Strategy for order-made treatment of diabetic macroangiopathy

Several genetic risk factors such as single nucleotide polymorphisms(SNPs) in candidate genes have been reported to be responsible for diabetic macroangiopathy. We determined their genotypes regarding more than 100 SNPs in candidate genes responsible for average IMT of Japanese type 2 diabetic patients. We depicted some SNPs which were found to be significantly (p<0.05) responsible to the increase in AveIMT. Then, two combinations of double SNPs were evaluated as responsible for significant increases in AveIMT. Also, these two combinations were probably responsible for a high frequency of history of old myocardial infarction. The present analysis may provide one approach to evaluate combination of multiple genetic risk factors, which is synergistically associated with carotid atherosclerosis and myocardial infarction.     

Angiotensin-converting enzyme gene polymorphism, carotid intima-media thickness, and left ventricular mass index in adolescent hypertension

PURPOSE: The aim of this study was to determine whether a positive correlation exists between the DD genotype of angiotensin-converting enzyme (ACE) and the carotid intima-media thickness (IMT) or left ventricular mass index (LVMI) in adolescents with hypertension. METHODS: We studied 120 hypertensive and 58 normotensive (control) adolescents. ACE gene polymorphism was determined by a standardized method. The IMT was measured in the common carotid arteries, and the LVMI was calculated on transthoracic echocardiography. The severity of hypertension was graded according to the results of ambulatory blood pressure monitoring as white coat, borderline, or proven hypertension. The association between ACE gene polymorphism and the obtained parameters was analyzed using analysis of variance and chi-square testing. RESULTS: Both the IMT and LVMI were higher in hypertensive than in control adolescents. In hypertensive subjects, no relationship was found between the different ACE genotypes and the IMT: the mean (+/- standard deviation) IMT in patients with the DD genotype was 0.57 +/- 0.11 mm; in those with the DI genotype, 0.53 +/- 0.01 mm; and in those with the II genotype, 0.55 +/- 0.01 mm. The LVMI was also similar in all 3 ACE genotypes: DD, 106.7 +/- 32.3 g/m(2); DI, 102.2 +/- 38.1 g/m(2); and II, 103.2 +/- 26.3 g/m(2). The severity of hypertension as assessed by ambulatory blood pressure monitoring was independent of the ACE genotype. CONCLUSIONS: Target-organ damage (left ventricular hypertrophy and carotid atherosclerosis) is detectable in adolescents with hypertension and, in those subjects, ACE genotype polymorphism is not correlated with the severity of target-organ damage as measured by IMT and LVMI.     

Association of NAD(P)H oxidase p22 phox gene variation with advanced carotid atherosclerosis in Japanese type 2 diabetes

OBJECTIVE: To evaluate the association between the C242T polymorphism of the p22 phox gene, an essential component of NAD(P)H oxidase in the vasculature, with intima-media thickness (IMT) of the carotid artery and risk factors for atherosclerosis in type 2 diabetic subjects. RESEARCH DESIGN AND METHODS: C242T polymorphism of the p22 phox gene was detected by polymerase chain reaction-restriction fragment-length polymorphism in 200 Japanese type 2 diabetic subjects and 215 nondiabetic subjects. We examined the association with this mutation and carotid atherosclerosis as well as the patients' clinical characteristics and the level of 8-hydroxy-2'deoxyguanosine (8-OHdG) as an index of oxidative DNA damage. RESULTS: The diabetic subjects with the TC+TT genotypes displayed a significantly lower average IMT (1.13 +/- 0.31 vs. 1.31 +/- 0.34 mm; P = 0.0099) and a not significantly lower serum 8-OHdG level than those with the CC genotype, despite no difference in the risk factors. Stepwise multiple regression analysis showed that the risk factors for increased IMT in the diabetic subjects were systolic blood pressure (P = 0.0042) and p22 phox CC genotype (P = 0.0151). In nondiabetic subjects, the average IMT of the TC+TT group was not different from that of the CC group (0.85 +/- 0.14 vs. 0.94 +/- 0.30 mm, P = 0.417). Fasting plasma insulin concentration (41.4 +/- 15.6 vs. 64.2 +/- 59.4 pmol/l, P = 0.0098) and insulin resistance index of homeostasis model assessment (HOMA-R) (1.58 +/- 0.66 vs. 2.60 +/- 2.56, P = 0.0066) were significantly lower in the TC+TT group than in the CC group. CONCLUSIONS: These results show that the C242T mutation in the p22 phox gene is associated with progression of asymptomatic atherosclerosis in the subjects with type 2 diabetes and is also associated with insulin resistance in nondiabetic subjects.     

Association of angiotensin II type 1 receptor gene polymorphism with carotid atherosclerosis.

BACKGROUND: Polymorphisms of the angiotensin II type 1 receptor (AGTR1) gene are associated with essential hypertension and cardiovascular disease, but the correlation between AGTR1 A1166C polymorphism and carotid intima-media thickness (IMT) remains unclear. We sought to demonstrate correlation between AGTR1 gene polymorphism and carotid atherosclerosis in a Chinese population. METHOD: A total of 150 patients diagnosed with essential hypertension were included in this study. The AGTR1 A1166C polymorphism was detected by restriction analysis of the polymerase chain reaction product with Ddel digestion. Carotid IMT was measured by B-mode ultrasonography. RESULTS: The AC genotype frequency and the C1166 allele frequency of the AGTR1 gene in essential hypertensive patients were significantly higher than in controls (22.00% vs. 6.00% for AC, p < 0.01; 18.67% vs. 8.00% for the C allele, p < 0.05). Hypertensive subjects with the AC genotype had increased carotid artery IMT and IMT/D (common carotid artery diameter) ratio compared with the AA genotype (IMT 1.14 +/- 0.39 vs. 0.88 +/- 0.16, p < 0.05; IMT/D 14.08 +/- 2.88 vs. 10.51 +/- 1.94, p < 0.01). CONCLUSION: These results suggest that the AGTR1 A1166C polymorphism is associated with essential hypertension and carotid atherosclerosis in a Chinese population.     

脑梗死患者载脂蛋白A5基因多态性与颈动脉粥样硬化程度的相关性研究

目的分析脑梗死患者载脂蛋白A5（apo A5）-1131T／C和553G／T2位点基因多态性及单倍型与颈动脉粥样硬化程度的关系。方法采用聚合酶链反应．限制性片段长度多态性（PCR-RFLP）技术，分别检测272例脑梗死患者apo A5-1131T／C和553G／T多态性位点不同基因型和等位基因的分布，采用SNP Alyze V6．0软件构建并分析2多态性位点的个体单倍型；颈动脉粥样硬化程度由颈总动脉（CCA）和颈内动脉（ICA）内膜中层厚度（IMT）评估。结果272例脑梗死患者中-1131CC基因型和-1131TT＋TC基因型人群的CCA IMT和ICA IMT间的差异无统计学意义（P〉0．05）；553GG基因型和553TT＋GT基因型人群的CCA IMT分别为（1．09±0．18）mm和（1．17±0．18）mm，差异有统计学意义（P〈0．05），而两人群的ICA IMT的差异无统计学意义（P〉0．05）。单倍型配对分析结果表明，4种常见单倍型配对TG-TG、TG-CG、TG-CT、CG-CG间ICA IMT水平差异有统计学意义（P〈0．05）。结论apo A5 553G／T位点基因变异可能与-1131T／C位点在脑梗死患者颈动脉粥样硬化的进程中起协同作用。     

Atrial natriuretic peptide gene promoter polymorphism is associated with left ventricular hypertrophy in hypertension

Recent studies suggest that the ANP (atrial natriuretic peptide)/NPRA (type A natriuretic peptide receptor) system modulates ventricular remodelling and cardiac hypertrophy in hypertension in Western populations. In the present study, we tested for any association between two SNPs (single nucleotide polymorphisms) in the ANP gene (one in the promoter and one exonic) with cardiac hypertrophy. We tested the hypothesis in 2118 hypertensive patients, including 945 with LVH [LV (left ventricular) hypertrophy] and 1173 without LVH, as well as 816 healthy control subjects. All subjects were genotyped for the -A2843G and A188G polymorphisms. We found that the GG genotype at position -2843 conferred a 2.2-fold risk for LVH compared with the AA or AG genotypes, including septal wall thickness (11.8+/-1.4 mm for GG compared with 10.9+/-1.4 and 10.7+/-1.3 mm for AA and AG respectively; P<0.01), posterior wall thickness (11.8+/-2.8 mm for GG compared with 10.6+/-1.2 and 10.6+/-1.4 mm for AA and AG respectively; P<0.01), LV mass index (62.7+/-13.6 g/m(2.7) for GG compared with 57.9+/-8.6 and 57.8+/-8.4 g/m(2.7) for AA and AG respectively; P<0.05) and relative wall thickness (50.7+/-10.8% for GG compared with 44.3+/-7.3 and 43.5+/-6.8% for AA and AG respectively; P<0.05). Plasma levels of ANP were significantly lower in the hypertensive patients with LVH carrying the GG genotypes compared with those carrying the AA or AG genotypes (P<0.01). No association of GG genotype with echocardiographic variables and plasma ANP levels was identified in hypertensive patients without LVH and in control subjects (P>0.05). No significant association between the A188G genotype and echocardiographic variables was found in either hypertensive patients or controls (P>0.05). In conclusion, our findings indicate that the -A2843G polymorphism in the ANP gene promoter might be a genetic risk factor for the development of LVH in patients with hypertension.     

The association of myeloperoxidase promoter polymorphism with carotid atherosclerosis is abolished in patients with type 2 diabetes

ObjectivesType 2 diabetes mellitus (DM) enhances the development of atherosclerosis and reduces the activity of the oxidative myeloperoxidase (MPO) enzyme. MPO gene has a functional promoter polymorphism ?463G/A which leads to high- (GG) and low-expression (AG, AA) genotypes.Design and methodsWe studied the association of MPO polymorphism with carotid artery intima-media thickness (IMT) in 198 randomly selected Finnish men of Caucasian origin, 161 non-diabetics and 37 with type 2 DM. Their carotid IMT was measured by high-resolution ultrasonography, and the overall mean IMT value was calculated. MPO genotypes were determined by the PCR-RFLP method.ResultsWe found significant MPO genotype-by-study-group (control/DM) interactions with the overall mean IMT and internal carotid IMT (p = 0.05 and p = 0.04, respectively). Among non-diabetic subjects, the overall carotid IMT was 7.3% higher in subjects with the low-activity genotype when compared to the high-activity (G/G) group. The results remained significant after adjustment for total cholesterol and smoking (p = 0.015). No similar genotypic association was found for the subjects with type 2 DM.ConclusionsThis data suggests that in subjects with normal glucose metabolism, MPO gene variation may modify the carotid artery IMT.     

Structural and functional changes of coronary and carotid arteries in patients with ischemic heart disease

AIM: To assess prevalence of atherosclerotic changes in coronary arteries by computed tomography (CT) and carotid arteries by ultrasound duplex scanning (UDS) in patients with ischemic heart disease (IHD); to analyse viscoelastic properties of the walls of the common carotid arteries and their correlation with the results of carotid artery UDS and coronary artery CT. MATERIAL AND METHODS: CT and UDS were made in 100 patients with clinically and coronarographycally verified diagnosis of IHD. RESULTS: Calcinates in coronary arteries were found in 96% patients. The mean coronary calcium index (MCCI) was 544.8 +/- 718.5 units (from 0 to 3954 units). Atherosclerotic affection of carotid arteries was registered in 89% patients. Mean thickness of intima-media complex (IMT) of the common carotid arteries was 0.96 +/- 0.02 mm (0.60 mm - 1.87 mm). A correlation was found between coronary MCCI and IMT of the common carotid arteries. The stepwide regression analysis determined such predictors of coronary calcinosis as increased value of IMT of the common carotid arteries and atherosclerotic plaques (ASP) in carotid arteries. Viscoelasticity of the walls of the common carotid arteries in IHD patients differ from that of healthy subjects. This demonstrates stiffness of arterial wall in patients with IHD. There is a correlation between these parameters and IMT of the common carotid arteries. CONCLUSION: Combination of UDS with CT in diagnosis of atherosclerotic lesions of different arteries provides more complete information about structural-functional changes in patients with IHD. Such non-invasive tests as measurement of IMT of common carotid arteries and detection of ASP in carotid arteries by UDS, determination of coronary MCCI may serve screening parameters in diagnosis of coronary atherosclerosis.     

The haptoglobin 2-2 genotype is associated with carotid atherosclerosis in 64-year old women with established diabetes

BackgroundHaptoglobin polymorphism generates three common human genotypes: Hp1-1, Hp2-1 and Hp2-2. Among subjects with diabetes, Hp2-2 is associated with an elevated risk to develop cardiovascular disease. The impact of haptoglobin genotype on subclinical carotid atherosclerosis is not known. We hypothesized that Hp2-2 was associated with increased occurrence of carotid atherosclerosis in subjects with diabetes.MethodsWe studied a population-based sample of 64-year old women with diabetes (n = 226), either established diabetes known before study entry (n = 116) or new diabetes detected at study screening (n = 110). Haptoglobin genotype was determined by PCR. Carotid atherosclerosis was assessed by ultrasound imaging.ResultsIn the entire diabetes cohort, no differences were observed in carotid intima-media thickness (IMT) or plaque prevalence between the genotype groups. However, among those with established diabetes, Hp2-2 was associated with higher plaque prevalence and larger carotid IMT compared with the Hp2-1 and Hp1-1 genotypes. Common cardiovascular risk factors did not differ between the genotype groups.ConclusionsThe Hp2-2 genotype was associated with increased occurrence of subclinical carotid atherosclerosis in 64-year old women with established diabetes. This association was not explained by traditional risk factors for cardiovascular disease. These results extend previous observations that Hp2-2 is associated with clinical cardiovascular disease in diabetes.     

Haplotype-based association of four lymphotoxin-alpha gene polymorphisms with the risk of coronary artery disease in Han Chinese

Lymphotoxin-alpha (LTA), a pro-inflammatory cytokine, has been implicated in the pathogenesis of coronary atherosclerosis. Meanwhile, association of some single nucleotide polymorphisms (SNPs) of LTA gene with coronary artery disease (CAD) has been evaluated; however, the results are irreproducible. We therefore investigated the relationship between four SNPs of LTA gene and CAD in Han Chinese: G+10A (rs1800683, 5'-untranslated region), A+80C (rs2239704, 5'-untranslated region), T+496C (Cys13Arg, rs2229094, exon 2), and C+804A (Thr26Asn, rs1041981, exon 3). Genotyping was performed in 438 CAD patients and 330 healthy controls. Single-locus analysis showed that the genotype and allele frequencies of G+10A polymorphism exhibited marginal differences between CAD patients and controls, although no statistical significance was observed after the Bonferroni correction. Logistic regression analysis revealed that GG genotype of G+10A polymorphism was significantly associated with the risk of CAD under the dominant mode, whereas no significant association was detected between A+80C polymorphism and CAD. In contrast, individuals carrying TT or TC genotype of T+496C polymorphism showed a decreased CAD risk relative to those with CC genotype under the recessive mode. Likewise, CC genotype of C+804A polymorphism was associated with a protective effect on CAD under the dominant mode. Further, in haplotype analysis, the haplotype G-C-T-C (in order of rs1800683, rs2239704, rs2229094 and rs1041981) was significantly associated with a decreased risk of CAD after assigning the most common haplotype A-C-T-A as a reference. In conclusion, we show a protective effect of the haplotype G-C-T-C on the occurrence of CAD, suggesting the involvement of LTA in CAD pathogenesis.     

Carotid intima-media thickness in Japanese type 2 diabetic subjects: predictors of progression and relationship with incident coronary heart disease

OBJECTIVE: To examine carotid intima-media thickness (IMT), predictors of its progression, and its relationship with incident coronary heart disease (CHD) in type 2 diabetic Japanese patients. RESEARCH DESIGN AND METHODS: Carotid IMT of 287 subjects with type 2 diabetes (mean age 61.6 years) without CHD or cerebrovascular disease was examined at baseline and after a mean follow-up of 3.1 years. RESULTS: The annual progression of IMT (means +/- SEM) was 0.04+/-0.004 mm/year. Stepwise multivariate analysis demonstrated that independent risk factors for progress of IMT were the initial IMT (P<0.001), the average HbA1c level (P<0.001), and age (P = 0.001). Both the initial IMT (odds ratio [OR] 4.9, 95% CI 1.7-14.1) and a low average HDL cholesterol (OR 0.2, 0.1-0.8) were identified as predictors of incident nonfatal CHD (angina pectoris or nonfatal myocardial infarction; 3-year incidence 10.1%) after adjusting for age, sex, average HbA1c, and other risk factors. CONCLUSIONS: The predictors of the progression of carotid IMT in Japanese type 2 diabetic subjects were its baseline thickness and the average HbA1c during the follow-up. Baseline carotid IMT and low HDL cholesterol predicted the incidence of nonfatal CHD.     

A variant 2677A allele of the MDR1 gene affects fexofenadine disposition

BACKGROUND AND OBJECTIVES: There have been considerable disagreements regarding the influence of MDR1 (ABCB1) polymorphisms on the disposition of P-glycoprotein (P-gp) substrates. We speculated that the unknown function of the A allele of exon 21 G2677T/A (Ala893Ser/Thr) provides one of the reasons for the contradictory results. This study was performed to clarify the effects of major MDR1 gene polymorphisms, including a variant A allele in exon 21, on fexofenadine pharmacokinetics. METHODS: We investigated the occurrence of 3 high-frequency single-nucleotide polymorphisms (SNPs) in exons 12 (C1236T), 21 (G2677T/A), and 26 (C3435T) of the MDR1 gene in 232 healthy Koreans, using a polymerase chain reaction-restriction fragment length polymorphism method, and performed haplotype analysis on these 3 SNPs. A single oral dose of 180 mg fexofenadine hydrochloride was administered to 33 healthy Korean male volunteers, who were divided into 6 groups based on the MDR1 genotype for the G2677T/A polymorphism in exon 21 and the C3435T polymorphism in exon 26. RESULTS: A strong linkage disequilibrium was observed among the 3 SNPs. The frequencies of the 4 major haplotypes, 1236C-2677A-3435C, C-G-C, T-G-C, and T-T-T, were 16.4%, 18.6%, 21.6%, and 32.2%, respectively. Fexofenadine disposition varied considerably among the groups. In the 2677AA/3435CC genotype group (n=3), the values of area under the concentration-time curve from time 0 to 24 hours [AUC(0-24)] were significantly lower (P=.014) than those of the other 5 genotype groups (GG/CC, GT/CT, TT/TT, GA/CC, and TA/CT). As compared with the 2677GG/3435CC subjects, the AUC(0-24) values were 17% lower in the 2677AA/3435CC subjects and 47% higher in the 2677TT/3435TT subjects (GG/CC versus AA/CC versus TT/TT, 4017 +/- 1137 ng . h/mL versus 3315 +/- 958 ng . h/mL versus 5934 +/- 2,064 ng . h/mL; P=.018). By stratification for genotypes at position 3435, homozygous 3435TT subjects were found to have significantly higher AUC(0-24) (P=.024) and maximum plasma concentration (P=.040) values than CC subjects [AUC(0-24), 5934 +/- 2064 ng . h/mL versus 3998 +/- 1241 ng . h/mL; maximum plasma concentration, 958 +/- 408 ng/mL versus 673 +/- 242 ng/mL]. CONCLUSIONS: The plasma concentrations of fexofenadine after a single oral administration were lower in 2677AA/3435CC subjects than in subjects with the other 5 genotype combinations of the SNPs of G2677T/A and C3435T. These findings confirm the importance of analyzing MDR1 haplotypes and provide a plausible explanation for the conflicting results regarding the effect of MDR1 polymorphisms on the disposition of P-gp substrates.     

Antiatherogenic mitochondrial genotype in patients with type 2 diabetes

OBJECTIVE: To evaluate the significance of a longevity-associated mitochondrial genotype (Mt5178A) derived from a C --> A transversion at nucleotide position 5178 of mitochondrial DNA, which causes a Leu-to-Met substitution within the NADH dehydrogenase subunit 2 gene, in type 2 diabetic subjects. RESEARCH DESIGN AND METHODS: Mt5178 typing was done by polymerase chain reaction-restriction fragment-length polymorphism with the restriction enzyme AluI in 1,148 type 2 diabetic Japanese subjects, and the results were compared with the clinical characteristics. Then, the association of Mt5178 type with early atherosclerotic changes of the bilateral carotid arteries on ultrasonography was assessed in 412 diabetic subjects randomly selected from the original 1,148 type 2 diabetic subjects, while maintaining the same frequency of Mt5178A and Mt5178C. RESULTS: The frequency of Mt5178A in the type 2 diabetic subjects (454 of 1,148; 40%) was not different from that previously found in healthy blood donors (114 of 252; 45%). Clinical characteristics regarding diabetes were not significantly different between the Mt5178A group (n = 454) and the Mt5178C group (n = 694). However, the mean intima-media thickness (IMT) at six sites in the bilateral carotid arteries was significantly smaller in the Mrt5178A group than in the Mt5178C group (0.906 +/- 0.018 vs. 0.995 +/- 0.021 mm, mean +/- SEM, P = 0.022), and the Mt5178 type was significantly correlated with both the mean IMT and the presence of plaque on multiple regression analysis and discriminant analysis. CONCLUSIONS: The Mt5178A genotype may be unrelated to the etiology of type 2 diabetes. However, Mt5178A seems to have an antiatherogenic effect, at least in type 2 diabetic individuals.     

Influence of leukotriene pathway polymorphisms on clinical responses to montelukast in Japanese patients with asthma

What is known and Objective: Montelukast, a cysteinyl leukotriene receptor 1 antagonist, is safe and efficacious in patients with asthma. The mechanisms underlying the significant interpatient variability in response to montelukast are not clear but are believed to be, in part, because of genetic variability. Methods: To examine the associations between polymorphisms in candidate genes in the leukotriene pathway and outcomes in patients with asthma on montelukast for 4–8 weeks, we evaluated the changes in peak expiratory flow (PEF), forced expiratory volume in 1 s (FEV_1·0) and patients’ subjective symptom before and after montelukast treatment. DNA was collected from 252 Japanese participants. Results and Discussion: Two single‐nucleotide polymorphisms (SNPs) in the ALOX5 (rs2115819) and LTA4H (rs2660845) genes were successfully typed. There was no difference between members of the general population (n = 200) and patients (n = 52) in each genotype frequency. Significant associations were found between SNP genotypes in the LTA4H gene and changes in PEF and FEV_1·0. The PEF and FEV_1·0 responses to montelukast in the A/A genotypes (n = 4) for the LTA4H SNP were significantly higher than those in the G allele carriers (A/G+G/G) (n = 17). What is new and Conclusion: Despite the small sample size, our results suggest that genetic variation in leukotriene pathway candidate genes contributes to variability in clinical responses to montelukast in Japanese patients with asthma.     

Prognostic value of carotid intima-media thickness in detection of coronary atherosclerosis in patients with calcified aortic valve stenosis.

OBJECTIVE: Aortic stenosis (AS) coexists with coronary artery disease (CAD) in at least 30% of patients. Patients with concomitant CAD may benefit from simultaneous coronary bypass grafting. This study aimed to evaluate the prognostic value of carotid intima-media thickness (IMT) in patients with AS in assessing concomitant CAD. METHODS: Group I consisted of 33 patients (mean age +/- SD, 61.0 +/- 8.2 years; 18 men and 15 women) with AS but without CAD on angiograms. Group II consisted of 34 patients (64.4 +/- 8.0 years; 25 men and 9 women) with AS and CAD confirmed angiographically. A control group included 36 patients (61.2 +/- 4.9 years; 18 men and 18 women) with normal coronary arteries and no AS. Maximal IMT was assessed in all patients at the common carotid artery, bulb, and internal carotid artery and expressed as a mean value. RESULTS: There were no differences among the respective groups with regard to age, sex, frequency of hypertension, diabetes, and smoking habit, although patients with CAD were more often hyperlipemic (P = .038). The IMT of the common carotid artery, bulb, and internal carotid artery was significantly higher in patients with AS and CAD compared with both the control group and patients with AS only. The multivariable regression model revealed that CAD (P < .001), AS (P = .006), male sex (P = .034), age (P < .001), and diabetes mellitus (P = .047) were independent risk factors for IMT thickening. A mean IMT value of greater than 1.2 mm was predictive (sensitivity, 73.5%; specificity, 72.7%) of concomitant CAD in patients with AS. CONCLUSIONS: Intima-media thickness increases in patients with AS. The greatest IMT values are observed in patients with both AS and CAD. Patients with AS might be suspected of having CAD when the IMT value exceeds 1.2 mm.     

Endothelial nitric oxide synthase Glu(298)-->Asp polymorphism, carotid atherosclerosis and intima-media thickness in a general population sample

The Glu(298)-->Asp (E298D; 894G-->T) polymorphism of eNOS (endothelial nitric oxide synthase) has been related with cardiovascular disease. In the present study, we investigated the association of Glu(298)-->Asp with atherosclerotic plaques in different carotid vessel segments and with carotid IMT (intima-media thickness). The Glu(298)-->Asp eNOS polymorphism was determined by 5'-exonuclease assay among 2448 participants of the SHIP (Study of Health in Pomerania). Mean and maximum common carotid IMT, as well as carotid atherosclerosis, were measured by high-resolution ultrasound. The Asp/Asp(298) genotype was associated with an increased risk of atherosclerotic plaques at the level of the common carotid arteries [multivariate odds ratio, 1.57 and 95% CI (confidence interval), 1.05-2.34; P=0.025], but not in the carotid bifurcations or internal or external carotid arteries. Glu(298)-->Asp genotype was not associated with carotid IMT in the whole sample. However, the Asp/Asp(298) genotype was independently associated with both higher mean [adjusted increase by 0.046 mm (95% CI, 0.013-0.078); P=0.006] and maximum carotid IMT [0.137 mm (95% CI, 0.064-0.209); P<0.001] in the low-risk group of subjects without carotid atherosclerosis. In conclusion, the Asp/Asp(298) genotype is associated with atherosclerosis in the common carotid arteries and, in a low-risk group, also with carotid IMT. This suggests that the association of the Glu(298)-->Asp genotype with atherosclerosis in the carotid arteries is site-specific and is modified by overall cardiovascular risk.     

Low HDL cholesterol concentration is associated with increased intima-media thickness independent of arterial stiffness in healthy subjects from families with low HDL cholesterol

BACKGROUND: Low high-density lipoprotein cholesterol (HDL-C) is associated with increased risk for developing coronary artery disease. Cardiovascular disease is characterized by increased intima-media thickness (IMT) and arterial stiffness, but the effect of low HDL on these measurements has not been reported. MATERIALS AND METHODS: We studied 18 apparently healthy subjects from families with low HDL-C and 18 control subjects, which were pair-matched to maximize statistical power. Intima-media thickness was assessed using ultrasound examination of the carotid arteries. Arterial stiffness was measured using applanation tonometry on the radial artery and pulse-wave analysis to obtain central aortic pulse-pressure waveform, from which the augmentation index, a measure of global large artery stiffness, was calculated. RESULTS: Low HDL subjects (age 41 +/- 3 years, BMI 26.6 +/- 1.0 kg m(-2) had significantly lower HDL-C than the control subjects (age 41 +/- 3 years, BMI 26.5 +/- 1.0 kg m-2; 1.00 +/- 0.05 vs. 1.49 +/- 0.09 mmol L-1, low HDL vs. control subjects, P < 0.0001). Subjects with low HDL-C had significantly thicker mean IMTs than the control subjects (0.77 +/- 0.03 vs. 0.70 +/- 0.02 mm, low HDL vs. control subjects, P < 0.01). The maximal (0.99 +/- 0.04 vs. 0.89 +/- 0.03 mm, P < 0.01), far wall (0.76 +/- 0.04 vs. 0.69 +/- 0.02 mm, P < 0.05) and carotid bulb (1.11 +/- 0.06 vs. 0.97 +/- 0.04 mm) IMTs were also significantly increased, whereas the mean common carotid and the internal artery IMT were not. The age-related increase in mean IMT was more pronounced in the low HDL subjects than the control subjects (P < 0.01 for difference between elevations of age vs. IMT slopes). There were no differences in central pressure augmentation, the augmentation index, peripheral or central blood pressures between the groups. CONCLUSIONS: A low HDL-C concentration is associated with thickening of carotid IMT independent of other risk factors in healthy affected members of low HDL families.     

Preclinical atherosclerosis and inflammation in 61-year-old men with newly diagnosed diabetes and established diabetes

OBJECTIVE: The aim of this study was to investigate the occurrence of subclinical atherosclerosis and underlying mechanisms in men with newly diagnosed diabetes and established diabetes compared with healthy control subjects. RESEARCH DESIGN AND METHODS: In a population-based study of 61-year-old Caucasian men (n = 271) with established diabetes (n = 50) and newly diagnosed diabetes (n = 24) and healthy control subjects (n = 197), standard risk factors and highly sensitive (hs) C-reactive protein (CRP) were measured. Ultrasound measurements of intima-media thickness (IMT) were performed bilaterally in the common carotid artery, and a composite measure was calculated from common carotid and carotid bulb IMT (composite IMT). The plaque status was assessed. RESULTS: Composite IMT and carotid plaque size increased gradually among the healthy control subjects, newly diagnosed diabetic patients, and established diabetic patients (P for trend < or =0.001, respectively). CRP was higher in newly and established diabetes (NS between diabetes groups) compared with healthy control subjects (P < 0.001). Total cholesterol levels were lower in newly diagnosed diabetes (5.51 +/- 1.13 mmol/l, P < 0.05) and established diabetes (5.45 +/- 1.15 mmol/l, P < 0.01) compared with those of healthy control subjects (5.77 +/- 1.03 mmol/l). In men with diabetes (n = 74), diabetes onset status (newly diagnosed versus established), waist-to-hip ratio (WHR), and serum triglycerides, but not CRP, explained 16% of the variance in composite IMT. CONCLUSIONS: This is the first study to show increased preclinical atherosclerotic changes (IMT and plaque size) and increased inflammation (hs-CRP) in men with newly diagnosed diabetes as well as in patients with established diabetes compared with healthy control subjects. WHR, diabetes onset status (newly diagnosed versus established), and triglycerides, but not CRP, were independent correlates of carotid artery IMT in men with diabetes.     

Elevated C-reactive protein associates with early-stage carotid atherosclerosis in young subjects with type 1 diabetes

OBJECTIVE: To evaluate whether low-grade inflammation contributes to early-stage advanced carotid atherosclerosis in young subjects with type 1 diabetes. RESEARCH DESIGN AND METHODS: The mean and maximum (max) intima-media thicknesses (IMT) of the carotid artery were assessed using ultrasound B-mode imaging in 55 patients with type 1 diabetes (22 men and 33 women, aged 22.1 +/- 3.6 years (+/- SD), duration of diabetes 14.2 +/- 5.7 years) and 75 age-matched healthy nondiabetic subjects (28 men and 47 women). High-sensitive C-reactive protein (hs-CRP) levels were measured with a latex-enhanced immunonephelometer. RESULTS: The patients with type 1 diabetes had significantly higher hs-CRP levels (median 0.35, range 0.05-1.47 mg/l vs. median 0.14, range 0.05-1.44 mg/l; P = 0.001) as well as significantly higher mean IMT and max IMT than the nondiabetic subjects (mean IMT 0.76 +/- 0.09 vs. 0.72 +/- 0.04 mm, P = 0.003; max IMT 0.84 +/- 0.11 vs. 0.77 +/- 0.06 mm, P < 0.0001). Hs-CRP levels were significantly correlated with the mean and max IMT of patients with type 1 diabetes and with the max IMT of nondiabetic patients. Multivariate regression analyses for both diabetic and nondiabetic subjects as a single group showed that hs-CRP levels are independently correlated with the mean IMT and max IMT levels (P = 0.002 and P = 0.023, respectively) as well as with diastolic blood pressure, sex, and duration of diabetes. CONCLUSIONS: Our data indicate that hs-CRP levels are elevated in young patients with type 1 diabetes, possibly corresponding with early-stage advanced carotid atherosclerosis.     

Lack of association of the Glu298Asp polymorphism of endothelial nitric oxide synthase with manifest coronary artery disease,carotid atherosclerosis and forearm vascular reactivity in two Austrian populations

OBJECTIVE: Conflicting data exists about the possible contribution of the homozygous Asp/Asp genotype of the Glu298Asp polymorphism of endothelial nitric oxide synthase to human atherosclerotic vascular disease. We investigated the polymorphism in two independent study populations: a case-control study including patients with angiographically verified coronary artery disease (CAD) on the one hand and a cross-sectional epidemiological study on the other hand. METHODS: The Glu298Asp polymorphism was determined by PCR-RFLP as established. In the case-control study (240 patients and 248 controls) a possible association between the polymorphism and CAD, and age of onset of CAD and myocardial infarction was investigated. In the cross-sectional epidemiological study (932 subjects) intima-media thickness (IMT) of the carotid artery as well as morphological plaque burden and forearm vascular reactivity (peak postischemic reactive hyperaemia, determined by venous occlusion plethysmography) were measured. RESULTS: In the case-control study genotype distribution (Glu/Glu; Glu/Asp; Asp/Asp) was not different between the CAD patients (43/46/11%) and the controls (49/41/10%, P = NS). No association of the polymorphism with age of onset of CAD or myocardial infarction was found. In the epidemiological study no influence of the genetic variant on IMT was observed after correction for classical determinants of IMT (average IMT: Asp/ Asp: 0.077 +/- 0.011 mm; Glu/Glu and Glu/Asp: 0.080 +/- 0.012 mm, P = NS). Forearm vascular reactivity was also not different between homozygous Asp/Asp subjects and Glu/Glu and Glu/Asp subjects (peak-reactive hyperaemia 20.1 +/- 7.3 mL min-1 100 mL-1 vs. 20.0 +/- 6.5 mL min-1 100 mL-1, P = NS). CONCLUSIONS: Our results suggest that there is no association of the Glu298Asp polymorphism with coronary or carotid atherosclerosis or forearm vascular reactivity in these populations recruited in a country with a rather high risk for atherosclerosis. We suggest additional investigations to be performed in populations at different risk for coronary events to further elucidate the possible contribution of this polymorphism to vascular disease.