Odds Ratio For Ischemic Heart Disease Research Articles

Genetic variants in SUSD2 are associated with the risk of ischemic heart disease

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.

Liver fat content, non-alcoholic fatty liver disease, and ischaemic heart disease: Mendelian randomization and meta-analysis of 279 013 individuals.

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. 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). 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.

0313 An assessment of the impact of misclassification error on an estimate of effect for occupational exposure to TCDD-contaminated chemicals and ischaemic heart disease0313 An assessment of the impact of misclassification error on an estimate of effect for occupational exposure to TCDD-contaminated chemicals and ischaemic heart disease

ObjectivesTo quantify the effect of exposure and disease misclassification on the odds ratio (OR) for ischaemic heart disease (IHD) mortality in a retrospective cohort study of trichlorophenol workers exposed to...

The Effect of Elevated Body Mass Index on Ischemic Heart Disease Risk: Causal Estimates from a Mendelian Randomisation Approach

Adiposity, assessed as elevated body mass index (BMI), is associated with increased risk of ischemic heart disease (IHD); however, whether this is causal is unknown. We tested the hypothesis that positive observational associations between BMI and IHD are causal. In 75,627 individuals taken from two population-based and one case-control study in Copenhagen, we measured BMI, ascertained 11,056 IHD events, and genotyped FTO(rs9939609), MC4R(rs17782313), and TMEM18(rs6548238). Using genotypes as a combined allele score in instrumental variable analyses, the causal odds ratio (OR) between BMI and IHD was estimated and compared with observational estimates. The allele score-BMI and the allele score-IHD associations used to estimate the causal OR were also calculated individually. In observational analyses the OR for IHD was 1.26 (95% CI 1.19-1.34) for every 4 kg/m(2) increase in BMI. A one-unit allele score increase associated with a 0.28 kg/m(2) (95 CI% 0.20-0.36) increase in BMI and an OR for IHD of 1.03 (95% CI 1.01-1.05) (corresponding to an average 1.68 kg/m(2) BMI increase and 18% increase in the odds of IHD for those carrying all six BMI increasing alleles). In instrumental variable analysis using the same allele score the causal IHD OR for a 4 kg/m(2) increase in BMI was 1.52 (95% CI 1.12-2.05). For every 4 kg/m(2) increase in BMI, observational estimates suggested a 26% increase in odds for IHD while causal estimates suggested a 52% increase. These data add evidence to support a causal link between increased BMI and IHD risk, though the mechanism may ultimately be through intermediate factors like hypertension, dyslipidemia, and type 2 diabetes. This work has important policy implications for public health, given the continuous nature of the BMI-IHD association and the modifiable nature of BMI. This analysis demonstrates the value of observational studies and their ability to provide unbiased results through inclusion of genetic data avoiding confounding, reverse causation, and bias.

Association of Loss-of-Function Mutations in the <emph type="ital">ABCA1</emph> Gene With High-Density Lipoprotein Cholesterol Levels and Risk of Ischemic Heart Disease

Low levels of high-density lipoprotein (HDL) cholesterol are inversely related to cardiovascular risk. Whether this is a causal effect is unclear. To determine whether genetically reduced HDL cholesterol due to heterozygosity for 4 loss-of-function mutations in ABCA1 cause increased risk of ischemic heart disease (IHD). Three studies of white individuals from Copenhagen, Denmark, were used: the Copenhagen City Heart Study (CCHS), a 31-year prospective general population study (n = 9022; 28 heterozygotes); the Copenhagen General Population Study (CGPS), a cross-sectional general population study (n = 31,241; 76 heterozygotes); and the Copenhagen Ischemic Heart Disease Study (CIHDS), a case-control study (n = 16,623; 44 heterozygotes). End points in all 3 studies were recorded during the period of January 1, 1976, through July 9, 2007. Levels of HDL cholesterol in the general population, cellular cholesterol efflux, and the association between IHD and HDL cholesterol and genotype. Heterozygotes vs noncarriers for 4 ABCA1 mutations (P1065S, G1216V, N1800H, R2144X) had HDL cholesterol levels of 41 mg/dL (interquartile range, 31-50 mg/dL) vs 58 mg/dL (interquartile range, 46-73 mg/dL), corresponding to a reduction in HDL cholesterol of 17 mg/dL (P < .001). A 17-mg/dL lower HDL cholesterol level in the CCHS was associated with a multifactorially adjusted hazard ratio for IHD of 1.70 (95% confidence interval [CI], 1.57-1.85). However, for IHD in heterozygotes vs noncarriers, the multifactorially adjusted hazard ratio was 0.67 (95% CI, 0.28-1.61; 1741 IHD events) in the CCHS, the multifactorially adjusted odds ratio was 0.82 (95% CI, 0.34-1.96; 2427 IHD events) in the CGPS, and the multifactorially adjusted odds ratio was 0.86 (95% CI, 0.32-2.32; 2498 IHD cases) in the CIHDS. The corresponding odds ratio for IHD in heterozygotes vs noncarriers for the combined studies (n = 41,961; 6666 cases; 109 heterozygotes) was 0.93 (95% CI, 0.53-1.62). Lower plasma levels of HDL cholesterol due to heterozygosity for loss-of-function mutations in ABCA1 were not associated with an increased risk of IHD.

Hepatic lipase mutations,elevated high-density lipoprotein cholesterol, and increased risk of ischemic heart disease: The Copenhagen City Heart Study

ObjectivesWe investigated associations between single nucleotide polymorphisms (SNPs) in the hepatic lipase promoter, levels of high-density lipoprotein (HDL), and risk of ischemic heart disease (IHD). Our primary hypothesis was that these SNPs associate with IHD after adjustment for HDL levels. BackgroundHepatic lipase influences HDL metabolism, and may thus affect reverse cholesterol transport and consequently risk of IHD. MethodsWe genotyped 9,121 white subjects aged 20 to 93 years from the Copenhagen City Heart Study, 456 of whom had incident IHD, as well as 921 Danish patients with IHD for the −216, −480, and −729 SNPs in the hepatic lipase promoter. ResultsFrequencies of wild-type, triple heterozygotes, and triple mutation homozygotes in the general population were 61%, 33%, and 5%, respectively. Compared with wild-type, HDL cholesterol levels were 4% (0.06 mmol/l) and 10% (0.15 mmol/l) higher in heterozygotes and mutation homozygotes; the equivalent values for apolipoprotein A1 were 3% and 7% higher. In prospective and case-control studies, mutation homozygotes versus wild-type had relative risk (RR) and odds ratio (OR) for IHD of 1.5 (95% confidence interval [CI]: 1.0 to 2.2) and 1.4 (CI: 1.1 to 1.9) when adjusted for age, gender, and HDL cholesterol. In individuals with the ϵ43 apolipoprotein E genotype, RR and OR for IHD in mutation homozygotes versus wild-type was 2.9 (CI: 1.5 to 5.6) and 2.0 (CI: 1.2 to 3.2). ConclusionsHepatic lipase promoter SNPs are associated with increased HDL cholesterol and, paradoxically, an increased risk of IHD after adjustment for HDL cholesterol, and particularly in individuals with apolipoprotein E ϵ43 genotype. Implications are that increased HDL levels may in certain situations be not protective, but rather associated with increased IHD risk.

Relationship between socioeconomic status and ischaemic heart disease in cohort and case-control studies: 1960-1993.

Much of the information on the relationship between socioeconomic status (SES) and ischaemic heart disease (IHD) comes from ecological, cross-sectional and longitudinal mortality studies. Such studies may present methodological problems which affect cohort studies and case-control studies to a lesser degree. A systematic review was conducted into the relationship between SES and IHD, as reported by cohort and case-control studies in which SES had been measured by education or occupation. A bibliographic search, covering the period 1960-1993, was carried out using Index Medicus, MEDLINE, Sociological Abstracts, Social Scisearch and the references cited in papers identified in such databases. Finally, 34 studies were selected, with data being extracted separately by two reviewers working independently. Where differences of opinion arose, these were resolved by discussion between the two. Multiple linear regression analysis was used to identify determinants of inter-study heterogeneity. Risk of IHD was inversely related to educational level in the period 1982-1993. There was a lower risk of IHD among manual workers versus non-manual workers until approximately 1970; thereafter the relationship became inverted. The odds ratio for IHD in manual workers rose progressively over the period 1960-1993, something that could not be explained by study design, study size, study country or control for confounding factors. Education- and occupation-related differences in risk of IHD affected all SES levels. These findings agree with those yielded by ecological, cross-sectional and longitudinal mortality studies, although they cannot be extrapolated to women, non-white ethnic groups, or developing countries. The inversion of the relationship between SES and IHD, and the increase in socioeconomic differences in IHD in recent years suggest that the problem is potentially controllable and that the necessary policies should be implemented as a matter of urgency.