Showing papers by "Christopher J. O'Donnell published in 2007"
TL;DR: This chapter describes the most important sources and the types of data the AHA uses from them and other government agencies to derive the annual statistics in this Update.
Abstract: 1. About These Statistics…e70
2. Cardiovascular Diseases…e72
3. Coronary Heart Disease, Acute Coronary Syndrome, and Angina Pectoris…e89
4. Stroke…e99
5. High Blood Pressure…e111
6. Congenital Cardiovascular Defects…e116
7. Heart Failure…e119
8. Other Cardiovascular Diseases…e122
9. Risk Factor: Smoking/Tobacco Use…e128
10. Risk Factor: High Blood Cholesterol and Other Lipids…e132
11. Risk Factor: Physical Inactivity…e136
12. Risk Factor: Overweight and Obesity…e139
13. Risk Factor: Diabetes Mellitus…e143
14. End-Stage Renal Disease and Chronic Kidney Disease…e149
15. Metabolic Syndrome…e151
16. Nutrition…e153
17. Quality of Care…e155
18. Medical Procedures…e159
19. Economic Cost of Cardiovascular Diseases…e162
20. At-a-Glance Summary Tables…e164
21. Glossary and Abbreviation Guide…e168
Writing Group Disclosures…e171
Appendix I: List of Statistical Fact Sheets:
http://www.americanheart.org/presenter.jhtml?identifier=2007
We thank Drs Robert Adams, Philip Gorelick, Matt Wilson, and Philip Wolf (members of the Statistics Committee or Stroke Statistics Subcommittee); Brian Eigel; Gregg Fonarow; Kathy Jenkins; Gail Pearson; and Michael Wolz for their valuable comments and contributions. We would like to acknowledge Tim Anderson and Tom Schneider for their editorial contributions and Karen Modesitt for her administrative assistance.
# 1. About These Statistics {#article-title-2}
The American Heart Association (AHA) works with the Centers for Disease Control and Prevention’s National Center for Health Statistics (CDC/NCHS); the National Heart, Lung, and Blood Institute (NHLBI); the National Institute of Neurological Disorders and Stroke (NINDS); and other government agencies to derive the annual statistics in this Update. This chapter describes the most important sources and the types of data we use from them. For more details and an alphabetical list of abbreviations, see Chapter 21 of this document, the Glossary and Abbreviation Guide.
The surveys used are:
5,393 citations
TL;DR: These findings are consistent with the hypothesized role of visceral fat as a unique, pathogenic fat depot and Measurement of VAT may provide a more complete understanding of metabolic risk associated with variation in fat distribution.
Abstract: Background— Visceral adipose tissue (VAT) compartments may confer increased metabolic risk. The incremental utility of measuring both visceral and subcutaneous abdominal adipose tissue (SAT) in association with metabolic risk factors and underlying heritability has not been well described in a population-based setting. Methods and Results— Participants (n=3001) were drawn from the Framingham Heart Study (48% women; mean age, 50 years), were free of clinical cardiovascular disease, and underwent multidetector computed tomography assessment of SAT and VAT volumes between 2002 and 2005. Metabolic risk factors were examined in relation to increments of SAT and VAT after multivariable adjustment. Heritability was calculated using variance-components analysis. Among both women and men, SAT and VAT were significantly associated with blood pressure, fasting plasma glucose, triglycerides, and high-density lipoprotein cholesterol and with increased odds of hypertension, impaired fasting glucose, diabetes mellitus, ...
2,501 citations
TL;DR: The present cross-sectional data support an association between both SAT and VAT with inflammation and oxidative stress and suggest that the contribution of visceral fat to inflammation may not be completely accounted for by clinical measures of obesity.
Abstract: Background— Excess adiposity is associated with greater systemic inflammation. Whether visceral adiposity is more proinflammatory than subcutaneous abdominal adiposity is unclear. Methods and Results— We examined the relations of abdominal subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT), assessed by multidetector computerized tomography, to circulating inflammatory and oxidative stress biomarkers in 1250 Framingham Heart Study participants (52% women; age 60±9 years). Biomarkers were examined in relation to increments of SAT and VAT after adjustment for age, sex, smoking, physical activity, menopause, hormone replacement therapy, alcohol, and aspirin use; additional models included body mass index and waist circumference. SAT and VAT were positively and similarly (with respect to strength of association) related to C-reactive protein, fibrinogen, intercellular adhesion molecule-1, interleukin-6, P-selectin, and tumor necrosis factor receptor-2 (multivariable model R2 0.06 to 0.28 [SAT]...
825 citations
TL;DR: The comparison of Third Generation Cohort data with measures previously collected from the first two generations will facilitate investigations of genetic and environmental risk factors for subclinical and overt diseases, with a focus on cardiovascular and lung disorders.
Abstract: For nearly 60 years, the Framingham Heart Study has examined the natural history, risk factors, and prognosis of cardiovascular, lung, and other diseases. Recruitment of the Original Cohort began in 1948. Twenty-three years later, 3,548 children of the Original Cohort, along with 1,576 of their spouses, enrolled in the Offspring Cohort. Beginning in 2002, 4,095 adults having at least one parent in the Offspring Cohort enrolled in the Third Generation Cohort, along with 103 parents of Third Generation Cohort participants who were not previously enrolled in the Offspring Cohort. The objective of new recruitment was to complement phenotypic and genotypic information obtained from prior generations, with priority assigned to larger families. From a pool of 6,553 eligible individuals, 1,912 men and 2,183 women consented and attended the first examination (mean age: 40 (standard deviation: 9) years; range: 19-72 years). The examination included clinical and laboratory assessments of vascular risk factors and imaging for subclinical atherosclerosis, as well as assessment of cardiac structure and function. The comparison of Third Generation Cohort data with measures previously collected from the first two generations will facilitate investigations of genetic and environmental risk factors for subclinical and overt diseases, with a focus on cardiovascular and lung disorders.
795 citations
TL;DR: The observation that high vitamin K status was associated with lower concentrations of inflammatory markers suggests that a possible protective role for vitamin K in inflammation merits further investigation.
Abstract: In vitro data suggest protective roles for vitamins K and D in inflammation. To examine associations between vitamins K and D and inflammation in vivo, the authors used multiple linear regression analyses, adjusted for age, sex, body mass index, triglyceride concentrations, use of aspirin, use of lipid-lowering medication, season, menopausal status, and hormone replacement therapy. Participants were from the Framingham Offspring Study (1997-2001; n = 1,381; mean age = 59 years; 52% women). Vitamin K status, measured by plasma phylloquinone concentration and phylloquinone intake, was inversely associated with circulating inflammatory markers as a group and with several individual inflammatory biomarkers (p < 0.01). Percentage of undercarboxylated osteocalcin, a functional measure of vitamin K status, was not associated with overall inflammation but was associated with C-reactive protein (p < 0.01). Although plasma 25-hydroxyvitamin D was inversely associated with urinary isoprostane concentration, an indicator of oxidative stress (p < 0.01), overall associations between vitamin D status and inflammation were inconsistent. The observation that high vitamin K status was associated with lower concentrations of inflammatory markers suggests that a possible protective role for vitamin K in inflammation merits further investigation.
286 citations
TL;DR: It is suggested that volumetric measurements can depict age- and gender-related differences of visceral and subcutaneous abdominal adipose tissue deposition and may substantially improve the predictive value of obesity measures for insulin resistance, type 2 diabetes mellitus and other diseases.
Abstract: Cross-sectional imaging may enable accurate localization and quantification of subcutaneous and visceral adipose tissue. The reproducibility of multi-detector computed tomography (MDCT)-based volumetric quantification of abdominal adipose tissue and the ability to depict age- and gender-related characteristics of adipose tissue deposition have not been reported. We evaluated a random subset of 100 Caucasian subjects (age range: 37–83 years; 49% women) of the Framingham Heart Study offspring cohort who underwent MDCT scanning. Two readers measured subcutaneous and visceral adipose tissue volumes (SAV and VAV; cm3) and areas (SAA and VAA; cm2) as well as abdominal sagital diameter (SD) and waist circumference (WC). Inter-reader reproducibility was excellent (relative difference: −0.34±0.52% for SAV and 0.59±0.93% for VAV, intra-class correlation (ICC)=0.99 each). The mean SAA/VAA ratio was significantly different from the mean SAV/VAV ratio (2.0±1.2 vs 1.7±0.9; P 60 years (1.9±1.0 vs 1.5±0.7; P<0.001) and between men and women (1.2±0.5 vs 2.2±0.9; P<0.001). This study demonstrates that MDCT-based volumetric quantification of abdominal adipose tissue is highly reproducible. In addition, our results suggest that volumetric measurements can depict age- and gender-related differences of visceral and subcutaneous abdominal adipose tissue deposition. Further research is warranted to assess whether volumetric measurements may substantially improve the predictive value of obesity measures for insulin resistance, type 2 diabetes mellitus and other diseases.
269 citations
TL;DR: Using single nucleotide polymorphisms from a 100K genome-wide scan, this work examines the associations of common polymorphisms with phenotypic variation in this community-based cohort and provides a full-disclosure, web-based resource of results for future replication studies.
Abstract: Background
The Framingham Heart Study (FHS), founded in 1948 to examine the epidemiology of cardiovascular disease, is among the most comprehensively characterized multi-generational studies in the world. Many collected phenotypes have substantial genetic contributors; yet most genetic determinants remain to be identified. Using single nucleotide polymorphisms (SNPs) from a 100K genome-wide scan, we examine the associations of common polymorphisms with phenotypic variation in this community-based cohort and provide a full-disclosure, web-based resource of results for future replication studies.
228 citations
TL;DR: The approaches researchers are using to advance understanding of the genetic basis of CVD are described and the current state of knowledge regarding the genetics of myocardial infarction, atherosclerotic CVD, hypercholesterolemia, and hypertension are details.
Abstract: Atherosclerotic cardiovascular disease (CVD) is a major health problem in the United States and around the world. Evidence accumulated over decades convincingly demonstrates that family history in a parent or a sibling is associated with atherosclerotic CVD, manifested as coronary heart disease, stroke, and/or peripheral arterial disease. Although there are several mendelian disorders that contribute to CVD, most common forms of CVD are believed to be multifactorial and to result from many genes, each with a relatively small effect working alone or in combination with modifier genes and/or environmental factors. The identification and the characterization of these genes and their modifiers would enhance prediction of CVD risk and improve prevention, treatment, and quality of care. This scientific statement describes the approaches researchers are using to advance understanding of the genetic basis of CVD and details the current state of knowledge regarding the genetics of myocardial infarction, atherosclerotic CVD, hypercholesterolemia, and hypertension. Current areas of interest and investigation--including gene-environment interaction, pharmacogenetics, and genetic counseling--are also discussed. The statement concludes with a list of specific recommendations intended to help incorporate usable knowledge into current clinical and public health practice, foster and guide future research, and prepare both researchers and practitioners for the changes likely to occur as molecular genetics moves from the laboratory to clinic.
207 citations
TL;DR: A community-based genome-wide association study of major CVD outcomes finds genetic variants associated with CVD may point to novel disease pathways and identify potential targeted preventive therapies.
Abstract: National Institute of Health and the National Heart, Lung, and Blood Institute (N01-HC 25195); National Health Institutes National Center for Research Resources Shared Instrumentation grant (ISI0RR163736-01A1)
197 citations
TL;DR: There is a continuous gradient of increasing risk of BP progression across ARR levels in nonhypertensive individuals, and ARR is a heritable trait influenced by clinical and genetic factors.
Abstract: Aldosterone:renin ratio (ARR) is used to screen for hyperaldosteronism. Data regarding correlates of ambulatory ARR in the community and its relation to hypertension incidence are limited. We defined clinical correlates of ARR, determined its heritability, tested for association and linkage, and related ARR to blood pressure (BP) progression in nonhypertensive individuals among 3326 individuals from the Framingham Heart Study (53% women; mean age: 59 years). Ambulatory morning ARR (serum aldosterone and plasma renin concentrations) were related to clinical covariates, genetic variation across the REN locus, a 10-cM linkage map, and among nonhypertensive participants (n=1773) to progression of >or=1 Sixth Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure BP category (optimal: or=140/90 mm Hg), or incident hypertension (systolic BP: >or=140 mm Hg, diastolic BP: >or=90 mm Hg, or use of antihypertensive treatment). ARR was positively associated with age, female sex, untreated hypertension, total/high-density lipoprotein cholesterol ratio, hormone replacement therapy, and beta-blocker use, but negatively associated with angiotensin-converting enzyme inhibitor and diuretic use. ARR was heritable (h(2)=0.40), had modest linkage to chromosome 11p (logarithm of the odds: 1.89), but was not associated with 17 common variants in REN (n=1729). On follow-up (mean: 3 years), 607 nonhypertensive individuals (34.2%) developed BP progression, and 283 (16.0%) developed hypertension. Higher baseline logARR was associated with increased risk of BP progression (odds ratio per SD increment: 1.23; 95% CI: 1.11 to 1.37) and hypertension incidence (odds ratio per SD increment: 1.16; 95% CI: 1.00 to 1.33). ARR is a heritable trait influenced by clinical and genetic factors. There is a continuous gradient of increasing risk of BP progression across ARR levels in nonhypertensive individuals.
181 citations
TL;DR: It is shown that single-site mutations in plastid ACCase confer herbicide resistance to wheat plastids, and that these mutations are very likely to confer resistance to any grass weed species under selection imposed by the extensive agricultural use of the herbicides.
Abstract: Grass weed populations resistant to aryloxyphenoxypropionate (APP) and cyclohexanedione herbicides that inhibit acetyl-CoA carboxylase (ACCase; EC 6.4.1.2) represent a major problem for sustainable agriculture. We investigated the molecular basis of resistance to ACCase-inhibiting herbicides for nine wild oat (Avena sterilis ssp. ludoviciana Durieu) populations from the northern grain-growing region of Australia. Five amino acid substitutions in plastid ACCase were correlated with herbicide resistance: Ile-1,781-Leu, Trp-1,999-Cys, Trp-2,027-Cys, Ile-2,041-Asn, and Asp-2,078-Gly (numbered according to the Alopecurus myosuroides plastid ACCase). An allele-specific PCR test was designed to determine the prevalence of these five mutations in wild oat populations suspected of harboring ACCase-related resistance with the result that, in most but not all cases, plant resistance was correlated with one (and only one) of the five mutations. We then showed, using a yeast gene-replacement system, that these single-site mutations also confer herbicide resistance to wheat plastid ACCase: Ile-1,781-Leu and Asp-2,078-Gly confer resistance to APPs and cyclohexanediones, Trp-2,027-Cys and Ile-2,041-Asn confer resistance to APPs, and Trp-1,999-Cys confers resistance only to fenoxaprop. These mutations are very likely to confer resistance to any grass weed species under selection imposed by the extensive agricultural use of the herbicides.
TL;DR: A genome-wide association study for SCA measurements in the community-based Framingham Heart Study generates hypotheses regarding several SNPs that may be associated with SCA phenotypes in multiple arterial beds.
Abstract: Subclinical atherosclerosis (SCA) measures in multiple arterial beds are heritable phenotypes that are associated with increased incidence of cardiovascular disease. We conducted a genome-wide association study (GWAS) for SCA measurements in the community-based Framingham Heart Study. Over 100,000 single nucleotide polymorphisms (SNPs) were genotyped (Human 100K GeneChip, Affymetrix) in 1345 subjects from 310 families. We calculated sex-specific age-adjusted and multivariable-adjusted residuals in subjects tested for quantitative SCA phenotypes, including ankle-brachial index, coronary artery calcification and abdominal aortic calcification using multi-detector computed tomography, and carotid intimal medial thickness (IMT) using carotid ultrasonography. We evaluated associations of these phenotypes with 70,987 autosomal SNPs with minor allele frequency ≥ 0.10, call rate ≥ 80%, and Hardy-Weinberg p-value ≥ 0.001 in samples ranging from 673 to 984 subjects, using linear regression with generalized estimating equations (GEE) methodology and family-based association testing (FBAT). Variance components LOD scores were also calculated. There was no association result meeting criteria for genome-wide significance, but our methods identified 11 SNPs with p < 10-5 by GEE and five SNPs with p < 10-5 by FBAT for multivariable-adjusted phenotypes. Among the associated variants were SNPs in or near genes that may be considered candidates for further study, such as rs1376877 (GEE p < 0.000001, located in ABI2) for maximum internal carotid artery IMT and rs4814615 (FBAT p = 0.000003, located in PCSK2) for maximum common carotid artery IMT. Modest significant associations were noted with various SCA phenotypes for variants in previously reported atherosclerosis candidate genes, including NOS3 and ESR1. Associations were also noted of a region on chromosome 9p21 with CAC phenotypes that confirm associations with coronary heart disease and CAC in two recently reported genome-wide association studies. In linkage analyses, several regions of genome-wide linkage were noted, confirming previously reported linkage of internal carotid artery IMT on chromosome 12. All GEE, FBAT and linkage results are provided as an open-access results resource at http://www.ncbi.nlm.nih.gov/projects/gap/cgi-bin/study.cgi?id=phs000007
. The results from this GWAS generate hypotheses regarding several SNPs that may be associated with SCA phenotypes in multiple arterial beds. Given the number of tests conducted, subsequent independent replication in a staged approach is essential to identify genetic variants that may be implicated in atherosclerosis.
TL;DR: There were modest associations of inflammatory markers, particularly IL-6, with carotid atherosclerosis, and this association appears more pronounced in current smokers than in former smokers and nonsmokers.
Abstract: Inflammatory markers, particularly C-reactive protein (CRP), predict incident cardiovascular disease and are associated with the presence of subclinical atherosclerosis. The relations between multiple inflammatory markers and direct measures of atherosclerosis are less well established. Participants in the Offspring Cohort of the Framingham Heart Study (n = 2,885, 53% women, mean age 59 years) received routine assessments of common carotid artery intima-media thickness (CCA-IMT), internal carotid artery intima-media thickness (ICA-IMT), and the presence or absence of > or =25% carotid stenosis by ultrasonography. Circulating inflammatory markers assessed from an examination 4 years later included CRP, interleukin-6 (IL-6), intercellular adhesion molecule-1, monocyte chemoattractant protein-1, P-selectin, and CD40 ligand. Assessed as a group, inflammatory markers were significantly associated with ICA-IMT (p = 0.01), marginally with carotid stenosis (p = 0.08), but not with CCA-IMT. Individually, with an increase from the 25th to 75th percentile in IL-6, there were significant increases in ICA-IMT and carotid stenosis (for ICA-IMT, estimated fold increase 1.04, 95% confidence interval 1.03 to 1.06, p = 0.0004; for carotid stenosis, odds ratio 1.25, 95% confidence interval 1.06 to 1.47, p = 0.007) after adjustment for age, gender, and established risk factors for atherosclerosis. There was a similar significant multivariate-adjusted association of CRP with ICA-IMT but not with carotid stenosis. Smoking appeared to modify the associations of ICA-IMT with CRP (p = 0.009) and with IL-6 (p = 0.006); the association was more pronounced in current (vs former or never) smokers. In conclusion, there were modest associations of inflammatory markers, particularly IL-6, with carotid atherosclerosis. This association appears more pronounced in current smokers than in former smokers and nonsmokers.
TL;DR: Risk conferred by parental premature CVD on vascular calcification may be mediated through novel mechanisms not accounted for by classic CVD risk factors known to cause atherosclerosis, particularly in younger middle-aged adults.
Abstract: Background— Parental premature cardiovascular disease (CVD) is a risk factor for coronary heart disease (CHD). We related validated parental premature CVD with the subclinical measures of coronary artery (CAC) and abdominal aortic (AAC) calcification in the community. Methods and Results— We studied 2 generations of Framingham Heart Study subjects who underwent multidetector computed tomography measurements of CAC and AAC and who had 2 parents in the study. Subjects included 797 Framingham Offspring (mean age, 63 years; 56% women) and 1238 Third Generation (Gen3) (mean age, 46 years; 47% women) participants free of CVD. Generalized estimating equations adjusted for major CVD risk factors were used to relate validated parental premature CVD and CHD to CAC and AAC, defined by >90th percentile age- and sex-specific cut points from a healthy subsample. Parental premature CVD was associated with CAC among Gen3 (odds ratio=2.17 [1.41 to 3.33]; P<0.001) and nonsignificantly among Offspring (odds ratio=1.42 [0.91...
TL;DR: In this community-based sample, individuals with MetS have a high prevalence of subclinical atherosclerosis that likely contributes to the increased risk of overt CVD associated with the condition.
Abstract: Data are limited regarding prevalence and prognostic significance of subclinical cardiovascular disease (CVD) in individuals with metabolic syndrome (MetS). We investigated prevalence of subclinical CVD in 1,945 Framingham Offspring Study participants (mean age 58 years; 59% women) using electrocardiography, echocardiography, carotid ultrasound, ankle-brachial blood pressure, and urinary albumin excretion. We prospectively evaluated the incidence of CVD associated with MetS and diabetes according to presence versus absence of subclinical disease. Cross-sectionally, 51% of 581 participants with MetS had subclinical disease in at least one test, a frequency higher than individuals without MetS (multivariable-adjusted odds ratio 2.06 [95% CI 1.67-2.55]; P < 0.0001). On follow-up (mean 7.2 years), 139 individuals developed overt CVD, including 59 with MetS (10.2%). Overall, MetS was associated with increased CVD risk (multivariable-adjusted hazards ratio [HR] 1.61 [95% CI 1.12-2.33]). Participants with MetS and subclinical disease experienced increased risk of overt CVD (2.67 [1.62-4.41] compared with those without MetS, diabetes, or subclinical disease), whereas the association of MetS with CVD risk was attenuated in absence of subclinical disease (HR 1.59 [95% CI 0.87-2.90]). A similar attenuation of CVD risk in absence of subclinical disease was observed also for diabetes. Subclinical disease was a significant predictor of overt CVD in participants without MetS or diabetes (1.93 [1.15-3.24]). In our community-based sample, individuals with MetS have a high prevalence of subclinical atherosclerosis that likely contributes to the increased risk of overt CVD associated with the condition.
TL;DR: In hypothesis-generating GWAS of echocardiography, ETT and BA vascular function in a moderate-sized community-based sample, several SNPs are identified that are candidates for replication attempts and the resource is provided to provide a web-based GWAS resource for the research community.
Abstract: National Heart, Lung, and Blood Institute's Framingham Heart Study (N01-HC-25195); National Institutes of Health National Center for Research Resources Shared Instrumentation grant (1S10RR163736-01A1); National Institutes of Health (K23-HL-074077, K23-HL080025, 6R01-NS 17950, 1R01 HL 60040, RO1 HL70100, HL080124, K24-HL04334)
TL;DR: There is high prevalence of common and uncommon inflammatory conditions in individuals with high CRP concentrations, and these individuals should be interpreted with caution in cardiovascular disease risk assessment.
TL;DR: In the community-based Framingham Heart Study none of the ECG and HRV results individually attained genomewide significance, however, the presence of bona fide QT-associated SNPs among the top 117 results for QT duration supports the importance of efforts to validate top results from the reported scans.
Abstract: Heritable electrocardiographic (ECG) and heart rate variability (HRV) measures, reflecting pacemaking, conduction, repolarization and autonomic function in the heart have been associated with risks for cardiac arrhythmias. Whereas several rare monogenic conditions with extreme phenotypes have been noted, few common genetic factors contributing to interindividual variability in ECG and HRV measures have been identified. We report the results of a community-based genomewide association study of six ECG and HRV intermediate traits. Genotyping using Affymetrix 100K GeneChip was conducted on 1345 related Framingham Heart Study Original and Offspring cohort participants. We analyzed 1175 Original and Offspring participants with ECG data (mean age 52 years, 52% women) and 548 Offspring participants with HRV data (mean age 48 years, 51% women), in relation to 70,987 SNPs with minor allele frequency ≥ 0.10, call rate ≥ 80%, Hardy-Weinberg p-value ≥ 0.001. We used generalized estimating equations to test association of SNP alleles with multivariable-adjusted residuals for QT, RR, and PR intervals, the ratio of low frequency to high frequency power (LF/HFP), total power (TP) and the standard deviation of normal RR intervals (SDNN). Associations at p < 10-3 were found for 117 (QT), 105 (RR), 111 (PR), 102 (LF/HF), 121 (TP), and 102 (SDNN) SNPs. Several common variants in NOS1AP (4 SNPs with p-values < 10-3; lowest p-value, rs6683968, p = 1 × 10-4) were associated with adjusted QT residuals, consistent with our previously reported finding for NOS1AP in an unrelated sample of FHS Offspring and other cohorts. All results are publicly available at NCBI's dbGaP at http://www.ncbi.nlm.nih.gov/projects/gap/cgi-bin/study.cgi?id=phs000007
. In the community-based Framingham Heart Study none of the ECG and HRV results individually attained genomewide significance. However, the presence of bona fide QT-associated SNPs among the top 117 results for QT duration supports the importance of efforts to validate top results from the reported scans. Finding genetic variants associated with ECG and HRV quantitative traits may identify novel genes and pathways implicated in arrhythmogenesis and allow for improved recognition of individuals at high risk for arrhythmias in the general population.
TL;DR: Two common genetic variants at the KCNH2 locus are associated with continuous QT interval duration in an unselected community-based sample, and the influence of these variants on risk of sudden cardiac death and drug-induced arrhythmias should be considered.
Abstract: Background— QT prolongation is associated with increased risk of sudden cardiac death in the general population and in people exposed to QT-prolonging drugs. Mutations in the KCNH2 gene encoding the HERG potassium channel cause 30% of long-QT syndrome, and binding to this channel leads to drug-induced QT prolongation. We tested common KCNH2 variants for association with continuous QT interval duration. Methods and Results— We selected 17 single nucleotide polymorphisms and rs1805123, a previously associated missense single nucleotide polymorphism, for genotyping in 1730 unrelated men and women from the Framingham Heart Study. rs3807375 genotypes were associated with continuous QT interval duration in men and women (2-df P=0.002), with a dominant model suggested (P=0.0004). An independent sample of 871 Framingham Heart Study men and women replicated the association (1-sided dominant P=0.02). On combined analysis of 2123 subjects, individuals with AA or AG genotypes had a 0.14-SD (SE, 0.04) or 3.9-ms higher...
TL;DR: Using genome-wide association methodology, a SNP in complete LD with a sequence variant previously shown to be strongly associated with factor VII is successfully identified, providing proof of principle for this approach.
Abstract: Increased circulating levels of hemostatic factors as well as anemia have been associated with increased risk of cardiovascular disease (CVD). Known associations between hemostatic factors and sequence variants at genes encoding these factors explain only a small proportion of total phenotypic variation. We sought to confirm known putative loci and identify novel loci that may influence either trait in genome-wide association and linkage analyses using the Affymetrix GeneChip 100K single nucleotide polymorphism (SNP) set. Plasma levels of circulating hemostatic factors (fibrinogen, factor VII, plasminogen activator inhibitor-1, von Willebrand factor, tissue plasminogen activator, D-dimer) and hematological phenotypes (platelet aggregation, viscosity, hemoglobin, red blood cell count, mean corpuscular volume, mean corpuscular hemoglobin concentration) were obtained in approximately 1000 Framingham Heart Study (FHS) participants from 310 families. Population-based association analyses using the generalized estimating equations (GEE), family-based association test (FBAT), and multipoint variance components linkage analyses were performed on the multivariable adjusted residuals of hemostatic and hematological phenotypes. In association analysis, the lowest GEE p-value for hemostatic factors was p = 4.5*10-16 for factor VII at SNP rs561241, a variant located near the F7 gene and in complete linkage disequilibrium (LD) (r2 = 1) with the Arg353Gln F7 SNP previously shown to account for 9% of total phenotypic variance. The lowest GEE p-value for hematological phenotypes was 7*10-8 at SNP rs2412522 on chromosome 4 for mean corpuscular hemoglobin concentration. We presented top 25 most significant GEE results with p-values in the range of 10-6 to 10-5 for hemostatic or hematological phenotypes. In relating 100K SNPs to known candidate genes, we identified two SNPs (rs1582055, rs4897475) in erythrocyte membrane protein band 4.1-like 2 (EPB41L2) associated with hematological phenotypes (GEE p < 10-3). In linkage analyses, the highest linkage LOD score for hemostatic factors was 3.3 for factor VII on chromosome 10 around 15 Mb, and for hematological phenotypes, LOD 3.4 for hemoglobin on chromosome 4 around 55 Mb. All GEE and FBAT association and variance components linkage results can be found at http://www.ncbi.nlm.nih.gov/projects/gap/cgi-bin/study.cgi?id=phs000007
Using genome-wide association methodology, we have successfully identified a SNP in complete LD with a sequence variant previously shown to be strongly associated with factor VII, providing proof of principle for this approach. Further study of additional strongly associated SNPs and linked regions may identify novel variants that influence the inter-individual variability in hemostatic factors and hematological phenotypes.
TL;DR: In this free-living longitudinally followed cohort, subclinical aortic atherosclerosis was seen in nearly half of subjects and increased with advancing age, and HTN was associated with increased aortsic plaque burden.
Abstract: Objective— The purpose of this study was to investigate the impact of age, sex, and hypertension (HTN) on aortic atherosclerotic burden using cardiovascular MRI (CMR) in a free-living longitudinally followed cohort. Methods and Results— 1763 participants (829 M and 934 F; 38 to 88 years of age) of the Framingham Heart Study Offspring cohort underwent CMR of the thoracoabdominal aorta using an ECG-gated 2D T2-weighted black-blood sequence. Of these, 1726 subjects (96%) with interpretable CMR were characterized by sex, age-quartile, and presence or absence of HTN and clinical cardiovascular disease (CVD). Aortic plaque prevalence and volume increased with increasing age in both sexes. For the nonhypertensive (no-HTN) group, plaque was identified in 702 (46%) with greater prevalence in women than in men ( P P P Conclusions— In this free-living longitudinally followed cohort, subclinical aortic atherosclerosis was seen in nearly half of subjects and increased with advancing age. HTN was associated with increased aortic plaque burden. Among no-HTN subjects, women had greater plaque burden than men. These data suggest that subclinical atherosclerosis is more common in no-HTN women and emphasize the importance of focusing on preventive measures in both sexes.
TL;DR: The relation between severity of aortic calcification in middle‐age years and subsequent risk of hip fracture in women and men in the population‐based Framingham Study is examined.
Abstract: Osteoporosis and atherosclerosis frequently occur in the same individuals and may share similar pathogenic mechanisms. This study examined the relation between severity of aortic calcification in middle-age years and subsequent risk of hip fracture in women and men in the population-based Framingham Study.
Introduction: We assessed vascular calcification in women and men in middle age and risk of hip fracture at advanced age.
Materials and Methods: Participants included 2499 Framingham cohort members (mean age, 61 yr; range, 47–80 yr). Semiquantitative methods were used to determine severity of abdominal aortic calcification on baseline radiographs. Information on potential confounding factors was obtained from study examinations conducted at, or before, baseline radiography. Hip fractures were ascertained by active surveillance and confirmed by medical records.
Results: Thirty-five-year cumulative incidence of hip fracture was 16% in women and 5% in men with prevalent aortic calcification at baseline (score 1+) and 14% in women and 4% in men without aortic calcification (score 0). Hazard ratios (HRs) and 95% CIs for hip fracture did not increase from the lowest to the highest category of aortic calcification. HRs were 1.0, 1.2 (95% CI, 0.9–1.8), 1.2 (95% CI, 0.7–1.9), 1.1 (95% CI, 0.7–1.7), and 1.4 (95% CI, 0.8–2.3) in women (p for trend = 0.44) and 1.0, 1.8 (95% CI, 0.8–3.8), 1.8 (95% CI, 0.7–4.6), 1.5 (95% CI, 0.6–3.9), and 1.2 (95% CI, 0.2–5.7) in men (p for trend = 0.29) for aortic calcification scores 0 (reference), 1–4, 4–5, 6–10, and 11+, respectively. However, aortic calcification score was strongly associated with increased risk of death (p for trend < 0.0001 in women and men). HRs (95% CIs) for mortality from the lowest to highest aortic calcification score were 1.0, 1.6 (1.4–1.9), 1.7 (1.4–2.1), 1.8 (1.5–2.2), and 2.1 (1.7–2.6) for women, and for men were 1.0, 1.4 (1.1–1.6), 1.4 (1.2–1.8), 1.6 (1.3–2.0), and 1.9 (1.5–2.5).
Conclusions: Vascular calcification in middle-aged adults does not increase long-term hip fracture risk.
TL;DR: In this community-based sample, overweight and obesity were associated with high prevalence of subclinical disease, which partly contributed to the increased risk of overt CVD in these strata.
Abstract: Background— The burden and prognostic importance of subclinical cardiovascular disease (CVD) in obesity has not been investigated systematically. Methods and Results— We examined prevalence of subclinical disease in 1938 Framingham Study participants (mean age, 57 years; 59% women) by use of 5 tests (electrocardiography, echocardiography, carotid ultrasound, ankle-brachial pressure, and urinary albumin excretion) and stratified by body mass index (BMI) (normal, <25; overweight, 25 to <30.0; obese, ≥30 kg/m2) and waist circumference (WC) (increased, ≥88 cm for women or ≥102 cm for men). We investigated risk of overt CVD associated with adiposity according to presence versus absence of subclinical disease on any of the 5 tests. Prevalence of subclinical disease was higher in overweight (40.0%; adjusted odds ratio, 1.68) and obese individuals (49.7%; odds ratio, 2.82) compared with individuals with normal BMI (29.3%) and in individuals with increased WC (44.9%; odds ratio, 1.67) compared with normal WC (31.9...
TL;DR: In a community-based sample, correlations among subclinical Atherosclerosis test results are low, and a substantial proportion has high levels of subclinical atherosclerosis detected on >or=2 imaging tests.
Abstract: Screening for subclinical atherosclerosis has been advocated for individuals at intermediate global risk for coronary heart disease (CHD). However, the distribution of subclinical atherosclerosis test values across CHD risk strata is unknown. We studied a stratified random sample of 292 participants (mean age 59.5 years, 50% women) from the offspring cohort of the Framingham Heart Study who were free of clinically apparent cardiovascular disease. We assessed abdominal and thoracic aortic plaque burden by cardiovascular magnetic resonance (CMR), coronary artery calcification (CAC) and thoracic aortic calcification (TAC) by electron beam computed tomography, and common carotid intima-media thickness (C-IMT) by ultrasonography. We categorized the upper 20% of each measurement as a high level of atherosclerosis and evaluated these variables across clinically relevant Framingham CHD risk score strata (low, intermediate, and high risk). In age-adjusted analyses in men and women, correlations across CMR aortic plaque, CAC, TAC, and C-IMT were low (maximum r = 0.30 for CAC:TAC in women, p or=2 measurements. However, different participants were identified as having high atherosclerosis by each modality. For example, in a comparison of the overlap across CMR aortic plaque, CAC, and C-IMT, only 4% of men and 16% of women were classified as having high atherosclerosis on all 3 measurements. In conclusion, in a community-based sample, correlations among subclinical atherosclerosis test results are low, and a substantial proportion has high levels of subclinical atherosclerosis detected on >or=2 imaging tests.
TL;DR: The present study was suggestive of modest relations between common genetic variants at the NOS3 locus and arterial stiffness, and single nucleotide polymorphisms capturing ≈90% of underlying common variation in NOS
Abstract: Arterial stiffness is a moderately heritable trait that is affected by alterations in the bioavailability of NO. Previous studies have found associations between variants in the gene for endothelial NO synthase (NOS3) and arterial properties. We previously identified a linkage peak for forward pressure wave amplitude in the immediate vicinity of NOS3. Therefore, we evaluated relations between arterial stiffness measures and common genetic variants at this locus. Eighteen single nucleotide polymorphisms capturing approximately 90% of underlying common variation in NOS3 were genotyped in unrelated Framingham Heart Study participants (N=1157; 52.2% women; mean age: 62 years) with routinely ascertained tonometry data that provided 5 arterial phenotypes (forward and reflected pressure wave amplitude, central pulse pressure, carotid-femoral pulse wave velocity, and mean arterial pressure). In women but not men, the genotype for the common NOS3 missense mutation (Glu298Asp, rs1799983) was related to central pulse pressure (women: GG=53+/-0.9, GT=54+/-0.9, and TT=47+/-2.0 mm Hg, P=0.0047; men: GG=50+/-1.0, GT=49+/-0.9, and TT=47+/-1.8 mm Hg, P=0.30) and forward wave amplitude (women: GG=41+/-0.7, GT=42+/-0.7, and TT=38+/-1.6 mm Hg, P=0.029; men: GG=42+/-0.9, GT=41+/-0.8, and TT=39+/-1.5 mm Hg, P=0.47). The only other nominally significant sex-specific association in men but not women was between an intronic polymorphism (rs1800781) and reflected wave amplitude (women: AA=10.4+/-0.4, AG=11.1+/-0.6, and GG=8.9+/-2.2 mm Hg, P=0.50; men: AA=6.1+/-0.3, AG=7.3+/-0.5, and GG=11.3+/-2.3 mm Hg, P=0.014). After adjusting for multiple testing (18 polymorphisms and 5 phenotypes), these nominal associations were no longer significant. The present study was suggestive of modest relations between common genetic variants at the NOS3 locus and arterial stiffness.
TL;DR: It is suggested that further studies are warranted to identify potential causal genetic variants for RBC size and count and related erythrocyte indices.
Abstract: Red blood cell (RBC) count and size are major criteria for evaluating anemia and related hematology disease diagnoses. While environmental factors influence RBC count (RBCC) and size, mean corpuscular volume (MCV), and mean corpuscular hemoglobin (MCH), studies have indicated that each of these measures has a substantial genetic component. So far, no linkage analysis or genome scan has been reported. We carried out 10 cM genome-wide scans on RBCC, MCV, and MCH in a community-based Caucasian cohort, the Framingham Heart Study, using 325 pedigrees with 1,144 individuals genotyped and phenotyped. Using variance-component linkage methods, heritabilities were estimated as 56, 52, and 52% after covariate adjusted for RBCC, MCV, and MCH, respectively. For RBCC, we found a maximum LOD score of 3.2 on chromosome 19, 24 cM (7.0 Mbp). Near this region, there lie a few important candidate genes, including erythropoietin receptor and erythroid Kruppel-like factor. For linkage analyses for MCV and MCH, there were coinciding maximized LOD scores on chromosome 11, 9 cM (5.2 Mbp) with values of 3.8 and 3.6, respectively. Under the peak resides the hemoglobin beta cluster - several beta-like genes, which are important candidates for RBC size. In subsequent analyses, we excluded individuals with low MCV to assess the possible influence of beta-thalassemia carriers, and there continued to be evidence for linkage in the same region on chromosome 11p15 (LOD scores of 2.6 and 2.7 for MCV and MCH, respectively). For MCV, we also identified a new region on chromosome 6q24 with a LOD score of 2.9. These findings suggest that further studies are warranted to identify potential causal genetic variants for RBC size and count and related erythrocyte indices.
TL;DR: Hemodynamic and chronotropic responses to exercise are heritable and demonstrate suggestive linkage to select loci, and genetic mapping with newer approaches such as genome-wide association may yield novel insights into the physiological responses to Exercise.
Abstract: Background— The blood pressure (BP) and heart rate responses to exercise treadmill testing predict incidence of cardiovascular disease, but the genetic determinants of hemodynamic and chronotropic responses to exercise are largely unknown. Methods and Results— We assessed systolic BP, diastolic BP, and heart rate during the second stage of the Bruce protocol and at the third minute of recovery in 2982 Framingham Offspring participants (mean age 43 years; 53% women). With use of residuals from multivariable models adjusted for clinical correlates of exercise treadmill testing responses, we estimated the heritability (variance-components methods), genetic linkage (multipoint quantitative trait analyses), and association with 235 single-nucleotide polymorphisms in 14 candidate genes selected a priori from neurohormonal pathways for their potential role in exercise treadmill testing responses. Heritability estimates for heart rate during exercise and during recovery were 0.32 and 0.34, respectively. Heritabil...
TL;DR: In this paper, the authors formally assess competitive buying and selling behavior in the Australian grains and oilseeds industries using a more realistic empirical model and a less aggregated data set than previously available.
Abstract: We formally assess competitive buying and selling behavior in the Australian grains and oilseeds industries using a more realistic empirical model and a less aggregated data set than previously available. We specify a duality model of profit maximization that allows for imperfect competition in both input and output markets and for variable-proportions technologies. Aggregate input-output data are used to define the structure of the relevant industries, and time series data are then used to implement the model for 13 grains and oilseeds products handled by seven groups of agents. The model is estimated in a Bayesian econometrics framework. We find evidence of flour and cereal food product manufacturers exerting market power when purchasing wheat, barley, oats and triticale; beer and malt manufacturers exerting market power when purchasing wheat and barley; and other food product manufacturers exerting market power when purchasing wheat, barley, oats and triticale. [EconLit citations: C11, L66, Q11]. (c) 2007 Wiley Periodicals, Inc.