👤 KEYNOTE-355 Investigators

Opicinumab is a human monoclonal antibody against LINGO-1, an inhibitor of oligodendrocyte differentiation and axonal regeneration. Previous findings suggested that opicinumab treatment might enhance remyelination in patients with CNS demyelinating diseases. We aimed to assess the safety and efficacy of opicinumab in patients with relapsing multiple sclerosis. We did a randomised, double-blind, placebo-controlled, dose-ranging, phase 2 study (SYNERGY) at 72 sites in 12 countries. Participants (aged 18-58 years) with relapsing multiple sclerosis (relapsing-remitting multiple sclerosis and secondary progressive multiple sclerosis with relapses) were randomised in a 1:2:2:2:2 ratio by an interactive voice and web response system to opicinumab 3 mg/kg, 10 mg/kg, 30 mg/kg, or 100 mg/kg, or placebo. An identical volume of study drug was administered intravenously once every 4 weeks. All participants self-administered intramuscular interferon beta-1a as background anti-inflammatory treatment once a week. The primary endpoint was the percentage of participants achieving confirmed disability improvement over 72 weeks, which was a multicomponent endpoint measured by the Expanded Disability Status Scale, the Timed 25-Foot Walk, the Nine-Hole Peg Test, and the 3 s Paced Auditory Serial Addition Test. The primary endpoint was analysed under intention-to-treat principles. This study is registered at ClinicalTrials.gov, number NCT01864148. Between Aug 13, 2013, and July 31, 2014, 419 patients were enrolled and randomly assigned either placebo (n=93) or opicinumab 3 mg/kg (n=45), 10 mg/kg (n=95), 30 mg/kg (n=94; one patient did not receive the assigned treatment), or 100 mg/kg (n=92). The last patient visit was on March 29, 2016. Confirmed disability improvement over 72 weeks was seen in 45 (49%) of 91 patients assigned to placebo, 21 (47%) of 45 assigned to opicinumab 3 mg/kg, 59 (63%) of 94 assigned to opicinumab 10 mg/kg, 59 (65%) of 91 assigned to opicinumab 30 mg/kg, and 36 (40%) of 91 assigned to opicinumab 100 mg/kg. A linear dose-response in the probability of confirmed disability improvement was not seen (linear trend test p=0·89). Adverse events occurred in 79 (85%) patients assigned placebo and in 275 (85%) assigned any dose of opicinumab. The most common adverse events of any grade in patients assigned any dose of opicinumab included influenza-like illness (140 [43%] with any dose of opicinumab vs 37 [40%] with placebo), multiple sclerosis relapses (117 [36%] vs 30 [32%]), and headache (51 [16%] vs 23 [25%]). Serious adverse events reported as related to treatment were urinary tract infection in one (1%) participant in the the placebo group, suicidal ideation and intentional overdose in one (1%) participant in the 30 mg/kg opicinumab group, bipolar disorder in one (1%) participant in the 100 mg/kg opicinumab group, and hypersensitivity in four (4%) participants in the 100 mg/kg opicinumab group. One patient in the opicinumab 30 mg/kg group died during the study due to a traffic accident, which was not considered related to study treatment. Our findings did not show a significant dose-linear improvement in disability compared with placebo in patients with relapsing multiple sclerosis. Further studies are needed to investigate whether some subpopulations identified in the study might benefit from opicinumab treatment at an optimum dose. Biogen. Show less

Sudden cardiac death (SCD) risk stratification in dilated cardiomyopathy (DCM) has been based on left ventricular ejection fraction (LVEF), even though SCD may occur with LVEF > 35%. Family history of unexplained SCD, especially in the young, raises concern about potential inheritable risk factors. It remains largely unknown how genetic tests can be integrated into clinical practice, particularly in the selection of implantable cardioverter defibrillator (ICD) candidates. We aimed to assess the diagnostic yield of genetic testing in DCM patients with a class I recommendation for ICD implantation, based on current guidelines. We included ambulatory stable adult patients with idiopathic or familial DCM with previously implanted ICD. Molecular analysis included 15 genes ( We evaluated 21 patients, 12 (57%) males and 9 (43%) with familial DCM, including 3 (14%) with a family history of premature unexplained SCD. Mean age at DCM diagnosis was 40 ± 2 years, and mean age at ICD implantation was 50 ± 12 years. LVEF was 27 ± 9%, and LV end-diastolic diameter was 65 ± 7 mm. Genetic variants were found in six (29%) patients, occurring in 5 genes: In patients with DCM and ICD, genetic variants could be identified in a significant proportion of patients in several genes, highlighting the potential role of genetics in DCM SCD risk stratification. Show less

Dilated cardiomyopathy (DCM) is a disease of the heart muscle characterized by ventricular dilatation and impaired systolic function. Familial forms account for 30-50% of cases. Autosomal dominant inheritance is the predominant pattern of transmission. Causal genetic variants have been identified in several genes and molecular diagnosis has implications for genetic counseling and risk stratification. We aimed to estimate the frequency of genetic variants and the molecular basis of DCM in Portugal. We performed a multicenter study of unrelated patients, recruited between 2013 and 2014. Variants in 15 genes were screened using PCR with direct sequencing (next-generation sequencing with at least 30-fold coverage combined with Sanger sequencing). A total of 107 patients were included, 64 (60%) men, mean age at diagnosis 38±13 years, with 48 (45%) familial cases. In total, 31 rare variants in eight genes (mainly in MYBPC3, TNNT2 and LMNA) were identified, in 28 patients (26%). Only four variants had been previously described in association with DCM, 11 with hypertrophic cardiomyopathy, and nine variants were novel. Four variants were likely pathogenic and the remainder were of uncertain significance. We found no major differences in the main clinical and imaging characteristics between patients with or without rare variants and patients with likely pathogenic variants. Our results reflect the complexity and diversity of DCM genetics. For better interpretation of the pathogenicity of the variants found and their causative roles in DCM, molecular cascade screening of families is imperative. Further insight into genotype-phenotype correlations and risk stratification is desirable. Show less

Genome-wide association studies (GWAS) have identified >250 loci for body mass index (BMI), implicating pathways related to neuronal biology. Most GWAS loci represent clusters of common, noncoding variants from which pinpointing causal genes remains challenging. Here we combined data from 718,734 individuals to discover rare and low-frequency (minor allele frequency (MAF) < 5%) coding variants associated with BMI. We identified 14 coding variants in 13 genes, of which 8 variants were in genes (ZBTB7B, ACHE, RAPGEF3, RAB21, ZFHX3, ENTPD6, ZFR2 and ZNF169) newly implicated in human obesity, 2 variants were in genes (MC4R and KSR2) previously observed to be mutated in extreme obesity and 2 variants were in GIPR. The effect sizes of rare variants are ~10 times larger than those of common variants, with the largest effect observed in carriers of an MC4R mutation introducing a stop codon (p.Tyr35Ter, MAF = 0.01%), who weighed ~7 kg more than non-carriers. Pathway analyses based on the variants associated with BMI confirm enrichment of neuronal genes and provide new evidence for adipocyte and energy expenditure biology, widening the potential of genetically supported therapeutic targets in obesity. Show less

Multifocal visual evoked potential (MF-VEP) assesses a wider visual field than full-field VEP (FF-VEP) and potentially offers a more precise analysis of optic nerve injury and repair following optic neuritis. MF-VEP may offer advantages over FF-VEP as an endpoint in clinical trials of remyelinating therapies. MF-VEP testing was used to study changes in visual pathways in 48% of RENEW [phase II, opicinumab (anti-LINGO-1; BIIB033) vs. placebo after first acute unilateral optic neuritis] participants. This exploratory MF-VEP RENEW substudy compared mean outcomes at weeks 24 and 32 among participants in the intent-to-treat (ITT; n = 39; 72% female; mean age: 32.3 years) and per-protocol (PP; n = 31; 71% female; mean age: 32.2 years) populations in affected and fellow eye latency from fellow eye baseline latency and affected and fellow eye amplitude from their own baselines. Treatment differences were evaluated using analysis of covariance (week 24) and a mixed-effect model of repeated measures (week 32). Last observation carried forward was used to impute missing data at week 24. A trend for improvement in affected eye MF-VEP latency with opicinumab versus placebo was seen in the ITT and PP populations at weeks 24 and 32. Both treatment groups in the ITT population experienced partial recovery of amplitude in the affected eye at week 32. Notably, the mean change in fellow eye amplitude at weeks 24 and 32 was - 17.57 and - 31.41 nanovolts (nV) in placebo but only - 0.59 and 1.93 nV in the opicinumab group [differences at weeks 24 and 32: 16.98 nV (p = 0.050) and 33.33 nV (p < 0.01), respectively]. Results from this substudy showed advantages of MF-VEP over FF-VEP in multicenter studies of central nervous system reparative therapies and provide novel evidence that fellow eye visual pathway amplitude loss occurs after optic neuritis but can potentially be prevented by opicinumab treatment. ClinicalTrials.gov identifier NCT01721161. Show less

Background Although atrial fibrillation (AF) is common in hypertrophic cardiomyopathy (HCM) patients, the relationship between genetic variation and AF has been poorly defined. Characterizing genetic subtypes of HCM and their associations with AF may help to improve personalized medical care. We aimed to investigate the link between sarcomeric gene variation and incident AF in HCM patients. Methods and Results Patients from the multinational Sarcomeric Human Cardiomyopathy Registry were followed for incident AF. Those with likely pathogenic or pathogenic variants in sarcomeric genes were included. The AF incidence was ascertained by review of medical records and electrocardiograms at each investigative site. One thousand forty adult HCM patients, without baseline AF and with likely pathogenic or pathogenic variation in either MYH7 (n=296), MYBPC3 (n=659), or thin filament genes (n=85), were included. Compared with patients with variation in other sarcomeric genes, those with MYH7 variants were younger on first clinical encounter at the Sarcomeric Human Cardiomyopathy Registry site and more likely to be probands than the MYBPC3 variants. During an average follow-up of 7.2 years, 198 incident AF events occurred. Patients with likely pathogenic or pathogenic mutations in MYH7 had the highest incidence of AF after adjusting for age, sex, proband status, left atrial size, maximal wall thickness, and peak pressure gradient (hazard ratio, 1.7; 95% CI, 1.1-2.6; P=0.009). Conclusions During a mean follow-up of 7.2 years, new-onset AF developed in 19% of HCM patients with sarcomeric mutations. Compared with other sarcomeric genes, patients with likely pathogenic or pathogenic variation in MYH7 had a higher rate of incident AF independent of clinical and echocardiographic factors. Show less

The optimal approaches to management of patients treated with moderate statin doses on lipid parameters are unknown. The ACCENTUATE study aimed to compare the effects of adding the cholesteryl ester transfer protein inhibitor (CETP) evacetrapib, ezetimibe or increasing statin dose in atorvastatin-treated high-vascular risk patients on lipid parameters. 366 patients with atherosclerotic cardiovascular disease (ASCVD) and/or diabetes were treated with atorvastatin 40 mg/day for 28 days prior to randomization to atorvastatin 40 mg plus evacetrapib 130 mg, atorvastatin 80 mg, atorvastatin 40 mg plus ezetimibe 10 mg or atorvastatin 40 mg plus placebo, daily for 90 days at 64 centers in the United States. Lipid parameters, safety and tolerability were measured. Addition of evacetrapib significantly reduced LDL-C (-33%) compared with ezetimibe (-27%, p=0.045), increasing statin dose (-6%) and statin alone (0%, p<0.001). Evacetrapib also decreased apoB by 23% compared to 19% with ezetimibe (p=0.06) and 7% with increased statin dose (p<0.001), and reduced Lp(a) by 29% (p<0.001 vs. other groups). Evacetrapib increased HDL-C (+125%), apoA-I (+46%), apoC-III (+50%) and apoE (+28%) (p<0.001 vs. other groups). Non-ABCA1-mediated efflux increased by 53% (p<0.001 vs. other groups) with evacetrapib. ABCA1-mediated efflux also increased by 13% with evacetrapib (p<0.001 vs. ezetimibe, p=0.002 vs. increasing statin dose, and p=0.004 vs. statin alone). Addition of evacetrapib to atorvastatin produced an increase in hsCRP compared with ezetimibe (p=0.02). While evacetrapib improved traditional atherogenic and putative protective lipid measures compared with ezetimibe and increasing statin dose in patients with ASCVD and/or diabetes, it also adversely affected novel atherogenic risk factors. These findings may contribute to the lack of clinical benefit observed in the ACCELERATE trial. Show less

Genome-wide association studies have so far identified 56 loci associated with risk of coronary artery disease (CAD). Many CAD loci show pleiotropy; that is, they are also associated with other diseases or traits. This study sought to systematically test if genetic variants identified for non-CAD diseases/traits also associate with CAD and to undertake a comprehensive analysis of the extent of pleiotropy of all CAD loci. In discovery analyses involving 42,335 CAD cases and 78,240 control subjects we tested the association of 29,383 common (minor allele frequency >5%) single nucleotide polymorphisms available on the exome array, which included a substantial proportion of known or suspected single nucleotide polymorphisms associated with common diseases or traits as of 2011. Suggestive association signals were replicated in an additional 30,533 cases and 42,530 control subjects. To evaluate pleiotropy, we tested CAD loci for association with cardiovascular risk factors (lipid traits, blood pressure phenotypes, body mass index, diabetes, and smoking behavior), as well as with other diseases/traits through interrogation of currently available genome-wide association study catalogs. We identified 6 new loci associated with CAD at genome-wide significance: on 2q37 (KCNJ13-GIGYF2), 6p21 (C2), 11p15 (MRVI1-CTR9), 12q13 (LRP1), 12q24 (SCARB1), and 16q13 (CETP). Risk allele frequencies ranged from 0.15 to 0.86, and odds ratio per copy of the risk allele ranged from 1.04 to 1.09. Of 62 new and known CAD loci, 24 (38.7%) showed statistical association with a traditional cardiovascular risk factor, with some showing multiple associations, and 29 (47%) showed associations at p < 1 × 10 We identified 6 loci associated with CAD at genome-wide significance. Several CAD loci show substantial pleiotropy, which may help us understand the mechanisms by which these loci affect CAD risk. Show less

Recent genome-wide association studies (GWAS) and pathway analyses supported long-standing observations of an association between immune-mediated diseases and Parkinson disease (PD). The post-GWAS era provides an opportunity for cross-phenotype analyses between different complex phenotypes. To test the hypothesis that there are common genetic risk variants conveying risk of both PD and autoimmune diseases (ie, pleiotropy) and to identify new shared genetic variants and their pathways by applying a novel statistical framework in a genome-wide approach. Using the conjunction false discovery rate method, this study analyzed GWAS data from a selection of archetypal autoimmune diseases among 138 511 individuals of European ancestry and systemically investigated pleiotropy between PD and type 1 diabetes, Crohn disease, ulcerative colitis, rheumatoid arthritis, celiac disease, psoriasis, and multiple sclerosis. NeuroX data (6927 PD cases and 6108 controls) were used for replication. The study investigated the biological correlation between the top loci through protein-protein interaction and changes in the gene expression and methylation levels. The dates of the analysis were June 10, 2015, to March 4, 2017. The primary outcome was a list of novel loci and their pathways involved in PD and autoimmune diseases. Genome-wide conjunctional analysis identified 17 novel loci at false discovery rate less than 0.05 with overlap between PD and autoimmune diseases, including known PD loci adjacent to GAK, HLA-DRB5, LRRK2, and MAPT for rheumatoid arthritis, ulcerative colitis and Crohn disease. Replication confirmed the involvement of HLA, LRRK2, MAPT, TRIM10, and SETD1A in PD. Among the novel genes discovered, WNT3, KANSL1, CRHR1, BOLA2, and GUCY1A3 are within a protein-protein interaction network with known PD genes. A subset of novel loci was significantly associated with changes in methylation or expression levels of adjacent genes. The study findings provide novel mechanistic insights into PD and autoimmune diseases and identify a common genetic pathway between these phenotypes. The results may have implications for future therapeutic trials involving anti-inflammatory agents. Show less

The human monoclonal antibody opicinumab (BIIB033, anti-LINGO-1) has shown remyelinating activity in preclinical studies. We therefore assessed the safety and tolerability, and efficacy of opicinumab given soon after a first acute optic neuritis episode. This randomised, double-blind, placebo-controlled, phase 2 study (RENEW) was done at 33 sites in Australia, Canada, and Europe in participants (aged 18-55 years) with a first unilateral acute optic neuritis episode within 28 days from study baseline. After treatment with high-dose methylprednisolone (1 g/day, intravenously, for 3-5 days), participants were assigned with a computer-generated sequence with permuted block randomisation (1:1) using a centralised interactive voice and web response system to receive 100 mg/kg opicinumab intravenously or placebo once every 4 weeks (six doses) and followed up to week 32. All study participants and all study staff, including the central readers, were masked to treatment assignment apart from the pharmacist responsible for preparing the study treatments and the pharmacy monitor at each site. The primary endpoint was remyelination at 24 weeks, measured as recovery of affected optic nerve conduction latency using full-field visual evoked potential (FF-VEP) versus the unaffected fellow eye at baseline. Analysis was by intention-to-treat (ITT); prespecified per-protocol (PP) analyses were also done. This study is registered with ClinicalTrials.gov, number NCT01721161. The study was done between Dec 21, 2012, and Oct 21, 2014. 82 participants were enrolled, and 41 in each group comprised the ITT population; 33 participants received opicinumab and 36 received placebo in the PP population. Adjusted mean treatment difference of opicinumab versus placebo was -3·5 ms (17·3 vs 20·8 [95% CI -10·6 to 3·7]; 17%; p=0·33) in the ITT population, and -7·6 ms in the PP population (14·7 vs 22·2 [-15·1 to 0·0]; 34%; p=0·050) at week 24 and -6·1 ms (15·1 vs 21·2 [-12·7 to 0·5]; 29%; p=0·071) in the ITT population and -9·1 ms (13·2 vs 22·4 [-16·1 to -2·1]; 41%; p=0·011) in the PP population at week 32. The overall incidence (34 [83%] of 41 in each group) and severity of adverse events (two [5%] of 41 severe adverse events with placebo vs three [7%] of 41 with opicinumab) were similar between groups and no significant effects on brain MRI measures were noted in either group (mean T2 lesion volume change, 0·05 mL [SD 0·21] for placebo vs 0·20 mL [0·52] with opicinumab; 27 [77%] of 35 participants with no change in gadolinium-enhancing [Gd+] lesion number with opicinumab vs 27 [79%] of 34 with placebo; mean 0·4 [SD 0·79 for the placebo group and 0·85 for the opicinumab group] new Gd+ lesions per participant in both groups). Treatment-related serious adverse events were reported in three (7%) of 41 participants in the opicinumab group (hypersensitivity [n=2], asymptomatic increase in transaminase concentrations [n=1]) and none of the participants in the placebo group. Remyelination did not differ significantly between the opicinumab and placebo groups in the ITT population at week 24. However, results from the prespecified PP population suggest that enhancing remyelination in the human CNS with opicinumab might be possible and warrant further clinical investigation. Biogen. Show less

Observational studies have shown a positive association between obesity (body mass index [BMI] ≥ 30 kg/m2) and depression. Around 120 obesity-associated loci have been identified, but genetic variants associated with depression remain elusive. Recently, our team reported that the fat mass and obesity-associated (FTO) gene rs9939609 obesity-risk variant is paradoxically inversely associated with the risk of depression. This finding raises the question as to whether other obesity-associated genetic variants are also associated with depression. Twenty-one obesity gene variants other than FTO were selected from a custom ∼50,000 single-nucleotide polymorphisms (SNPs) genotyping array (ITMAT-Broad-CARe array). Associations of these 21 SNPs and an unweighted genotype score with BMI and major depressive disorder (determined using the DSM-IV diagnostic criteria) were tested in 3,209 cases and 14,195 noncases, using baseline data collected from July 2001 to August 2003 from the multiethnic EpiDREAM study. Body mass index was positively associated with depression status (odds ratio [OR] = 1.02; 95% CI, 1.02-1.03 per BMI unit; P = 2.9 × 10(-12), adjusted for age, sex, and ethnicity). Six of 21 genetic variants (rs1514176 [TNN13K], rs2206734 [CDKAL1], rs11671664 [GIPR], rs2984618 [TAL1], rs3824755 [NT5C2], and rs7903146 [TCF7L2]) and the genotype score were significantly associated with BMI (1.47 × 10(-14) ≤ P ≤ .04). Of the 21 SNPs, TAL1 rs2984618 obesity-risk allele was associated with a higher risk of major depressive disorder (P = 1.79 × 10(-4), adjusted for age, sex, BMI, and ethnicity), and BDNF rs1401635 demonstrated significant ethnic-dependent association with major depressive disorder (OR = 0.88; 95% CI, 0.80-0.97; P = .01 in non-Europeans and OR = 1.11; 95% CI, 1.02-1.20; P = .02 in Europeans; Pinteraction = 2.73 × 10(-4)). The genotype score, calculated with or without FTO rs9939609, and adjusted for the same covariates, was not associated with depression status. Our data support the view that the association between obesity and major depressive disorder at the observational level may be explained, at least in part, by shared genetic factors. Show less

The PREDIMED (PREvención con DIeta MEDiterránea) multicenter, randomized, primary prevention trial assessed the long-term effects of the Mediterranean diet (MeDiet) on clinical events of cardiovascular disease (CVD). We randomized 7447 men and women at high CVD risk into three diets: MeDiet supplemented with extra-virgin olive oil (EVOO), MeDiet supplemented with nuts, and control diet (advice on a low-fat diet). No energy restriction and no special intervention on physical activity were applied. We observed 288 CVD events (a composite of myocardial infarction, stroke or CVD death) during a median time of 4.8years; hazard ratios were 0.70 (95% CI, 0.53-0.91) for the MeDiet+EVOO and 0.70 (CI, 0.53-0.94) for the MeDiet+nuts compared to the control group. Respective hazard ratios for incident diabetes (273 cases) among 3541 non-diabetic participants were 0.60 (0.43-0.85) and 0.82 (0.61-1.10) for MeDiet+EVOO and MeDiet+nuts, respectively versus control. Significant improvements in classical and emerging CVD risk factors also supported a favorable effect of both MeDiets on blood pressure, insulin sensitivity, lipid profiles, lipoprotein particles, inflammation, oxidative stress, and carotid atherosclerosis. In nutrigenomic studies beneficial effects of the intervention with MedDiets showed interactions with several genetic variants (TCF7L2, APOA2, MLXIPL, LPL, FTO, M4CR, COX-2, GCKR and SERPINE1) with respect to intermediate and final phenotypes. Thus, the PREDIMED trial provided strong evidence that a vegetable-based MeDiet rich in unsaturated fat and polyphenols can be a sustainable and ideal model for CVD prevention. Show less

We evaluated whether the association of insulin sensitivity with HDL cholesterol (HDL) and triglycerides is influenced by major plasma apolipoproteins, as suggested by recent experimental evidence. This study included a cross-sectional analysis of the RISC Study, a multicenter European clinical investigation in 1,017 healthy volunteers balanced in sex (women 54%) and age strata (range 30-60 years). Insulin sensitivity (M/I in µmol ⋅ min(-1) ⋅ kgFFM(-1) ⋅ nM(-1)) was measured by the clamp technique and apolipoproteins (ApoB, -C3, -A1, and -E) by Multiplex Technology. The center-, sex-, and age-adjusted standardized regression coefficients (STDβ) with M/I were similar for HDL and triglycerides (+19.9 ± 1.9 vs. -20.0 ± 2.0, P < 0.0001). Further adjustment for triglycerides (or HDL), BMI, and adiponectin (or nonesterified fatty acid) attenuated the strength of the association of M/I with both HDL (STDβ +6.4 ± 2.3, P < 0.01) and triglycerides (-9.5 ± 2.1, P < 0.001). Neither ApoA1 nor ApoE and ApoB showed any association with M/I independent from plasma HDL cholesterol and triglycerides. ApoC3, in contrast, in both men and women, was positively associated with M/I independently of plasma lipids. A relative enrichment of plasma lipids with ApoC3 is associated with lower body fat percentage and lower plasma alanine amino transferase. Our results suggest that HDL cholesterol modulates insulin sensitivity through a mechanism that is partially mediated by BMI and adiponectin but not by ApoA1. Similarly, the influence of triglycerides on insulin sensitivity is in part mediated by BMI and is unrelated to ApoE or ApoB, but it is significantly modulated by ApoC3, which appears to protect from the negative effect of plasma lipids. Show less

Circulating metabolites associated with insulin sensitivity may represent useful biomarkers, but their causal role in insulin sensitivity and diabetes is less certain. We previously identified novel metabolites correlated with insulin sensitivity measured by the hyperinsulinemic-euglycemic clamp. The top-ranking metabolites were in the glutathione and glycine biosynthesis pathways. We aimed to identify common genetic variants associated with metabolites in these pathways and test their role in insulin sensitivity and type 2 diabetes. With 1,004 nondiabetic individuals from the RISC study, we performed a genome-wide association study (GWAS) of 14 insulin sensitivity-related metabolites and one metabolite ratio. We replicated our results in the Botnia study (n = 342). We assessed the association of these variants with diabetes-related traits in GWAS meta-analyses (GENESIS [including RISC, EUGENE2, and Stanford], MAGIC, and DIAGRAM). We identified four associations with three metabolites-glycine (rs715 at CPS1), serine (rs478093 at PHGDH), and betaine (rs499368 at SLC6A12; rs17823642 at BHMT)-and one association signal with glycine-to-serine ratio (rs1107366 at ALDH1L1). There was no robust evidence for association between these variants and insulin resistance or diabetes. Genetic variants associated with genes in the glycine biosynthesis pathways do not provide consistent evidence for a role of glycine in diabetes-related traits. Show less

Apolipoprotein A-IV (apoA-IV) is an anti-atherogenic and anti-oxidative plasma glycoprotein involved in reverse cholesterol transport. The aim of this study was to examine the association between apoA-IV and all-cause mortality, cardiovascular endpoints and parameters of protein-energy wasting and nutrition in haemodialysis patients. This post hoc analysis was performed in the German Diabetes Dialysis Study (4D Study) evaluating atorvastatin in 1255 haemodialysis patients with type 2 diabetes mellitus, followed for a median of 4 years. The association between apoA-IV and relevant outcomes was analysed using Cox proportional hazards regression analyses. Body mass index (BMI) was used as a marker of protein-energy wasting. In addition, a definition of extended wasting was applied, combining median values of BMI, serum albumin, creatinine and sensitive C-reactive protein, to classify patients. Mean (±SD) apoA-IV concentration was 49.8 ± 14.2 mg dL(-1). Age- and gender-adjusted apoA-IV concentrations were strongly associated with the presence of congestive heart failure at baseline [odds ratio = 0.81, 95% confidence interval (CI) 0.74-0.88 per 10 mg dL(-1) increase; P < 0.001). During the prospective follow-up, the strongest association was found for all-cause mortality [hazard ratio (HR) = 0.89, 95% CI 0.85-0.95, P = 0.001), which was mainly because of patients with BMI > 23 kg m(-2) (HR = 0.87, 95% CI 0.82-0.94, P < 0.001) and those in the nonwasting group according to the extended definition (HR = 0.89, 95% CI 0.84-0.96, P = 0.001). This association remained significant after additionally adjusting for parameters associated with apoA-IV at baseline. Further associations were observed for sudden cardiac death. ApoA-IV was less strongly associated with atherogenic events such as myocardial infarction. Low apoA-IV levels seem to be a risk predictor of all-cause mortality and sudden cardiac death. This association might be modified by nutritional status. Show less

OBJECTIVE Recent genome-wide association studies have revealed loci associated with glucose and insulin-related traits. We aimed to characterize 19 such loci using detailed measures of insulin processing, secretion, and sensitivity to help elucidate their role in regulation of glucose control, insulin secretion and/or action. RESEARCH DESIGN AND METHODS We investigated associations of loci identified by the Meta-Analyses of Glucose and Insulin-related traits Consortium (MAGIC) with circulating proinsulin, measures of insulin secretion and sensitivity from oral glucose tolerance tests (OGTTs), euglycemic clamps, insulin suppression tests, or frequently sampled intravenous glucose tolerance tests in nondiabetic humans (n = 29,084). RESULTS The glucose-raising allele in MADD was associated with abnormal insulin processing (a dramatic effect on higher proinsulin levels, but no association with insulinogenic index) at extremely persuasive levels of statistical significance (P = 2.1 x 10(-71)). Defects in insulin processing and insulin secretion were seen in glucose-raising allele carriers at TCF7L2, SCL30A8, GIPR, and C2CD4B. Abnormalities in early insulin secretion were suggested in glucose-raising allele carriers at MTNR1B, GCK, FADS1, DGKB, and PROX1 (lower insulinogenic index; no association with proinsulin or insulin sensitivity). Two loci previously associated with fasting insulin (GCKR and IGF1) were associated with OGTT-derived insulin sensitivity indices in a consistent direction. CONCLUSIONS Genetic loci identified through their effect on hyperglycemia and/or hyperinsulinemia demonstrate considerable heterogeneity in associations with measures of insulin processing, secretion, and sensitivity. Our findings emphasize the importance of detailed physiological characterization of such loci for improved understanding of pathways associated with alterations in glucose homeostasis and eventually type 2 diabetes. Show less

Glucose levels 2 h after an oral glucose challenge are a clinical measure of glucose tolerance used in the diagnosis of type 2 diabetes. We report a meta-analysis of nine genome-wide association studies (n = 15,234 nondiabetic individuals) and a follow-up of 29 independent loci (n = 6,958-30,620). We identify variants at the GIPR locus associated with 2-h glucose level (rs10423928, beta (s.e.m.) = 0.09 (0.01) mmol/l per A allele, P = 2.0 x 10(-15)). The GIPR A-allele carriers also showed decreased insulin secretion (n = 22,492; insulinogenic index, P = 1.0 x 10(-17); ratio of insulin to glucose area under the curve, P = 1.3 x 10(-16)) and diminished incretin effect (n = 804; P = 4.3 x 10(-4)). We also identified variants at ADCY5 (rs2877716, P = 4.2 x 10(-16)), VPS13C (rs17271305, P = 4.1 x 10(-8)), GCKR (rs1260326, P = 7.1 x 10(-11)) and TCF7L2 (rs7903146, P = 4.2 x 10(-10)) associated with 2-h glucose. Of the three newly implicated loci (GIPR, ADCY5 and VPS13C), only ADCY5 was found to be associated with type 2 diabetes in collaborating studies (n = 35,869 cases, 89,798 controls, OR = 1.12, 95% CI 1.09-1.15, P = 4.8 x 10(-18)). Show less

Levels of circulating glucose are tightly regulated. To identify new loci influencing glycemic traits, we performed meta-analyses of 21 genome-wide association studies informative for fasting glucose, fasting insulin and indices of beta-cell function (HOMA-B) and insulin resistance (HOMA-IR) in up to 46,186 nondiabetic participants. Follow-up of 25 loci in up to 76,558 additional subjects identified 16 loci associated with fasting glucose and HOMA-B and two loci associated with fasting insulin and HOMA-IR. These include nine loci newly associated with fasting glucose (in or near ADCY5, MADD, ADRA2A, CRY2, FADS1, GLIS3, SLC2A2, PROX1 and C2CD4B) and one influencing fasting insulin and HOMA-IR (near IGF1). We also demonstrated association of ADCY5, PROX1, GCK, GCKR and DGKB-TMEM195 with type 2 diabetes. Within these loci, likely biological candidate genes influence signal transduction, cell proliferation, development, glucose-sensing and circadian regulation. Our results demonstrate that genetic studies of glycemic traits can identify type 2 diabetes risk loci, as well as loci containing gene variants that are associated with a modest elevation in glucose levels but are not associated with overt diabetes. Show less

Blood lipids are important cardiovascular disease (CVD) risk factors with both genetic and environmental determinants. The Whitehall II study (n=5592) was genotyped with the gene-centric HumanCVD BeadChip (Illumina). We identified 195 SNPs in 16 genes/regions associated with 3 major lipid fractions and 2 apolipoprotein components at p<10(-5), with the associations being broadly concordant with prior genome-wide analysis. SNPs associated with LDL cholesterol and apolipoprotein B were located in LDLR, PCSK9, APOB, CELSR2, HMGCR, CETP, the TOMM40-APOE-C1-C2-C4 cluster, and the APOA5-A4-C3-A1 cluster; SNPs associated with HDL cholesterol and apolipoprotein AI were in CETP, LPL, LIPC, APOA5-A4-C3-A1, and ABCA1; and SNPs associated with triglycerides in GCKR, BAZ1B, MLXIPL, LPL, and APOA5-A4-C3-A1. For 48 SNPs in previously unreported loci that were significant at p<10(-4) in Whitehall II, in silico analysis including the British Women's Heart and Health Study, BRIGHT, ASCOT, and NORDIL studies (total n>12,500) revealed previously unreported associations of SH2B3 (p<2.2x10(-6)), BMPR2 (p<2.3x10(-7)), BCL3/PVRL2 (flanking APOE; p<4.4x10(-8)), and SMARCA4 (flanking LDLR; p<2.5x10(-7)) with LDL cholesterol. Common alleles in these genes explained 6.1%-14.7% of the variance in the five lipid-related traits, and individuals at opposite tails of the additive allele score exhibited substantial differences in trait levels (e.g., >1 mmol/L in LDL cholesterol [approximately 1 SD of the trait distribution]). These data suggest that multiple common alleles of small effect can make important contributions to individual differences in blood lipids potentially relevant to the assessment of CVD risk. These genes provide further insights into lipid metabolism and the likely effects of modifying the encoded targets therapeutically. Show less

Recent genome-wide association studies (GWAS) have reproducibly identified loci associated with plasma triglycerides (TG), HDL cholesterol, and LDL cholesterol. We sought to replicate these findings in a multiethnic population-based cohort using the curated single nucleotide polymorphism (SNP) set found on the new Illumina cardiovascular disease (CVD) beadchip, which contains approximately 50,000 SNPs densely mapping approximately 2,100 genes, selected based on their potential role in CVD. The sample consisted of individuals with European (n = 272), South Asian (n = 330), and Chinese (n = 304) ancestry. Identity by state clustering successfully classified individuals according to self-reported ethnicities. Associations between TG and APOA5, TG and LPL, HDL and CETP, and LDL and APOE were all identified (P < 2 x 10(-6)). In 13 loci, associations with the same SNP or a proxy SNP were identified in the same direction as previously reported (P < 0.05). Assessing the cumulative number of risk-associated alleles at multiple replicated SNPs increased the proportion of explained lipoprotein variance over and above traditional variables such as age, sex, body mass index, and ethnicity. The findings indicate the potential utility of the Illumina CVD beadchip, but they underscore the need to consider meta-analysis of results from commonly studied clinical or epidemiological samples. Show less

Deletions within the neurexin 1 gene (NRXN1; 2p16.3) are associated with autism and have also been reported in two families with schizophrenia. We examined NRXN1, and the closely related NRXN2 and NRXN3 genes, for copy number variants (CNVs) in 2977 schizophrenia patients and 33 746 controls from seven European populations (Iceland, Finland, Norway, Germany, The Netherlands, Italy and UK) using microarray data. We found 66 deletions and 5 duplications in NRXN1, including a de novo deletion: 12 deletions and 2 duplications occurred in schizophrenia cases (0.47%) compared to 49 and 3 (0.15%) in controls. There was no common breakpoint and the CNVs varied from 18 to 420 kb. No CNVs were found in NRXN2 or NRXN3. We performed a Cochran-Mantel-Haenszel exact test to estimate association between all CNVs and schizophrenia (P = 0.13; OR = 1.73; 95% CI 0.81-3.50). Because the penetrance of NRXN1 CNVs may vary according to the level of functional impact on the gene, we next restricted the association analysis to CNVs that disrupt exons (0.24% of cases and 0.015% of controls). These were significantly associated with a high odds ratio (P = 0.0027; OR 8.97, 95% CI 1.8-51.9). We conclude that NRXN1 deletions affecting exons confer risk of schizophrenia. Show less