Abstract Background Approximately 7% of American adults have severe hypercholesterolemia (untreated low-density lipoprotein LDL cholesterol ≥190 mg/dl), which may be due to familial ...hypercholesterolemia (FH). Lifelong LDL cholesterol elevations in FH mutation carriers may confer coronary artery disease (CAD) risk beyond that captured by a single LDL cholesterol measurement. Objectives This study assessed the prevalence of an FH mutation among those with severe hypercholesterolemia and determined whether CAD risk varies according to mutation status beyond the observed LDL cholesterol level. Methods Three genes causative for FH ( LDLR , APOB , and PCSK9 ) were sequenced in 26,025 participants from 7 case-control studies (5,540 CAD case subjects, 8,577 CAD-free control subjects) and 5 prospective cohort studies (11,908 participants). FH mutations included loss-of-function variants in LDLR , missense mutations in LDLR predicted to be damaging, and variants linked to FH in ClinVar, a clinical genetics database. Results Among 20,485 CAD-free control and prospective cohort participants, 1,386 (6.7%) had LDL cholesterol ≥190 mg/dl; of these, only 24 (1.7%) carried an FH mutation. Within any stratum of observed LDL cholesterol, risk of CAD was higher among FH mutation carriers than noncarriers. Compared with a reference group with LDL cholesterol <130 mg/dl and no mutation, participants with LDL cholesterol ≥190 mg/dl and no FH mutation had a 6-fold higher risk for CAD (odds ratio: 6.0; 95% confidence interval: 5.2 to 6.9), whereas those with both LDL cholesterol ≥190 mg/dl and an FH mutation demonstrated a 22-fold increased risk (odds ratio: 22.3; 95% confidence interval: 10.7 to 53.2). In an analysis of participants with serial lipid measurements over many years, FH mutation carriers had higher cumulative exposure to LDL cholesterol than noncarriers. Conclusions Among participants with LDL cholesterol ≥190 mg/dl, gene sequencing identified an FH mutation in <2%. However, for any observed LDL cholesterol, FH mutation carriers had substantially increased risk for CAD.
Genome-wide association studies (GWAS) have identified common genetic variants that predispose to atrial fibrillation (AF). It is unclear whether rare and low-frequency variants in genes implicated ...by such GWAS confer additional risk of AF.
To study the association of genetic variants with AF at GWAS top loci.
In the Cohorts for Heart and Aging Research in Genomic Epidemiology (CHARGE) Targeted Sequencing Study, we selected and sequenced 77 target gene regions from GWAS loci of complex diseases or traits, including 4 genes hypothesized to be related to AF (PRRX1, CAV1, CAV2, and ZFHX3). Sequencing was performed in participants with (n = 948) and without (n = 3330) AF from the Atherosclerosis Risk in Communities Study, the Cardiovascular Health Study, the Framingham Heart Study, and the Massachusetts General Hospital.
One common variant (rs11265611; P = 1.70 × 10(-6)) intronic to IL6R (interleukin-6 receptor gene) was significantly associated with AF after Bonferroni correction (odds ratio 0.70; 95% confidence interval 0.58-0.85). The variant was not genotyped or imputed by prior GWAS, but it is in linkage disequilibrium (r(2) = .69) with the single-nucleotide polymorphism, with the strongest association with AF so far at this locus (rs4845625). In the rare variant joint analysis, damaging variants within the PRRX1 region showed significant association with AF after Bonferroni correction (P = .01).
We identified 1 common single-nucleotide polymorphism and 1 gene region that were significantly associated with AF. Future sequencing efforts with larger sample sizes and more comprehensive genome coverage are anticipated to identify additional AF-related variants.
Background Chronic kidney disease is associated with cardiovascular disease. We tested for evidence of a shared genetic basis to these traits. Study Design We conducted 2 targeted analyses. First, we ...examined whether known single-nucleotide polymorphisms (SNPs) underpinning kidney traits were associated with a series of vascular phenotypes. Additionally, we tested whether vascular SNPs were associated with markers of kidney damage. Significance was set to 1.5×10−4 (0.05/325 tests). Setting & Participants Vascular outcomes were analyzed in participants from the AortaGen (20,634), CARDIoGRAM (86,995), CHARGE Eye (15,358), CHARGE IMT (31,181), ICBP (69,395), and NeuroCHARGE (12,385) consortia. Tests for kidney outcomes were conducted in up to 67,093 participants from the CKDGen consortium. Predictor We used 19 kidney SNPs and 64 vascular SNPs. Outcomes & Measurements Vascular outcomes tested were blood pressure, coronary artery disease, carotid intima-media thickness, pulse wave velocity, retinal venular caliber, and brain white matter lesions. Kidney outcomes were estimated glomerular filtration rate and albuminuria. Results In general, we found that kidney disease variants were not associated with vascular phenotypes (127 of 133 tests were nonsignificant). The one exception was rs653178 near SH2B3 (SH2B adaptor protein 3), which showed direction-consistent association with systolic ( P = 9.3 ×10−10 ) and diastolic ( P = 1.6 ×10−14 ) blood pressure and coronary artery disease ( P = 2.2 ×10−6 ), all previously reported. Similarly, the 64 SNPs associated with vascular phenotypes were not associated with kidney phenotypes (187 of 192 tests were nonsignificant), with the exception of 2 high-correlated SNPs at the SH2B3 locus ( P = 1.06 ×10−07 and P = 7.05 ×10−08 ). Limitations The combined effect size of the SNPs for kidney and vascular outcomes may be too low to detect shared genetic associations. Conclusions Overall, although we confirmed one locus ( SH2B 3) as associated with both kidney and cardiovascular disease, our primary findings suggest that there is little overlap between kidney and cardiovascular disease risk variants in the overall population. The reciprocal risks of kidney and cardiovascular disease may not be genetically mediated, but rather a function of the disease milieu itself.
Variations in candidate genes participating in oxidative stress, inflammation, and their interactions are potentially associated with diseases of atherosclerotic origin. We investigated independent ...and joint associations of variations in cholesterol ester transfer protein ( CETP ), interleukin-8 ( IL8 ), peroxisome proliferator activator receptor-α ( PPARA ), and Toll-like receptor 4 ( TLR4 ) genes with incident nonfatal myocardial infarction (MI) or ischemic stroke. In a population-based case–control study, patients (848 with MI and 368 with ischemic stroke) and controls (2,682) were recruited from postmenopausal women and hypertensive men/women who were members of Group Health in western Washington State. Common tag single-nucleotide polymorphisms (SNPs; n = 34) representing gene-wide variations were selected from gene sequencing data using pairwise linkage disequilibrium. Haplotypes were inferred using a modified expectation maximization algorithm. Multivariate logistic regression evaluated individual haplotype and SNP-disease associations in log-additive models. Global haplotype tests assessed overall gene–disease associations. Logic regression was used to evaluate gene–gene interactions. False discovery rates and permutation tests were used for multiple testing adjustment in evaluating independent associations and interactions, respectively. Overall, gene-wide variations in PPARA and TLR4 genes were associated with MI. The minor allele of the PPARA SNP, rs4253623 , was associated with a higher risk of MI (odds ratio 1.25, 95% confidence interval 1.08 to 1.46), whereas the minor allele of the TLR4 SNP, rs1927911 , was associated with a lower risk of MI (odds ratio 0.88, 95% confidence interval 0.77 to 0.99). No within-gene or gene–gene interaction was associated with MI or ischemic stroke risk. In conclusion, potential SNP–disease associations identified in the present study are novel and need further investigation.
Summary On the continuum of maternal health care, two extreme situations exist: too little, too late (TLTL) and too much, too soon (TMTS). TLTL describes care with inadequate resources, below ...evidence-based standards, or care withheld or unavailable until too late to help. TLTL is an underlying problem associated with high maternal mortality and morbidity. TMTS describes the routine over-medicalisation of normal pregnancy and birth. TMTS includes unnecessary use of non-evidence-based interventions, as well as use of interventions that can be life saving when used appropriately, but harmful when applied routinely or overused. As facility births increase, so does the recognition that TMTS causes harm and increases health costs, and often concentrates disrespect and abuse. Although TMTS is typically ascribed to high-income countries and TLTL to low-income and middle-income ones, social and health inequities mean these extremes coexist in many countries. A global approach to quality and equitable maternal health, supporting the implementation of respectful, evidence-based care for all, is urgently needed. We present a systematic review of evidence-based clinical practice guidelines for routine antenatal, intrapartum, and postnatal care, categorising them as recommended, recommended only for clinical indications, and not recommended. We also present prevalence data from middle-income countries for specific clinical practices, which demonstrate TLTL and increasing TMTS. Health-care providers and health systems need to ensure that all women receive high-quality, evidence-based, equitable and respectful care. The right amount of care needs to be offered at the right time, and delivered in a manner that respects, protects, and promotes human rights.
Objectives This study sought to identify nonredundant atrial fibrillation (AF) genetic susceptibility signals and examine their cumulative relations with AF risk. Background AF-associated loci span ...broad genomic regions that may contain multiple susceptibility signals. Whether multiple signals exist at AF loci has not been systematically explored. Methods We performed association testing conditioned on the most significant, independently associated genetic markers at 9 established AF loci using 2 complementary techniques in 64,683 individuals of European ancestry (3,869 incident and 3,302 prevalent AF cases). Genetic risk scores were created and tested for association with AF in Europeans and an independent sample of 11,309 individuals of Japanese ancestry (7,916 prevalent AF cases). Results We observed at least 4 distinct AF susceptibility signals on chromosome 4q25 upstream of PITX2 , but not at the remaining 8 AF loci. A multilocus score comprised 12 genetic markers demonstrated an estimated 5-fold gradient in AF risk. We observed a similar spectrum of risk associated with these markers in Japanese. Regions containing AF signals on chromosome 4q25 displayed a greater degree of evolutionary conservation than the remainder of the locus, suggesting that they may tag regulatory elements. Conclusions The chromosome 4q25 AF locus is architecturally complex and harbors at least 4 AF susceptibility signals in individuals of European ancestry. Similar polygenic AF susceptibility exists between Europeans and Japanese. Future work is necessary to identify causal variants, determine mechanisms by which associated loci predispose to AF, and explore whether AF susceptibility signals classify individuals at risk for AF and related morbidity.
Summary Background Various genome-wide association studies (GWAS) have been done in ischaemic stroke, identifying a few loci associated with the disease, but sample sizes have been 3500 cases or ...less. We established the METASTROKE collaboration with the aim of validating associations from previous GWAS and identifying novel genetic associations through meta-analysis of GWAS datasets for ischaemic stroke and its subtypes. Methods We meta-analysed data from 15 ischaemic stroke cohorts with a total of 12 389 individuals with ischaemic stroke and 62 004 controls, all of European ancestry. For the associations reaching genome-wide significance in METASTROKE, we did a further analysis, conditioning on the lead single nucleotide polymorphism in every associated region. Replication of novel suggestive signals was done in 13 347 cases and 29 083 controls. Findings We verified previous associations for cardioembolic stroke near PITX2 (p=2·8×10−16 ) and ZFHX3 (p=2·28×10−8 ), and for large-vessel stroke at a 9p21 locus (p=3·32×10−5 ) and HDAC9 (p=2·03×10−12 ). Additionally, we verified that all associations were subtype specific. Conditional analysis in the three regions for which the associations reached genome-wide significance ( PITX2, ZFHX3 , and HDAC9 ) indicated that all the signal in each region could be attributed to one risk haplotype. We also identified 12 potentially novel loci at p<5×10−6 . However, we were unable to replicate any of these novel associations in the replication cohort. Interpretation Our results show that, although genetic variants can be detected in patients with ischaemic stroke when compared with controls, all associations we were able to confirm are specific to a stroke subtype. This finding has two implications. First, to maximise success of genetic studies in ischaemic stroke, detailed stroke subtyping is required. Second, different genetic pathophysiological mechanisms seem to be associated with different stroke subtypes. Funding Wellcome Trust, UK Medical Research Council (MRC), Australian National and Medical Health Research Council, National Institutes of Health (NIH) including National Heart, Lung and Blood Institute (NHLBI), the National Institute on Aging (NIA), the National Human Genome Research Institute (NHGRI), and the National Institute of Neurological Disorders and Stroke (NINDS).
Purpose To investigate the shape of the relation between amount of leisure-time physical activity (LTPA) and myocardial infarction (MI) risk. Methods Data were from a case-control study in a ...Washington State health maintenance organization, 1986 to 2002. Participants had no prior cardiovascular disease and good self-reported health before selection. Telephone interviews asked 697 nonfatal MI cases and 3,397 control subjects about 26 types of LTPA. Models adjusted for age, sex, year, treated hypertension, family history of heart disease, smoking, alcohol, aspirin, race, retirement, income, and education. Results Some LTPA was reported by 90% of control subjects and 84% of cases. Compared with no LTPA, participation in LTPA was associated with lower risk of MI (adjusted odds ratio OR = 0.67, 95% confidence interval CI: 0.52, 0.86). Among active participants, LTPA time was associated with risk of MI (OR = 0.66 for high versus low quartile, 95% CI: 0.51, 0.86). Risk of MI decreased with increasing total or nonstrenuous LTPA time up to the median, beyond which we could not detect an association between LTPA time and MI risk. Conclusions Time engaged in LTPA, even nonstrenuous LTPA, was associated with lower risk of MI, and the shape of this relationship was nonlinear.
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