[Show abstract][Hide abstract] ABSTRACT: The QT interval, an electrocardiographic measure reflecting myocardial repolarization, is a heritable trait. QT prolongation is a risk factor for ventricular arrhythmias and sudden cardiac death (SCD) and could indicate the presence of the potentially lethal mendelian long-QT syndrome (LQTS). Using a genome-wide association and replication study in up to 100,000 individuals, we identified 35 common variant loci associated with QT interval that collectively explain ∼8-10% of QT-interval variation and highlight the importance of calcium regulation in myocardial repolarization. Rare variant analysis of 6 new QT interval-associated loci in 298 unrelated probands with LQTS identified coding variants not found in controls but of uncertain causality and therefore requiring validation. Several newly identified loci encode proteins that physically interact with other recognized repolarization proteins. Our integration of common variant association, expression and orthogonal protein-protein interaction screens provides new insights into cardiac electrophysiology and identifies new candidate genes for ventricular arrhythmias, LQTS and SCD.
[Show abstract][Hide abstract] ABSTRACT: Biomarkers of cardiovascular stress have been associated with incident cardiovascular outcomes. Their relations with measures of subclinical atherosclerosis, as assessed by carotid intima-media thickness, have not been well described.
[Show abstract][Hide abstract] ABSTRACT: This study sought to evaluate pattern and clinical correlates of change in left ventricular (LV) geometry over a 4-year period in the community; it also assessed whether the pattern of change in LV geometry over 4 years predicts incident cardiovascular disease (CVD), including myocardial infarction, heart failure, and cardiovascular death, during an additional subsequent follow-up period.
[Show abstract][Hide abstract] ABSTRACT: Osteoprotegerin (OPG) is involved in bone homeostasis and tumor cell survival. Circulating OPG levels are also important biomarkers of various clinical traits, such as cancers and atherosclerosis. OPG levels were measured in serum or in plasma. In a meta-analysis of genome-wide association studies in up to 10,336 individuals from European and Asian origin, we discovered that variants >100 Kb upstream of the TNFRSF11B gene encoding OPG and another new locus on chromosome 17q11.2 were significantly associated with OPG variation. We also identified a suggestive locus on chromosome 14q21.2 associated with the trait. Moreover, we estimated that over half of the heritability of OPG levels could be explained by all variants examined in our study. Our findings provide further insight into the genetic regulation of circulating OPG levels.
Human Molecular Genetics 07/2014; · 7.69 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: CXCL12 encodes stromal cell-derived factor 1 α (SDF-1), which binds to the receptor encoded by CXCR4. Variation at the CXCL12 locus is associated with coronary artery disease and endothelial progenitor cell numbers, whereas variation at the CXCR4 locus is associated with leukocyte telomere length, which has been shown to be associated with coronary artery disease. Therefore, we examined the relationships of plasma SDF-1 levels to cardiovascular disease (CVD)-related outcomes, risk factors, leukocyte telomere length, and endothelial progenitor cells.
Arteriosclerosis Thrombosis and Vascular Biology 07/2014; · 6.34 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: B-type natriuretic peptide (BNP) and C-reactive protein (CRP) predict atrial fibrillation (AF) risk. However, their risk stratification abilities in the broad community remain uncertain. We sought to improve risk stratification for AF using biomarker information.
[Show abstract][Hide abstract] ABSTRACT: Blood pressure (BP) is a heritable, quantitative trait with intraindividual variability and susceptibility to measurement error. Genetic studies of BP generally use single-visit measurements and thus cannot remove variability occurring over months or years. We leveraged the idea that averaging BP measured across time would improve phenotypic accuracy and thereby increase statistical power to detect genetic associations. We studied systolic BP (SBP), diastolic BP (DBP), mean arterial pressure (MAP), and pulse pressure (PP) averaged over multiple years in 46,629 individuals of European ancestry. We identified 39 trait-variant associations across 19 independent loci (p < 5 × 10(-8)); five associations (in four loci) uniquely identified by our LTA analyses included those of SBP and MAP at 2p23 (rs1275988, near KCNK3), DBP at 2q11.2 (rs7599598, in FER1L5), and PP at 6p21 (rs10948071, near CRIP3) and 7p13 (rs2949837, near IGFBP3). Replication analyses conducted in cohorts with single-visit BP data showed positive replication of associations and a nominal association (p < 0.05). We estimated a 20% gain in statistical power with long-term average (LTA) as compared to single-visit BP association studies. Using LTA analysis, we identified genetic loci influencing BP. LTA might be one way of increasing the power of genetic associations for continuous traits in extant samples for other phenotypes that are measured serially over time.
The American Journal of Human Genetics 06/2014; · 11.20 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Although age-dependent effects on blood pressure (BP) have been reported, they have not been systematically investigated in large-scale genome-wide association studies (GWASs). We leveraged the infrastructure of three well-established consortia (CHARGE, GBPgen, and ICBP) and a nonstandard approach (age stratification and metaregression) to conduct a genome-wide search of common variants with age-dependent effects on systolic (SBP), diastolic (DBP), mean arterial (MAP), and pulse (PP) pressure. In a two-staged design using 99,241 individuals of European ancestry, we identified 20 genome-wide significant (p ≤ 5 × 10(-8)) loci by using joint tests of the SNP main effect and SNP-age interaction. Nine of the significant loci demonstrated nominal evidence of age-dependent effects on BP by tests of the interactions alone. Index SNPs in the EHBP1L1 (DBP and MAP), CASZ1 (SBP and MAP), and GOSR2 (PP) loci exhibited the largest age interactions, with opposite directions of effect in the young versus the old. The changes in the genetic effects over time were small but nonnegligible (up to 1.58 mm Hg over 60 years). The EHBP1L1 locus was discovered through gene-age interactions only in whites but had DBP main effects replicated (p = 8.3 × 10(-4)) in 8,682 Asians from Singapore, indicating potential interethnic heterogeneity. A secondary analysis revealed 22 loci with evidence of age-specific effects (e.g., only in 20 to 29-year-olds). Age can be used to select samples with larger genetic effect sizes and more homogenous phenotypes, which may increase statistical power. Age-dependent effects identified through novel statistical approaches can provide insight into the biology and temporal regulation underlying BP associations.
The American Journal of Human Genetics 06/2014; · 11.20 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Novel biomarkers are being investigated to identify patients with kidney disease. We measured a panel of 13 urinary biomarkers in participants from the Offspring Cohort of the Framingham Heart Study. Using an Affymetrix chip with imputation to 2.5 M single-nucleotide polymorphisms (SNPs), we conducted a GWAS of these biomarkers (n=2640) followed by exonic sequencing and genotyping. Functional studies in zebrafish were used to investigate histologic correlation with renal function. Across all 13 biomarkers, there were 97 significant SNPs at three loci. Lead SNPs at each locus were rs6555820 (P=6.7×10(-49); minor allele frequency [MAF]=0.49) in HAVCR1 (associated with kidney injury molecule-1), rs7565788 (P=2.15×10(-16); MAF=0.22) in LRP2 (associated with trefoil factor 3 [TFF3]), and rs11048230 (P=4.77×10(-8); MAF=0.10) in an intergenic region near RASSF8 (associated with vascular endothelial growth factor). Validation in the CKDGen Consortium (n=67,093) showed that only rs7565788 at LRP2, which encodes megalin, was associated with eGFR (P=0.003). Sequencing of exons 16-72 of LRP2 in 200 unrelated individuals at extremes of urinary TFF3 levels identified 197 variants (152 rare; MAF<0.05), 31 of which (27 rare) were nonsynonymous. In aggregate testing, rare variants were associated with urinary TFF3 levels (P=0.003), and the lead GWAS signal was not explained by these variants. Knockdown of LRP2 in zebrafish did not alter the renal phenotype in static or kidney injury models. In conclusion, this study revealed common variants associated with urinary levels of TFF3, kidney injury molecule-1, and vascular endothelial growth factor and identified a cluster of rare variants independently associated with TFF3.
Journal of the American Society of Nephrology : JASN. 05/2014;
[Show abstract][Hide abstract] ABSTRACT: Central pressure augmentation is associated with greater backward wave amplitude and shorter transit time and is higher in women for reasons only partially elucidated. Augmentation also is affected by left ventricular function and shapes of the forward and backward waves. The goal of this study was to examine the relative contributions of forward and backward wave morphology to central pressure augmentation in men and women. From noninvasive measurements of central pressure and flow in 7437 participants (4036 women) aged from 19 to 90 years (mean age, 51 years), we calculated several variables: augmentation index, backward wave arrival time, reflection factor, forward wave amplitude, forward wave peak width, and slope of the backward wave upstroke. Linear regression models for augmentation index, adjusted for height and heart rate, demonstrated nonlinear relations with age (age: B=4.6±0.1%; P<0.001; age(2): B=-4.2±0.1%; P<0.001) and higher augmentation in women (B=4.5±0.4%; P<0.001; model R(2)=0.35). Addition of reflection factor and backward wave arrival time improved model fit (R(2)=0.62) and reduced the age coefficients: age (B=2.3±0.1%; P<0.001) and age(2) (B=-2.2±0.1%; P<0.001). Addition of width of forward wave peak, slope of backward wave upstroke, and forward wave amplitude further improved model fit (R(2)=0.75) and attenuated the sex coefficient (B=1.9±0.2%; P<0.001). Thus, shape and amplitude of the forward wave may be important correlates of augmentation index, and part of the sex difference in augmentation index may be explained by forward and backward wave morphology.
[Show abstract][Hide abstract] ABSTRACT: Metabolic syndrome (MetS) has become a health and financial burden worldwide. The MetS definition captures clustering of risk factors that predict higher risk for diabetes mellitus and cardiovascular disease. Our study hypothesis is that additional to genes influencing individual MetS risk factors, genetic variants exist that influence MetS and inflammatory markers forming a predisposing MetS genetic network. To test this hypothesis a staged approach was undertaken. (a) We analyzed 17 metabolic and inflammatory traits in more than 85,500 participants from 14 large epidemiological studies within the Cross Consortia Pleiotropy Group. Individuals classified with MetS (NCEP definition), versus those without, showed on average significantly different levels for most inflammatory markers studied. (b) Paired average correlations between 8 metabolic traits and 9 inflammatory markers from the same studies as above, estimated with two methods, and factor analyses on large simulated data, helped in identifying 8 combinations of traits for follow-up in meta-analyses, out of 130,305 possible combinations between metabolic traits and inflammatory markers studied. (c) We performed correlated meta-analyses for 8 metabolic traits and 6 inflammatory markers by using existing GWAS published genetic summary results, with about 2.5 million SNPs from twelve predominantly largest GWAS consortia. These analyses yielded 130 unique SNPs/genes with pleiotropic associations (a SNP/gene associating at least one metabolic trait and one inflammatory marker). Of them twenty-five variants (seven loci newly reported) are proposed as MetS candidates. They map to genes MACF1, KIAA0754, GCKR, GRB14, COBLL1, LOC646736-IRS1, SLC39A8, NELFE, SKIV2L, STK19, TFAP2B, BAZ1B, BCL7B, TBL2, MLXIPL, LPL, TRIB1, ATXN2, HECTD4, PTPN11, ZNF664, PDXDC1, FTO, MC4R and TOMM40. Based on large data evidence, we conclude that inflammation is a feature of MetS and several gene variants show pleiotropic genetic associations across phenotypes and might explain a part of MetS correlated genetic architecture. These findings warrant further functional investigation.
Molecular Genetics and Metabolism 05/2014; · 2.83 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Galectin 3 (Gal-3) is a potential mediator of cardiac fibrosis, and Gal-3 concentrations predict incident heart failure. The same mechanisms that lead to cardiac fibrosis in heart failure may influence development of atrial fibrosis and atrial fibrillation (AF). We examined the association of Gal-3 and incident AF in the community.
Plasma Gal-3 concentrations were measured in 3,306 participants of the Framingham Offspring cohort who attended the sixth examination cycle (1995-1998, mean age 58 years, 54% women). Cox proportional hazards regression models were used to assess the association of baseline Gal-3 concentrations and incident AF.
Over a median follow-up period of 10 years, 250 participants developed incident AF. Crude incidence rates of AF by increasing sex-specific Gal-3 quartiles were 3.7%, 5.9%, 9.1%, and 11.5% (log-rank test P < .0001). In age- and sex-adjusted analyses, each 1-SD increase in loge-Gal-3 was associated with a 19% increased hazard of incident AF (hazard ratio 1.19, 95% CI 1.05-1.36, P = .009). This association was not significant after adjustment for traditional clinical AF risk factors (hazard ratio 1.12, 95% CI 0.98-1.28, P = .10).
Higher circulating Gal-3 concentrations were associated with increased risk of developing AF over the subsequent 10 years in age- and sex-adjusted analyses but not after accounting for other traditional clinical AF risk factors. Our results do not support a role for Gal-3 in AF risk prediction. Further studies are needed to evaluate whether Gal-3 plays a role in the development of AF substrate similar to HF.
American heart journal 05/2014; 167(5):729-734.e1. · 4.65 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To examine the relation of endothelial microparticles (EMPs) with cardiometabolic risk in the community.
Circulating EMPs are small membrane vesicles released after endothelial cell injury. Endothelial microparticles are reportedly increased among individuals with a high burden of cardiovascular risk factors. However, prior investigations have been limited to small, highly selected samples.
We studied 844 individuals without a history of cardiovascular disease in the Framingham Offspring cohort (mean age 66 ± 9 years, 57% women). We used standardized flow cytometry methods to identify and quantify circulating CD144+ and CD31+/CD41- EMPs. We then used multivariable regression analyses to investigate the relations of EMP phenotypes with cardiovascular and metabolic risk factors.
In multivariable analyses, the following cardiovascular risk factors were associated with one or more of the circulating EMP populations: hypertension (P = 0.025 for CD144+,), elevated triglycerides (P = 0.002 for CD144+, P < 0.0001 for CD31+/CD41-), and metabolic syndrome (P < 0.0001 for CD144+,). Overall, each tertile increase in the Framingham risk score corresponded to a 9% increase in log-CD31+/CD41- EMPs (P = 0.022). Furthermore, the presence of hypertriglyceridaemic waist status was associated with 38% higher levels of CD144+ EMPs (P < 0.0001) and 46% higher levels of CD31+/CD41- EMPs (P < 0.0001).
In a large community-based sample, circulating EMP levels were associated with the presence of cardiometabolic risk factors, particularly dyslipidaemia. These data underscore the potential influence of high-risk metabolic profiles on endothelial integrity.
European Heart Journal 04/2014; · 14.72 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Incorporation of novel plasma protein biomarkers may improve current models for prediction of atherosclerotic cardiovascular disease (ASCVD) risk.
We used discovery mass spectrometry (MS) to determine plasma concentrations of 861 proteins in 135 myocardial infarction (MI) cases and 135 matched controls. Then, we measured 59 markers by targeted MS in 336 ASCVD case-control pairs. Associations with MI or ASCVD were tested in single-marker and multiple-marker analyses adjusted for established ASCVD risk factors. Twelve single markers from discovery MS were associated with MI incidence (at P<0.01), adjusting for clinical risk factors. Seven proteins in aggregate (cyclophilin A, CD5 antigen-like, cell-surface glycoprotein MUC18, collagen-α 1 [XVIII] chain, salivary α-amylase 1, C-reactive protein, and multimerin-2) were highly associated with MI (P<0.0001) and significantly improved its prediction compared with a model with clinical risk factors alone (C-statistic of 0.71 versus 0.84). Through targeted MS, 12 single proteins were predictors of ASCVD (at P<0.05) after adjusting for established risk factors. In multiple-marker analyses, 4 proteins in combination (α-1-acid glycoprotein 1, paraoxonase 1, tetranectin, and CD5 antigen-like) predicted incident ASCVD (P<0.0001) and moderately improved the C-statistic from the model with clinical covariates alone (C-statistic of 0.69 versus 0.73).
Proteomics profiling identified single- and multiple-marker protein panels that are associated with new-onset ASCVD and may lead to a better understanding of underlying disease mechanisms. Our findings include many novel protein biomarkers that, if externally validated, may improve risk assessment for MI and ASCVD.
Arteriosclerosis Thrombosis and Vascular Biology 02/2014; · 6.34 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Interleukin 1 Receptor 1 (IL1R1) and its ligand, IL1β, are upregulated in cardiovascular disease, obesity, and infection. Previously, we reported a higher level of IL1R1 transcripts in platelets from obese individuals of the Framingham Heart Study (FHS) but its functional effect in platelets has never been described. Additionally, IL1β levels are increased in atherosclerotic plaques and in bacterial infections. The aim of this work is to determine whether IL1β, through IL1R1, can activate platelets and megakaryocytes to promote atherothrombosis.
We found that IL1β-related genes from platelets, as measured in 1819 FHS participants, were associated with increased body mass index, and a direct relationship was shown in wild-type mice fed a high-fat diet. Mechanistically, IL1β activated NFκB and MAPK signaling pathways in megakaryocytes. IL1β, through IL1R1, increased ploidy of megakaryocytes to 64 N or more by 2-fold over control. IL1β increased agonist-induced platelet aggregation by 1.2-fold with thrombin and 4.2-fold with collagen. IL1β increased adhesion to both collagen and fibrinogen, and heterotypic aggregation by 1.9-fold over resting. High-fat diet-enhanced platelet adhesion was absent in IL1R1(-/-) mice. Wild-type mice infected with Porphyromonas gingivalis had circulating heterotypic aggregates (1.5-fold more than control at 24 hours and 6.2-fold more at 6 weeks) that were absent in infected IL1R1(-/-) and IL1β(-/-) mice.
In summary, IL1R1- and IL1β-related transcripts are elevated in the setting of obesity. IL1R1/IL1β augment both megakaryocyte and platelet functions, thereby promoting a prothrombotic environment during infection and obesity; potentially contributing to the development of atherothrombotic disease.
Arteriosclerosis Thrombosis and Vascular Biology 01/2014; · 6.34 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: MicroRNA (miRNA) expression in atrial tissue has been implicated in pathologic susceptibility to atrial fibrillation (AF). Nevertheless, data are limited on how circulating levels relate to AF.
To test the hypothesis that circulating miRNAs would be associated with AF.
Among 2445 Framingham Heart Study Offspring participants, we measured the expression of 385 circulating whole blood miRNAs by high-throughput quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR). We related miRNA levels with prevalent and new-onset AF.
The mean age in the cohort was 66.3 ± 8.9 years and 56% were women; 153 participants had clinically apparent AF at baseline and 107 developed AF during a median of 5.4 years of follow-up. miRNA-328 (miR-328) expression was lower among participants with prevalent AF [7.75 cycle threshold (Ct)] compared to individuals with no AF (8.76 Ct, p <0.001). The association between miR-328 and prevalent AF persisted after adjustment for age, sex, and technical covariates (OR=1.21, P = 1.8 x 10(-4)) but was attenuated in analyses adjusting for clinical AF risk factors (OR=1.14, P = 0.017). In contrast to the associations between miR-328 and prevalent AF, none of the circulating miRNAs were associated with incident AF.
Circulating levels of miR-328, a miRNA known to promote atrial electrical remodeling by reducing L-type Ca(2+) channel density, were associated with prevalent AF. Adjustment for risk factors that promote atrial remodeling, including hypertension, attenuated the association between miR-328 and AF, potentially implicating miR-328 as a potential mediator of atrial remodeling and AF vulnerability.
Heart rhythm: the official journal of the Heart Rhythm Society 01/2014; · 4.56 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The transcriptional coactivator peroxisome proliferator-activated receptor-gamma coactivator-1α (PGC-1α) regulates metabolic genes in skeletal muscle and contributes to the response of muscle to exercise. Muscle PGC-1α transgenic expression and exercise both increase the expression of thermogenic genes within white adipose. How the PGC-1α-mediated response to exercise in muscle conveys signals to other tissues remains incompletely defined. We employed a metabolomic approach to examine metabolites secreted from myocytes with forced expression of PGC-1α, and identified β-aminoisobutyric acid (BAIBA) as a small molecule myokine. BAIBA increases the expression of brown adipocyte-specific genes in white adipocytes and β-oxidation in hepatocytes both in vitro and in vivo through a PPARα-mediated mechanism, induces a brown adipose-like phenotype in human pluripotent stem cells, and improves glucose homeostasis in mice. In humans, plasma BAIBA concentrations are increased with exercise and inversely associated with metabolic risk factors. BAIBA may thus contribute to exercise-induced protection from metabolic diseases.
[Show abstract][Hide abstract] ABSTRACT: We investigated whether circulating concentrations of soluble ST2, growth differentiation factor-15 (GDF-15), and high-sensitivity troponin I (hsTnI) are associated with incident atrial fibrillation (AF) and whether these biomarkers improve current risk prediction models including AF risk factors, B-type natriuretic peptide (BNP), and C-reactive protein (CRP).
We studied the relation between soluble ST2, GDF-15, and hsTnI and development of AF in Framingham Heart Study participants without prevalent AF. We used Cox proportional hazard regression analysis to examine the relation of incident AF during a 10-year follow-up period with each biomarker. We adjusted for standard AF clinical risk factors, BNP, and CRP.
The mean age of the 3,217 participants was 59 ± 10 years, and 54% were women. During a 10-year follow-up, 242 participants developed AF. In age- and sex-adjusted models, GDF-15 and hsTnI were associated with risk of incident AF; however, after including the AF risk factors and BNP and CRP, only hsTnI was significantly associated with AF (hazard ratio per 1 SD of loge hsTnI, 1.12, 95% CI 1.00-1.26, P = .045). The c statistic of the base model including AF risk factors, BNP, and CRP was 0.803 (95% CI 0.777-0.830) and did not improve by adding individual or all 3 biomarkers. None of the discrimination and reclassification statistics were significant compared with the base model.
In a community-based cohort, circulating hsTnI concentrations were associated with incident AF. None of the novel biomarkers evaluated improved AF risk discrimination or reclassification beyond standard clinical AF risk factors and biomarkers.
American heart journal 01/2014; 167(1):109-115.e2. · 4.65 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Higher heart rate has been associated with an adverse prognosis, but most prior studies focused on individuals with known cardiovascular disease or examined a limited number of outcomes. We sought to examine the association of baseline heart rate with both fatal and nonfatal outcomes during 2 decades of follow-up.
Our study included 4058 Framingham Heart Study participants (mean age 55 years, 56% women). Cox models were performed with multivariable adjustment for clinical risk factors and physical activity. A total of 708 participants developed incident cardiovascular disease (303 heart failure, 343 coronary heart disease, and 216 stroke events), 48 received a permanent pacemaker, and 1186 died. Baseline heart rate was associated with incident cardiovascular disease (hazard ratio [HR] 1.15 per 1 SD [11 bpm] increase in heart rate, 95% CI 1.07 to 1.24, P=0.0002), particularly heart failure (HR 1.32, 95% CI 1.18 to 1.48, P<0.0001). Higher heart rate was also associated with higher all-cause (HR 1.17, 95% CI 1.11 to 1.24, P<0.0001) and cardiovascular mortality (HR 1.18, 95% CI 1.04 to 1.33, P=0.01). Spline analyses did not suggest a lower threshold beyond which the benefit of a lower heart rate abated or increased. In contrast, individuals with a higher heart rate had a lower risk of requiring permanent pacemaker placement (HR 0.55, 95% CI 0.38 to 0.79, P=0.001).
Individuals with a higher heart rate are at elevated long-term risk for cardiovascular events, in particular, heart failure, and all-cause death. On the other hand, a higher heart rate is associated with a lower risk of future permanent pacemaker implantation.
Journal of the American Heart Association. 01/2014; 3(3):e000668.
[Show abstract][Hide abstract] ABSTRACT: Research has shown that several types of erythrocyte fatty acids (i.e., omega-3, omega-6, and trans) are associated with risk for cardiovascular diseases. However, there are complex metabolic and dietary relations among fatty acids, which induce correlations that are typically ignored when using them as risk predictors. A latent variable approach could summarize these complex relations into a few latent variable scores for use in statistical models. Twenty-two red blood cell (RBC) fatty acids were measured in Framingham (N = 3196). The correlation matrix of the fatty acids was modeled using structural equation modeling; the model was tested for goodness-of-fit and gender invariance. Thirteen fatty acids were summarized by three latent variables, and gender invariance was rejected so separate models were developed for men and women. A score was developed for the polyunsaturated fatty acid (PUFA) latent variable, which explained about 30% of the variance in the data. The PUFA score included loadings in opposing directions among three omega-3 and three omega-6 fatty acids, and incorporated the biosynthetic and dietary relations among them. Whether the PUFA factor score can improve the performance of risk prediction in cardiovascular diseases remains to be tested.
Computational and Mathematical Methods in Medicine 01/2014; 2014:160520. · 0.79 Impact Factor