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The correlation of paraoxonase (PON1) activity with lipid and lipoprotein levels differs with vascular disease status

2005; Elsevier BV; Volume: 46; Issue: 9 Linguagem: Inglês

10.1194/jlr.m400489-jlr200

1539-7262

Laura S. Rozek, Thomas S. Hatsukami, Rebecca J. Richter, Jane Ranchalis, Karen Nakayama, Laura McKinstry, David A. Gortner, Edward J. Boyko, Gerard Schellenberg, Clement E. Furlong, Gail P. Jarvik,

Apelin-related biomedical research

Paraoxonase (PON1) is an HDL-associated enzyme. Low PON1 activity predicts vascular disease status and is a more reliable predictor of vascular disease than are functional PON1 genotypes. There is evidence that the relationship of PON1 to vascular disease is, in part, due to its antioxidant activity. However, the physical relationship of PON1 with HDL and the existence of cholesterol pathway regulatory elements at the PON1 locus suggest a further relationship of PON1 with lipoproteins, which may contribute to its role in vascular disease. We investigated the relationship of PON1 activity and genotype to lipid-related traits in 91 Caucasian men with severe carotid artery disease and 184 without vascular disease who were not on lipid-lowering medications. Prior studies of PON1 relationship to lipids have not stratified by disease status..We found that PON1 activity was correlated with HDL traits in controls and with LDL- and VLDL-related traits in cases. We hypothesize differences in the joint regulation of PON1 and lipoproteins in cases and controls. Paraoxonase (PON1) is an HDL-associated enzyme. Low PON1 activity predicts vascular disease status and is a more reliable predictor of vascular disease than are functional PON1 genotypes. There is evidence that the relationship of PON1 to vascular disease is, in part, due to its antioxidant activity. However, the physical relationship of PON1 with HDL and the existence of cholesterol pathway regulatory elements at the PON1 locus suggest a further relationship of PON1 with lipoproteins, which may contribute to its role in vascular disease. We investigated the relationship of PON1 activity and genotype to lipid-related traits in 91 Caucasian men with severe carotid artery disease and 184 without vascular disease who were not on lipid-lowering medications. Prior studies of PON1 relationship to lipids have not stratified by disease status.. We found that PON1 activity was correlated with HDL traits in controls and with LDL- and VLDL-related traits in cases. We hypothesize differences in the joint regulation of PON1 and lipoproteins in cases and controls. There is a growing body of evidence that reduced activity of the HDL-associated (1Mackness M.I. Arrol S. Abbott C. Durrington P.N. Protection of low-density lipoprotein against oxidative modification by high-density lipoprotein associated paraoxonase.Atherosclerosis. 1993; 104: 129-135Google Scholar, 2Mackness M.I. The human paraoxonase polymorphism and atherosclerosis.in: Mackness M.I. Cleric M. Esterases, Lipases, and Phospholipases. Plenum Press, New York1994: 65-73Google Scholar, 3Watson A.D. Berliner J.A. Hama S.Y. La Du B.N. Fuall K.F. Fogelman A.M. Navab M. Protective effect of high density lipoprotein associated paraoxonase. Inhibition of the biological activity of minimally oxidized low density lipoprotein.J. Clin. 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Distribution spectrum of paraoxonase activity in HDL fractions.Clin. Chem. 2004; 50: 2309-2315Google Scholar) enzyme paraoxonase (PON1) is predictive of vascular disease in humans (8Ayub A. Mackness M.I. Arrol S. Mackness B. Patel J. Durrington P.N. Serum paraoxonase after myocardial infarction.Arterioscler. Thromb. Vasc. Biol. 1999; 19: 330-335Google Scholar, 9Jarvik G.P. Rozek L.S. Brophy V.H. Hatsukami T.S. Richter R.J. Schellenberg G.D. Furlong C.E. Paraoxonase (PON1) phenotype is a better predictor of vascular disease than is PON1(192) or PON1(55) genotype.Arterioscler. Thromb. Vasc. Biol. 2000; 20: 2441-2447Google Scholar, 10Mackness B. Gershan K.D. Turkie W. Lee E. Roberts D.H. Hill E. Roberts C. Durrington P. Mackness M. Paraoxonase status in coronary heart disease: are activity and concentration more important than genotype?.Arterioscler. Thromb. Vasc. Biol. 2001; 21: 1451-1457Google Scholar, 11Jarvik G.P. Hatsukami T.S. Carlson C. Richter R.J. Jampsa R. Brophy V.H. 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Hama S. Castellani L.W. Furlong C.E. Costa L.G. Fogelman A.M. et al.Mice lacking serum paraoxonase are susceptible to organophosphate toxicity and atherosclerosis.Nature. 1998; 394: 284-287Google Scholar), with a 42% excess in stenosis (15Rozenberg O. Rosenblat M. Coleman R. Shih D.M. Aviram M. Paraoxonase (PON1) deficiency is associated with increased macrophage oxidative stress: studies in PON1-knockout mice.Free Radic. Biol. Med. 2003; 34: 774-784Google Scholar). Conversely, human PON1 transgenic mice with 2- to 4-fold increased PON1 levels have a reduced susceptibility (16Tward A. Xia Y.R. Wang X.P. Shi Y.S. Park C. Castellani L.W. Lusis A.J. Shih D.M. Decreased atherosclerotic lesion formation in human serum paraoxonase transgenic mice.Circulation. 2002; 106: 484-490Google Scholar). There is a 10- to 40-fold interindividual difference in serum PON1 paraoxonase activity (17Playfer J.R. Eze L.C. Bullen M.F. Evans D.A.P. Genetic polymorphism and inter-ethnic variability of plasma paraoxonase activity.J. Med. Genet. 1976; 13: 337-342Google Scholar, 18Furlong C.E. Richter R.J. Seidel S.L. Motulsky A.G. Role of genetic polymorphism of human plasma paraoxonase/arylesterase in hydrolysis of the insecticide metabolites chlorpyrifos oxon and paraoxon.Am. J. Hum. Genet. 1988; 43: 230-238Google Scholar, 19Brophy V.H. Jarvik G.P. Richter R.J. Rozek L.S. Schellenberg G.D. Furlong C.E. Analysis of paraoxonase (PON1) L55M status requires both genotype and phenotype.Pharmacogenetics. 2000; 10: 453-460Google Scholar) due, in part, to four common polymorphisms: functional promoter region polymorphisms include PON1C-108T and PON1G-162A (19Brophy V.H. Jarvik G.P. Richter R.J. Rozek L.S. Schellenberg G.D. Furlong C.E. Analysis of paraoxonase (PON1) L55M status requires both genotype and phenotype.Pharmacogenetics. 2000; 10: 453-460Google Scholar), and the functional coding polymorphisms are PON1Q192R and PON1L55M. Variations at these four common polymorphisms explain 44% of the phenylacetate and 88% of the paraoxon hydrolysis activity of PON1 in subjects without vascular disease (11Jarvik G.P. Hatsukami T.S. Carlson C. Richter R.J. Jampsa R. Brophy V.H. Margolin S. Rieder M. Nickerson D. Schellenberg G.D. et al.Paraoxonase activity, but not haplotype utilizing the linkage disequilibrium structure, predicts vascular disease.Arterioscler. Thromb. Vasc. Biol. 2003; 23: 1465-1471Google Scholar) and 25% of the phenylacetate and 82% of the paraoxon hydrolysis activity in subjects with severe carotid artery disease, with PON1192 largely accounting for the paraoxon hydrolysis variation. The promoter region polymorphisms affect protein level, best represented by the PON1 phenylacetate hydrolysis activity, which is reasonably independent of the PON1192 polymorphism (20Davies H. Richter R.J. Keifer M. Broomfield C. Sowalla J. Furlong C.E. The effect of human serum paraoxonase polymorphism is reversed with diazoxon, soman, and sarin.Nat. Genet. 1996; 14: 334-336Google Scholar, 21Eckerson H.W. Wyte C.M. La Du B.N. The human serum paraoxonase/arylesterase polymorphism.Am. J. Hum. Genet. 1983; 35: 1126-1138Google Scholar). Despite the large impact of PON1 genetic variation on PON1 activity, this variation is inconsistently associated with vascular disease status (11Jarvik G.P. Hatsukami T.S. Carlson C. Richter R.J. Jampsa R. Brophy V.H. Margolin S. Rieder M. Nickerson D. Schellenberg G.D. et al.Paraoxonase activity, but not haplotype utilizing the linkage disequilibrium structure, predicts vascular disease.Arterioscler. Thromb. Vasc. Biol. 2003; 23: 1465-1471Google Scholar, 12Mackness B. Durrington P. McElduff P. Yarnell J. Azam N. Watt M. Mackness M. Low paraoxonase activity predicts coronary events in the Caerphilly Prospective Study.Circulation. 2003; 107: 2775-2779Google Scholar, 13Robertson K.S. Hawe E. Miller G.J. Talmud P.J. Humphries S.E. Human paraoxonase gene cluster polymorphisms as predictors of coronary heart disease risk in the prospective Northwick Park Heart Study II.Biochim. Biophys. Acta. 2003; 1639: 203-212Google Scholar, 22Mackness M. Mackness B. Paraoxonase 1 and atherosclerosis: is the gene or the protein more important?.Free Radic. Biol. Med. 2004; 37: 1317-1323Google Scholar), and meta-analyses have not detected a significant predictive effect for a limited set of PON1 genotypes (23Lohmueller K.E. Pearce C.L. Pike M. Lander E.S. Hirschhorn J.N. Meta-analysis of genetic association studies supports a contribution of common variants to susceptibility to common disease.Nat. Genet. 2003; 33: 177-182Google Scholar, 24Wheeler J.G. Keavney B.D. Watkins H. Collins R. Danesh J. Four paraoxonase gene polymorphisms in 11212 cases of coronary heart disease and 12786 controls: meta-analysis of 43 studies.Lancet. 2004; 363: 689-695Google Scholar) that was not attributable to evident publication bias. Why PON1 activity affects vascular disease and its important genetic variability does not remains unexplained. Mechanisms by which PON1 activity may impact cardiovascular disease (CVD) risk that are independent of this genetic variation must be sought. The mechanisms by which PON1 activity influences risk of vascular disease continue to be evaluated. It is generally held that PON1 contributes to the antioxidant, thus, anti-atherogenic properties of HDL. Virtually all of PON1's activity is associated with HDL-cholesterol (HDL-C) (25Blatter M.C. James R.W. Messmer S. Barja F. Pometta D. Identification of a distinct human high-density lipoprotein subspecies defined by a lipoprotein-associated protein, K-45. Identity of K-45 with paraoxonase.Eur. J. Biochem. 1993; 211: 871-879Google Scholar). PON1 appears to prevent LDL and HDL oxidation (26Mackness M.I. Arrol S. Durrington P.N. Paraoxonase prevents accumulation of lipoperoxides in low-density lipoprotein.FEBS Lett. 1991; 286 ([Erratum 1991. FEBS Lett. 292: 307.]): 152-154Google Scholar, 27Mackness B. Hine D. Liu Y. Mastorikou M. Mackness M. Paraoxonase-1 inhibits oxidised LDL-induced MCP-1 production by endothelial cells.Biochem. Biophys. Res. Commun. 2004; 318: 680-683Google Scholar). The PON1192 polymorphism has been reported to affect the hydrolysis of oxidized LDL-C and HDL-C (28Mackness B. Mackness M.I. Arrol S. Turkie W. Durrington P.N. Effect of the human serum paraoxonase 55 and 192 genetic polymorphisms on the protection by high density lipoprotein against low density lipoprotein oxidative modification.FEBS Lett. 1998; 423: 57-60Google Scholar, 29Aviram M. Billecke S. Sorenson R. Bisgaier C. Newton R. Rosenblat M. Erogul J. Hsu C. Dunlop C. Du B. La Paraoxonase active site required for protection against LDL oxidation involves its free sulfhydryl group and is different from that required for its arylesterase/paraoxonase activities: selective action of human paraoxonase allozymes Q and R.Arterioscler. Thromb. Vasc. Biol. 1998; 18: 1617-1624Google Scholar). In accordance with this, HDL from PON1 knockout mice does not protect LDL from oxidation (30Shih D.M. Xia Y.R. Wang X.P. Miller E. Castellani L.W. Subbanagounder G. Cheroutre H. Faull K.F. Berliner J.A. Witztum J.L. et al.Combined serum paraoxonase knockout/apolipoprotein E knockout mice exhibit increased lipoprotein oxidation and atherosclerosis.J. Biol. Chem. 2000; 275: 17527-17535Google Scholar) and PON1 transgenic mice have improved protection of LDL (31Oda M.N. Bielicki J.K. Ho T.T. Berger T. Rubin E.M. Forte T.M. Paraoxonase 1 overexpression in mice and its effect on high-density lipoproteins.Biochem. Biophys. Res. Commun. 2002; 290: 921-927Google Scholar). The relationship between PON1 activity and vascular disease may be influenced by the relationship of PON1 activity or genotype to lipid and lipoprotein levels. The physical association of PON1 and the HDL subfraction 3 (HDL3) component of HDL in subjects with (5Chemnitius J.M. Winkel H. Meyer I. Schirrmacher K. Armstrong V.W. Kreuzer H. Zech R. Age related decrease of high density lipoproteins (HDL) in women after menopause. Quantification of HDL with genetically determined HDL arylesterase in women with healthy coronary vessels and in women with angiographically verified coronary heart disease.Med. Klin. (Munich). 1998; 93: 137-145Google Scholar) and without vascular disease (5Chemnitius J.M. Winkel H. Meyer I. Schirrmacher K. Armstrong V.W. Kreuzer H. Zech R. Age related decrease of high density lipoproteins (HDL) in women after menopause. Quantification of HDL with genetically determined HDL arylesterase in women with healthy coronary vessels and in women with angiographically verified coronary heart disease.Med. Klin. (Munich). 1998; 93: 137-145Google Scholar, 7Bergmeier C. Siekmeier R. Gross W. Distribution spectrum of paraoxonase activity in HDL fractions.Clin. Chem. 2004; 50: 2309-2315Google Scholar, 25Blatter M.C. James R.W. Messmer S. Barja F. Pometta D. Identification of a distinct human high-density lipoprotein subspecies defined by a lipoprotein-associated protein, K-45. Identity of K-45 with paraoxonase.Eur. J. Biochem. 1993; 211: 871-879Google Scholar) and the presence of an important cholesterol transcriptional regulator, SREBP-2 (bp −104 to −95), in the proximal PON1 promoter region (32Deakin S. Leviev I. Guernier S. James R.W. Simvastatin modulates expression of the PON1 gene and increases serum paraoxonase: a role for sterol regulatory element-binding protein-2.Arterioscler. Thromb. Vasc. Biol. 2003; 23: 2083-2089Google Scholar) suggest an important PON1-lipoprotein relationship. SREBP-2 was found to increase PON1 promoter activity in a dose-dependent manner (32Deakin S. Leviev I. Guernier S. James R.W. Simvastatin modulates expression of the PON1 gene and increases serum paraoxonase: a role for sterol regulatory element-binding protein-2.Arterioscler. Thromb. Vasc. Biol. 2003; 23: 2083-2089Google Scholar), indicating an additional lipid-related mechanism of PON1 activation. As summarized in the discussion, previous reports of PON1-lipid relationships have been contradictory and do not consider a stratum of subjects affected by vascular disease. A further understanding of the relationship between the PON1 phenotypes and genotypes and lipids and lipoproteins may help to clarify the role of PON1 in vascular disease and, in particular, may address why PON1 activity level is more important than PON1 genetic variation. The current study evaluated the effects of PON1 activities in the hydrolysis of paraoxon, diazoxon, and phenylacetate as well as the genotype at functional, common promoter region (PON1−162 and PON1−108) and coding (PON155 and PON1192) polymorphisms on lipids and lipoproteins in subjects with and without carotid artery disease (CAAD). The aim was to determine which PON1 parameters are most correlated with these known cardiovascular risk factors, with the eventual goal of determining whether any role of PON1 in vascular disease may be attributable, in part, to PON1's relationship with lipids, lipoproteins, and apolipoproteins. The vascular disease subjects, having >80% carotid stenosis, and the nonvascular disease subjects, having 80% internal carotid artery stenosis, unilaterally or bilaterally, on angiography using standardized guidelines. CAAD subjects who had carotid endarterectomy without prior angiogram were also included. Non-CAAD subjects were drawn from patients in a general internal medicine clinic database who did not have computerized codes for cardiovascular or peripheral vascular disease. Subject interview and medical record review confirmed the lack of any known vascular disease. All non-CAAD subjects had 400 mg/dl and those with coagulopathies were excluded. A study physician or nurse performed chart and pharmacy record reviews for lipid-lowering medication use, which was then reconciled with the patient's own report of medications. Current smoking status was determined by self-report in a written survey. The study was approved by the Human Subjects review processes at the University of Washington, VMMC, and the PSVAHCS, Seattle. Written informed consent was obtained prior to participation. All laboratory measures were done blinded to clinical characteristics. DNA was prepared from buffy coat preparations by a modification of the procedure of Miller, Dykes, and Polesky (33Miller S.A. Dykes D.D. Polesky H.F. A simple salting out procedure for extracting DNA from human nucleated cells.Nucleic Acids Res. 1988; 16: 1215Google Scholar). Genotyping was conducted by PCR amplification followed by polymorphism-specific restriction digestion and gel electrophoresis. The genotypes of the PON1Q192R, PON1L55M, PON1C–108T, and PON1A–162G polymorphisms were determined as previously published (34Humbert R. Adler D.A. Disteche C.M. Hassett C. Omiecinski C.J. Furlong C.E. The molecular basis of the human serum paraoxonase activity polymorphism.Nat. Genet. 1993; 3: 73-76Google Scholar, 35Brophy V.H. Hastings M.D. Clendenning J.B. Richter R. Jarvik G.P. Furlong C.E. Polymorphisms in the human paraoxonase (PON1) promoter.Pharmacogenetics. 2001; 11: 77-84Google Scholar, 36Brophy V.H. Jampsa R.L. Clendenning J.B. McKinstry L.A. Jarvik G.P. Furlong C.E. Promoter polymorphism effects on paraoxonase (PON1) expression.Am. J. Hum. Genet. 2001; 68: 1428-1436Google Scholar). All of the 91 CAAD and 171 of the 184 non-CAAD subjects also had genotyping performed for the PON155 polymorphism by Illumina, Inc. There was a 1% difference in genotypes. Illumina genotypes were used when genotypes did not match. Four subjects were missing one or more genotypes. Genotype distributions did not significantly differ from Hardy-Weinberg equilibrium expectations. The activity of PON1 in the hydrolysis of paraoxon, diazoxon, and phenylacetate (arylesterase activity) was measured by a continuous spectrophotometric assay, as described elsewhere (20Davies H. Richter R.J. Keifer M. Broomfield C. Sowalla J. Furlong C.E. The effect of human serum paraoxonase polymorphism is reversed with diazoxon, soman, and sarin.Nat. Genet. 1996; 14: 334-336Google Scholar, 36Brophy V.H. Jampsa R.L. Clendenning J.B. McKinstry L.A. Jarvik G.P. Furlong C.E. Promoter polymorphism effects on paraoxonase (PON1) expression.Am. J. Hum. Genet. 2001; 68: 1428-1436Google Scholar, 37Furlong C.E. Richter R.J. Seidel S.L. Costa L.G. Motulsky A.G. Spectrophotometric assays for the enzymatic hydrolysis of the active metabolites of chlorpyrifos and parathion by plasma paraoxonase/arylesterase.Anal. Biochem. 1989; 180: 242-247Google Scholar, 38Richter R.J. Furlong C.E. Determination of paraoxonase (PON1) status requires more than genotyping.Pharmacogenetics. 1999; 9: 745-753Google Scholar). These are termed POase, DZOase, and Arylase, respectively. Arylase was measured in triplicate. The plot of POase versus DZOase accurately predicts PON1192 genotype in both cases and controls; this plot was used to fill in three missing genotypes (39Jarvik G.P. Jampsa R. Richter R.J. Carlson C.S. Rieder M.J. Nickerson D.A. Furlong C.E. Novel paraoxonase (PON1) nonsense and missense mutations predicted by functional genomic assay of PON1 status.Pharmacogenetics. 2003; 13: 291-295Google Scholar). Lipid-related measurements were performed by Northwest Lipid Research Laboratories, Seattle, WA. Subjects fasted for 12 h prior to sampling. HDL-C, HDL2, HDL3, apolipoprotein A-I (apoA-I), total cholesterol (TC), LDL-C, apoB, triglycerides (TGs), and VLDL-C were measured. Standard enzymatic methods were used to determine levels of TC, TG, VLDL-C, and HDL-C in whole plasma on an Abbott Spectrum analyzer (40Warnick G.R. Benderson J. Albers J.J. Dextran sulfate-Mg2+ precipitation procedure for quantitation of high-density-lipoprotein cholesterol.Clin. Chem. 1982; 28: 1379-1388Google Scholar, 41Bachorik P.S. Albers J.J. Precipitation methods for quantification of lipoproteins.Methods Enzymol. 1986; 129: 78-100Google Scholar, 42Warnick G.R. Enzymatic methods for quantification of lipoprotein lipids.Methods Enzymol. 1986; 129: 101-123Google Scholar). HDL2 and HDL3 were determined by precipitation of HDL2 from total HDL-C, and measurement of the HDL3 remaining in the supernate (HDL-C − HDL3 = HDL2). ApoA-I measurement used calibrators and quality control samples from in-house plasma pools with values assigned against World Health Organization international reference material (43Marcovina S.M. Albers J.J. Henderson L.O. Hannon W.H. International Federation of Clinical Chemistry standardization project for measurements of apolipoproteins A-I and B. III. Comparability of apolipoprotein A-I values by use of international reference material.Clin. Chem. 1993; 39: 773-781Google Scholar). ApoB associated with LDL (LDL-B) was measured after pooling the LDL-containing density gradient ultracentrifugation (DGUC) fractions (44Zambon A. Austin M.A. Brown B.G. Hokanson J.E. Brunzell J.D. Effect of hepatic lipase on LDL in normal men and those with coronary artery disease.Arterioscler. Thromb. 1993; 13: 147-153Google Scholar). LDL density was evaluated by nonequilibrium DGUC as described previously (45Auwerx J.H. Marzetta C.A. Hokanson J.E. Brunzell J.D. Large buoyant LDL-like particles in hepatic lipase deficiency.Arteriosclerosis. 1989; 9: 319-325Google Scholar). LDL buoyancy was calculated as the peak LDL fraction divided by 38, the total number of fractions collected. Due to departures from normality, HDL-C, HDL2, HDL3, TC, TG, and VLDL-C were natural log-transformed prior to the analysis (lnHDL, lnHDL2, lnHDL3, lnTC, lnTG, and lnVLDL-C). Student t-tests or chi-squared tests were used to evaluate differences in characteristics between CAAD and non-CAAD subjects. The relationship of PON1 activity and lipid measures was assessed separately for cases and controls. Bivariate Pearson correlations were calculated between POase, DZOase, and Arylase and lipid-related measures. This was done considering both raw PON1 activities and PON1 activities adjusted for the variation in PON1−162, PON1−108, PON155, and PON1192 genotypes by dummy variable regression, which considers each genotype as two separate variables. The effects of the covariates age, body mass index (BMI), and smoking on the Arylase activity-lipid-related trait relationship were also tested by regression, with and without PON1 genotype dummy variables, using the lipid traits as dependents and including Arylase, BMI, age, and smoking status. The results with these additional covariates were the same as those found using the simple correlations, and they are not separately reported here. The simultaneous effects of PON1 polymorphisms on lipid measures were assessed by the same linear regressions, using genotype dummy variables and including current age, smoking, and BMI as covariates. No adjustment was done for multiple contrasts for the correlation analyses, because both multiple PON1 and multiple lipid-related measures are highly correlated. For the genotype effects, a very minimal adjustment for multiple contrasts was employed, using P = 0.01 as a criterion for statistical significance. All analyses were performed using SPSS 10.0 for Windows (46SPSS.SPSS Statistical Algorithims. SPSS, Inc., Chicago, IL1991Google Scholar). Sample descriptives, stratified by CAAD status, are shown in Table 1. Subjects on lipid-lowering medications at the time of sampling were excluded from the primary analysis by design. The sample was Caucasian and male. Because the study design matched age of CAAD onset (censored age) with current control subject age, the CAAD subjects were slightly older than the non-CAAD subjects. The CAAD subjects had a higher prevalence of smoking; lower HDL-C, HDL3, and apoA-I levels; and lower BMI than did non-CAAD subjects. As expected, PON1 activities were lower in CAAD than non-CAAD subjects. There were no significant differences in genotype distributions for any of the PON1 polymorphisms between CAAD subjects and non-CAAD subjects. Minor (rarer) allele frequencies for the PON1 polymorphisms are summarized in Table 1.TABLE 1Sample descriptives stratified by CAAD statusNo Lipid-Lowering MedicationsTaking Lipid-Lowering MedicationsCAAD (SD)Non-CAAD (SD)PCAAD (SD)Non-CAAD (SD)PN91184NA11067NACaucasian100%100%NA100%100%NAMale100%100%NA100%100%NACensored age mean (range), years 67.0 (48–83) 66.7 (47–83) 0.87 65.3 (41–84) 63.5 (50–80) 0.17Current age mean (range), years 70.4 (49–83) 66.7 (47–83) 0.002 69.6 (46–89) 63.5 (50–80)<0.001Lipid-lowering medications0%0%NA100%100%NACurrent smoker42%15%<0.00132%9% 0.001Ever smoker92%74%<0.00295%68%<0.001Type 2 diabetes15%17% 0.7322%16% 0.44BMI 26.6 (5.0) 29.1 (6.3) 0.001 28.4 (5.2) 30.2 (4.7) 0.020HDL-C mg/dl 40.5 (14.0) 46.9 (16.1) 0.002 41.7 (14.2) 41.4 (9.9) 0.69HDL2 mg/dl 8.1 (6.2) 8.2 (5.8) 0.45 7.0 (4.8) 6.3 (3.2) 0.36HDL3 mg/dl 34.1 (13.7) 37.7 (11.4)<0.001 34.7 (10.0) 35.2 (7.3) 0.40ApoA-I 121.3 (22.0) 134.5 (24.5)<0.001 120.5 (35.0) 128.9 (16.3) 0.11TG mg/dl 159.4 (121.8) 145.0 (97.6) 0.13 180.9 (129.9) 206.8 (193.2) 0.40VLDL-C mg/dl 31.9 (24.4) 29.3 (21.3) 0.14 36.1 (25.0) 36.9 (24.8) 0.68TC mg/dl 197.1 (38.3) 190.7 (37.0) 0.12 186.6 (39.2) 192.7 (41.3) 0.30LDL-B mg/dl 69.5 (17.4) 65.8 (18.4) 0.12 61.1 (16.2) 64.5 (17.7) 0.20LDL-C mg/dl 106.4 (28.5) 103.5 (30.0) 0.38 89.2 (27.6) 96.7 (30.6) 0.10LDL density (Rf) mg/dl 0.27 (0.03) 0.26 (0.03) 0.48 0.26 (0.03) 0.24 (0.03) 0.015Arylase units/l 93.8 (42.4) 106.1 (42.1) 0.023 104.1 (41.8) 117.0 (41.8) 0.049DZOase units/l8,867.3 (3016.1)9,684.4 (3297.7) 0.0489,556.1 (3246.1)10,326.8 (2818.5) 0.11POase units/l 603.2 (424.1) 673.0 (429.1) 0.19 688.2 (484.6) 653.0 (418.8) 0.62PON1−162A MAF0.250.26 0.880.26 0.25 0.85PON1−108T MAF0.470.50 0.390.50 0.41 0.12PON155M MAF0.350.38 0.410.35 0.41 0.40PON1192R MAF0.300.31 0.970.32 0.25 0.13ApoA-I, apolipoprotein A-I; BMI, body mass index; CAAD, carotid artery disease; LDL-B, LDL associated apoB; LDL-C, LDL-cholesterol; MAF, minor allele frequency; NA, not applicable; TC, total cholesterol; TG, triglyceride. Although the lipid values in the table are untransformed for ease of interpretation, the statistical tests for these lipid values used ln transformations for the following variables: HDL-C, HDL2, HDL3, TGs, VLDL-C, and TC. P values reflect the test of the genotype distribution difference between groups, not allele frequency differences. Open table in a new tab ApoA-I, apolipoprotein A-I; BMI, body mass index; CAAD, carotid artery disease; LDL-B, LDL associated apoB; LDL-C, LDL-cholesterol; MAF, minor allele frequency; NA, not applicable; TC, total cholesterol; TG, triglyceride. Although the lipid values in the table are untransformed for ease of interpretation, the statistica