Competing risks analysis for neutrophil to lymphocyte ratio as a predictor of diabetic retinopathy incidence in the Scottish population.

BACKGROUND: Diabetic retinopathy (DR) is a major sight-threatening microvascular complication in individuals with diabetes. Systemic inflammation combined with oxidative stress is thought to capture most of the complexities involved in the pathology of diabetic retinopathy. A high level of neutrophil-lymphocyte ratio (NLR) is an indicator of abnormal immune system activity. Current estimates of the association of NLR with diabetes and its complications are almost entirely derived from cross-sectional studies, suggesting that the nature of the reported association may be more diagnostic than prognostic. Therefore, in the present study, we examined the utility of NLR as a biomarker to predict the incidence of DR in the Scottish population. METHODS: The incidence of DR was defined as the time to the first diagnosis of R1 or above grade in the Scottish retinopathy grading scheme from type 2 diabetes diagnosis. The effect of NLR and its interactions were explored using a competing risks survival model adjusting for other risk factors and accounting for deaths. The Fine and Gray subdistribution hazard model (FGR) was used to predict the effect of NLR on the incidence of DR. RESULTS: We analysed data from 23,531 individuals with complete covariate information. At 10 years, 8416 (35.8%) had developed DR and 2989 (12.7%) were lost to competing events (death) without developing DR and 12,126 individuals did not have DR. The median (interquartile range) level of NLR was 2.04 (1.5 to 2.7). The optimal NLR cut-off value to predict retinopathy incidence was 3.04. After accounting for competing risks at 10 years, the cumulative incidence of DR and deaths without DR were 50.7% and 21.9%, respectively. NLR was associated with incident DR in both Cause-specific hazard (CSH = 1.63; 95% CI: 1.28-2.07) and FGR models the subdistribution hazard (sHR = 2.24; 95% CI: 1.70-2.94). Both age and HbA1c were found to modulate the association between NLR and the risk of DR. CONCLUSIONS: The current study suggests that NLR has a promising potential to predict DR incidence in the Scottish population, especially in individuals less than 65 years and in those with well-controlled glycaemic status.

Phospholemman Phosphorylation Regulates Vascular Tone, Blood Pressure, and Hypertension in Mice and Humans.

BACKGROUND: Although it has long been recognized that smooth muscle Na/K ATPase modulates vascular tone and blood pressure (BP), the role of its accessory protein phospholemman has not been characterized. The aim of this study was to test the hypothesis that phospholemman phosphorylation regulates vascular tone in vitro and that this mechanism plays an important role in modulation of vascular function and BP in experimental models in vivo and in humans. METHODS: In mouse studies, phospholemman knock-in mice (PLM3SA; phospholemman [FXYD1] in which the 3 phosphorylation sites on serines 63, 68, and 69 are mutated to alanines), in which phospholemman is rendered unphosphorylatable, were used to assess the role of phospholemman phosphorylation in vitro in aortic and mesenteric vessels using wire myography and membrane potential measurements. In vivo BP and regional blood flow were assessed using Doppler flow and telemetry in young (14-16 weeks) and old (57-60 weeks) wild-type and transgenic mice. In human studies, we searched human genomic databases for mutations in phospholemman in the region of the phosphorylation sites and performed analyses within 2 human data cohorts (UK Biobank and GoDARTS [Genetics of Diabetes Audit and Research in Tayside]) to assess the impact of an identified single nucleotide polymorphism on BP. This single nucleotide polymorphism was expressed in human embryonic kidney cells, and its effect on phospholemman phosphorylation was determined using Western blotting. RESULTS: Phospholemman phosphorylation at Ser63 and Ser68 limited vascular constriction in response to phenylephrine. This effect was blocked by ouabain. Prevention of phospholemman phosphorylation in the PLM3SA mouse profoundly enhanced vascular responses to phenylephrine both in vitro and in vivo. In aging wild-type mice, phospholemman was hypophosphorylated, and this correlated with the development of aging-induced essential hypertension. In humans, we identified a nonsynonymous coding variant, single nucleotide polymorphism rs61753924, which causes the substitution R70C in phospholemman. In human embryonic kidney cells, the R70C mutation prevented phospholemman phosphorylation at Ser68. This variant's rare allele is significantly associated with increased BP in middle-aged men. CONCLUSIONS: These studies demonstrate the importance of phospholemman phosphorylation in the regulation of vascular tone and BP and suggest a novel mechanism, and therapeutic target, for aging-induced essential hypertension in humans.

Impact of EU regulatory label changes for diclofenac in people with cardiovascular disease in four countries: Interrupted time series regression analysis.

OBJECTIVE: Due to cardiovascular safety concerns, the European Medicines Agency (EMA) recommended new contraindications and changes to product information for diclofenac across Europe in 2013. This study aims to measure their impact among targeted populations. METHOD: Quarterly interrupted time series regression (ITS) analyses of diclofenac initiation among cohorts with contraindications (congestive cardiac failure [CHF], ischaemic heart disease [IHD], peripheral arterial disease [PAD], cerebrovascular disease [CVD]) and cautions (hypertension, hyperlipidaemia, diabetes) from Denmark, the Netherlands, England and Scotland. RESULTS: The regulatory action was associated with significant immediate absolute reductions in diclofenac initiation in all countries for IHD (Denmark -0.08%, 95%CI -0.13, -0.03; England -0.09%, 95%CI -0.13 to -0.06%; the Netherlands -1.84%, 95%CI -2.51 to -1.17%; Scotland -0.34%, 95%CI -0.38 to -0.30%), PAD and hyperlipidaemia, the Netherlands, England and Scotland for hypertension and diabetes, and England and Scotland for CHF and CVD. Post-intervention there was a significant negative trend in diclofenac initiation in the Netherlands for IHD (-0.12%, 95%CI -0.19 to -0.04), PAD (-0.13%, 95%CI -0.22 to -0.05), hypertension, hyperlipidaemia and diabetes, and in Scotland for CHF (-0.01%, 95%CI -0.02 to -0.007%), IHD (-0.017, 95%CI -0.02, -0.01%), PAD and hypertension. In England, diclofenac initiation rates fell less steeply. In Denmark changes were more strongly associated with the earlier EMA 2012 regulatory action. CONCLUSION: Although significant reductions in diclofenac initiation occurred, patients with contraindications continued to be prescribed diclofenac, the extent of which varied by country and target condition. Understanding reasons for such variation may help to guide the design or dissemination of future safety warnings.

Impact of EMA regulatory label changes on hydroxyzine initiation, discontinuation and switching to other medicines in Denmark, Scotland, England and the Netherlands: An interrupted time series regression analysis.

BACKGROUND: Hydroxyzine is indicated for the management of anxiety, skin and sleep disorders. In 2015, the European Medicines Agency (EMA) concluded that hydroxyzine was pro-arrhythmogenic and changes to the product information were implemented in Europe. This study aimed to evaluate their impact in Denmark, Scotland, England and the Netherlands. METHOD: Quarterly time series analyses measuring hydroxyzine initiation, discontinuation, and switching to other antihistamines, benzodiazepines and antidepressants in Denmark, England, Scotland and the Netherlands from 2009 to 2018. Data were analysed using interrupted time series regression. RESULTS: Hydroxyzine initiation in quarter one 2010 in Denmark, Scotland, England and the Netherlands per 100 000 was: 23.5, 91.5, 35.9 and 34.4 respectively. Regulatory action was associated with a significant: immediate fall in hydroxyzine initiation per 100 000 in England (-12.05, 95%CI -18.47 to -5.63) and Scotland (-19.01, 95%CI -26.99 to -11.02); change to a negative trend in hydroxyzine initiation per 100 000/quarter in England (-1.72, 95%CI -2.69 to -0.75) and Scotland (-2.38, 95%CI -3.32 to -1.44). Regulatory action was associated with a significant: immediate rise in hydroxyzine discontinuation per 100 000 in England (3850, 95%CI 440-7240). No consistent changes were observed in the Netherlands or Denmark. Regulatory action was associated with no switching to other antihistamines, benzodiazepines or antidepressants following hydroxyzine discontinuation in any country. CONCLUSION: The 2015 EMA regulatory action was associated with heterogeneous impact with reductions in hydroxyzine initiation varying by country. There was limited impact on discontinuation with no strong evidence suggesting unintended consequences of major switching to other antihistamines, benzodiazepines or antidepressants.

Investigation of associations between retinal microvascular parameters and albuminuria in UK Biobank: a cross-sectional case-control study.

BACKGROUND: Associations between microvascular variation and chronic kidney disease (CKD) have been reported previously. Non-invasive retinal fundus imaging enables evaluation of the microvascular network and may offer insight to systemic risk associated with CKD. METHODS: Retinal microvascular parameters (fractal dimension [FD] - a measure of the complexity of the vascular network, tortuosity, and retinal arteriolar and venular calibre) were quantified from macula-centred fundus images using the Vessel Assessment and Measurement Platform for Images of the REtina (VAMPIRE) version 3.1 (VAMPIRE group, Universities of Dundee and Edinburgh, Scotland) and assessed for associations with renal damage in a case-control study nested within the multi-centre UK Biobank cohort study. Participants were designated cases or controls based on urinary albumin to creatinine ratio (ACR) thresholds. Participants with ACR ≥ 3 mg/mmol (ACR stages A2-A3) were characterised as cases, and those with an ACR < 3 mg/mmol (ACR stage A1) were categorised as controls. Participants were matched on age, sex and ethnic background. RESULTS: Lower FD (less extensive microvascular branching) was associated with a small increase in odds of albuminuria independent of blood pressure, diabetes and other potential confounding variables (odds ratio [OR] 1.18, 95% confidence interval [CI] 1.03-1.34 for arterioles and OR 1.24, CI 1.05-1.47 for venules). Measures of tortuosity or retinal arteriolar and venular calibre were not significantly associated with ACR. CONCLUSIONS: This study supports previously reported associations between retinal microvascular FD and other metabolic disturbances affecting the systemic vasculature. The association between retinal microvascular FD and albuminuria, independent of diabetes and blood pressure, may represent a useful indicator of systemic vascular damage associated with albuminuria.

Novel Genetic Locus Influencing Retinal Venular Tortuosity Is Also Associated With Risk of Coronary Artery Disease.

OBJECTIVE: The retina may provide readily accessible imaging biomarkers of global cardiovascular health. Increasing evidence suggests variation in retinal vascular traits is highly heritable. This study aimed to identify the genetic determinants of retinal vascular traits. Approach and Results: We conducted a meta-analysis of genome-wide association studies for quantitative retinal vascular traits derived using semi-automatic image analysis of digital retinal photographs from the GoDARTS (Genetics of Diabetes Audit and Research in Tayside; N=1736) and ORCADES (Orkney Complex Disease Study; N=1358) cohorts. We identified a novel genome-wide significant locus at 19q13 (ACTN4/CAPN12) for retinal venular tortuosity (TortV), and one at 13q34 (COL4A2) for retinal arteriolar tortuosity (TortA); these 2 loci were subsequently confirmed in 3 independent cohorts (Ntotal=1413). In the combined analysis of discovery and replication cohorts, the lead single-nucleotide polymorphism in ACTN4/CAPN12 was rs1808382 (ßs.d.=-0.109; SE=0.015; P=2.39×10-13) and in COL4A2 was rs7991229 (ßs.d.=0.103; SE=0.015; P=4.66×10-12). Notably, the ACTN4/CAPN12 locus associated with TortV is also associated with coronary artery disease, heart rate, and atrial fibrillation. CONCLUSIONS: Genetic determinants of retinal vascular tortuosity are also linked to cardiovascular health. These findings provide a molecular pathophysiological foundation for the use of retinal vascular traits as biomarkers for cardiovascular diseases.

Impact of EMA regulatory label changes on systemic diclofenac initiation, discontinuation, and switching to other pain medicines in Scotland, England, Denmark, and The Netherlands.

PURPOSE: In June 2013 a European Medicines Agency referral procedure concluded that diclofenac was associated with an elevated risk of acute cardiovascular events and contraindications, warnings, and changes to the product information were implemented across the European Union. This study measured the impact of the regulatory action on the prescribing of systemic diclofenac in Denmark, The Netherlands, England, and Scotland. METHODS: Quarterly time series analyses measuring diclofenac prescription initiation, discontinuation and switching to other systemic nonsteroidal anti-inflammatory (NSAIDs), topical NSAIDs, paracetamol, opioids, and other chronic pain medication in those who discontinued diclofenac. Absolute effects were estimated using interrupted time series regression. RESULTS: Overall, diclofenac prescription initiations fell during the observation periods of all countries. Compared with Denmark where there appeared to be a more limited effect, the regulatory action was associated with significant immediate reductions in diclofenac initiation in The Netherlands (-0.42%, 95% CI, -0.66% to -0.18%), England (-0.09%, 95% CI, -0.11% to -0.08%), and Scotland (-0.67%, 95% CI, -0.79% to -0.55%); and falling trends in diclofenac initiation in the Netherlands (-0.03%, 95% CI, -0.06% to -0.01% per quarter) and Scotland (-0.04%, 95% CI, -0.05% to -0.02% per quarter). There was no significant impact on diclofenac discontinuation in any country. The regulatory action was associated with modest differences in switching to other pain medicines following diclofenac discontinuation. CONCLUSIONS: The regulatory action was associated with significant reductions in overall diclofenac initiation which varied by country and type of exposure. There was no impact on discontinuation and variable impact on switching.

Lp-PLA2 activity is associated with increased risk of diabetic retinopathy: a longitudinal disease progression study.

AIMS/HYPOTHESIS: The aim of the study was to examine the association between lipoprotein-associated phospholipase A2 (Lp-PLA2) activity levels and incident diabetic retinopathy and change in retinopathy grade. METHODS: This was a cohort study of diabetic participants with serum collected at baseline and routinely collected diabetic retinal screening data. Participants with type 2 diabetes from the GoDARTS (Genetics of Diabetes Audit and Research in Tayside Scotland) cohort were used. This cohort is composed of individuals of white Scottish ancestry from the Tayside region of Scotland. Survival analysis accounting for informative censoring by modelling death as a competing risk was performed for the development of incident diabetic retinopathy from a disease-free state in a 3 year follow-up period (n = 1364) by stratified Lp-PLA2 activity levels (in quartiles). The same analysis was performed for transitions to more severe grades. RESULTS: The hazard of developing incident diabetic retinopathy was 2.08 times higher (95% CI 1.64, 2.63) for the highest quartile of Lp-PLA2 activity compared with the lowest. Higher Lp-PLA2 activity levels were associated with a significantly increased risk for transitions to all grades. The hazards of developing observable (or more severe) and referable (or more severe) retinopathy were 2.82 (95% CI 1.71, 4.65) and 1.87 (95% CI 1.26, 2.77) times higher for the highest quartile of Lp-PLA2 activity compared with the lowest, respectively. CONCLUSIONS/INTERPRETATION: Higher Lp-PLA2 levels are associated with increased risk of death and the development of incident diabetic retinopathy, as well as transitions to more severe grades of diabetic retinopathy. These associations are independent of calculated LDL-cholesterol and other traditional risk factors. Further, this biomarker study shows that the association is temporally sensitive to the proximity of the event to measurement of Lp-PLA2.

Meta-analysis of genome-wide association studies on the intolerance of angiotensin-converting enzyme inhibitors.

OBJECTIVES: To identify single nucleotide polymorphisms (SNPs) associated with switching from an angiotensin-converting enzyme (ACE)-inhibitor to an angiotensin receptor blocker. METHODS: Two cohorts of patients starting ACE-inhibitors were identified within the Rotterdam Study in the Netherlands and the Genetics of Diabetes Audit and Research in Tayside Scotland study in Scotland. Cases were intolerant patients who switched from an ACE-inhibitor to an angiotensin receptor blocker and controls were individuals who used ACE-inhibitors continuously for at least 2 years and did not switch. Genome-wide association study (GWAS) using an additive model was run in these sets and the results were meta-analysed using Genome-Wide Association Meta Analysis software. RESULTS: A total of 972 cases out of 5161 ACE-inhibitor starters were identified. Eight SNPs within four genes reached the genome-wide association study significance level (P<5×10) in the meta-analysis [RNA binding protein, Fox-1 homolog (Caenorhabditis elegans), γ-aminobutyric acid receptor subunit γ-2, sarcoma (Src) homology 2 (SH2) B adaptor protein 1 and membrane bound O-acyltransferase domain containing 1]. The strongest associated SNP was located in an intron of RNA binding protein, Fox-1 homolog (Caenorhabditis elegans), which contains an RNA binding protein [rs2061538: minor allele frequency=0.16, odds ratio=1.52 (95% confidence interval: 1.32-1.76), P=6.2×10]. CONCLUSION: These results indicate that genetic variation in the above-mentioned genes may increase the risk of ACE-inhibitor-induced adverse reactions.

Electronic case report forms and electronic data capture within clinical trials and pharmacoepidemiology.

AIMS: Researchers in clinical and pharmacoepidemiology fields have adopted information technology (IT) and electronic data capture, but these remain underused despite the benefits. This review discusses electronic case report forms and electronic data capture, specifically within pharmacoepidemiology and clinical research. METHODS: The review used PubMed and the Institute of Electrical and Electronic Engineers library. Search terms used were agreed by the authors and documented. PubMed is medical and health based, whereas Institute of Electrical and Electronic Engineers is technology based. The review focuses on electronic case report forms and electronic data capture, but briefly considers other relevant topics; consent, ethics and security. RESULTS: There were 1126 papers found using the search terms. Manual filtering and reviewing of abstracts further condensed this number to 136 relevant manuscripts. The papers were further categorized: 17 contained study data; 40 observational data; 27 anecdotal data; 47 covering methodology or design of systems; one case study; one literature review; two feasibility studies; and one cost analysis. CONCLUSION: Electronic case report forms, electronic data capture and IT in general are viewed with enthusiasm and are seen as a cost-effective means of improving research efficiency, educating participants and improving trial recruitment, provided concerns about how data will be protected from misuse can be addressed. Clear operational guidelines and best practises are key for healthcare providers, and researchers adopting IT, and further work is needed on improving integration of new technologies with current systems. A robust method of evaluation for technical innovation is required.

Modulation of intracellular ATP determines adenosine release and functional outcome in response to metabolic stress in rat hippocampal slices and cerebellar granule cells.

Cerebral ischaemia rapidly depletes cellular ATP. Whilst this deprives brain tissue of a valuable energy source, the concomitant production of adenosine mitigates the damaging effects of energy failure by suppressing neuronal activity. However, the production of adenosine and other metabolites, and their loss across the blood-brain barrier, deprives the brain of substrates for the purine salvage pathway, the primary means by which the brain makes ATP. Because of this, cerebral ATP levels remain depressed after brain injury. To test whether manipulating cellular ATP levels in brain tissue could affect functional neuronal outcomes in response to oxygen/glucose deprivation (OGD), we examined the effects of creatine and d-ribose and adenine (RibAde). In hippocampal slices creatine delayed ATP breakdown, reduced adenosine release, retarded both the depression of synaptic transmission and the anoxic depolarization caused by OGD, and improved the recovery of transmission. In contrast, RibAde increased cellular ATP, caused increased OGD-induced adenosine release and accelerated the depression of synaptic transmission, but did not improve functional recovery. However, RibAde improved the viability of cerebellar granule cells when administered after OGD. Our data indicate that RibAde may be effective in promoting recovery of brain tissue after injury, potentially via enhancement of salvage-mediated ATP production.

UMOD Genotype-Blinded Trial of Ambulatory Blood Pressure Response to Torasemide.

BACKGROUND: UMOD (uromodulin) has been linked to hypertension through potential activation of Na+-K+-2Cl- cotransporter (NKCC2), a target of loop diuretics. We posited that hypertensive patients carrying the rs13333226-AA UMOD genotype would demonstrate greater blood pressure responses to loop diuretics, potentially mediated by this UMOD/NKCC2 interaction. METHODS: This prospective, multicenter, genotype-blinded trial evaluated torasemide (torsemide) efficacy on systolic blood pressure (SBP) reduction over 16 weeks in nondiabetic, hypertensive participants uncontrolled on ≥1 nondiuretic antihypertensive for >3 months. The primary end point was the change in 24-hour ambulatory SBP (ABPM SBP) and SBP response trajectories between baseline and 16 weeks by genotype (AA versus AG/GG) due to nonrandomized groups at baseline (ClinicalTrials.gov: NCT03354897). RESULTS: Of 251 enrolled participants, 222 received torasemide and 174 demonstrated satisfactory treatment adherence and had genotype data. The study participants were middle-aged (59±11 years), predominantly male (62%), obese (body mass index, 32±7 kg/m2), with normal eGFR (92±17 mL/min/1.73 m²) and an average baseline ABPM of 138/81 mm Hg. Significant reductions in mean ABPM SBP were observed in both groups after 16 weeks (AA, -6.57 mm Hg [95% CI, -8.44 to -4.69]; P<0.0001; AG/GG, -3.22 [95% CI, -5.93 to -0.51]; P=0.021). The change in mean ABPM SBP (baseline to 16 weeks) showed a difference of -3.35 mm Hg ([95% CI, -6.64 to -0.05]; P=0.048) AA versus AG/GG genotypes. The AG/GG group displayed a rebound in SBP from 8 weeks, differing from the consistent decrease in the AA group (P=0.004 for difference in trajectories). CONCLUSIONS: Our results confirm a plausible interaction between UMOD and NKCC2 and suggest a potential role for genotype-guided use of loop diuretics in hypertension management. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03354897.

The role of adiposity in cardiometabolic traits: a Mendelian randomization analysis.

BACKGROUND: The association between adiposity and cardiometabolic traits is well known from epidemiological studies. Whilst the causal relationship is clear for some of these traits, for others it is not. We aimed to determine whether adiposity is causally related to various cardiometabolic traits using the Mendelian randomization approach. METHODS AND FINDINGS: We used the adiposity-associated variant rs9939609 at the FTO locus as an instrumental variable (IV) for body mass index (BMI) in a Mendelian randomization design. Thirty-six population-based studies of individuals of European descent contributed to the analyses. Age- and sex-adjusted regression models were fitted to test for association between (i) rs9939609 and BMI (n  =  198,502), (ii) rs9939609 and 24 traits, and (iii) BMI and 24 traits. The causal effect of BMI on the outcome measures was quantified by IV estimators. The estimators were compared to the BMI-trait associations derived from the same individuals. In the IV analysis, we demonstrated novel evidence for a causal relationship between adiposity and incident heart failure (hazard ratio, 1.19 per BMI-unit increase; 95% CI, 1.03-1.39) and replicated earlier reports of a causal association with type 2 diabetes, metabolic syndrome, dyslipidemia, and hypertension (odds ratio for IV estimator, 1.1-1.4; all p < 0.05). For quantitative traits, our results provide novel evidence for a causal effect of adiposity on the liver enzymes alanine aminotransferase and gamma-glutamyl transferase and confirm previous reports of a causal effect of adiposity on systolic and diastolic blood pressure, fasting insulin, 2-h post-load glucose from the oral glucose tolerance test, C-reactive protein, triglycerides, and high-density lipoprotein cholesterol levels (all p < 0.05). The estimated causal effects were in agreement with traditional observational measures in all instances except for type 2 diabetes, where the causal estimate was larger than the observational estimate (p  =  0.001). CONCLUSIONS: We provide novel evidence for a causal relationship between adiposity and heart failure as well as between adiposity and increased liver enzymes.

Genetic variants predicting left ventricular hypertrophy in a diabetic population: a Go-DARTS study including meta-analysis.

BACKGROUND: Left ventricular hypertrophy has multiple aetiologies including diabetes and genetic factors. We aimed to identify genetic variants predicting left ventricular hypertrophy in diabetic individuals. METHODS: Demographic, echocardiographic, prescribing, morbidity, mortality and genotyping databases connected with the Genetics of Diabetes Audit and Research in Tayside, Scotland project were accurately linked using a patient-specific identifier. Left ventricular hypertrophy cases were identified using echocardiographic data.Genotyping data from 973 cases and 1443 non-left ventricular hypertrophy controls were analysed, investigating whether single nucleotide polymorphisms associated with left ventricular hypertrophy in previous Genome Wide Association Studies predicted left ventricular hypertrophy in our population of individuals with type 2 diabetes. Meta-analysis assessed overall significance of these single nucleotide polymorphisms, which were also used to create gene scores. Logistic regression assessed whether these scores predicted left ventricular hypertrophy. RESULTS: Two single nucleotide polymorphisms previously associated with left ventricular hypertrophy were significant: rs17132261: OR 2.03, 95% CI 1.10-3.73, p-value 0.02 and rs2292462: OR 0.82, 95% CI 0.73-0.93 and p-value 2.26x10-3. Meta-analysis confirmed rs17132261 and rs2292462 were associated with left ventricular hypertrophy (p=1.03x10-8 and p=5.86x10-10 respectively) and one single nucleotide polymorphisms in IGF1R (rs4966014) became genome wide significant upon meta-analysis although was not significant in our study. Gene scoring based on published single nucleotide polymorphisms also predicted left ventricular hypertrophy in our study.Rs17132261, within SLC25A46, encodes a mitochondrial phosphate transporter, implying abnormal myocardial energetics contribute to left ventricular hypertrophy development. Rs2292462 lies within the obesity-implicated neuromedin B gene. Rs4966014 lies within the IGF1R1 gene. IGF1 signalling is an established factor in cardiac hypertrophy. CONCLUSIONS: We created a resource to study genetics of left ventricular hypertrophy in diabetes and validated our left ventricular hypertrophy phenotype in replicating single nucleotide polymorphisms identified by previous genome wide association studies investigating left ventricular hypertrophy.

The cholesterol-lowering effect of statins is modified by LILRB5 intolerance genotype: Results from a recruit-by-genotype clinical trial.

Background/Aims: Statin intolerance leads to poor adherence to statin therapy, resulting in a failure to achieve desired cholesterol reduction and adverse outcomes. The LILRB5 Asp247Gly genotype has been identified as being associated with statin intolerance and statin-induced myalgia. We conducted a randomized clinical trial to examine its role in immune response through T regulatory cell aggregation and in achieving cholesterol reduction targets. Methods: A double-blind, cross-over, recruit-by-genotype trial was undertaken. A total of 18 participants who had either the Asp247Asp (T/T) genotype or the Gly247Gly (C/C) genotype were recruited to the study. Participants were randomised to receive placebo or atorvastatin 80 mg daily for 28 days. Following a washout period of 3 weeks, they were then switched to the opposite treatment. Biochemical and immunological measurements as well as interviews were performed prior to and after both treatment periods. Within genotype group comparisons were performed using repeated measures Wilcoxon tests. Two-way repeated measures ANOVA with genotype and treatment as factors were used to compare changes in biochemical parameters between groups during placebo and atorvastatin periods. Results: Individuals with the Asp247Asp genotype had a greater increase in creatine kinase (CK) compared to those with Gly247Gly genotype in response to atorvastatin (p = 0.03). Those with Gly247Gly genotype had a mean non-HDL cholesterol reduction of 2.44 (95% CI:1.59 - 3.29) mmol/L while in Asp247Asp genotype group the mean reduction was 1.28 (95%CI: 0.48 - 2.07) mmol/L. The interaction between the genotype and atorvastatin treatment for total cholesterol (p = 0.007) and non-HDL cholesterol response was significant (p = 0.025). Immunological assessment showed no significant changes in aggregation of T regulatory cells by genotype. Conclusion: The Asp247Gly variant in LILRB5, previously associated with statin intolerance, was associated with differential increases in creatine kinase and total cholesterol and non-HDL cholesterol-lowering response to atorvastatin. Taken together, these results suggest that this variant could have utility in precision cardiovascular therapy.

Common and Distinct Genetic Architecture of Age at Diagnosis of Diabetes in South Indian and European Populations.

OBJECTIVE: South Asians are diagnosed with type 2 diabetes (T2D) more than a decade earlier in life than seen in European populations. We hypothesized that studying the genomics of age of diagnosis in these populations may give insight into the earlier age diagnosis of T2D among individuals of South Asian descent. RESEARCH DESIGN AND METHODS: We conducted a meta-analysis of genome-wide association studies (GWAS) of age at diagnosis of T2D in 34,001 individuals from four independent cohorts of European and South Asian Indians. RESULTS: We identified two signals near the TCF7L2 and CDKAL1 genes associated with age at the onset of T2D. The strongest genome-wide significant variants at chromosome 10q25.3 in TCF7L2 (rs7903146; P = 2.4 × 10-12, ß = -0.436; SE 0.02) and chromosome 6p22.3 in CDKAL1 (rs9368219; P = 2.29 × 10-8; ß = -0.053; SE 0.01) were directionally consistent across ethnic groups and present at similar frequencies; however, both loci harbored additional independent signals that were only present in the South Indian cohorts. A genome-wide signal was also obtained at chromosome 10q26.12 in WDR11 (rs3011366; P = 3.255 × 10-8; ß = 1.44; SE 0.25), specifically in the South Indian cohorts. Heritability estimates for the age at diagnosis were much stronger in South Indians than Europeans, and a polygenic risk score constructed based on South Indian GWAS explained ∼2% trait variance. CONCLUSIONS: Our findings provide a better understanding of ethnic differences in the age at diagnosis and indicate the potential importance of ethnic differences in the genetic architecture underpinning T2D.

Intracellular ATP influences synaptic plasticity in area CA1 of rat hippocampus via metabolism to adenosine and activity-dependent activation of adenosine A1 receptors.

The extent to which brain slices reflect the energetic status of the in vivo brain has been a subject of debate. We addressed this issue to investigate the recovery of energetic parameters and adenine nucleotides in rat hippocampal slices and the influence this has on synaptic transmission and plasticity. We show that, although adenine nucleotide levels recover appreciably within 10 min of incubation, it takes 3 h for a full recovery of the energy charge (to ≥ 0.93) and that incubation of brain slices at 34°C results in a significantly higher ATP/AMP ratio and a threefold lower activity of AMP-activated protein kinase compared with slices incubated at room temperature. Supplementation of artificial CSF with d-ribose and adenine (Rib/Ade) increased the total adenine nucleotide pool of brain slices, which, when corrected for the influence of the dead cut edges, closely approached in vivo values. Rib/Ade did not affect basal synaptic transmission or paired-pulse facilitation but did inhibit long-term potentiation (LTP) induced by tetanic or weak theta-burst stimulation. This decrease in LTP was reversed by strong theta-burst stimulation or antagonizing the inhibitory adenosine A(1) receptor suggesting that the elevated tissue ATP levels had resulted in greater activity-dependent adenosine release during LTP induction. This was confirmed by direct measurement of adenosine release with adenosine biosensors. These observations provide new insight into the recovery of adenine nucleotides after slice preparation, the sources of loss of such compounds in brain slices, the means by which to restore them, and the functional consequences of doing so.

Persistence, adherence and outcomes with antiplatelet regimens following cerebral infarction in the Tayside Stroke Cohort.

BACKGROUND: Co-prescribed aspirin and dipyridamole are more effective than aspirin alone following cerebral infarction; however, patients may struggle with this more complex regimen. The objectives of this study were: (1) to describe postdischarge prescribing of antiplatelet regimens, (2) to measure patient persistence with different antiplatelet regimens, and (3) to measure whether persistence impacts on outcomes. METHODS: We used record linkage of the Tayside Stroke Cohort with community dispensed prescribing data from 1994 to 2005. All patients had suffered a radiologically confirmed cerebral infarction and were excluded if they had previously used or had other indications for antiplatelet agents. We measured persistence to initial and any antiplatelet regimen using survival analysis. To assess the impact of therapy we used survival analysis to follow up until the APTC endpoint of serious vascular event (myocardial infarction, stroke or vascular death) or censored. Antiplatelet regimen was entered as a time-dependent covariate in a Cox model that also adjusted for age, sex, history of diabetes and baseline use of nitrates and statins. RESULTS: The study cohort contained 1,407 stroke patients (mean age 70.3 years, 46.8% male), with a total follow-up of 4,243 patient-years. Patients initiated on aspirin with dipyridamole had a worse persistence to their initial regimen compared with those initiated on aspirin alone (hazard ratio for non-persistence 1.62; 95% CI 1.37-1.92), but better persistence with any antiplatelet medication long term (hazard ratio 0.86; 95% CI 0.73-1.02). Compared to aspirin monotherapy, receiving no antiplatelet therapy was associated with significantly worse patient outcomes (hazard ratio 1.50; 95% CI 1.21-1.87), whilst receiving prescribed aspirin with dipyridamole was associated with better outcomes (hazard ratio 0.75; 95% CI 0.56-0.99). Only a few patients received clopidogrel or other antiplatelet regimens. CONCLUSIONS: Patients discharged on dual therapy have worse adherence to their initial regimen but better persistence to any antiplatelet agents in the long term. Continued exposure to antiplatelet regimens predicts good outcomes in patients with cerebral infarction.