Differential effects of smoking on myocardial infarction risk according to the Gln/Arg 192 variants of the human paraoxonase gene.

Paraoxonase (PON1) seems to exert a major antioxidant effect by removing lipid peroxidation products. A common polymorphism of the PON1 gene modulates paraoxonase activity and has been related in some studies to coronary heart disease. PON1 genetic polymorphism includes PON1 Q, an isoform with a low activity toward paraoxon hydrolysis that has a glutamine at position 192, and PON1 R, the high-activity isoform with an arginine at position 192. In the present study, we investigated whether smoking, which is related to increased susceptibility to lipoprotein oxidation, has a differential effect by PON1-192 genotype on the risk of myocardial infarction (MI). One hundred fifty-six consecutive MI patients and 310 control subjects were studied. PON1 genotypes in the controls were distributed as follows: 154 (49.7%) QQ, 123 (39.7%) QR, and 33 (10.6%) RR. This distribution did not significantly differ from that of the MI patients: 84 (53.8%) QQ, 60 (38.5%) QR, and 12 (7.7%) RR. Subjects were classified into two groups, those who never smoked (n = 209) and those who were current smokers (n = 135) or ex-smokers (n = 122). In the latter, the variable "cigarette packs smoked per year" was defined as the number of packs smoked daily multiplied by the number of smoking years. As expected, smoking was significantly associated with an increased MI risk in the overall group. Subjects were then stratified by PON1 genotype. The packs smoked per year were significantly associated with an increased MI risk only in QQ homozygotes. This risk was higher among those in the higher tertile for cigarette packs smoked per year (odds ratio [OR] = 5.24, 95% confidence interval = 1.67 to 16.44, Pfor trend <.001). In contrast, the packs smoked per year were not significantly associated with MI risk in R-carrier subjects. We conclude that the risk of MI associated with smoking appears to be increased in subjects who are homozygous for the low-activity PON1 QQ genotype compared with R carriers, and this risk seems to be time- and dose-dependent.

Relationship of abdominal adiposity and dyslipemic status in women with a common mutation in the lipoprotein lipase gene. The REGICOR investigators.

Abdominal obesity constitutes an important risk factor for cardiovascular disease. Hypertriglyceridemia and low high-density lipoprotein (HDL) cholesterol concentration constitute the major lipid alterations observed in obesity. A common variant of the lipoprotein lipase (LPL) gene, the HindIII polymorphism, has been found to be associated with changes in triglyceride and HDL-cholesterol levels. We have investigated the impact of the LPL HindIII polymorphism on the relationship between abdominal adiposity and lipoprotein concentrations in 156 randomly selected women in a cross-sectional study conducted in the province of Gerona, in the northeast of Spain. The waist-to-hip ratio was used as an estimate of regional fat distribution. Serum lipid and lipoprotein measurements as well as lipoprotein lipase-HindIII genotypes were determined. Percentile 50 of waist-to-hip ratio (WHR) (0.81) was used as a cutoff to define low or high WHR groups, which significantly differed in blood pressure and lipid trait concentrations. Serum triglyceride concentrations and mean log triglyceride-to-HDL-cholesterol ratio were significantly higher in H+ homozygous women compared with H- carriers. Whereas no statistically-significant differences were observed in HDL-cholesterol concentration and log triglyceride-to-HDL-cholesterol ratio of H- carriers between WHR groups, H+ homozygous women showed significant differences in these lipid traits. It is noteworthy that high-WHR H- carrier women showed a mean HDL-cholesterol value similar to those of both genotypes in the low WHR group. A statistically significant interaction between WHR and genotype was observed for HDL-cholesterol concentration (P=0. 027) and log triglyceride-to-HDL-cholesterol ratio (P=0.040). These results stress the compensating effects that weight loss may have on women with adverse genetic factors. From a complementary viewpoint, the presence of the H- allele seems to confer a protective lipid profile, even when an adverse anthropometric factor such as abdominal adiposity is present.

Effect of physical activity on lipid levels in a population-based sample of men with and without the Arg192 variant of the human paraoxonase gene.

The prevalence of cardiovascular risk factors in Gerona, Spain, is high for the low myocardial infarction incidence and mortality rates in the province. Physical activity is a protective factor against coronary heart disease. We investigated whether the genetic variants Q and R of the paraoxonase Gln-Arg 192 polymorphism were involved in different responses of lipids to physical activity. Serum triglycerides, HDL-cholesterol concentrations, and the paraoxonase Gln-Arg 192 polymorphism were determined in 262 men randomly selected from a representative population sample in a cross-sectional study conducted in Gerona, Spain. The Minnesota Leisure Time Physical Activity Questionnaire was used to assess energy expenditure in leisure time physical activity. No differences were found in lipid levels among tertiles of physical activity distribution in subjects with the QQ genotype. However, R carriers showed a significant decreasing trend in triglyceride levels and in log-triglyceride-to-HDL-cholesterol ratio and a significant increasing trend in HDL-cholesterol concentration with the amount of physical activity. R carriers included in the low tertile of physical activity distribution had HDL-cholesterol levels significantly lower than those of QQ homozygous men in the same physical activity category (1.04 mmol/L vs. 1.22 mmol/L, P = 0.024). R carriers of the higher tertile of physical activity distribution showed the most favorable lipid profile in this genetic group. A statistically-significant interaction between paraoxonase genotypes and physical activity was observed for log triglycerides (P = 0.018), HDL-cholesterol concentration (P = 0.017), and log triglyceride-to-HDL-cholesterol ratio (P = 0.008). The beneficial association of the amount of physical activity and lipid traits found in men with the R allele suggests that this population subgroup needs to be physically active to achieve a favorable lipoprotein phenotype similar to that observed in QQ homozygous men.

Risk of myocardial infarction associated with Gln/Arg 192 polymorphism in the human paraoxonase gene and diabetes mellitus. The REGICOR Investigators.

AIMS: There is increasing evidence that paraoxonase, an HDL-linked enzyme, exerts its effect by removing lipid-peroxidation products. We have conducted a case-control study in Gerona, Spain, to find out whether paraoxonase1 polymorphism at codon 192 (Q and R alleles) is associated with increased risk of coronary heart disease, and how diabetes mellitus, associated with high oxidative risk, influences such an association. METHODS AND RESULTS: One hundred and fifty six consecutive myocardial infarction patients and 310 age- and sex-matched control subjects were studied. There were no differences in the distribution of genotype and allele frequencies between patients and controls. The odds ratios for diabetes and dyslipaemia in control and patients stratified by genotype group were compared. Whereas dyslipaemic status was significantly related to myocardial infarction in QQ homozygotes and R carriers, diabetes mellitus was significantly associated with myocardial infarction only in R-carrier subjects. In logistic regression analysis, diabetic R carriers demonstrated a more than two and a half-fold increase in myocardial infarction risk compared with non-diabetic R carriers (OR: 2.65, P<0.05). CONCLUSION: These data indicate that the R allele of the paraoxonase1-192 polymorphism is not an independent risk factor for myocardial infarction in our population. However, the interaction between this polymorphism and diabetes mellitus leads to increased myocardial infarction risk in diabetic patients with the R allele.

The relationship between smoking and triglyceride-rich lipoproteins is modulated by genetic variation in the glycoprotein IIIa gene.

In the last year, several studies have reported conflicting results concerning an association between the PI(A2) allele of the PI(A1/A2) polymorphism of platelet glycoprotein IIIa and the risk of myocardial infarction. In the present study, we analyzed the hypothesis of whether glycoprotein IIIa genotypes have any association with lipids and lipoproteins as classical cardiovascular risk factors. Smoking, associated with changes in triglyceride-rich lipoprotein (TRL) concentrations and with both hypercoagulability and reduced fibrinolysis, was also analyzed as an environmental factor. Blood samples were obtained from 170 subjects (83 men and 87 women; mean age, 57 years; SD 15) recruited by random sampling from the census of Girona, Spain. Subjects were classified as current smokers (n=41) and nonsmokers or exsmokers (n=129). Whereas no differences were found in lipid and lipoprotein concentrations between smokers and nonsmokers in subjects with the PI(A1/A1) genotype, smokers with the PI(A1/A2) or PI(A2/A2) genotypes showed significantly higher triglyceride and very-low-density lipoprotein (VLDL) triglyceride concentrations than nonsmokers or exsmokers with the same genotypes. Similarly, the VLDL triglyceride/HDL cholesterol ratio was significantly different in subjects with the PI(A1/A2) or PI(A2/A2) genotypes stratified according to smoking status. Further analysis revealed a significant interaction between smoking and genotype when those homozygous for the allele PI(A1) were compared with one or two PI(A2) alleles for the three lipidic parameters. The observed effects appear to show links between smoking, triglyceride metabolism, and a glycoprotein involved in platelet aggregation. It is likely that the pI(A) polymorphism is in linkage disequilibrium with other functional mutations that might influence triglyceride metabolism under some environmental factors such as smoking. This finding may provide a new perspective in the complex relationship between glycoprotein IIIa gene, environment, and their interactions.

Platelet glycoprotein IIb/IIIa genetic polymorphism is associated with plasma fibrinogen levels in myocardial infarction patients. The REGICOR Investigators.

Fibrinogen is the major ligand of platelet glycoprotein IIb/IIIa platelet receptor. Genes coding for platelet fibrinogen receptor glycoprotein IIb/IIIa are polymorphic. The PLA alloantigen has two antigenic determinants, PLA1 and PLA2, located in a 17-23 kD fragment of glycoprotein IIIa. We analyzed whether PLA genotype has any effect on plasma fibrinogen concentration and investigated if the effect has different magnitude in myocardial infarction patients compared with subjects free of angina or myocardial infarction. One hundred sixteen consecutive patients who suffered a myocardial infarction and 136 subjects recruited by random sampling from the local census were included in the study. PLA genotype distribution and allele frequencies in patients did not significantly differ from those in the control group. Mean fibrinogen concentration tended to be higher in controls with genotype PLA1PLA1 than in those with genotype PLA1PLA2 or PLA2PLA2, and in patients this difference reached statistical significance (p < 0.001). We conclude that the PLA polymorphism may be in linkage disequilibrium with another functional mutation in or near the promoter area of the fibrinogen gene or even in another gene, which controls the production or the clearance of fibrinogen.

[Anthropometric and dietary determinants of blood levels of HDL cholesterol in a population-based study. The REGICOR study. Researchers of the REGICOR study]. / Determinantes antropométricos y dietéticos de la concentración sérica del colesterol de las lipoproteínas de alta densidad en un estudio de base poblacional. El estudio REGICOR. Investigadores del Estudio REGICOR.

OBJECTIVES: The aim of the present study was to identify dietary and anthropometric factors influencing HDL cholesterol levels in the region of Girona. POBLATION AND METHODS: A cross-sectional study was designed with random recruitment and 798 men and 862 women were included. Anthropometric variables were collected, the energy expenditure in physical activity was calculated and a dietary questionnaire was supplied in order to obtain nutritional data. Furthermore, lipid levels and lipoprotein concentrations were determined. RESULTS: Significant differences were found in serum triglycerides, body mass index, glucose levels and alcohol intake between the upper and the lower tertils of HDL cholesterol in both men and women. In men, energy expenditure in physical activity was significantly associated with HDL cholesterol levels, as well as total fat and monounsaturated fat. In women, together with the waist-to-hip ratio and fasted glycemia, vitamin C was the dietary factor positively associated with HDL cholesterol levels. CONCLUSIONS: Moderate alcohol intake, physical activity, vitamin C consumption and optimizing body weight strongly contribute to increased HDL cholesterol levels in our region.

High prevalence of cardiovascular risk factors in Gerona, Spain, a province with low myocardial infarction incidence. REGICOR Investigators.

STUDY OBJECTIVE: To establish the prevalence of main cardiovascular risk factors in the province of Gerona, where the incidence of myocardial infarction is known to be low. DESIGN: This was a cross sectional study of prevalence of cardiovascular risk factors conducted on a large random population sample. SETTING: The province of Gerona, Spain. PARTICIPANTS: Two thousand four hundred and four eligible inhabitants of Gerona aged between 25 and 74 years were randomly selected for a multi-stage sample stratified by age and sex. The following were standardly measured: lipids (total cholesterol, high density, low density, lipoprotein (a) and triglycerides), fibrinogen, basal glycaemia, arterial pressure, anthropometric variables, smoking, history of angina (Rose questionnaire), and a medical history questionnaire. Population measurements were standardised for the world population of 24 to 74 years of age. RESULTS: The participation rate was 72.7% (1748). Total mean cholesterol was 5.69 mmol/l in men and 5.61 mmol/l in women and mean high density cholesterol was 1.22 mmol/l and 1.47 mmol/l, respectively. Median lipoprotein (a) was 0.22 g/l. These three lipids increased significantly with age. Mean fibrinogen was 2.92 g/l in men and 3.09 g/l in women, and was higher in smokers. The prevalence of hypertension (systolic arterial tension > or = 140 mm Hg or diastolic > or = 90 mm Hg or drug treatment) was 31.3% in men and 27.7% in women. The proportion of male smokers was 33.8% and female smokers 22.7%. The proportion of female smokers in the 25-34 year age group exceeded that of the remaining age groups for both men and women. CONCLUSIONS: The prevalence of cardiovascular risk factors in Gerona is relatively high for the low myocardial infarction incidence typical of the area, although similar to that of other Spanish areas. The factors that confer sufficient protection to compensate for the effect of the prevalence of these risk factors remain to be elucidated.

Interaction of family history of atherosclerosis with atherogenic lipid traits in men with non-coronary atherosclerosis.

Family history of atherosclerosis has been recognised as an nonmodifiable cardiovascular risk factor. Lipid levels, together with hypertension and diabetes, appear to have an inheritable component. The aim of the study was to ascertain whether lipoprotein abnormalities of 169 adult patients with non-coronary atherosclerosis were associated with a family history of atherosclerosis. Besides intermediate density lipopoprotein composition and Lp(a) levels, we focused on apo(a) and apo E phenotypes, LDL cholesterol/apo B ratio, VLDL triglyceride/HDL cholesterol ratio, and environmental factors. We found that patients with a family history of atherosclerosis had a higher prevalence of VLDL triglyceride/HDL cholesterol ratio above 1.8 (51.3% vs 34.7%) than patients without. Similarly, there was a significant inverse correlation between both considered ratios (r = -0.24, p < 0.05). The odds ratio of the presence of both abnormal ratios (4.60, 95% CI, 1.41-15.00) and low molecular weight apo(a) isoforms (3.30, 95% CI, 1.05-10.30 and family history of atherosclerosis was independent of smoking and hypertension. Apo(a) isoform size seems to be more important than Lp(a) concentrations in the family history of atherosclerosis risk determination. Subsequent analysis showed that patients with a family history of atherosclerosis had a greater-than-fourfold increased risk of having one or both abnormal ratios reflecting metabolic disturbances which probably constitute a combined trait. Family history of atherosclerosis may constitute a specific lipoprotein-related marker of atherosclerosis. Such a marker often precedes the onset of overt disease and may contribute to identifying patients with an atherogenic lipoprotein profile even in the absence of classical lipid risk factors.

Antibodies to human immunodeficiency virus (HIV-1) in autoimmune diseases: primary Sjögren's syndrome, systemic lupus erythematosus, rheumatoid arthritis and autoimmune thyroid diseases.

The aetiology of autoimmune diseases remains unknown. The relationship between virus, and more recently retrovirus, has been suggested with this group of diseases. Immunoblotting is a useful method for determining the presence of proteins coded by different retrovirus genes. Since the prevalence of these types of proteins in patients with primary Sjögren's syndrome (SS), systemic lupus erythematosus (SLE), rheumatoid arthritis (RA) and autoimmune thyroid diseases has not been fully established, the aim of this work was to determine the prevalence of antibodies to immunodeficiency human virus type 1 (HIV-1) proteins in these diseases and their possible relationship with the presence of anti-nuclear, anti-DNA, anti-SSA (Ro) and anti-SSB (La) autoantibodies. Antibodies to human immunodeficiency virus (HIV-1) were studied in a group of 341 patients with autoimmune diseases (77 SS, 98 SLE, 75 RA, 91 autoimmune thyroid diseases) and 126 blood donors as a control group. A Western blot was used to detect antibodies to HIV-1, and a double polymerase chain reaction (PCR) using nested primers in the gag and pol gene of HIV-1. Antinuclear antibodies, anti-DNA, anti-SSA (Ro) and anti-SSB (La) were determined by enzyme-linked immunosorbent assays. At least one band was shown on immunoblotting in 26% of patients with autoimmune diseases and 35% of controls. The presence of antibodies to p55 or p68 proteins in patients with SS or SLE proved to be the only statistically significant difference between the other autoimmune diseases studied and the control group. These antibodies were not associated with autoantibodies ANA, DNA, SSA (Ro) or SSB (La).(ABSTRACT TRUNCATED AT 250 WORDS)

Apolipoprotein(a) genetic polymorphism and serum lipoprotein(a) concentration in patients with peripheral vascular disease.

Serum lipoprotein(a) (Lp(a)) levels were measured in 89 men with peripheral vascular disease (PVD) and 129 (100 male and 29 woman) healthy controls. Apolipoprotein(a) genetic polymorphism was determined by immunoblotting in all subjects. Patients with PVD had significantly higher serum Lp(a) levels than controls. Apolipoprotein(a) phenotype frequencies in patients with PVD did not differ from those of the control group. Both patients and controls with phenotype S2 had higher serum Lp(a) levels than those with phenotype S4. It should be emphasized that serum Lp(a) levels were significantly higher in PVD patients than controls for those with phenotype S2, S3/S4 and S4. Raised serum Lp(a) levels together with other lipoprotein abnormalities in patients with PVD imply a high cardiovascular risk. Genetic polymorphism clearly influences serum Lp(a) levels both in patients and controls. In patients with PVD, environmental and/or other genetic factors must play a role in raising Lp(a) levels.