Identification and validation of seven new loci showing differential DNA methylation related to serum lipid profile: an epigenome-wide approach. The REGICOR study.

Lipid traits (total, low-density and high-density lipoprotein cholesterol, and triglycerides) are risk factors for cardiovascular disease. DNA methylation is not only an inherited but also modifiable epigenetic mark that has been related to cardiovascular risk factors. Our aim was to identify loci showing differential DNA methylation related to serum lipid levels. Blood DNA methylation was assessed using the Illumina Human Methylation 450 BeadChip. A two-stage epigenome-wide association study was performed, with a discovery sample in the REGICOR study (n = 645) and validation in the Framingham Offspring Study (n = 2,542). Fourteen CpG sites located in nine genes (SREBF1, SREBF2, PHOSPHO1, SYNGAP1, ABCG1, CPT1A, MYLIP, TXNIP and SLC7A11) and 2 intergenic regions showed differential methylation in association with lipid traits. Six of these genes and 1 intergenic region were new discoveries showing differential methylation related to total cholesterol (SREBF2), HDL-cholesterol (PHOSPHO1, SYNGAP1 and an intergenic region in chromosome 2) and triglycerides (MYLIP, TXNIP and SLC7A11). These CpGs explained 0.7%, 9.5% and 18.9% of the variability of total cholesterol, HDL cholesterol and triglycerides in the Framingham Offspring Study, respectively. The expression of the genes SREBF2 and SREBF1 was inversely associated with methylation of their corresponding CpGs (P-value = 0.0042 and 0.0045, respectively) in participants of the GOLDN study (n = 98). In turn, SREBF1 expression was directly associated with HDL cholesterol (P-value = 0.0429). Genetic variants in SREBF1, PHOSPHO1, ABCG1 and CPT1A were also associated with lipid profile. Further research is warranted to functionally validate these new loci and assess the causality of new and established associations between these differentially methylated loci and lipid metabolism.

Cardiac delivery of modified mRNA using lipid nanoparticles: Cellular targets and biodistribution after intramyocardial administration.

Despite research efforts being made towards preserving (or even regenerating) heart tissue after an ischemic event, there is a lack of resources in current clinical treatment modalities for patients with acute myocardial infarction that specifically address cardiac tissue impairment. Modified messenger RNA (modRNA) presents compelling properties that could allow new therapeutic strategies to tackle the underlying molecular pathways that ultimately lead to development of chronic heart failure. However, clinical application of modRNA for the heart is challenged by the lack of effective and safe delivery systems. Lipid nanoparticles (LNPs) represent a well characterized class of RNA delivery systems, which were recently approved for clinical usage in mRNA-based COVID-19 vaccines. In this study, we evaluated the potential of LNPs for cardiac delivery of modRNA. We tested how variations in C12-200 modRNA-LNP composition affect transfection levels and biodistribution after intramyocardial administration in both healthy and myocardial-infarcted mice, and determined the targeted cardiac cell types. Our data revealed that LNP-mediated modRNA delivery outperforms the current state of the art (modRNA in citrate buffer) upon intramyocardial administration in mice, with only minor differences among the formulations tested. Furthermore, we determined both in vitro and in vivo that the cardiac cells targeted by modRNA-LNPs include fibroblasts, endothelial cells and epicardial cells, suggesting that these cell types could represent targets for therapeutic interference with these LNP formulations. These outcomes may serve as a starting point for LNP development specifically for therapeutic mRNA cardiac delivery applications.

Paraoxonase1-192 polymorphism modulates the nonfatal myocardial infarction risk associated with decreased HDLs.

Serum paraoxonase1 (PON1), a high density lipoprotein (HDL)-linked enzyme, appears to have a role in the protection of low density lipoproteins from oxidative stress. PON1 enzyme activity for paraoxon as a substrate is modulated, along with others at the PON1 locus, by the PON1-192 polymorphism, which contains low paraoxon-activity and high paraoxon-activity alleles (Q and R, respectively). The association of PON1 with HDL suggests that impaired serum concentrations of the lipoprotein could have consequences for the susceptibility to oxidative stress. Because PON1-192 polymorphism strongly influences PON1 activity toward paraoxon, we tested the hypothesis that this polymorphism may modulate the myocardial infarction (MI) risk associated with low HDL cholesterol concentrations. Two hundred eighty consecutive MI patients and 396 control subjects were studied. When considered as a whole, PON1-192 genetic polymorphism was not associated with higher MI risk. In the entire population, decreased HDL cholesterol concentration (<0.90 mmol/L in men and <1.11 mmol/L in women) conferred an MI risk of 2.56 (P=0.0001) compared with normal HDL levels. The risk increased to 4.51 (P<0.0001) in QQ homozygous HDL-deficient subjects relative to QQ homozygotes with normal HDL levels, decreased to 1.83 (P=0.1046) in QR heterozygote HDL-deficient subjects, and also decreased (to 1.41, P=0.6243) in RR homozygote HDL-deficient individuals compared with RR carriers with normal HDL cholesterol concentration. The effect of PON1-192 genotypes on the association of low HDL cholesterol levels and MI was related to gene dosage. A significantly decreased enzyme activity was found in HDL-deficient MI patients compared with HDL-deficient control subjects (median 208 U/L [interquartile range 136 to 298 U/L] versus median 235 U/L [interquartile range 163 to 350 U/L], respectively; P=0.025]. QQ homozygous MI patients showed the greatest difference of PON1 activity levels between normal and HDL-deficiency state groups (14.9%, P=0.002). Our observations raise the question of whether the decrease in PON1 activity and the MI risk associated with HDL deficiency are more evident in the low paraoxon-activity QQ genotype. It can be argued that the low paraoxon-activity QQ genotype, which may be adequate to prevent lipid peroxidation in normolipidemic subjects, may be insufficient when an HDL-deficiency state and low PON1 activity reflecting oxidative stress coexist. The risk of nonfatal MI is increased in HDL-deficiency states, principally among subjects carrying the low paraoxon-activity QQ genotype.

Effect of simvastatin therapy on paraoxonase activity and related lipoproteins in familial hypercholesterolemic patients.

Human paraoxonase (PON1) is a calcium-dependent esterase closely associated with high density lipoprotein (HDL)-containing apolipoprotein AI (apoAI), which has been shown to confer antioxidant properties to HDL. PON1 has been recently implicated in the pathogenesis of atherosclerosis. Low PON1 activities have been found in familial hypercholesterolemia (FH) and diabetes mellitus. We have undertaken a study of the effect of the lipid-lowering drug simvastatin on serum PON1 activity (in relation to paraoxon and arylesterase activity), on apoAI-containing and apolipoprotein B (apoB)-containing lipoproteins, and on lipid peroxide concentrations in 64 (39 women and 25 men) unrelated FH patients. We have also analyzed the influence of the PON1-192 and PON1-55 genetic polymorphisms on the response of PON1 activity to simvastatin therapy. A venous blood sample for a baseline analysis and another after 4 months of simvastatin therapy at a dosage of 20 mg per day were taken. The major effect of simvastatin on lipid traits was to decrease serum cholesterol, low density lipoprotein (LDL) cholesterol, and lipid peroxide concentrations by 19.9%, 26.3%, and 37.3%, respectively. There was also a significant decrease in serum apoB, LDL apoB, and triglyceride concentrations (20.5%, 21.1%, and 15.6%, respectively). Conversely, simvastatin had no significant influence on very low density lipoprotein-lipid content, HDL cholesterol, apoAI concentrations, and lipoprotein AI and AI:AII particles. Remarkably, serum PON1 activity toward paraoxon significantly increased during treatment with simvastatin (168. 7+/-100.3 U/L before therapy versus 189.5+/-116.5 U/L after therapy, P:=0.005). Arylesterase activity displayed only a nonsignificant trend to increase after therapy. Whereas PON1 activity levels were significantly lower in FH patients before simvastatin therapy compared with those of 124 normolipidemic subjects (168.7+/-100.3 versus 207.6+/-125.2 U/L, respectively; P:<0.05), this difference disappeared after simvastatin therapy. After simvastatin therapy, a significantly negative correlation between PON1 activity and lipid peroxide concentration was observed (r=-0.35, P:=0.028). The latter also strongly correlated with LDL cholesterol concentration (r=0.64, P:<0.001). Serum PON1 activity levels were significantly lower in the low-activity PON1-192 QQ and PON1-55 M carriers than in R carriers and in LL carriers, respectively. No significant differences were found in the therapeutic response of PON1 activity between genotype groups (8.5% and 11.1% increase for QQ homozygous and R-carrier FH patients, respectively, and 12.7% and 9.5% increase for LL homozygotes and M carriers, respectively). We conclude that simvastatin may have important antioxidant properties through increasing serum PON1 activity, perhaps as a consequence of reducing oxidative stress, by a mechanism independent of apoAI-containing lipoprotein concentration and without the influence of PON1-192 and PON1-55 genetic polymorphisms. Further studies are clearly warranted to clarify the precise mechanism by which simvastatin therapy is associated with increased PON1 activity.

Relationship between lipoprotein profile and urinary albumin excretion in type II diabetic patients with stable metabolic control.

OBJECTIVE: To assess lipids and lipoprotein composition and the relationship between lipoprotein abnormalities and urinary albumin excretion (UAE) in select type II diabetic patients with stable metabolic control. RESEARCH DESIGN AND METHODS: Fifty-five type II diabetic patients and 55 healthy control subjects both with a body mass index < 30 kg/m2 were studied. Patients were classified according to their level of UAE as normoalbuminuric (n = 37), microalbuminuric (n = 11), and macroalbuminuric (n = 7). In all cases, serum creatinine and albumin concentrations were in the normal range. RESULTS: Normoalbuminuric patients showed increased triglyceride (TG) contents in intermediate-density lipoprotein (IDL) (P < 0.01), low-density lipoprotein (LDL) (P < 0.001), and high-density lipoprotein (HDL) (P < 0.001) compared with control subjects. Lipoprotein concentration in microalbuminuric patients did not differ from that of normoalbuminuric patients. On the other hand, patients with macroalbuminuria showed a significant increase in IDL cholesterol (P < 0.01) and IDL (P < 0.01), LDL (P < 0.05), and HDL TGs (P < 0.01) compared with the other groups. Diabetic patients with nephropathy, both microalbuminuric and macroalbuminuric, tended to have higher mean lipoprotein(a) (Lp[a]) concentrations than normoalbuminuric patients and control subjects. A strongly positive correlation was observed between UAE and serum TGs (r = 0.56) and very-low-density lipoprotein (r = 0.55), IDL (r = 0.52), LDL (r = 0.54), and HDL TGs (r = 0.52). CONCLUSIONS: Lipoprotein alterations observed in diabetic patients, specifically IDL abnormalities and a tendency toward high Lp(a) levels, which are more marked in those with increased UAE, may contribute to the excess of cardiovascular disease in type II diabetic patients, particularly those with nephropathy.

Calculated low-density lipoprotein cholesterol should not be used for management of lipoprotein abnormalities in patients with diabetes mellitus.

OBJECTIVE: To assess the validity of calculated low-density lipoprotein cholesterol by the Friedewald formula for management of lipoprotein abnormalities in patients with diabetes mellitus. RESEARCH DESIGN AND METHODS: Calculated LDL cholesterol by the Friedewald formula was compared with measured LDL cholesterol after separation by ultracentrifugation in 61 patients with type I diabetes, 50 patients with type II diabetes, and 116 healthy control subjects. RESULTS: Calculated LDL cholesterol coincided with measured LDL cholesterol, with < 10% error, in 54 (49%) patients with diabetes mellitus, and 85 (73%) control subjects. Calculated LDL cholesterol was overestimated, with an error of > or = 10% of measured LDL cholesterol in 39% of patients and 26% of control subjects, and underestimated in 13 and 1%, respectively. Despite a good correlation between calculated and measured LDL cholesterol, the intraclass correlation coefficients demonstrated a poor concordance between calculated and measured LDL cholesterol, both in patients and control subjects. When comparing the mean differences of calculated and measured LDL cholesterol for diabetic subjects versus control subjects, significantly greater differences in type II (but not type I) diabetic subjects were seen. CONCLUSIONS: Calculation of LDL cholesterol by the Friedewald formula may be inaccurate for assessment of cardiovascular risk in patients with type II diabetes and may not be appropriate for management of lipoprotein abnormalities in those diabetic patients.

Relationship of age-related myocardial infarction risk and Gln/Arg 192 variants of the human paraoxonase1 gene: the REGICOR study.

Paraoxonase1 (PON1) seems to exert a major antioxidant effect by removing lipid-peroxidation products. A common polymorphism of the PON1 gene, the PON1-192 genetic polymorphism, modulates PON1 activity and has been related in some studies to coronary heart disease. Oxidized LDL is believed to play a crucial role in the pathogenesis of atherosclerosis and there are studies providing support for the oxidative stress theory of aging. We have conducted a case-control study to determine whether PON1 activity and PON1-192 genetic variants have a different impact on myocardial infarction (MI) risk among individuals stratified by tertiles of age distribution. PON1-192 genotypes and PON1 activity were determined in 280 consecutive MI patients and 396 control subjects. Serum PON1 activity levels were significantly higher in controls than in MI patients [226 U/l (159-351) vs. 216 U/l (146-298), median (interquartile range), P=0.005]. A decline of PON1 activity levels with advancing age in subjects carrying the low-activity QQ genotype was observed, particularly in MI patients. PON1 activity and age negatively correlated in MI patients but not in controls. In the entire population, middle-aged and older subjects showed MI risks of 1.89 (P=0.012) and 2.69 (P<0.001) respectively, compared with young subjects. These risks increased to 2.41 (P=0.016) and 4.39 (P<0.001), respectively, in QQ homozygotes in comparison with younger QQ homozygotes, decreased to 1.53 (P=0.314) and 2.08 (P=0.112), respectively, in QR heterozygotes, and also lowered to 1.95 (P=0.410) and 0.51 (P=0.508) in RR homozygotes who were middle-aged and older, respectively, compared with younger RR carriers. The effect of PON1-192 genotypes on the association of the older age-category and MI risk was gene-dosage related. PON1 activity decreases as a function of age in subjects homozygous for the Q allele. Age may also act on MI risk as a function of PON1-192 alleles. The risk of MI increases with advancing age, principally among subjects carrying the low-activity QQ genotype.

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.

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.

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.

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.

Interaction between the Gln-Arg 192 variants of the paraoxonase gene and oleic acid intake as a determinant of high-density lipoprotein cholesterol and paraoxonase activity.

Olive oil, rich in oleic acid, could play a particular beneficial role in the anti-atherogenic effects attributed to the Mediterranean diet. Paraoxonase (PON1) has emerged as the component of high-density lipoproteins (HDL) most likely to explain its ability to attenuate the oxidation of low-density lipoproteins. We hypothesised that oleic acid intake might be associated with changes in PON1-HDL associated particles, and investigated the impact, if any, on this association of the PON1-192 polymorphism, a common polymorphism that strongly modulates PON1 activity. Six hundred and fifty-four men randomly selected from the census were studied. Oleic acid intake was calculated from a 72-h recall questionnaire with specific software. Oleic acid intake groups (low vs. high) were created by stratifying the population according the median value as a cut-point. After adjusting for confounding variables, high oleic acid intake was associated with increased HDL cholesterol levels and PON1 activity only in subjects with the QR and the RR genotypes, respectively. Analyses of the variance showed a statistically significant interaction between PON1-192 genotypes and oleic acid intake for log PON1 activity (P=0.005) and a marginally significant interaction for HDL cholesterol (P=0.066). These results suggest that the beneficial effect of increasing oleic acid intake on HDL and PON1 activity at population level is especially observed in subjects carrying the R allele of the PON1-192 polymorphism.

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.

Short-term mortality of myocardial infarction patients with diabetes or hyperglycaemia during admission.

AIM: The hypothesis that patients with hyperglycaemia during admission, regardless of previous diagnosis of diabetes, have worse prognosis than those with normal glucose values is controversial. The objective was to assess the role of hyperglycaemia on short-term mortality after myocardial infarction (MI). METHODS AND RESULTS: A cohort study nested in a prospective registry of MI patients in the reference hospital of Gerona, Spain was performed. All consecutive MI patients under 75 were registered between 1993 and 1996. Patient and clinical characteristics, including previous diagnosis of diabetes, glycaemia on admission and in the next four days, were recorded. Patients with glycaemia on admission or four day mean glycaemia >6.67 mmol/l were considered hyperglycaemic. The main outcome measure was mortality at 28 days. Of 662 patients with MI included, 195 (29.7%) had previously known diabetes mellitus, but 457 (69.0%) had glycaemia >6.67 mmol/l on admission. Patients with hyperglycaemia on admission were older, more often female, more frequently had a previous diagnosis of diabetes, developed more complications, and had higher 28 day mortality. The effect of admission glycaemia >6.67 mmol/l on 28 day mortality was independent of major confounding factors, particularly previous diagnosis of diabetes (OR=4.20, 95% confidence intervals 1.18 to 14.96). CONCLUSIONS: Higher 28 day mortality was observed among MI patients with glycaemia on admission >6.67 mmol/l compared with patients with lower levels, independently of major confounding variables and, particularly, previous diagnosis of diabetes. This early, simple, and inexpensive marker of bad prognosis after MI should prompt the application of more aggressive treatment of MI and risk factors and, probably, of glycaemia during admission.

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.

Lipoprotein composition in the insulin-deficient non-acidotic phase of type I diabetic patients and early evolution after the start of insulin therapy.

Lipoproteins, including intermediate density lipoproteins and lipoprotein(a), and apolipoproteins A-I, B, C-II, C-III and E, were studied in 13 newly-diagnosed type I diabetic patients with severe insulinopenia without dehydration or acidosis. At baseline, the main finding was a significant increase in serum triglycerides due to raised triglyceride concentrations in all lipoproteins, particularly triglyceride-rich lipoproteins. Cholesterol concentrations were slightly increased in lipoproteins and led to a significant increase in serum cholesterol. Two days after the start of insulin therapy, lipoprotein profiles had normalized except for the LDL triglyceride contents, which remained significantly increased on the fifth day of treatment. No significant modifications were observed in lipoprotein(a), apolipoproteins A-I and E concentrations throughout the study. However, serum apolipoproteins B, C-II and C-III were increased at baseline and fell to normal levels 2 days after the start of insulin therapy. On the other hand, apolipoprotein C-II/C-III ratios in high and very low density lipoprotein, showed no significant differences at baseline compared with controls, suggesting that an apolipoprotein C-II deficiency or apolipoproteins Cs imbalance can be ruled out. In conclusion, significant lipoprotein abnormalities were observed in the insulin-deficient state of type I diabetes mellitus; insulin therapy normalizes the lipoprotein profile in two days, except for low density lipoprotein triglyceride contents which remain increased at the fifth day.

Secondary prevention of coronary heart disease in patients with extracoronary atherosclerosis: a need for accuracy of low density lipoprotein determination.

According to the new guidelines of the National Cholesterol Education Program (NCEP) for secondary prevention in adults with evidence of coronary heart disease or other clinical atherosclerotic disease, lipoprotein analysis is required and classification is based on low density lipoprotein (LDL) cholesterol. The aim of the present study was to analyze the reliability of calculated LDL cholesterol by the Friedewald formula compared with measured LDL cholesterol after separation by ultracentrifugation in 202 male patients with extracoronary atherosclerosis (100 patients with ischemic cerebrovascular disease and 102 patients with peripheral vascular disease) and in 117 health control subjects. Calculated LDL cholesterol coincided with measured LDL cholesterol, with less than 10% error, in 118 patients (58.4%) with extracoronary atherosclerosis and in 87 controls (74.4%). Calculated LDL cholesterol was overestimated, with an error of 10% or more compared with measured LDL cholesterol, in 34.6% of patients and 22.2% of controls, and underestimated in 6.9% and 3.4% respectively. Despite a good correlation between calculated and measured LDL cholesterol, the intraclass correlation coefficients demonstrate a poor concordance between calculated and measured LDL cholesterol, both in patients and controls. The authors underline the need for caution in assessing the reliability of calculated LDL cholesterol.

Serum lipoprotein (a) levels in men with peripheral vascular disease.

The authors quantified serum lipoprotein (a) (Lp) (a) by enzymo-immuno-analysis in 86 outpatient men suffering peripheral vascular disease (PVD) and in 53 age-matched healthy men. They further measured serum cholesterol, serum triglycerides, low density lipoproteins-cholesterol, high density lipoproteins (HDL)-cholesterol and serum apolipoprotein B. Serum triglycerides were significantly increased in patients with PVD versus controls (148 +/- 8 and 114 +/- 7 mg/dL, mean +/- SEM). HDL-cholesterol levels were significantly lower in patients versus controls (36 +/- 1 and 43 +/- 2 mg/dL, respectively). Serum Lp(a) levels in patients with PVD were 20 +/- 2 mg/dL, whereas in controls they were 16 +/- 3 (p: NS). Serum Lp(a) concentrations were identical in smoker and nonsmoker patients. There was no correlation between Lp(a) concentration and the other lipid parameters. Conversely, as occurs in coronary heart disease and in cerebrovascular disease, Lp(a) does not seem to be a marker for PVD, although a trend toward a higher mean levels was found.

[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.