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Biomedical subjects

David L Rainwater

Publications and source records attributed to David L Rainwater.

At least 19 recordsLinked to original sources

Sex-specific QTL effects on variation in paraoxonase 1 (PON1) activity in Mexican Americans.

Paraoxonase 1 (PON1), a high-density lipoprotein-associated enzyme known to protect against cellular damage from toxic agents, may also have antioxidant properties. PON1 activity levels have been reported to differ by sex in human and animal studies with females exhibiting higher basal levels. We measured PON1 activity frozen serum for 1,406 individuals in over 40 extended pedigrees from the San Antonio Family Heart Study (SAFHS). We used a maximum likelihood-based, variance decomposition approach implemented in SOLAR to test for genotype-by-sex (G x S) interaction on variation in PON1 activity and to determine if any of the four PON1 quantitative trait loci (QTL) previously reported by us for this population might account for sex differences in PON1 activity levels. The residual additive genetic correlation (rho(G) = 0.82) between males and females is significantly different from 1 (P = 0.009), suggesting that some of the genes that influence PON1 activity act differently in females and males or, possibly, that a different combination of genes influences this trait in each sex. In addition to the QTL at or near the PON structural locus on 7q21-22, three other potential QTLs were evaluated for sex-specific effects: one each on chromosomes 12, 17 and 19. The QTL on chromosome 17 (LOD = 2.32, P = 0.0003; flanked by microsatellite marker loci D17S974 and D17S969) shows a significant (P = 0.005) sex-specific effect on PON1 activity; accounting for 6% of the additive genetic variance in males and 20% in females. This study represents the first formal statistical genetic test for G x S interactions on normal quantitative variation in PON1 activity in humans.

Adult↗

Genotype x adiposity interaction linkage analyses reveal a locus on chromosome 1 for lipoprotein-associated phospholipase A2, a marker of inflammation and oxidative stress.

Because obesity leads to a state of chronic, low-grade inflammation and oxidative stress, we hypothesized that the contribution of genes to variation in a biomarker of these two processes may be influenced by the degree of adiposity. We tested this hypothesis using samples from the San Antonio Family Heart Study that were assayed for activity of lipoprotein-associated phospholipase A(2) (Lp-PLA(2)), a marker of inflammation and oxidative stress. Using an approach to model discrete genotypexenvironment (GxE) interaction, we assigned individuals to one of two discrete diagnostic states (or "adiposity environments"): nonobese or obese, according to criteria suggested by the World Health Organization. We found a genomewide maximum LOD of 3.39 at 153 cM on chromosome 1 for Lp-PLA(2). Significant GxE interaction for Lp-PLA(2) at the genomewide maximum (P=1.16 x 10(-4)) was also found. Microarray gene-expression data were analyzed within the 1-LOD interval of the linkage signal on chromosome 1. We found two transcripts--namely, for Fc gamma receptor IIA and heat-shock protein (70 kDa)--that were significantly associated with Lp-PLA(2) (P<.001 for both) and showed evidence of cis-regulation with nominal LOD scores of 2.75 and 13.82, respectively. It would seem that there is a significant genetic response to the adiposity environment in this marker of inflammation and oxidative stress. Additionally, we conclude that GxE interaction analyses can improve our ability to identify and localize quantitative-trait loci.

1-Alkyl-2-acetylglycerophosphocholine Esterase↗

High lipoprotein-associated phospholipase A2 is a risk factor for recurrent coronary events in postinfarction patients.

BACKGROUND: Recent studies demonstrate that lipoprotein-associated phospholipase A2 (Lp-PLA2) is a risk factor for cardiovascular disease presumably deriving from generation of proinflammatory and proatherogenic species through its hydrolytic activity on lipoprotein-associated phospholipids. The goal of this study was to assess the relationship of Lp-PLA2 with a set of thrombogenic, lipid, inflammatory, and metabolic blood markers and to determine whether plasma Lp-PLA2 is a risk factor for recurrent coronary events in postinfarction patients. METHODS: Factor analysis on the set of blood markers and Lp-PLA2 was performed for 766 patients of the Thrombogenic Factors and Recurrent Coronary Events (THROMBO) postinfarction study. Recurrent coronary event risk was assessed as a function of blood marker concentrations and Lp-PLA2 by Cox proportional hazards multivariable regression adjusted for significant clinical covariates. RESULTS: Factor analysis revealed that Lp-PLA2 was associated with one factor dominated by cholesterol and apolipoprotein B and another factor dominated by HDL-cholesterol and triglycerides, with little association with an inflammatory factor dominated by C-reactive protein. Multivariable analysis demonstrated as significant and independent predictors of risk of secondary coronary events only apolipoprotein B in a model without Lp-PLA2 (hazard ratio, 1.66; 95% confidence interval, 1.14-2.40) and only Lp-PLA2 in a model with Lp-PLA2 included [1.90 (1.31-2.75)]. CONCLUSIONS: Lp-PLA2 is a significant and independent predictor of risk for recurrent coronary events in postinfarction patients, and Lp-PLA2 is related to both hypercholesterolemia and high triglyceride-low HDL dyslipidemia in this study population.

1-Alkyl-2-acetylglycerophosphocholine Esterase↗

Association of genetic variation within UBL5 with phenotypes of metabolic syndrome.

The BEACON gene was initially identified using the differential display polymerase chain reaction on hypothalamic mRNA samples collected from lean and obese Psammomys obesus, a polygenic animal model of obesity. Hypothalamic BEACON gene expression was positively correlated with percentage of body fat, and intracerebroventricular infusion of the Beacon protein resulted in a dose-dependent increase in food intake and body weight. The human homolog of BEACON, UBL5, is located on chromosome 19p in a region previously linked to quantitative traits related to obesity. Our previous studies showed a statistically significant association between UBL5 sequence variation and several obesity- and diabetes-related quantitative physiological measures in Asian Indian and Micronesian cohorts. Here we undertake a replication study in a Mexican American cohort where the original linkage signal was first detected. We exhaustively resequenced the complete gene plus the putative promoter region for genetic variation in 55 individuals and identified five single nucleotide polymorphisms (SNPs), one of which was novel. These SNPs were genotyped in a Mexican American cohort of 900 individuals from 40 families. Using a quantitative trait linkage disequilibrium test, we found significant associations between UBL5 genetic variants and waist-to-hip ratio (p = 0.027), and the circulating concentrations of insulin (p = 0.018) and total cholesterol (p = 0.023) in fasted individuals. These data are consistent with our earlier published studies and further support a functional role for the UBL5 gene in influencing physiological traits that underpin the development of metabolic syndrome.

Adult↗

Multiple QTLs influence variation in paraoxonase 1 activity in Mexican Americans.

Paraoxonase 1 (PON1), a high-density-lipoprotein-associated enzyme known to protect against cellular damage from toxic agents, may also have antioxidant properties. Although the importance of the influence of the PON1 structural locus on chromosome 7q21-22 for variation in the concentration and activity of the enzyme is well-documented, the contribution of other loci is poorly understood. Based on the recent observations of at least one additional quantitative trait locus (QTL) for PON1 activity in pedigreed baboons, we conducted a whole-genome linkage screen for QTLs other than the PON1 structural locus that may influence PON1 activity in humans. We measured PON1 activity in frozen serum for 1,406 individuals in more than 40 extended pedigrees from the San Antonio Family Heart Study (SAFHS). We used a maximum-likelihood-based variance decomposition approach implemented in SOLAR to test for QTLs that may influence PON1 activity. In addition to a QTL for which we detected the strongest, significant evidence (LOD = 31.41) at or near the PON1 structural locus on chromosome 7q21-22, we also localized at least one additional significant QTL on chromosome 12 (LOD = 3.56). Furthermore, we detected suggestive evidence for two more PON-related QTLs on chromosomes 17 and 19. We have provided evidence that other genes, in addition to the well-known ones on chromosome 7, play a role in influencing normal variation in PON1 activity.

Adult↗

Elevated HDL is a risk factor for recurrent coronary events in a subgroup of non-diabetic postinfarction patients with hypercholesterolemia and inflammation.

Recent studies demonstrate important roles for inflammation in development of atherosclerosis with current attention focusing on interactions of inflammation with traditional lipoprotein risk factors. Since the nature of such relationships is largely unknown, we sought to investigate interactions of inflammation with hyperlipidemia in generating cardiovascular risk in a way that would allow recognition of such interactions whether anticipated or not. Thus, we searched for subgroups at high risk for recurrent coronary events in 767 non-diabetic postinfarction patients using an exploratory three-dimensional graphical screening technique with previously established factor analysis-derived inflammatory and lipoprotein-related factors. Results indicated a high-risk patient subgroup defined by factor interaction that was best characterized clinically by high levels of C-reactive protein (CRP) and total cholesterol. Kaplan-Meier and Cox multivariate analysis confirmed high-risk. Additionally, within-subgroup risk related to metabolic, inflammatory, and thrombogenic blood markers was assessed using Cox analysis with results showing only elevated HDL as a significant and independent predictor of risk with hazard ratio, 2.24 (95% CI; 1.12, 4.49; p = 0.023). We conclude that in non-diabetic postinfarction patients, elevated HDL is predictive of risk of recurrent coronary events within a subgroup of patients characterized by simultaneous elevations in serum CRP and total cholesterol.

C-Reactive Protein↗

Determinants of variation in serum paraoxonase enzyme activity in baboons.

Paraoxonase (PON), an HDL-associated enzyme, is one of many circulating antioxidants thought to play a vital protective role. To better understand the determinants of quantitative variation in serum PON activity, we assayed PON in samples from 611 pedigreed baboons fed three diets. PON was measured enzymatically; the main determinant of variation was genetic and consisted of at least three components: two loci detected by linkage analyses and a residual polygenic component. Multipoint linkage analyses gave peak log of the odds (LOD) scores on the baboon homolog of human chromosome 7q21-22 (near PON1, the structural gene) of 9.1 on the low-cholesterol, high-fat diet and 4.1 on the high-cholesterol, high-fat diet (genome-wide P values were 1 x 10(-8) and 0.0018, respectively). Surprisingly, a second locus on the baboon homolog of human chromosome 12q13 gave a LOD score of 2.9 on the high-cholesterol, high-fat diet (genome-wide P value was 0.032). We identified several significant covariates, including age, sex, diet, and apolipoprotein A-I concentrations. We estimate that 53% of total trait variation in baboons is explained by genes and 17% by covariates, thus accounting for approximately 70% of total variation in baboon PON. Although the generation of free radicals is influenced primarily by environmental factors, our findings suggest strong genetic regulation of one component in the antioxidant defense system that plays a major role in susceptibility to atherosclerosis.

Aging↗

Arterial endothelial dysfunction in baboons fed a high-cholesterol, high-fat diet.

BACKGROUND: Endothelial dysfunction signals the initiation and progression of atherosclerosis. Elevated LDL-cholesterol concentrations have been suggested to induce endothelial dysfunction, but direct in vivo evidence for the relation is still lacking. OBJECTIVE: We examined the hypothesis that a high-cholesterol, high-fat (HCHF) diet can directly cause endothelial dysfunction in vivo. DESIGN: We measured inflammatory and endothelial dysfunctional markers in circulating blood and directly in endothelial cells, which were collected by femoral artery biopsies, in 10 baboons before and after a 7-wk HCHF dietary challenge. RESULTS: We found that the HCHF diet induced a high inflammatory status, as indicated by increased concentrations of interleukin 6, tumor necrosis factor alpha (TNF-alpha), and monocyte chemoattractant protein 1. Although the concentrations of endothelial dysfunctional markers, such as soluble vascular cell adhesion molecule 1 (VCAM-1) and intercellular adhesion molecule 1, were not increased by the HCHF diet, membrane-bound VCAM-1 and membrane-bound E-selectin on endothelial cells were highly increased after 7 wk of the HCHF diet (P < 0.01). In contrast, the concentrations of endothelial nitric oxide synthase in endothelial cells were significantly reduced by the 7-wk HCHF diet (P < 0.01). Furthermore, the dietary challenge attenuated endothelial cell responses to TNF-alpha, lipopolysaccharide, native LDL cholesterol, and oxidized LDL-cholesterol stimulation. CONCLUSIONS: Our results show that an HCHF diet can directly induce inflammation and endothelial dysfunction. Prior in vivo exposure to an HCHF diet attenuates the in vitro responses of endothelial cells to atherogenic risk factors. This preconditioning phenomenon may have significant clinical relevance.

Animals↗

Joint linkage and association analysis of the hepatic lipase promoter polymorphism and lipoprotein size phenotypes.

The hepatic lipase gene (LIPC) has been implicated as a potential regulator of HDL-cholesterol concentration and HDL and LDL particle size. Studies have centered on a C to T transition in the promoter region of LIPC, 514 base pairs upstream from the transcription initiation site. We performed a genome-wide linkage screen for several lipoprotein size phenotypes and tested for association of these traits with LIPC -514C-T in 798 individuals from the San Antonio Family Heart Study. Median diameters were measured for HDL particles stained for apoA1 (A1), apoA2 (A2), unesterified cholesterol (UC), and esterified cholesterol (EC) and for LDLs stained for EC. The median diameter of all phenotypes exhibited evidence of linkage to the LIPC region of chromosome 15 (LODs of 1.78 to 3.79). Linkage was also observed for HDL-EC size on chromosome 5p (LOD = 3.50). Association with the LIPC -514C-T polymorphism was detected for HDL-A1, HDL-A2, HDL-UC, and HDL-EC median diameters (p < 0.001) but not for LDL-EC size. Linkage analyses of HDL sizes conditional on the -514C-T polymorphism reduced the LOD scores in the LIPC region only slightly, suggesting that this polymorphism does not explain the observed linkage of lipoprotein sizes to chromosome 15. These results indicate the presence of a lipoprotein size locus in the LIPC region but suggest that -514C-T is not the primary functional variant in this region, implying that additional functional mutations influencing HDL and potentially LDL size variation occur in or near LIPC.

Cholesterol, HDL↗

Family history of type 2 diabetes is associated with increased carotid artery intimal-medial thickness in Mexican Americans.

OBJECTIVE: To evaluate whether the joint risk of diabetes and atherosclerosis tracked within families, we assessed the correlation between a family history of diabetes and intimal-medial thickness (IMT) of the common carotid artery (CCA). RESEARCH DESIGN AND METHODS: Study subjects included 620 nondiabetic individuals from 24 families enrolled in the San Antonio Family Heart Study. The thickness of the far walls of the CCA was measured by B-mode ultrasonography. Statistical analyses included familial correlations to account for the nonindependence of family data. RESULTS: After adjusting for sex, age, and IMT reader effects, the heritability of IMT in this population was 16% (P = 0.009). Using a more comprehensive family history score that accounted for diabetes status of the individual's parents and older siblings, we observed a significant correlation between family history score and increased CCA IMT (0.006 mm increase in CCA IMT for every point increase of diabetes family history score, P = 0.016). This association remained even after further adjustment for BMI, smoking, and fasting insulin and glucose levels. After adjusting for several cardiovascular risk factors, the mean CCA IMT in those with high family history scores for diabetes was still 0.037 mm thicker than those with low family history scores for diabetes (P = 0.040). CONCLUSIONS: These results suggest that the genetic contribution to CCA IMT variability is modest. Also, the small increase in subclinical atherosclerosis observed even among nondiabetic Mexican Americans with a positive family history of diabetes is probably transmitted along with the risk of diabetes through shared etiologic risk factors between diabetes and cardiovascular disease.

Adult↗

Haplotypes in the APOA1-C3-A4-A5 gene cluster affect plasma lipids in both humans and baboons.

Genetic studies in non-human primates serve as a potential strategy for identifying genomic intervals where polymorphisms impact upon human disease-related phenotypes. It remains unclear, however, whether independently arising polymorphisms in orthologous regions of non-human primates leads to similar variation in a quantitative trait found in both species. To explore this paradigm, we studied a baboon apolipoprotein gene cluster (APOA1/C3/A4/A5) for which the human gene orthologs have well-established roles in influencing plasma HDL-cholesterol and triglyceride concentrations. Our extensive polymorphism analysis of this 68 kb gene cluster in 96 pedigreed baboons identified several haplotype blocks each with limited diversity, consistent with haplotype findings in humans. To determine whether baboons, like humans, also have particular haplotypes associated with lipid phenotypes, we genotyped 634 well-characterized baboons using 16 haplotype tagging SNPs. Genetic analysis of single SNPs, as well as haplotypes, revealed an association of APOA5 and APOC3 variants with HDL-cholesterol and triglyceride concentrations, respectively. Thus, independent variation in orthologous genomic intervals does associate with similar quantitative lipid traits in both species, supporting the possibility of uncovering human quantitative trait loci genes in a highly controlled non-human primate model.

Animals↗

Improved method for making nondenaturing composite gradient gels for the electrophoretic separation of lipoproteins.

Nondenaturing gradient gel electrophoresis continues to be used widely for resolution and characterization of lipoprotein subclasses. Methods for making such gels in the laboratory have been published, but occasionally samples do not display uniform mobilities for all lanes in a laboratory-made gel. To help overcome this limitation, we recommend a modification

Electrophoresis, Polyacrylamide Gel↗

A quantitative trait locus influences coordinated variation in measures of ApoB-containing lipoproteins.

Lipoprotein phenotypes are known to be strongly intercorrelated. These intercorrelations are due to genetic and environmental effects on common metabolic pathways. The purpose of this study was to determine if we could localize genes that exert pleiotropic effects on multiple related lipoprotein traits in humans. Using data from the San Antonio Family Heart Study, we extracted principal components from a set of 12 intercorrelated lipoprotein traits that included phenotypes reflecting lipid and protein concentrations and size distributions for LDLs and HDLs. Five principal components were extracted from the data and all were significantly heritable (h(2) = 0.41-0.57). When subjected to linkage analyses, only one, Component 5, returned a LOD score > or = 3 (LOD score was 3.0 at 38cM on chromosome 15; genome-wide P-value = 0.039). LDL median diameter (-0.529), non-HDLC (-0.422), and ApoB (-0.403) concentrations were the only traits with loadings (absolute value) >0.4, suggesting Component 5 is related to LDL size or perhaps more generally to beta-lipoprotein metabolism. Surprisingly, none of the 12 original lipoprotein traits had a LOD >1 in this region of chromosome 15. These data provide evidence for a novel gene, influencing beta-lipoprotein phenotypes, whose effect(s) is detected only when several lipoprotein traits are considered together.

Adult↗

Bivariate linkage between acylation-stimulating protein and BMI and high-density lipoproteins.

OBJECTIVE: Given the importance of visceral adiposity in the metabolic syndrome, whether levels of adipokines have shared genetic effects (pleiotropy) with aspects of the metabolic syndrome should be addressed. Acylation-stimulating protein (ASP), an adipose-derived protein, influences lipid metabolism, obesity, and glucose use. Therefore, our objective was to examine the genetic regulation of ASP and associated pleiotropic effects. RESEARCH METHODS AND PROCEDURES: We assayed serum ASP levels in 435 Mexican Americans participating in the San Antonio Family Heart Study and performed univariate and bivariate variance components analysis. RESULTS: Additive genetic heritability of ASP was 26% (p = 0.0004). Bivariate genetic analysis detected significant genetic correlations between ASP and several lipid measures but not between ASP and adiposity or diabetes measures. We detected two potential quantitative trait loci influencing ASP levels. The strongest signal was on chromosome 17 near marker D17S1303 [log of the odds ratio (LOD) = 2.7]. The signal on chromosome 15 reached its peak near marker D15S641 (LOD = 2.1). Both signals localize in regions reported to harbor quantitative trait loci influencing obesity and lipid phenotypes in this population. Bivariate linkage analysis yielded LODs of 4.7 for ASP and BMI on chromosome 17 and 3.2 for ASP and high-density lipoprotein2a on chromosome 15. DISCUSSION: Given these findings, there seems to be a significant genetic contribution to variation in circulating levels of ASP and an interesting pattern of genetic correlation (i.e., pleiotropy) with other risk factors associated with the metabolic syndrome.

Adolescent↗

Cosupplementation with vitamin E and coenzyme Q10 reduces circulating markers of inflammation in baboons.

BACKGROUND: Inflammation and oxidative stress are processes that mark early metabolic abnormalities in vascular diseases. OBJECTIVES: We explored the effects of a high-fat, high-cholesterol (HFHC) diet on vascular responses in baboons and the potential response-attenuating effects of vitamin E and coenzyme Q(10) (CoQ(10)) supplementation. DESIGN: We used a longitudinal design by subjecting 21 baboons (Papio hamadryas) to sequential dietary challenges. RESULTS: After being maintained for 3 mo on a baseline diet (low in fat and cholesterol), 21 baboons were challenged with an HFHC diet for 7 wk. The serum C-reactive protein (CRP) concentrations did not change. Subsequent supplementation of the HFHC diet with the antioxidant vitamin E (250, 500, or 1000 IU/kg diet) for 2 wk reduced serum CRP concentrations from 0.91 +/- 0.02 to 0.43 +/- 0.06 mg/dL. Additional supplementation with CoQ(10) (2 g/kg diet) further reduced serum CRP to approximately 30% of baseline (0.28 +/- 0.03 mg/dL; P = 0.036 compared with the HFHC diet). Introduction of the HFHC diet itself significantly decreased serum P-selectin (from 48.8 +/- 7.2 to 32.9 +/- 3.7 ng/dL, P = 0.02) and von Willebrand factor (from 187.0 +/- 10.1 to 161.9 +/- 9.0%, P = 0.02) concentrations. However, neither vitamin E alone nor vitamin E plus CoQ(10) significantly altered the serum concentrations of P-selectin or von Willebrand factor. CONCLUSIONS: Dietary supplementation with vitamin E alone reduces the baseline inflammatory status that is indicated by the CRP concentration in healthy adult baboons. Cosupplementation with CoQ(10), however, significantly enhances this antiinflammatory effect of vitamin E.

Analysis of Variance↗

Gene by smoking interaction: evidence for effects on low-density lipoprotein size and plasma levels of triglyceride and high-density lipoprotein cholesterol.

We seek to determine whether significant gene x smoking interaction effects exist on plasma triglyceride (TG) levels, HDL cholesterol (HDL-C) level, and median LDL particle diameter (LDL-MPD) in Mexican American families enrolled in the San Antonio Family Heart Study. The sample consisted of 1,392 individuals distributed in 42 extended pedigrees, ranging in age from 16 years to 92 years. Separate quantitative genetic analyses were carried out for TG and HDL-C level and LDL-MPD using a maximum-likelihood-based variance decomposition approach while simultaneously adjusting for age and sex. Initial heritability estimates demonstrated significant (p < 0.001) additive genetic contributions to all three traits (h2 range 0.50 - 0.54). To test for a gene x smoking interaction, we included in the model additional smoking-status-specific variance terms and a genetic correlation term between smokers and nonsmokers. Comparisons of nested models revealed significant evidence (p < 0.01) for a gene X smoking interaction effect on TG level and LDL-MPD and possible evidence for an effect on HDL-C level. These results indicate that the gene or suite of genes regulating each of these phenotypes is likely the same in smokers and non-smokers but that smoking may alter the expression of genes, particularly those influencing TG level and LDL-MPD.

Adolescent↗

Intercellular adhesion molecule-1 concentration is genetically correlated with insulin resistance, obesity, and HDL concentration in Mexican Americans.

The metabolic syndrome and type 2 diabetes are associated with endothelial activation (and thus with inflammatory processes leading to atherosclerosis), but the mechanisms that underlie these associations are not fully understood. Endothelial intercellular adhesion molecule (ICAM)-1 plays an important role in the recruitment of immune cells during the development of atherosclerotic plaque and is a marker of inflammatory disease. We performed bivariate quantitative genetic analyses to estimate genetic and environmental correlations between circulating ICAM-1 concentration and 17 phenotypes associated with the metabolic syndrome. Our study population comprised 428 adults in 20 extended Mexican-American families from the San Antonio Family Heart Study (SAFHS). Circulating ICAM-1 concentration is heritable (h(2) = 0.56). ICAM-1 concentration showed significant positive genetic correlations (range 0.32-0.52, P < 0.05) with fasting insulin, insulin 2 h after oral glucose challenge, homeostasis model assessment of insulin resistance, BMI, waist circumference, and leptin concentration; negative genetic correlation with HDL3 cholesterol concentration; and negative environmental correlation with adiponectin concentration. Significant genetic correlations were not found between ICAM-1 and fasting or 2-h serum glucose or systolic or diastolic blood pressure. Thus, ICAM-1 expression may share common genetic modulation with traits related to obesity, insulin resistance, and HDL3 cholesterol, but not with hyperglycemia or hypertension per se.

Blood Glucose↗

Metabolic syndrome best defines the multivariate distribution of blood variables in postinfarction patients.

The hypothesis was tested that metabolic syndrome (MS) plays a leading role in approximating the multivariate distribution of thrombogenic and metabolic blood variables in a population of postinfarction patients. The multivariate statistical technique of factor analysis was used to determine blood variable clustering 2 months after myocardial infarction. Five clusters resulted in two separate independent factors, dyslipidemia and metabolic, reflecting MS and the remaining interpreted as cholesterol-lipoprotein, vascular-inflammatory, and coagulation. All five factors accounted for 55% of total variance with MS-associated factors accounting for 20% and individual factor contributions as follows: 11.6, 8.6, 12.9, 11.9, and 9.6%, respectively. There were no interactions of metabolic variables with thrombogenic variables or CRP in any factor. Results of subgroup analysis in males and females and in patients on and not on statins were all similar to the total group. We conclude there is no interaction of variables of MS or cholesterol-lipoprotein factors with those of thrombogenic factors. This independence yields the potential for use of factors in evaluating CVD risk. Further, the importance of MS in this group of postinfarction patients is emphasized, as the largest contribution to total variance was from MS factors, meaning that these variables best approximate the original multivariate distribution.

Aged↗