher than with simvastatin monotherapy (p = 0.003). Clinical chemistry profiles and proportions of adverse events were similar in both groups at baseline and follow-up. In conclusion, ezetimibe 10 mg-simvastatin 20 mg is a practical, effective and safe option for the treatment of primary hypercholesterolaemia in CHD patients, and brings more patients to new aggressive cholesterol targets compared with simvastatin 20 mg monotherapy.

Spatial negative priming in early Alzheimer's disease: evidence for reduced cognitive inhibition

Some studies of negative priming and other tasks assumed to reflect inhibitory functions suggest a decline in inhibitory processes in Alzheimer's disease. However, none of the measures used in previous studies can be interpreted as an unambiguous reflection of distractor inhibition. The present study investigates whether reductions in negative priming associated with Alzheimer's disease reflect reduced distractor inhibition, rather than perceptual review processes. Individuals with early Alzheimer's disease were predicted to show reduced negative priming on a spatial localization task designed to provide an unambiguous measure of distractor inhibition. Sixteen clinical participants showed significantly less negative priming than old and young healthy control groups, which is interpreted as evidence for reduced distractor inhibition in early dementia. A second analysis indicated that, within the clinical sample only, negative priming effect size was significantly correlated with prime trial response speed. Clinical participants showing the least negative priming were slower to respond to an initial stimulus. The results may mean that people with early Alzheimer's disease have a reduced capacity to use excitatory as well as inhibitory processes in selection.

Abnormal soluble CD40 ligand and C-reactive protein concentrations in hypertension: relationship to indices of angiogenesis

BACKGROUND

Abnormal inflammation, platelets and angiogenesis are involved in the pathophysiology of cardiovascular disease (CVD).

OBJECTIVE

To test the hypothesis that concentrations of high sensitive C-reactive protein (CRP, an index of inflammation) and soluble CD40 ligand (sCD40L, an index of platelet activation) would be abnormal in hypertension, and in turn, be related to plasma indices of angiogenesis, the angiopoietins-1 and -2, and vascular endothelial growth factor (VEGF), in addition to the presence or absence of CVD.

METHODS

Using a cross-sectional approach, we measured plasma concentrations of CRP, sCD40L, VEGF, and angiopoietins-1 and -2 in 147 patients with hypertension (85 with a history of CVD event/s, 62 CVD event-free) and 68 age- and sex-matched healthy controls.

RESULTS

Concentrations of sCD40L (P = 0.039), CRP (P < 0.001), angiopoietin-1 (P < 0.001), angiopoietin-2 (P = 0.003) and VEGF (P < 0.001) were all greater amongst hypertensive patients than in controls. There were no significant differences in sCD40L and VEGF concentrations between hypertensive individuals with and without CVD events, but CRP and angiopoietin-1 concentrations were significantly greater amongst those with CVD events. On multiple regression analysis, sCD40L was associated with angiopoietin-2 (P = 0.01) and VEGF (P = 0.007) in hypertensive individuals, but no such associations were found within the healthy control group.

CONCLUSION

In patients with hypertension, sCD40L was associated with increased circulating markers of abnormal angiogenesis (angiopoietin-2, VEGF). The interaction between sCD40L and angiogenesis may contribute to the pathophysiology of CVD in hypertension.

Left Ventricular Systolic Dysfunction in Rheumatoid Disease

OBJECTIVES

This study sought to ascertain whether left ventricular systolic dysfunction (LVSD) is more common among clinic patients with rheumatoid disease (RD) compared with the general population, and to assess the diagnostic utility of brain natriuretic peptide (BNP).

BACKGROUND

Patients with RD are at increased risk of ischemic heart disease. However, there are few large echocardiographic studies identifying cardiac dysfunction in RD. We hypothesized that LVSD would be more prevalent in RD patients than in the general population.

METHODS

A total of 226 hospital out-patients with RD (65% women) underwent clinical evaluation, electrocardiography (ECG), echocardiography, and plasma BNP assay (218 patients). Prevalence of LVSD was compared with local population estimates.

RESULTS

Definite LVSD (left ventricular ejection fraction <40%) occurred in 5.3% of the RD group: standardized prevalence ratio, 3.20; 95% confidence interval, 1.65 to 5.59. Median BNP values were higher in patients with LVSD compared with those without: 16.6 pmol/l versus 8.5 pmol/l, p < 0.005, although values between the two groups overlapped. One in nine patients with an abnormal ECG had definite LVSD.

CONCLUSIONS

Definite LVSD was three times more common in RD patients than in the general population. Given the prognostic benefits of treating LVSD, echocardiographic screening of RD patients with an abnormal ECG may be worthwhile.

Plasma matrix metalloproteinase-9, tissue inhibitor of metalloproteinase-2, and CD40 ligand levels in patients with stable coronary artery disease

Endogenous matrix metalloproteinases (MMPs) and their inhibitors, tissue inhibitor of metalloproteinases (TIMPs), are important mediators of extracellular matrix remodeling, which is integral to plaque progression in coronary artery disease. In addition, high levels of the soluble fragment of CD40 ligand (sCD40L) have previously been associated with adverse cardiovascular outcomes. We hypothesized that circulating levels of MMP-9, TIMP-1, TIMP-2, and sCD40L were abnormal in patients who had stable coronary artery disease, and these levels were compared with those in matched controls. We also hypothesized correlations of MMPs, TIMPs, and sCD40L to each other and to high-sensitivity C-reactive protein (a proinflammatory marker), white blood cell count, severity of coronary artery disease (based on angiographic measurements of atherosclerotic burden), and coronary collateralization. We studied 204 adult patients who attended our unit for outpatient diagnostic cardiac catheterization for the investigation of suspected coronary artery disease. Coronary angiograms were scored for atheroma burden and stenosis by 2 independent observers. Circulating levels of MMP-9, TIMP-1, TIMP-2, and sCD40L were measured by enzyme-linked immunosorbent assay. Plasma levels of MMP-9 (p = 0.0099), TIMP-2 (p = 0.0019), and sCD40L (p <0.001), but not TIMP-1 (p = 0.463) were high in patients compared with healthy controls. In patients who had coronary artery disease, MMP-9 and high-sensitivity C-reactive protein levels were significantly higher in women than in men. Only MMP-9 correlated modestly with total white blood cell count (Spearman's correlation, r = 0.274, p = 0.002). Logistic regression of cardiovascular risk factors showed that only white blood cell count was independently associated with MMP-9 (p = 0.02). After standardizing for atheroma and stenosis scores, there were no statistically significant differences in our research indexes in patients who had angiographic collaterals compared with those who did not. In conclusion, stable coronary artery disease is associated with abnormal circulating levels of MMP-9, TIMP-2, and sCD40L, which do not appear to related to each other or to severity of coronary artery disease or collateralization. The gender difference in high-sensitivity C-reactive protein and MMP-9 levels may provide insight into the pathophysiology of coronary artery disease in men and women, and further studies are warranted to explore this potential link.