Background

Experimental studies suggest long-chain n-3 polyunsaturated fatty acids (n-3 PUFA) may reduce risk of atrial fibrillation (AF). Prior studies evaluating fish or n-3 PUFA consumption from dietary questionnaires and incident AF have been conflicting. Circulating levels of n-3 PUFA provide an objective measurement of exposure.

Methods and Results

Among 3,326 US men and women age≥65y and free of AF or heart failure at baseline, plasma phospholipid levels of eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), and docosahexaenoic acid (DHA) were measured at baseline using standardized methods. Incident AF (789 cases) was prospectively identified from hospital discharge records and study visit electrocardiograms during 31,169 person-years of follow-up (1992-2006). In multivariable Cox models adjusted for other risk factors, the RR in the top versus lowest quartile of total n-3 PUFA (EPA+DPA+DHA) levels was 0.71 (95%CI=0.57-0.89, P-trend=0.004); and of DHA levels, 0.77 (95%CI=0.62-0.96, P-trend=0.01). EPA and DPA levels were not significantly associated with incident AF. Evaluated non-parametrically, both total n-3 PUFA and DHA showed graded and linear inverse associations with incidence of AF. Adjustment for intervening events such as heart failure or myocardial infarction during follow-up did not appreciably alter results.

Conclusions

In older adults, higher circulating total long-chain n-3 PUFA and DHA levels were associated with lower risk of incident AF. These results highlight the need to evaluate whether increased dietary intake of these fatty acids could be effective for primary prevention of AF.

OBJECTIVE

Many genetic variants have been associated with glucose homeostasis and type 2 diabetes in genome-wide association studies. Zinc is an essential micronutrient that is important for β-cell function and glucose homeostasis. We tested the hypothesis that zinc intake could influence the glucose-raising effect of specific variants.

RESEARCH DESIGN AND METHODS

We conducted a 14-cohort meta-analysis to assess the interaction of 20 genetic variants known to be related to glycemic traits and zinc metabolism with dietary zinc intake (food sources) and a 5-cohort meta-analysis to assess the interaction with total zinc intake (food sources and supplements) on fasting glucose levels among individuals of European ancestry without diabetes.

RESULTS

We observed a significant association of total zinc intake with lower fasting glucose levels (β-coefficient ± SE per 1 mg/day of zinc intake: −0.0012 ± 0.0003 mmol/L, summary P value = 0.0003), while the association of dietary zinc intake was not significant. We identified a nominally significant interaction between total zinc intake and the SLC30A8 rs11558471 variant on fasting glucose levels (β-coefficient ± SE per A allele for 1 mg/day of greater total zinc intake: −0.0017 ± 0.0006 mmol/L, summary interaction P value = 0.005); this result suggests a stronger inverse association between total zinc intake and fasting glucose in individuals carrying the glucose-raising A allele compared with individuals who do not carry it. None of the other interaction tests were statistically significant.

CONCLUSIONS

Our results suggest that higher total zinc intake may attenuate the glucose-raising effect of the rs11558471 SLC30A8 (zinc transporter) variant. Our findings also support evidence for the association of higher total zinc intake with lower fasting glucose levels.

Background

Few prior studies have evaluated long-chain omega-3 fatty acids and incidence of congestive heart failure (CHF), typically based on diet questionnaires and with conflicting results. Circulating fatty acid levels provide objective biomarkers of exposure.

Objective

We investigated whether plasma phospholipid levels of long-chain omega-3 fatty acids, including eicosapentaenoic acid (EPA, 20:5n-3), docosapentaenoic acid (DPA, 22:5n-3), and docosahexaenoic acid (DHA, 22:6n-3) were associated with incident CHF.

Design

Prospective cohort study, 1992–2006.

Setting

Four U.S. communities.

Patients

2,735 U.S. adults free of prevalent heart disease in the Cardiovascular Health Study.

Measurements

Plasma phospholipid fatty acids and other cardiovascular risk factors were measured in 1992 using standardized methods. Relationships with incident CHF (555 cases during 26,490 person-years, adjudicated using medical records) were assessed using Cox proportional-hazards.

Results

After multivariable-adjustment, plasma phospholipid EPA was inversely associated with incident CHF, with approximately 50% lower risk in the highest vs. lowest quartile [hazard ratio (95%CI)=0.52 (0.38–0.72), P-trend=0.001]. In similar analyses, trends toward lower risk were seen for DPA [0.76 (0.56–1.04), P-trend=0.057] and total long-chain n-3 fatty acids [0.70 (0.49–0.99); P-trend= 0.062], but not DHA [0.84 (0.58–1.21); P-trend=0.38]. In analyses censored to mid-follow-up (7 years) to minimize exposure misclassification over time, multivariable-adjusted hazard ratios (95%CI) were 0.48 for EPA (0.32–0.71; P-trend=0.005); 0.61 for DPA (0.39–0.95; P-trend=0.033); 0.64 for DHA (0.40–1.04; P-trend=0.057); and 0.51 for total n-3 fatty acids (0.32–0.80; P-trend=0.003).

Limitations

Temporal changes in fatty acid levels over time may have caused underestimation of associations. Unmeasured or imperfectly measured covariates may have caused residual confounding.

Conclusions

Circulating individual and total n-3 fatty acids are associated with lower incidence of CHF in older adults.

Primary Funding Source

National Institutes of Health.

Background

Palmitoleic acid (cis-16:1n-7), produced by endogenous fat synthesis, has been linked to both beneficial and deleterious metabolic effects, potentially confounded by diverse determinants and tissue sources of endogenous production. Trans-palmitoleate (trans-16:1n-7) represents a distinctly exogenous source of 16:1n-7, unconfounded by endogenous synthesis or its determinants, that may be uniquely informative.

Objective

We investigated whether circulating trans-palmitoleate was independently related to lower metabolic risk and incident type2 diabetes.

Design

Prospective cohort study (1992–2006).

Setting

Four US communities.

Patients

3,736 adults in the Cardiovascular Health Study.

Measurements

Plasma phospholipid fatty acids, anthropometry, blood lipids, inflammatory markers, and glucose-insulin levels were measured at baseline in 1992; and diet, 3 years earlier. In multivariable-adjusted models, we investigated how demographic, clinical, and lifestyle factors independently related to trans-palmitoleate; how trans-palmitoleate related to major metabolic risk factors; and how trans-palmitoleate related to new-onset diabetes (304 incident cases). We validated findings for metabolic risk factors in an independent cohort of 327 women.

Results

In multivariable-analyses, whole-fat dairy consumption was most strongly associated with higher trans-palmitoleate. Higher trans-palmitoleate was associated with slightly lower adiposity and, independently, higher high-density-lipoprotein(HDL)-cholesterol (across quintiles: +1.9%, P=0.04), lower triglycerides (−19.0%, P<0.001), lower total:HDL-cholesterol (−4.7%, P<0.001), lower C-reactive protein (−13.8%, P=0.05), and lower insulin resistance (−16.7%, P<0.001). Trans-palmitoleate was associated with substantially lower incidence of diabetes, with multivariable-hazard-ratios=0.41 (95%CI=0.27–0.64) and 0.38 (95%CI=0.24–0.62) in quintile-4 and quintile-5, versus quintile-1 (P-trend<0.001). Findings were independent of estimated dairy consumption or other fatty acid dairy biomarkers. Protective associations with metabolic risk factors were confirmed in the validation cohort.

Limitations

Measurement error; residual confounding.

Conclusions

Circulating trans-palmitoleate is associated with lower insulin resistance, atherogenic dyslipidemia, and incident diabetes. Our findings may explain previously observed metabolic benefits of dairy consumption and support need for detailed further experimental and clinical investigation.

Primary Funding Source

National Institutes of Health.

OBJECTIVE

Whole-grain foods are touted for multiple health benefits, including enhancing insulin sensitivity and reducing type 2 diabetes risk. Recent genome-wide association studies (GWAS) have identified several single nucleotide polymorphisms (SNPs) associated with fasting glucose and insulin concentrations in individuals free of diabetes. We tested the hypothesis that whole-grain food intake and genetic variation interact to influence concentrations of fasting glucose and insulin.

RESEARCH DESIGN AND METHODS

Via meta-analysis of data from 14 cohorts comprising ∼48,000 participants of European descent, we studied interactions of whole-grain intake with loci previously associated in GWAS with fasting glucose (16 loci) and/or insulin (2 loci) concentrations. For tests of interaction, we considered a P value <0.0028 (0.05 of 18 tests) as statistically significant.

RESULTS

Greater whole-grain food intake was associated with lower fasting glucose and insulin concentrations independent of demographics, other dietary and lifestyle factors, and BMI (β [95% CI] per 1-serving-greater whole-grain intake: −0.009 mmol/l glucose [−0.013 to −0.005], P < 0.0001 and −0.011 pmol/l [ln] insulin [−0.015 to −0.007], P = 0.0003). No interactions met our multiple testing–adjusted statistical significance threshold. The strongest SNP interaction with whole-grain intake was rs780094 (GCKR) for fasting insulin (P = 0.006), where greater whole-grain intake was associated with a smaller reduction in fasting insulin concentrations in those with the insulin-raising allele.

CONCLUSIONS

Our results support the favorable association of whole-grain intake with fasting glucose and insulin and suggest a potential interaction between variation in GCKR and whole-grain intake in influencing fasting insulin concentrations.

Background. The association between plasma omega-6 fatty acids and cardiovascular disease (CVD) is unclear, and discrepancy remains concerning the cardiovascular benefit of the omega-3 fatty acid alpha-linolenic acid. Methods. Associations of plasma phospholipid fatty acid levels (arachidonic acid, linoleic acid, eicosapentaenoic acid, docosahexaenoic acid (DHA), and alpha-linolenic acid) with cardiac magnetic resonance imaging measures of left ventricular (LV) mass, LV volume, ejection fraction, stroke volume, and aortic distensibility were investigated in 1,274 adults. Results. Results of multivariate analysis showed no statistically significant associations of plasma omega-6 or omega-3 levels with cardiac magnetic resonance imaging measures. Stratification by gender revealed a positive association between DHA and LV mass in women (β = 1.89, P = 0.02; P interaction = 0.003) and a trend for a positive association between DHA and ejection fraction in men (β = 0.009, P = 0.05; P interaction = 0.03). Conclusion. Additional research is warranted to clarify the effects of plasma DHA on cardiac structure and function in women versus men.

Long-chain n-3 polyunsaturated fatty acids (PUFAs) can derive from diet or from α-linolenic acid (ALA) by elongation and desaturation. We investigated the association of common genetic variation with plasma phospholipid levels of the four major n-3 PUFAs by performing genome-wide association studies in five population-based cohorts comprising 8,866 subjects of European ancestry. Minor alleles of SNPs in FADS1 and FADS2 (desaturases) were associated with higher levels of ALA (p = 3×10−64) and lower levels of eicosapentaenoic acid (EPA, p = 5×10−58) and docosapentaenoic acid (DPA, p = 4×10−154). Minor alleles of SNPs in ELOVL2 (elongase) were associated with higher EPA (p = 2×10−12) and DPA (p = 1×10−43) and lower docosahexaenoic acid (DHA, p = 1×10−15). In addition to genes in the n-3 pathway, we identified a novel association of DPA with several SNPs in GCKR (glucokinase regulator, p = 1×10−8). We observed a weaker association between ALA and EPA among carriers of the minor allele of a representative SNP in FADS2 (rs1535), suggesting a lower rate of ALA-to-EPA conversion in these subjects. In samples of African, Chinese, and Hispanic ancestry, associations of n-3 PUFAs were similar with a representative SNP in FADS1 but less consistent with a representative SNP in ELOVL2. Our findings show that common variation in n-3 metabolic pathway genes and in GCKR influences plasma phospholipid levels of n-3 PUFAs in populations of European ancestry and, for FADS1, in other ancestries.

Author Summary

Circulating long-chain n-3 polyunsaturated fatty acids (PUFAs) derive from fatty fish or from the conversion of the plant n-3 PUFA by elongation and desaturation. We looked for common genetic markers throughout the genome that might influence plasma phospholipid levels of the four major n-3 PUFAs in five large studies and pooled the results. We found that levels of all four n-3 PUFAs were associated with genetic markers in known desaturation and elongation genes. We also found evidence that conversion of the plant n-3 PUFA to longer chain n-3 PUFAs is less effective in people with certain desaturation-gene markers, which could be important for people who do not eat fish. We also found a marker in a gene involved in glucose metabolism, called the glucokinase regulator, to be associated with one intermediate n-3 PUFA. Some of these findings were seen across multiple race/ethnicities. Overall, these results have implications for how genes and the environment interact to influence circulating levels of fatty acids.

Little is known of the associations of endogenous fatty acids with sudden cardiac arrest (SCA). We investigated the associations of SCA with red blood cell membrane fatty acids that are end products of de novo fatty acid synthesis: myristic acid (14:0), palmitic acid (16:0), palmitoleic acid (16:1 n7), vaccenic acid (18:1 n7), stearic acid (18:0), oleic acid (18:1 n9) and a related fatty acid cis-7 hexadecenoic acid (16:1 n9). We used data from a population-based case-control study, where cases, aged 25-74 years, were out-of-hospital sudden cardiac arrest patients, attended by paramedics in Seattle, Washington (n=265). Controls, matched to cases by age, sex and calendar year, were randomly identified from the community (n=415). All participants were free of prior clinically-diagnosed heart disease. We observed associations of higher red blood cell membrane levels of 16:0, 16:1n-7, 18:1n-7 and 16:1n-9 with higher risk of SCA. In analyses adjusted for traditional SCA risk factors and trans- and n-3 fatty acids, a one-standard-deviation-higher level of 16:0 was associated with 38% higher risk of SCA (odds ratio [OR] 1.38, 95% confidence interval [CI]: 1.12-1.70) and a one-standard deviation-higher level of 16:1n-9 with 88% higher risk (OR 1.88, 95% CI: 1.27-2.78). Several fatty acids that are end products of fatty acid synthesis are associated with SCA risk. Further work is needed to investigate if conditions that favor de novo fatty acid synthesis, such as high carbohydrate/low fat diets, might also increase the risk of SCA.

Background

Angiotensin converting enzyme (ACE)-related pathways influence arrhythmias and sudden cardiac arrest (SCA) risk.

Objective

We investigated whether genetic variation in ACE-related pathways are associated with SCA risk. Because these pathways are sex-dependent and influenced by estrogen, we examined these genotype-SCA associations in the full study population, and tested for interaction with gender.

Methods

In a population-based case-control study set in King County WA, we genotyped 211 SCA cases (mean age 59, 80% male) and 730 age- and gender-matched controls of European descent for 47 single nucleotide polymorphisms (SNPs) in eight genes (ACE, AGT, REN, AGTR1, AGTR2, ACE2, KNG1, BDKRB2). We examined association of SNPs and haplotypes with SCA risk using logistic regression.

Results

AGTR1 SNP rs1492099 (allele frequency=15%) was associated with decreased SCA risk (OR=0.62, 95%CI=0.4–0.9). Haplotype variation in AGTR2 was associated with SCA risk (global haplotype test p=0.001), with haplotype 2 (allele frequency=27%) associated with increased risk (OR=1.26, 95%CI=1.1–1.5). There was interaction with gender on SCA risk for variation in KNG1 (interaction p-value range=0.0004–0.017 for 6/8 SNPs). KNG1 SNP rs710448 (allele frequency=42%) was associated with decreased risk (OR=0.44, 95%CI=0.3–0.8) among women but not men. Other SNPs and haplotypes in the eight genes examined were not associated with SCA risk after multiple testing correction.

Conclusions

Variation in AGTR1 and AGTR2 are associated with SCA risk in a population-based case-control study. There was evidence of interaction with gender on SCA risk for variation in KNG1. Our findings, if replicated, suggest that variation in genes in ACE-related pathways influence SCA risk.

Objectives

Eicosanoids are lipid mediators that may play a role in atherosclerosis. We investigated the association of common genetic variation in prostaglandin H synthase 1 (PTGS1), prostaglandin H synthase 2 (PTGS2), thromboxane A2 synthase (TBXAS1), prostacyclin synthase (PTGIS), prostaglandin E synthase (PTGES), 5-lipoxygenase activating protein (ALOX5AP), 12-lipoxygenase (ALOX12) and 15-lipoxygenase (ALOX15) with the risks of myocardial infarction (MI) and ischemic stroke. A secondary aim was to replicate the interaction of PTGS2 rs20417 (-765G to C) with aspirin use on coronary heart disease risk observed in the Atherosclerosis Risk in Communities Study.

Methods

We conducted a case-control study in a large Health Maintenance Organization. Cases were men and women, aged 30 to 79 years with incident non fatal myocardial infarction (n=1063) or ischemic stroke (n=469) between January 1995 and December 2004. Controls (n=3462) were randomly selected and frequency matched to cases on age, sex, hypertension and calendar year.

Results

Common variation in TBXAS1 and PTGIS was associated with MI risk (p-value for global Chi-square test, 0.01 and 0.03 respectively). Common variation in ALOX5AP, ALOX12, ALOX15, PTGS1, PTGS2 and PTGES was not associated with risks of MI and ischemic stroke. We replicated the observation of the Atherosclerosis Risk in Communities Study and observed an interaction of rs20417 with aspirin use on myocardial infarction risk (p for interaction=0.03).

Conclusions

Study results suggest that variation in TBXAS1 and PTGIS may influence MI risk, and carriers of rs20417 C allele might derive greater benefits from aspirin use in primary prevention.

Higher levels of long-chain n-3 polyunsaturated fatty acids in red blood cell membranes are associated with lower risk of sudden cardiac arrest. Whether membrane levels of α-linolenic acid, a medium-chain n-3 polyunsaturated fatty acid, show a similar association is unclear. We investigated the association of red blood cell membrane alpha-linolenic acid with sudden cardiac arrest risk in a population-based case-control study. Cases, aged 25–74 years, were out-of-hospital sudden cardiac arrest patients, attended by paramedics in Seattle, Washington (n=265). Controls, matched to cases by age, sex and calendar year, were randomly identified from the community (n=415). All participants were free of prior clinically-diagnosed heart disease. Blood was obtained at the time of cardiac arrest (cases) or at the time of an interview (controls). Higher membrane alpha-linolenic acid was associated with a higher risk of sudden cardiac arrest: after adjustment for matching factors and smoking, diabetes, hypertension, education, physical activity, weight, height and total fat intake, the odds ratios corresponding to increasing quartiles of alpha-linolenic acid were 1.7 (95% confidence interval [CI] 1.0–3.0), 1.9 (95% CI 1.1–3.3), and 2.5 (95% CI 1.3–4.8) compared to the lowest quartile. The association was independent of red blood cell levels of long-chain n-3 fatty acids, trans-fatty acids, and linoleic acid. Higher membrane levels of alpha-linolenic acid are associated with higher risk of sudden cardiac arrest.

Objective

Genetic polymorphisms are associated with lipid-lowering response to statins, but generalizeability to disease endpoints is unclear. The association between 82 common single nucleotide polymorphisms (SNPs) in 6 lipid- or statin-related genes (ABCB1, CETP, HMGCR, LDLR, LIPC, NOS3) and incident nonfatal myocardial infarction (MI) and ischemic stroke was analyzed according to current statin use and overall in a population-based case-control study (856 MI, 368 stroke, 2686 controls).

Methods

Common SNPs were chosen from resequencing data using pairwise linkage disequilibrium. Gene-level analyses (testing global association within a gene) and SNP-level analyses (comparing the number of observed versus expected associations across all genes) were performed using logistic regression, setting nominal statistical significance at p<0.05.

Results

No gene-level interactions with statin use on MI or stroke were identified. Across all genes, 2 SNP-statin interactions on MI were observed (1 ABCB1, 1 LIPC) and 5 interactions on stroke (1 CETP, 4 LIPC). The strongest SNP-statin interaction was for synonymous CETP SNP rs5883 on stroke (p = 0.008). Gene-level associations were present for LIPC and MI (p = 0.026), but not other genes or outcomes. SNP-level associations included 3 SNPs with MI (1 LDLR, 2 LIPC) and 2 SNPs with stroke (1 CETP, 1 LDLR). The number of observed SNP associations was no greater than expected by chance.

Conclusions

Several potential novel associations or interactions of SNPs in ABCB1, CETP, LDLR and LIPC with MI and stroke were identified; however, our results should be regarded as hypothesis-generating until corroborated by other studies.

Background—

Atrial fibrillation (AF) is the most common arrhythmia in clinical practice and is particularly common in the elderly. Although effects of fish intake, including potential antiarrhythmic effects, may favorably influence risk of AF, relationships between fish intake and AF incidence have not been evaluated.

Methods and Results—

In a prospective, population-based cohort of 4815 adults ≥age 65 years, usual dietary intake was assessed at baseline in 1989 and 1990. Consumption of tuna and other broiled or baked fish correlated with plasma phospholipid long-chain n-3 fatty acids, whereas consumption of fried fish or fish sandwiches (fish burgers) did not. AF incidence was prospectively ascertained on the basis of hospital discharge records and annual electrocardiograms. During 12 years’ follow-up, 980 cases of incident AF were diagnosed. In multivariate analyses, consumption of tuna or other broiled or baked fish was inversely associated with incidence of AF, with 28% lower risk with intake 1 to 4 times per week (HR=0.72, 95% CI=0.58 to 0.91, P=0.005), and 31% lower risk with intake ≥5 times per week (HR=0.69, 95% CI=0.52 to 0.91, P=0.008), compared with <1 time per month (P trend=0.004). Results were not materially different after adjustment for preceding myocardial infarction or congestive heart failure. In similar analyses, fried fish/fish sandwich consumption was not associated with lower risk of AF.

Conclusions—

Among elderly adults, consumption of tuna or other broiled or baked fish, but not fried fish or fish sandwiches, is associated with lower incidence of AF. Fish intake may influence risk of this common cardiac arrhythmia.

Background:

Associations between fish consumption and stroke risk have been inconsistent, possibly because of the differences in types of fish meals consumed. Additionally, such relationships have not been specifically evaluated in the elderly, in whom disease burden may be high and diet less influential.

Methods:

Among 4775 adults 65 years or older (range, 65–98 years) and free of known cerebrovascular disease at baseline in 1989–1990, usual dietary intake was assessed using a food frequency questionnaire. In a subset, consumption of tuna or other broiled or baked fish, but not fried fish or fish sandwiches (fish burgers), correlated with plasma phospholipid long-chain n-3 fatty acid levels. Incident strokes were prospectively ascertained.

Results:

During 12 years of follow-up, participants experienced 626 incident strokes, including 529 ischemic strokes. In multivariate analyses, tuna/other fish consumption was inversely associated with total stroke (P=.04) and ischemic stroke (P=.02), with 27% lower risk of ischemic strokewith an intake of 1 to 4 times per week (hazard ratio [HR], 0.73; 95% confidence interval [CI], 0.55–0.98) and 30% lower risk with intake of 5 or more times per week (HR, 0.70; 95% CI, 0.50–0.99) compared with an intake of less than once per month. In contrast, fried fish/fish sandwich consumption was positively associated with total stroke (P=.006) and ischemic stroke (P=.003), with a 44% higher risk of ischemic stroke with consumption of more than once per week (HR, 1.44; 95% CI, 1.12–1.85) compared with consumption of less than once per month. Fish consumption was not associated with hemorrhagic stroke.

Conclusions:

Among elderly individuals, consumption of tuna or other broiled or baked fish is associated with lower risk of ischemic stroke, while intake of fried fish or fish sandwiches is associated with higher risk. These results suggest that fish consumption may influence stroke risk late in life; potential mechanisms and alternate explanations warrant further study.

The reduction of mortality from sudden cardiac arrest (SCA) in the setting of coronary heart disease (CHD) remains a major challenge, especially among patients with type 2 diabetes. Diabetes is associated with an increased risk of SCA, at least in part, from an increased presence and extent of coronary atherosclerosis (macrovascular disease). Diabetes also is associated with microvascular disease and autonomic neuropathy; and, these non-coronary atherosclerotic pathophysiologic processes also have the potential to increase the risk of SCA. In this report, we review the absolute and relative risk of SCA associated with diabetes. We summarize recent evidence that suggests that the increase in risk in patients with diabetes is not specific for SCA, as diabetes also is associated with a similar increase in risk for non-SCA CHD death and non-fatal myocardial infarction. These data are consistent with prior observations that coronary atherosclerosis is a major contributor to the increased SCA risk associated with diabetes. We also present previously published and unpublished data that demonstrates that both clinically-recognized microvascular and autonomic neuropathy also are associated with the risk of SCA among treated patients with diabetes, after taking into account prior clinically-recognized heart disease and other risk factors for SCA. We then discuss how these data might inform research and clinical efforts to prevent SCA. Although the prediction of SCA in this “high” risk population is likely to remain a challenge, as it is in other “high” risk clinical populations, we suggest that current recommendations for the prevention of SCA in the community, related to both lifestyle prescriptions and risk factor reduction, are likely to reduce mortality from SCA among patients with diabetes.

Objective To examine the association of myocardial infarction and stroke incidence with several commonly used two drug antihypertensive treatment regimens.

Design Population based case-control study.

Setting Group Health Cooperative, Seattle, WA, USA.

Participants Cases (n=353) were aged 30-79 years, had pharmacologically treated hypertension, and were diagnosed with a first fatal or non-fatal myocardial infarction or stroke between 1989 and 2005. Controls (n=952) were a random sample of Group Health members who had pharmacologically treated hypertension. We excluded individuals with heart failure, evidence of coronary heart disease, diabetes, or chronic kidney disease.

Exposures One of three common two drug combinations: diuretics plus β blockers; diuretics plus calcium channel blockers; and diuretics plus angiotensin converting enzyme inhibitors or angiotensin receptor blockers.

Main outcome measures Myocardial infarction or stroke.

Results Compared with users of diuretics plus β blockers, users of diuretics plus calcium channel blockers had an increased risk of myocardial infarction (adjusted odds ratio (OR) 1.98, 95% confidence interval 1.37 to 2.87) but not of stroke (OR 1.02, 95% CI 0.63 to 1.64). The risks of myocardial infarction and stroke in users of diuretics plus angiotensin converting enzyme inhibitors or angiotensin receptor blockers were slightly but not significantly lower than in users of diuretics plus β blockers (myocardial infarction: OR 0.76, 95% CI 0.52 to 1.11; stroke: OR 0.71, 95% CI 0.46 to 1.10).

Conclusions In patients with hypertension, diuretics plus calcium channel blockers were associated with a higher risk of myocardial infarction than other common two drug treatment regimens. A large trial of second line antihypertensive treatments in patients already on low dose diuretics is required to provide a solid basis for treatment recommendations.

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 alpha (PPARA) and toll-like receptor 4 (TLR4) genes with incident non-fatal myocardial infarction (MI) or ischemic stroke. In a population-based case-control study, cases (848 MI and 368 ischemic stroke) and controls (2682) were recruited from postmenopausal women and hypertensive men/women who were members of Group Health in Western Washington State. Common tag single nucleotide polymorphisms (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%CI: 1.08–1.46) while the minor allele of the TLR4 SNP, rs1927911, was associated with a lower risk of MI (odds ratio: 0.88, 95%CI: 0.77–0.99). No within gene or gene-gene interaction was associated with MI or ischemic stroke risk. Potential SNP-disease associations identified in the current study are novel.