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Importance: Mendelian randomization (MR) studies use genetic variation associated with modifiable exposures to assess their possible causal relationship with outcomes and aim to reduce potential bias from confounding and reverse causation., Objective: To develop the STROBE-MR Statement as a stand-alone extension to the STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) guideline for the reporting of MR studies., Design, Setting, and Participants: The development of the STROBE-MR Statement followed the Enhancing the Quality and Transparency of Health Research (EQUATOR) framework guidance and used the STROBE Statement as a starting point to draft a checklist tailored to MR studies. The project was initiated in 2018 by reviewing the literature on the reporting of instrumental variable and MR studies. A group of 17 experts, including MR methodologists, MR study design users, developers of previous reporting guidelines, and journal editors, participated in a workshop in May 2019 to define the scope of the Statement and draft the checklist. The draft checklist was published as a preprint in July 2019 and discussed on the preprint platform, in social media, and at the 4th Mendelian Randomization Conference. The checklist was then revised based on comments, further refined through 2020, and finalized in July 2021., Findings: The STROBE-MR checklist is organized into 6 sections (Title and Abstract, Introduction, Methods, Results, Discussion, and Other Information) and includes 20 main items and 30 subitems. It covers both 1-sample and 2-sample MR studies that assess 1 or multiple exposures and outcomes, and addresses MR studies that follow a genome-wide association study and are reported in the same article. The checklist asks authors to justify why MR is a helpful method to address the study question and state prespecified causal hypotheses. The measurement, quality, and selection of genetic variants must be described and attempts to assess validity of MR-specific assumptions should be well reported. An item on data sharing includes reporting when the data and statistical code required to replicate the analyses can be accessed., Conclusions and Relevance: STROBE-MR provides guidelines for reporting MR studies. Improved reporting of these studies could facilitate their evaluation by editors, peer reviewers, researchers, clinicians, and other readers, and enhance the interpretation of their results.

Background & Aims: Fatty liver disease has been associated with higher all‐cause as well as liver‐related, ischemic heart disease (IHD)‐related and extrahepatic cancer‐related mortality in observational epidemiological studies. We tested the hypothesis that fatty liver disease is a causal risk factor for higher mortality. Methods: We genotyped seven genetic variants known to be associated with fatty liver disease (in PNPLA3, TM6SF2, HSD17B13, MTARC1, MBOAT7, GCKR, and GPAM) in 110 913 individuals from the Danish general population. Hepatic steatosis was measured by hepatic computed tomography in n = 6965. Using a Mendelian randomization framework, we tested whether genetically proxied hepatic steatosis and/or elevated plasma alanine transaminase (ALT) was associated with liver‐related mortality. Results: During a median follow‐up of 9.5 years, 16 119 individuals died. In observational analyses, baseline elevated plasma ALT was associated with higher all‐cause (1.26‐fold), liver‐related (9‐fold), and extrahepatic cancer‐related (1.25‐fold) mortality. In genetic analyses, the risk alleles in PNPLA3, TM6SF2, and HSD17B13 were individually associated with higher liver‐related mortality. The largest effects were seen for the PNPLA3 and TM6SF2 risk alleles, for which homozygous carriers had 3‐fold and 6‐fold, respectively, higher liver‐related mortality than non‐carriers. None of the risk alleles, individually or combined into risk scores, were robustly associated with all‐cause, IHD‐related, or extrahepatic cancer‐related mortality. In instrumental variable analyses, genetically proxied hepatic steatosis and higher plasma ALT were associated with liver‐related mortality. Conclusions: Human genetic data support that fatty liver disease is a causal driver of liver‐related mortality. [ABSTRACT FROM AUTHOR]

Context: To enable prevention and treatment of age-related macular degeneration (AMD), understanding risk factors for AMD is important.Objective: We tested the hypotheses that elevated plasma apolipoprotein A1 and high-density lipoprotein (HDL) cholesterol and low levels of low-density lipoprotein (LDL) cholesterol are associated with increased risk of AMD.Methods: From the Danish general population, we studied 106 703 and 16 032 individuals in the Copenhagen General Population Study (CGPS) and the Copenhagen City Heart Study (CCHS) with median follow-up of 9 and 32 years, respectively.The main outcome measures were 1787 AMD in CGPS and 206 in CCHS.Results: Higher concentrations of plasma apolipoprotein A1 and HDL cholesterol, and lower concentrations of LDL cholesterol, were associated with higher risk of AMD in CGPS. After multifactorial adjustment, individuals in the highest versus lowest quartile of plasma apolipoprotein A1 and HDL cholesterol had hazard ratios for AMD of 1.40 (95% CI: 1.20-1.63) and 1.22 (1.03-1.45). Corresponding hazard ratios for individuals in the lowest versus highest quartile of LDL cholesterol were 1.18 (1.02-1.37). Per 100 mg/dL higher plasma apolipoprotein A1, 1 mmol/L (39 mg/dL) higher HDL, and 1 mmol/L (39 mmol/L) lower LDL cholesterol, the hazard ratios for AMD were 1.53(1.31-1.80), 1.19 (1.07-1.32), and 1.05 (1.00-1.11), respectively, with similar results across strata of different risk factors. Higher concentrations of HDL cholesterol were also associated with higher risk of AMD in the CCHS.Conclusion: Elevated plasma apolipoprotein A1 and HDL cholesterol and lower LDL cholesterol are associated with increased risk of AMD. [ABSTRACT FROM AUTHOR]

Aims Dementia is a major global challenge for health and social care in aging populations. A third of all dementia may be preventable due to cardiovascular risk factors. Intensive multi-domain intervention trials targeting primarily cardiovascular risk factors show improved cognitive function in people at risk. Such interventions will, however, be expensive to implement in all individuals at risk and will represent unrealistic economic tasks for most societies. Therefore, a risk score identifying high-risk individuals is warranted. Methods and results In 61 664 individuals from two prospective cohorts of the Danish general population, we generated 10-year absolute risk scores for all-cause dementia from cardiovascular risk factors and genetics. In both sexes, 10-year absolute risk of all-cause dementia increased with increasing age, number of apolipoprotein E (APOE) ɛ4 alleles, number of genome-wide association studies (GWAS) risk alleles, and cardiovascular risk factors. The highest 10-year absolute risks of all-cause dementia seen in smoking women with diabetes, low education, APOE ɛ44 genotype, and 22–31 GWAS risk alleles were 6%, 23%, 48%, and 66% in those aged 50–59, 60–69, 70–79, and 80–100, respectively. Corresponding values for men were 5%, 19%, 42%, and 60%, respectively. Conclusion Ten-year absolute risk of all-cause dementia increased with age, APOE ɛ4 alleles, GWAS risk alleles, diabetes, low education, and smoking in both women and men. Ten-year absolute risk charts for dementia will facilitate identification of high-risk individuals, those who likely will benefit the most from an early intervention against cardiovascular risk factors. Open in new tab Download slide Open in new tab Download slide [ABSTRACT FROM AUTHOR]

Genetic factors partly determine the risk for premature myocardial infarction (MI). We report the identification of a novel rare genetic variant in a kindred with an autosomal dominant trait for premature MI and atherosclerosis and explored the association of a common nonsynonymous variant in the same gene with the risk of ischemic heart disease (IHD) in a population-based study. Next-generation sequencing was performed in a small pedigree with premature MI or subclinical atherosclerosis. A common variant, rs8141797 A>G (p.Asn466Ser), in sushi domain–containing protein 2 (SUSD2) was studied in the prospective Copenhagen General Population Studies (N = 105,408) for association with IHD. A novel heterozygous nonsense mutation in SUSD2 (c.G583T; p.Glu195Ter) was associated with the disease phenotype in the pedigree. SUSD2 protein was expressed in aortic specimens in the subendothelial cell layer and around the vasa vasorum. Furthermore, the minor G-allele of rs8141797 was associated with per allele higher levels of SUSD2 mRNA expression in the heart and vasculature. In the Copenhagen General Population Study, hazard ratios for IHD were 0.92 (95% CI: 0.87–0.97) in AG heterozygotes and 0.86 (0.62–1.19) in GG homozygotes vs noncarrriers (P -trend =.002). Finally, in meta-analysis including 73,983 IHD cases and 215,730 controls, the odds ratio for IHD per G-allele vs A-allele was 0.93 (0.90–0.96) (P = 4.6 × 10−7). The identification of a truncating mutation in SUSD2 , which was associated with premature MI and subclinical atherosclerosis, combined with the finding that a common missense variant in SUSD2 was strongly associated with a lower risk of IHD, suggest that SUSD2 may alter the risk of atherosclerosis. • A nonsense mutation in sushi domain–containing protein 2 (SUSD2) was associated with the coronary artery disease phenotype in the family. • In meta-analysis, a common variant in SUSD2 was strongly associated with the risk of ischemic heart disease. • This suggests that SUSD2 may alter the risk of coronary artery disease. • Further experimental work in animal models is needed to support these observations. [ABSTRACT FROM AUTHOR]

Aims Preclinical evidence has indicated that HDL may play an important role in the immune system; however, very little is known about the role of HDL in the immune system in humans. We tested the hypothesis that low and high concentrations of HDL cholesterol are associated with risk of infectious disease in the general population. Methods and results We included 97 166 individuals from the Copenhagen General Population Study and 9387 from the Copenhagen City Heart Study with measurements of HDL cholesterol at baseline. The primary endpoint was any infectious disease requiring hospital admission, ascertained in the Danish health registries from baseline in 2003-13 or 1991-94 through 2014; 9% and 31% of individuals in the two studies experienced one or more infectious disease events. Using restricted cubic splines, there was a U-shaped association between concentrations of HDL cholesterol and risk of any infection. Following multifactorial adjustment, individuals with HDL cholesterol below 0.8mmol/L (31mg/dL) and above 2.6mmol/L (100mg/dL) had hazard ratios for any infection of 1.75 (95% confidence interval 1.31-2.34) and 1.43 (1.16-1.76), compared to those with HDL cholesterol of 2.2-2.3mmol/L (85-95mg/dL). In the Copenhagen City Heart Study, corresponding hazard ratios for any infection were 2.00 (1.16-3.43) and 1.13 (0.80-1.60). Conclusion Low and high HDL cholesterol concentrations found in 21% and 8% of individuals were associated with higher risk of infectious disease in the general population. These findings do not necessarily indicate causality. [ABSTRACT FROM AUTHOR]

Aims In observational studies, non-alcoholic fatty liver disease (NAFLD) is associated with high risk of ischaemic heart disease (IHD). We tested the hypothesis that a high liver fat content or a diagnosis of NAFLD is a causal risk factor for IHD. Methods and results In a cohort study of the Danish general population (n = 94 708/IHD = 10 897), we first tested whether a high liver fat content or a diagnosis of NAFLD was associated observationally with IHD. Subsequently, using Mendelian randomization, we tested whether a genetic variant in the gene encoding the protein patatin-like phospholipase domain containing 3 protein (PNPLA3), I148M (rs738409), a strong and specific cause of high liver fat content and NAFLD, was causally associated with the risk of IHD. We found that the risk of IHD increased stepwise with increasing liver fat content (in quartiles) up to an odds ratio (OR) of 2.41 (1.28-4.51)(P-trend = 0.004). The corresponding OR for IHD in individuals with vs. without NAFLD was 1.65 (1.34-2.04)(P=3×10-6). PNPLA3 I148M was associated with a stepwise increase in liver fat content of up to 28% in MM vs. II-homozygotes (P-trend = 0.0001) and with ORs of 2.03 (1.52-2.70) for NAFLD (P=3×10-7), 3.28 (2.37-4.54) for cirrhosis (P=4×10-12), and 0.95 (0.86-1.04) for IHD (P = 0.46). In agreement, in meta-analysis (N= 279 013/IHD = 71 698), the OR for IHD was 0.98 (0.96-1.00) per M-allele vs. I-allele. The OR for IHD per M-allele higher genetically determined liver fat content was 0.98 (0.94-1.03) vs. an observational estimate of 1.05 (1.02-1.09)(P for comparison = 0.02). Conclusion Despite confirming the known observational association of liver fat content and NAFLD with IHD, lifelong, genetically high liver fat content was not causally associated with risk of IHD. These results suggest that the observational association is due to confounding or reverse causation. [ABSTRACT FROM AUTHOR]

Elevated blood pressure increases the risk of experiencing cardiovascular events like myocardial infarction and stroke. Current observational data suggest that body mass index may have a causal role in the etiology of hypertension, but this may be influenced by confounding and reverse causation. Through the use of instrumental variable methods, we aim to estimate the strength of the unconfounded and unbiased association between body mass index/adiposity and blood pressure. We explore these issues in the Copenhagen General Population Study. We used instrumental variable methods to obtain estimates of the causal association between body mass index and blood pressure. This was performed using both rs9939609 (FTO) and rs17782313 (MC4R) genotypes as instruments for body mass index. Avoiding the epidemiological problems of confounding, bias, and reverse causation, we confirmed observational associations between body mass index and blood pressure. In analyses including those taking antihypertensive drugs, but for whom appropriate adjustment had been made, systolic blood pressure was seen to increase by 3.85 mm Hg (95% CI: 1.88 to 5.83 mm Hg) for each 10% increase in body mass index (P=0.0002), with diastolic blood pressure showing an increase of 1.79 mm Hg (95% CI: 0.68 to 2.90 mm Hg) for each 10% increase in body mass index (P=0.002). Observed associations are large and illustrate the considerable benefits in terms of reductions in blood pressure-related morbidity that could be achieved through a reduction in body mass index. [ABSTRACT FROM AUTHOR]

Association of common aging signs (i.e., male pattern baldness, hair graying, and facial wrinkles) as well as other age-related appearance factors (i.e., arcus corneae, xanthelasmata, and earlobe crease) with increased risk of ischemic heart disease was initially described in anecdotal reports from clinicians observing trends in the physical appearance of patients with ischemic heart disease. Following these early observations numerous epidemiological studies have reported these associations. Since the prevalences of both visible aging signs and ischemic heart disease have a strong correlation with increasing age, it has been extensively debated whether the observed associations could be entirely explained by a common association with age. Furthermore, the etiologies of the visible aging signs are rarely fully understood, and pathophysiological explanations for these associations remain controversial, and are mostly speculative. As a consequence of inconsistent findings and lack of mechanistic explanations for the observed associations with ischemic heart disease, consensus on the clinical importance of these visible aging signs has been lacking. The aim of this review is for each of the visible aging signs to (i) review the etiology, (ii) to discuss the current epidemiological evidence for an association with risk of ischemic heart disease, and (iii) to present possible pathophysiological explanations for these associations. Finally this review discusses the potential clinical implications of these findings. [ABSTRACT FROM AUTHOR]

Background: The effect of alcohol consumption on liver function is difficult to determine because of reporting bias and potential residual confounding. Our aim was to determine this effect using genetic variants to proxy for the unbiased effect of alcohol. Methods: We used variants in ADH1B and ADH1C genes as instrumental variables (IV) to estimate the causal effect of long-term alcohol consumption on alanine aminotransferase (ALT), γ-glutamyl-transferase (γ-GT), alkaline phosphatase (ALP), bilirubin and prothrombin action. Analyses were undertaken on 58,313 Danes (mean age 56). Results: In both confounder adjusted multivariable and genetic-IV analyses greater alcohol consumption, amongst those who drank any alcohol, was associated with higher ALT [mean difference per doubling of alcohol consumption: 3.4% (95% CI: 3.1, 3.7) from multivariable analyses and 3.7% (−4.5, 11.9) from genetic-IV analyses] and γ-GT [8.2% (7.8, 8.5) and 6.8% (−2.8, 16.5)]. The point estimates from the two methods were very similar and statistically the results from the two methods were consistent with each other for effects with ALT and γ-GT (both pdiff>0.3). Results from the multivariable analyses suggested a weak inverse association of alcohol with ALP [−1.5% (−1.7, −1.3)], which differed from the strong positive effect found in genetic-IV analyses [11.6% (6.8, 16.4)] (pdiff<0.0001). In both multivariable and genetic-IV analyses associations with bilirubin and protrombin action were weak and close to the null. Conclusions: Our results suggest that greater consumption of alcohol is related to poorer liver function as indicated by higher ALT, γ-GT and ALP, but not to clotting or bilirubin. [ABSTRACT FROM AUTHOR]

Aims Activation of the angiotensin II type 1 (AT1) receptor has been shown to mediate the structural and electrical remodelling of the atrial myocardium associated with atrial fibrillation. We hypothesized that AT1 genotypic variation is associated with atrial fibrillation or diseases predisposing to atrial fibrillation, such as hypertension, heart failure, ischaemic heart disease and myocardial infarction, in the general population. Methods We resequenced the AT1 gene in 760 individuals with atrial fibrillation and identified two nonsynonymous variants ( I103 T and A244 S), which were subsequently genotyped in the prospective Copenhagen City Heart Study ( n = 10 603) and the prospective Copenhagen General Population Study ( n = 60 647). Results Risk of atrial fibrillation for heterozygotes for AT1 genetic variants A244 S and I103 T/ A244 S vs. noncarriers was increased by 2.7-fold (95% confidence interval 1.5- to 5.1-fold) and 2.6-fold (95% confidence interval 1.6- to 4.2-fold), respectively, for men. Conclusions Heterozygosity for the nonsynonymous AT1 genetic variants A244 S and I103 T/ A244 S was associated with increased risk of atrial fibrillation in men. The AT1 recptor might be a target for the pharmaceutical industry. This finding needs to be validated in independent studies. [ABSTRACT FROM AUTHOR]

Objectives: The purpose of this study was to test whether elevated nonfasting glucose levels associate with and cause ischemic heart disease (IHD) and myocardial infarction (MI). Background: Elevated fasting plasma glucose levels associate with increased risk of IHD, but whether this is also true for nonfasting levels and whether this is a causal relationship is unknown. Methods: Using a Mendelian randomization approach, we studied 80,522 persons from Copenhagen, Denmark. Of those, IHD developed in 14,155, and MI developed in 6,257. Subjects were genotyped for variants in GCK (rs4607517), G6PC2 (rs560887), ADCY5 (rs11708067), DGKB (rs2191349), and ADRA2A (rs10885122) associated with elevated fasting glucose levels in genome-wide association studies. Results: Risk of IHD and MI increased stepwise with increasing nonfasting glucose levels. The hazard ratio for IHD in subjects with nonfasting glucose levels ≥11 mmol/l (≥198 mg/dl) versus <5 mmol/l (<90 mg/dl) was 6.9 (95% confidence interval [CI]: 4.2 to 11.2) adjusted for age and sex, and 2.3 (95% CI: 1.3 to 4.2) adjusted multifactorially; corresponding values for MI were 9.2 (95% CI: 4.6 to 18.2) and 4.8 (95% CI: 2.1 to 11.2). Increasing number of glucose-increasing alleles was associated with increasing nonfasting glucose levels and with increased risk of IHD and MI. The estimated causal odds ratio for IHD and MI by instrumental variable analysis for a 1-mmol/l (18-mg/dl) increase in nonfasting glucose levels due to genotypes combined were 1.25 (95% CI: 1.03 to 1.52) and 1.69 (95% CI: 1.28 to 2.23), and the corresponding observed hazard ratio for IHD and MI by Cox regression was 1.18 (95% CI: 1.15 to 1.22) and 1.09 (95% CI: 1.07 to 1.11), respectively. Conclusions: Like common nonfasting glucose elevation, plasma glucose-increasing polymorphisms associate with increased risk of IHD and MI. These data are compatible with a causal association. [Copyright &y& Elsevier]

Pseudoxanthoma elasticum (PXE) is an autosomal recessive disease caused by loss-of-function mutations in ABCC6 and characterized by elastic calcification leading to dermal, ocular, and ischemic vascular disease. We tested the hypothesis that heterozygosity for R1141X, the most frequent PXE-causing mutation in Caucasians, associated with risk of ischemic vascular disease, as previous studies suggested 4- to 11-fold risk of ischemic heart disease (IHD) in heterozygotes.We studied 10 276 persons from the general population, including 1985 with IHD and 989 with ischemic cerebrovascular disease (ICVD). We examined 45 603 individuals from a cross-sectional general population study, of whom 3738 had IHD and 2335 had ICVD. Finally, we compared 4851 patients with IHD and 625 patients with ICVD with, respectively, 4851 and 625 matched control subjects. We genotyped participants in all studies for ABCC6 R1141X. The frequency of R1141X was 0.6% in all populations studied. ABCC6 R1141X genotype was not associated with an increased risk of IHD, myocardial infarction, ICVD, or ischemic stroke. Furthermore, R1141X genotype did not interact with age on risk of the largest end point, IHD. Finally, R1141X genotype did not associate with variation in plasma levels of high-sensitivity C-reactive protein, fibrinogen, blood pressure, or lipid and lipoproteins in the general population.In 4 studies including 66 831 participants and 13 642 cases with ischemic vascular events, heterozygosity for ABCC6 R1141X did not associate with risk of IHD, myocardial infarction, ICVD, or ischemic stroke. [ABSTRACT FROM AUTHOR]

Elevated levels of lipoprotein(a) are associated with an increased risk of myocardial infarction. Our study aimed to test whether genetic data are consistent with this association being causal. Accordingly, we developed a high-throughput realtime PCR assay to genotype for the lipoprotein(a) kringle IV type 2 (KIV-2) repeat polymorphism in the LPA gene in > 40,000 individuals. The LPA KIV-2 genotype associated with plasma levels of lipoprotein(a) (trend p < 0.001), and the LPA KIV-2 genotype associated with risk of myocardial infarction (trend p < 0.001 to 0.03) in a manner consistent with its effect on plasma levels of lipoprotein(a). The association of LPA KIV-2 genotypes raising plasma levels of lipoprotein(a) with increased risk of myocardial infarction strongly supports a causal association of lipoprotein(a) with risk of myocardial infarction. [ABSTRACT FROM AUTHOR]

Background Werner syndrome, a premature genetic aging syndrome, shares many clinical features reminiscent of normal physiological aging, and ischemic vascular disease is a frequent cause of death. We tested the hypothesis that genetic variation in the WRN gene was associated with risk of ischemic vascular disease in the general population. Methods We included 58,284 participants from two general population cohorts, the Copenhagen City Heart Study (CCHS) and the Copenhagen General Population Study (CGPS). Of these, 6,312 developed ischemic vascular disease during follow-up. In the CCHS ( n = 10,250), we genotyped all non-synonymous variants in WRN with reported minor allele frequencies ≥ 0.5% in Caucasians. Second, variants which were associated with ischemic vascular disease in the CCHS or in previous studies, were genotyped in the CGPS ( n = 48,034). Results A total of 11 non-synonymous variants were identified in the CCHS. In C1367R (rs1346044) TT homozygotes versus CC/CT, hazard ratios for ischemic stroke were 1.09 (95% confidence interval: 0.95–1.24; P = 0.22) in the CCHS, 1.16 (1.00–1.33; P = 0.04) in the CGPS, and 1.12 (1.01–1.23; P = 0.02) in studies combined (CCHS + CGPS), with similar trends for ischemic cerebrovascular disease ( P = 0.06). In meta-analyses including 59,190 individuals in 5 studies, the hazard ratio for ischemic stroke for C1367R TT homozygotes versus CC/CT was 1.14 (1.04–1.25; P = 0.008). Conclusions This study suggests that common genetic variation in WRN is associated with increased risk of ischemic stroke in the general population. [ABSTRACT FROM AUTHOR]

Background--Cardiovascular disease is 1 of the most common age-related diseases, and also 1 of the most common causes of death in the general population. We tested the hypothesis that visible age-related signs associate with risk of ischemie heart disease (IHD), myocardial infarction (MI), and death in the general population, independent of chronological age. Methods and Results--10,885 individuals aged 20 to 93 years free of IHD were followed from 1976 through 1978 until June 2011 with 100% complete follow-up. During these 35 years of follow-up, 3401 participants developed IHD and 1708 developed MI. Presence of frontoparietal baldness, crown top baldness, earlobe crease, and xanthelasmata was associated with increased risk of IHD or MI after multifactorial adjustment for chronological age and well-known cardiovascular risk factors. The risk of IHD and MI increased stepwise with increasing number of age-related signs with multifactorially adjusted hazard ratios up to 1.40 (95% confidence interval, 1.20-1.62) for IHD and 1.57(1.28-1.93) for MI, in individuals with 3 to 4 versus no age-related signs at baseline (P for trend <0.001). In all age groups in both women and men, absolute 10-year risk of IHD and MI increased with increasing number of visible age-related signs. Conclusions--Male pattern baldness, earlobe crease, and xanthelasmata--alone or in combination--associate with increased risk of ischemie heart disease and myocardial infarction independent of chronological age and other well-known cardiovascular risk factors. This is the first prospective study to show that looking old for your age is a marker of poor cardiovascular health. [ABSTRACT FROM AUTHOR]

Abstract: Background: Atrial fibrillation is associated with inflammation. In contrast to inflammatory markers like C-reactive protein (CRP) and fibrinogen produced in the liver, YKL-40 is produced at the site of inflammation including in the myocardium. We hypothesized that elevated plasma YKL-40 levels associate with increased risk of atrial fibrillation. Method and results: We measured plasma YKL-40 in 8731 participants from the prospective Copenhagen City Heart Study including 896 individuals who developed atrial fibrillation during up to 18years of follow-up. Additionally, we measured YKL-40 in 6621 individuals from the cross-sectional Copenhagen General Population Study including 337 cases with atrial fibrillation. A YKL-40 level >95% percentile (>204μg/L) versus <25% percentile (<36μg/L) associated prospectively with a 2.10-fold (95%CI:1.43–3.09) increased risk of atrial fibrillation. Hazard ratios attenuated slightly after multifactorial adjustment to 2.01 (1.35–2.98), and further after additional adjustment for heart failure to 1.89 (1.27–2.80), for plasma CRP to 1.79 (1.20–2.67), and for fibrinogen levels to 1.89 (1.27–2.81). Adjusting multifactorially including both heart failure, CRP, and fibrinogen attenuated the risk of atrial fibrillation to 1.79 (1.20–2.67). These findings were supported in the cross-sectional study with an odds ratio of 2.73 (1.46–5.11) for a YKL-40 level >95% percentile versus <25% percentile, attenuating to an odds ratio of 2.13 (1.09–4.18) when adjusting multifactorially including heart failure, CRP, and fibrinogen. Conclusions: Elevated plasma YKL-40 levels robustly associated with increased risk of atrial fibrillation originating from hospital admissions or visits to the emergency department, independent of heart failure, and CRP and fibrinogen levels. These findings need to be confirmed in other independent studies. [Copyright &y& Elsevier]

The article presents a study regarding the genetic association of valvular calcification with aortic stenosis. Methods used include the Cohorts for Heart and Aging Research in Genome Epidemiology (CHARGE) consortium, meta-analysis, and computed tomographic scanning. Result shows that aortic-valve calcification is related to the single nucleotide polymorphism (SNPs) level in the lipoprotein a (LPA).

Background & Aims: Drugs which reduce plasma low-density lipoprotein cholesterol (LDL-C) may protect against gallstone disease. Whether plasma levels of LDL-C per se predict risk of gallstone disease remains unclear. We tested the hypothesis that elevated LDL-C is a causal risk factor for symptomatic gallstone disease. Methods: We used a Mendelian randomization approach and genotyped 63,051 individuals from a prospective cohort study of the general Danish population, including 3323 subjects with symptomatic gallstones. We selected eight genetic variants in APOE, APOB, LDLR, and PCSK9 affecting LDL-C. Furthermore, studies of APOE rs429358/rs7412 (defining ε2/ε3/ε4 alleles; 12 studies) and APOB rs693 (eight studies) were included in meta-analyses. Results: The observational hazard ratio (HR) for symptomatic gallstone disease for the fifth versus first quintile of LDL-C was 0.94 (95% confidence interval: 0.76–1.17), despite a corresponding 134% increase in LDL-C. Furthermore, although individual genetic variants in APOE, APOB, LDLR, and PCSK9 associated with stepwise increases/decreases in LDL-C of up to +59% compared with non-carriers (p <0.001), none predicted the risk of symptomatic gallstone disease. Combining all variants into 10 genotypes, carriers of 9 versus ⩽3 LDL-C increasing alleles associated with 41% increased LDL-C (p <0.001), but predicted a HR for symptomatic gallstone disease of 1.09 (0.70–1.69). Finally, in meta-analyses, random effects odds ratios for gallstone disease were 0.91 (0.78–1.06) for carriers of APOE ε4 versus non-carriers, and 1.25 (0.95–1.63) for APOB rs693 CT+TT versus CC. Conclusions: Results from the observational study, genetic studies, and meta-analyses suggest that elevated plasma levels of LDL-C are not causally associated with increased risk of symptomatic gallstone disease. [ABSTRACT FROM AUTHOR]

Objectives: The aim of this study was to examine the effect of PCSK9 R46L on low-density lipoprotein cholesterol (LDL-C), risk of ischemic heart disease (IHD), and mortality. Background: The 46L allele has been associated with reductions in LDL-C and risk of IHD, but results vary between studies. Methods: We determined the association of R46L genotype with LDL-C, risk of IHD, myocardial infarction (MI), and mortality in the prospective CCHS (Copenhagen City Heart Study) (n = 10,032) and validated the results in: 1) the cross-sectional CGPS (Copenhagen General Population Study) (n = 26,013); and 2) the case-control CIHDS (Copenhagen Ischemic Heart Disease Study) (n = 9,654). We also performed meta-analyses of present and previous studies (n = 66,698). Results: In carriers (2.6%) versus noncarriers, the 46L allele was associated with reductions in LDL-C of 0.35 to 0.55 mmol/l (11% to 16%) from 20 to 80+ years in the general population (CCHS and CGPS; p values <0.0001). Observed risk reductions for IHD in 46L allele carriers were: 6% in the CCHS study (hazard ratio [HR]: 0.94; 95% confidence interval [CI]: 0.68 to 1.31), 46% in the CGPS study (odds ratio [OR]: 0.54; 95% CI: 0.39 to 0.77), 18% in the CIHDS study (OR: 0.82; 95% CI: 0.55 to 1.21), and 30% in the studies combined (OR: 0.70; 95% CI: 0.58 to 0.86). In the CCHS study, HR for mortality was 1.18 (95% CI: 0.93 to 1.50). In meta-analyses, 46L allele carriers had a 12% (0.43 mmol/l) reduction in LDL-C and a 28% reduction in risk of IHD (HR: 0.72; 95% CI: 0.62 to 0.84), similar to results in the CCHS, CGPS, and CIHDS studies combined. However, the observed 12% (0.43 mmol/l) reduction in LDL-C theoretically predicted an only 5% reduction in risk of IHD (HR: 0.95; 95% CI: 0.92 to 0.97). Conclusions: The PCSK9 46L allele was associated with reductions in LDL-C from 20 to 80+ years in the general population. The reduction in risk of IHD was larger than predicted by the observed reduction in LDL-C alone. This could be because genotype is a better predictor of lifelong exposure to LDL-C than LDL-C measured in adult life. [Copyright &y& Elsevier]

Objectives: This study was designed to test the hypotheses that single nucleotide polymorphisms (SNPs), in zinc finger protein 202 (ZNF202), predict severe atherosclerosis and ischemic heart disease (IHD). Background: ZNF202 is a transcriptional repressor controlling promoter elements in genes involved in vascular maintenance and lipid metabolism. Methods: We first determined genotype association for 9 ZNF202 SNPs with severe atherosclerosis (ankle brachial index >0.7 vs. ≤0.7) in a cross-sectional study of 5,355 individuals from the Danish general population. We then determined genotype association with IHD in 10,431 individuals from the Danish general population, the CCHS (Copenhagen City Heart Study), including 1,511 incident IHD events during 28 years of follow-up. Results were verified in 2 independent case-control studies including, respectively, 942 and 1,549 cases with IHD and 8,998 controls. Finally, we determined whether g.−660A>G altered transcriptional activity of the ZNF202 promoter in vitro. Results: Cross-sectionally, ZNF202 g.−660 GG versus AA homozygosity predicted an odds ratio for severe atherosclerosis of 2.01 (95% confidence interval [CI]: 1.34 to 3.01). Prospectively, GG versus AA homozygosity predicted a hazard ratio for IHD of 1.21 (95% CI: 1.02 to 1.43). In the 2 case-control studies, the equivalent odds ratios for IHD were 1.29 (95% CI: 1.02 to 1.62) and 1.60 (95% CI: 1.34 to 1.92), confirming the results from the prospective study. Only 2 other SNPs, which were highly correlated with g.−660A>G, also predicted risk of severe atherosclerosis and IHD. Finally, ZNF202 g.−660G versus g.−660A was associated with a 60% reduction in transcriptional activity in vitro, whereas none of the 2 correlated SNPs were predicted to be functional. Conclusions: Homozygosity for a common functional promoter variant in ZNF202 predicts severe atherosclerosis and an increased risk of IHD. [Copyright &y& Elsevier]