Angiotensin-converting enzyme gene polymorphism is associated with carotid arterial wall thickness in non-insulin-dependent diabetic patients

SARS-CoV-2 infections and COVID-19 mortalities strongly correlate with ACE1 I/D genotype

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COVID-19 infection is characterized by its prominent effect on specific ethnic group.

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SARS-CoV-2 cases/mortality were negatively associated with ACE1 II genotype.

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The ACE1 II genotype could be a predictive marker of SARS-CoV-2 risk and severity.

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) causes coronavirus disease 2019 (COVID-19). The relentless spread and pathogenicity of the virus have become a global public health emergency. One of the striking features of this pandemic is the pronounced impact on specific regions and ethnic groups. In particular, compared with East Asia, where the virus first emerged, SARS-CoV-2 has caused high rates of morbidity and mortality in Europe. This has not been experienced in past global viral infections, such as influenza, severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS) and is unique to SARS-CoV-2. For this reason, we investigated the involvement of genetic factors associated with SARS-CoV-2 infection with a focus on angiotensin-converting enzyme (ACE)-related genes, because ACE2 is a receptor for SARS-CoV-2. We found that the ACE1 II genotype frequency in a population was significantly negatively correlated with the number of SARS-CoV-2 cases. Similarly, the ACE1 II genotype was negatively correlated with the number of deaths due to SARS-CoV-2 infection. These data suggest that the ACE1 II genotype may influence the prevalence and clinical outcome of COVID-19 and serve as a predictive marker for COVID-19 risk and severity.

The Effect of ACE Gene Polymorphisms on Doppler Blood Flow Parameters of Carotid and Brachial Arteries in Patients With Myocardial Infarction

The authors investigated the relationship between the angiotensin-converting enzyme (ACE) insertion/deletion (I/D) polymorphism and the blood flow characteristics of common carotid (CCA) and brachial arteries (BA) by color Doppler ultrasound (CDUS) in patients with acute anterior myocardial infarction (AAMI). Sixty four patients (11 women and 53 men), aged 25 to 77 years, with AAMI were studied. The ACE genotypes were established. Peak-systolic (PSV) and end-diastolic velocity (EDV) of right and left CCA, PSV of right BA, and intimal-medial thickness (IMT) of both CCAs were measured by CDUS. All results were evaluated statistically. The ACE genotypes were distributed as follows: 43.8% DD, 43.8% ID, and 12.5% II. PSVs of BA and both CCAs were lower in patients with DD and ID than with II (p<0.05). EDVs of both CCAs were also lower in the same groups, but statistically not significant (p>0.05). IMTs of both CCAs did not differ among patients with various ACE genotypes (p>0.05). These results suggest that ACE I/D polymorphism influences Doppler blood flow parameters of both BA and CCA, but does not affect IMT of CCA.

Endothelial function and germ-line ACE I/D, eNOS and PAI-1 gene profiles in patients with coronary slow flow in the Canakkale population: multiple thrombophilic gene profiles in coronary slow flow

Background

We examined the effects of ACE, PAI-1 and eNOS gene polymorphisms on endothelial function. The genes are related to atherosclerosis and endothelial dysfunction in coronary slow flow (CSF).

Methods

Thirty-three patients with angiographically proven CSF and 48 subjects with normal coronary flow were enrolled in this study. Coronary flow patterns were determined by the thrombolysis in myocardial infarction (TIMI) frame count method. Endothelial function was assessed in the brachial artery by endothelium-dependent flow-mediated dilatation (FMD). PAI-1 4G/5G, eNOS T-786C and ACE I/D polymorphisms were determined by polymerase chain reaction (PCR) amplification.

Results

No difference was found between the groups regarding age, heart rate and blood pressure. Males were more prevalent among patients with CSF than control subjects (58.8 vs 29.8%, p = 0.009). Mean TIMI frame counts were significantly higher in CSF patients (24.2 ± 4.0 vs 13.1 ± 2.5 fpm, p = 0.001). FMD was significantly lower in CSF patients than in the controls (4.9 ± 6.6 vs 7.9 ± 5.6%, p = 0.029). TIMI frame count and FMD were found to be negatively correlated in a correlation analysis (r = –0.269, p = 0.015). PAI-1 4G/5G, eNOS T-786C and ACE I/D polymorphisms were similar in the two groups.

Conclusions

This study showed that endothelial function was impaired in patients with CSF. PAI-1, ACE and eNOS polymorphisms were not related to CSF in our study population.

Carotid intima-media thickness as a surrogate marker of cardiovascular disease in diabetes

BACKGROUND

Diabetes mellitus is associated with a high risk of cardiovascular disease. Carotid intima-media thickness (CIMT) is increasingly used as a surrogate marker for atherosclerosis. Its use relies on its ability to predict future clinical cardiovascular end points.

METHODS

This review examines the evidence linking CIMT as a surrogate marker of vascular complications in people with type 1 and type 2 diabetes. We have also reviewed the various treatment strategies which have been shown to influence CIMT.

CONCLUSIONS

CIMT measurement is an effective, noninvasive tool which can assist in identifying people with diabetes who are at higher risk of developing microvascular and macrovascular complications. It may also help to evaluate the effectiveness of various treatment strategies used to treat people with diabetes.

C-C chemokine receptor 2 expression by circulating monocytes influences atherosclerosis in patients on chronic hemodialysis

Mortality from cardiovascular or cerebrovascular disease due to atherosclerosis is increased in patients on chronic hemodialysis. Monocyte chemoattractant protein-1 and its receptor, C-C chemokine receptor 2, play an important role in recruiting monocytes to atherosclerotic lesions. The relationship between atherosclerosis in hemodialysis patients and C-C chemokine receptor 2 expression is unknown. Fifty-six patients on chronic hemodialysis and 27 age- and sex-matched controls were enrolled. Serum levels of monocyte chemoattractant protein-1 and expression of C-C chemokine receptor 2 by circulating monocytes were determined. Atherosclerosis was evaluated from the carotid intima-media thickness and cardio-ankle vascular index. Serum levels of monocyte chemoattractant protein-1 and expression of C-C chemokine receptor 2 by monocytes were significantly higher in the hemodialysis patients than the controls. Multiple regression analysis showed a positive correlation between receptor expression and both indexes of atherosclerosis. C-C chemokine receptor 2 expression by circulating monocytes influences atherosclerosis in patients on chronic hemodialysis.

Effects of age, genes, and pulse pressure on executive functions in healthy adults

Executive functions (EF) evidence significant age-related declines, but the mechanisms underpinning those changes are unclear. In this study, we focus on two potential sources of variation: a physiological indicator of vascular health, and genetic variants related to vascular functions. In a sample of healthy adults (n=158, ages 18-81), we examine the effects of age, pulse pressure, and two polymorphisms (comt val158met and ace insertion/deletion) on working memory and cognitive flexibility. Results indicate that in addition to often-replicated age differences, the alleles of two polymorphisms that promote vasoconstriction (comt val and ace D) and reduced availability of dopamine in neocortical synapses (comt val), negatively impact virtually all aspects of EF tasks that involve working memory. In some cases, suppression of cognitive performance is limited to men or necessitates a combination of both risk-associated alleles. After accounting for genetic and age-related variation, pulse pressure had no additional effect on EF. These findings suggest that in healthy adults, the effects of genetic risk factors significantly modulate the course of cognitive aging.

The geographic distribution of the ACE II genotype: a novel finding

Angiotensin converting enzyme (ACE) gene polymorphism insertion (I) or deletion (D) has been widely studied in different populations, and linked to various functional effects and associated with common diseases. The purpose of the present study was to investigate the relationship between the ACE I/D frequency in different populations and geographic location; ACE I/D allele frequency in the Lebanese population and ACE II genotype contribution to the geographic trend were also identified. Five hundred and seventy healthy volunteers were recruited from the Lebanese population. Genomic DNA was extracted from buccal cells, and amplified by polymerase chain reaction; products were then identified by gel electrophoresis. The frequencies of the different ACE I/D genotypes were determined and tested for Hardy-Weinberg equilibrium (HWE). To assess the relationship between ACE I/D frequency and geographic location, and to identify how the Lebanese population contributes to the geographic trend in ACE I/D frequencies, Eurasian population samples and Asians were incorporated in the analyses from the literature. The frequency of the I allele in the Lebanese population was 27% and the corresponding II genotype was at a frequency of 7.37% (in HWE; P=0.979). The ACE I allele and genotype frequencies show an association with longitude, with frequencies increasing eastwards and westwards from the Middle East.

Small dense low-density lipoprotein cholesterol concentration and carotid atherosclerosis

Low-density lipoprotein cholesterol (LDL-C) and the small dense LDL (SdLDL) phenotype are both predictors for ischemic heart disease. We examined whether cholesterol of SdLDL (SdLDL-C) is more closely associated with carotid artery intima-media thickness (CA-IMT), a surrogate measure of atherosclerosis, than LDL-C and other lipid parameters. The subjects were 326 consecutive participants including those with dyslipidemia, diabetes mellitus, hypertension, chronic kidney disease, and smokers. SdLDL-C was quantified by a newly developed precipitation method, and CA-IMT by high-resolution B-mode ultrasound. In univariate analysis, CA-IMT was most strongly correlated with SdLDL-C (Spearman's r=0.441, P<0.001), followed by apolipoprotein (apo) B, LDL-C, non-high-density lipoprotein cholesterol (Non-HDL-C), and plasma triglycerides (TG). HDL-C and apo A-I correlated inversely with CA-IMT. Non-lipid variables that were associated with CA-IMT were age, sex, presence of diabetes mellitus, presence of hypertension, estimate glomerular filtration rate (eGFR), and C-reactive protein (CRP). Even after adjustment for age, sex, diabetes mellitus, hypertension, smoking, eGFR and CRP, the positive association of CA-IMT with SdLDL-C remained significant, and again stronger than the associations with others lipid parameters. Further analyses revealed that the level of SdLDL-C was elevated in subgroups of the subjects including men, older subjects, smokers, those with higher CRP levels, those with diabetes mellitus, and hypertensive patients. These results indicate that SdLDL-C was the best marker of carotid atherosclerosis among the lipid parameters tested, and suggest that quantitative measurement of SdLDL-C gives useful information in the risk assessment for atherosclerotic disease.

Polymorphisms and the expression of genes encoding enzymes involved in cardiovascular diseases

BACKGROUND

Atherosclerosis, a multi-factorial disease, is the main determinant of cardiovascular disease (CVD) leading to high mortality and morbidity in westernized countries. Gene polymorphisms and gene expression related to the atherosclerosis process can be identified using a genome-wide approach or looking for candidate disease-causing genes.

METHODS

Using genome wide strategy or candidate gene approach various genes, including paraoxonase genes, which are involved in lipid metabolism, oxidation, inflammation and coagulation, have been associated to atherosclerosis.

CONCLUSION

Evaluation of gene polymorphisms, together with traditional and novel biochemical parameters, may help identify individuals at a high risk for CVD. Genetic characterization of susceptibility genes may also lead to new drugs for atherosclerosis prevention and treatment. In addition, gene expression studies can provide novel insights into the molecular mechanism of lesion development and progression.

Long-term trandolapril treatment is associated with reduced aortic stiffness: the prevention of events with angiotensin-converting enzyme inhibition hemodynamic substudy

The Prevention of Events with Angiotensin Converting Enzyme inhibition (PEACE) trial evaluated angiotensin-converting enzyme inhibition with trandolapril versus placebo added to conventional therapy in patients with stable coronary disease and preserved left ventricular function. The PEACE hemodynamic substudy evaluated effects of trandolapril on pulsatile hemodynamics. Hemodynamic studies were performed in 300 participants from 5 PEACE centers a median of 52 months (range, 25 to 80 months) after random assignment to trandolapril at a target dose of 4 mg per day or placebo. Central pulsatile hemodynamics and carotid-femoral pulse wave velocity were assessed by using echocardiography, tonometry of the carotid and femoral arteries, and body surface transit distances. Patients randomly assigned to trandolapril tended to be older (mean+/-SD: 64.2+/-7.9 versus 62.9+/-7.7 years; P=0.14), with a higher body mass index (28.5+/-4.0 versus 27.8+/-3.9 kg/m(2); P=0.09) and lower ejection fraction (57.1+/-8.1% versus 58.7+/-8.4%; P<0.01). At the time of the hemodynamic substudy, the trandolapril group had lower mean arterial pressure (93.1+/-10.2 versus 96.3+/-11.3 mm Hg; P<0.01) and lower carotid-femoral pulse wave velocity (geometric mean [95% CI]: 10.4 m/s [10.0 to 10.9 m/s] versus 11.2 m/s [10.7 to 11.8 m/s]; P=0.02). The difference in carotid-femoral pulse wave velocity persisted (P<0.01) in an analysis that adjusted for baseline characteristics and follow-up mean pressure. In contrast, there was no difference in aortic compliance, characteristic impedance, augmentation index, or total arterial compliance. Angiotensin-converting enzyme inhibition with trandolapril produced a modest reduction in carotid-femoral pulse wave velocity, a measure of aortic wall stiffness, beyond what would be expected from blood pressure lowering or differences in baseline characteristics alone.

Early sign of atherosclerosis in slow coronary flow and relationship with angiotensin-converting enzyme I/D polymorphism

Increase in carotid artery intima-media thickness (IMT) is an early sign of atherosclerosis. Slow coronary flow (SCF) is characterized by delay of opacification of coronary arteries in coronary angiography in the absence of any evident obstructive lesion, but its etiopathogenesis remains unclear. Genes that regulate the renin angiotensin system also play a role in developing cardiovascular system disorders. The presence of deletion (D) allele in angiotensin converting enzyme (ACE) gene polymorphism is associated with coronary artery disease. The aim of this study was to investigate the carotid artery IMT measurement, as an early sign of atherosclerosis, in patients with SCF and without SCF and also to assess the effect of the renin-angiotensin gene system on carotid IMT. Forty-four patients with angiographically proven SCF and 44 cases with normal coronary flow (NCF) pattern with similar risk profile were enrolled in the study. Coronary flow patterns of the cases were determined by thrombolysis in myocardial infarction (TIMI) frame count method. Intima-media thickness was measured by recording ultrasonographic images of both the left and right common carotid artery with a 12-MHz linear array transducer. ACE I/D polymorphism and Angiotensin II tip 1 receptor (AT1R) A/C gene polymorphism were determined by polymerase chain reaction (PCR) amplification. Demographic characteristics and coronary artery disease risk factors of SCF and NCF groups were similar. Mean TIMI frame count and carotid IMT (mm) were significantly higher in the SCF group than controls (45.9 +/- 12 vs 23.3 +/- 3.7, P = 0.0001; 0.75 +/- 0.08 vs 0.69 +/- 0.06, P = 0.0001, respectively). Mean TIMI frame count was positively correlated with IMT of carotid artery in correlation analysis (r = 0.45, P = 0.0001). When analyzed in regard to ACE genotype in all subjects, IMT values were statistically different (0.78 +/- 0.06 for DD genotype, 0.72 +/- 0.05 for ID genotype, and 0.64 +/- 0.06 for II genotype, P = 0.0001). This difference remained significant in subgroup analyses for each genotype. No association could be observed between the AT1R A/C(1166) polymorphism and IMT of carotid artery measurement (P > 0.05). Lack of association was still observed with analysis carried out when genotype effect was assumed to be inherited as additive (CC versus AA versus AC) or dominant (AA versus AC+CC). Increased IMT in patients with SCF shows that subclinical atherosclerosis may play role in this phenomenon. This increase was most marked in the presence of D allele of ACE genotype, which is associated with vascular hypertrophy.

Association between plasma angiopoietin-like protein 3 and arterial wall thickness in healthy subjects

BACKGROUND

Angiopoietin-like protein 3 (ANGPTL3) is a liver-derived plasma protein that modulates plasma triglyceride clearance, angiogenesis and atherosclerosis in experimental models. So far, no study has examined its role in atherosclerosis in human subjects. We evaluated the possible association between plasma ANGPTL3 level and carotid artery intima-media thickness (CA-IMT) and femoral artery intima-media thickness (FA-IMT) in healthy human subjects.

METHODS

The subjects were 381 healthy volunteers. Plasma ANGPTL3 was determined by a specific ELISA. CA-IMT and FA-IMT were measured by high-resolution B-mode ultrasonography.

RESULTS

The plasma ANGPTL3 level was 764 +/- 291 ng/ml (mean +/- SD). CA-IMT showed a significant positive correlation with plasma ANGPTL3 and other classical risk factors such as age, blood pressure, and plasma glucose and lipid levels. The positive association between ANGPTL3 and CA-IMT remained significant after adjustment for age, sex, smoking, body mass index, systolic blood pressure, plasma glucose, insulin resistance index, triglyceride, and high-density and low-density lipoprotein cholesterol levels. ANGPTL3 also showed a positive association with FA-IMT independent of these factors.

CONCLUSIONS

These results demonstrate for the first time that ANGPTL3 is closely associated with arterial wall thickness in human subjects.

Regional arterial stiffness associated with ischemic heart disease in type 2 diabetes mellitus

Arterial stiffness is increased in type 2 diabetes mellitus, and diabetes preferentially affects arterial stiffness of the central (elastic, capacitive) over peripheral (muscular, conduit) arteries. We hypothesized that arterial stiffness of the central artery may be more closely associated with ischemic heart disease (IHD) than stiffness of peripheral arteries in type 2 diabetes mellitus. The subjects were 595 type 2 diabetes patients including 70 with IHD. Arterial stiffness was measured as pulse wave velocity (PWV) in the heart-carotid, heart-femoral, heart-brachial, and femoral-ankle regions. The PWV values of the four segments correlated with each other in patients without IHD. However, the correlations were less impressive in those with IHD, suggesting unequal stiffening of regional arteries in IHD. As compared with patients without IHD, the IHD group showed significantly higher PWV values of the four arterial segments, particularly of the heart-femoral region. The presence of IHD was significantly associated with higher heart-femoral PWV, and this association remained significant and independent of other factors in a multiple logistic regression analysis. Pulse pressure was more strongly correlated with PWV of the heart-femoral than other arterial regions. Thus, diabetic patients with IHD have increased stiffness of arteries, particularly of the aorta, supporting the concept that central arterial stiffness plays an important role in the development of IHD.

Polymorphism of the angiotensin-converting enzyme (ACE) and angiotesinogen (AGT) genes and their associations with blood pressure and carotid artery intima media thickness among healthy Finnish young adults--the Cardiovascular Risk in Young Finns Study

The roles of angiotensin converting enzyme (ACE) insertion-deletion (I/D) and angiotensinogen (AGT) m235t polymorphisms in cardiovascular diseases have been investigated extensively during the past decade but results have been inconsistent. A sex-specific association between the ACE I/D polymorphism and systolic blood pressure (BP) was seen among Finnish children and adolescents previously. We investigated if these polymorphisms associate with the BP and carotid artery intima media thickness (IMT) in the same cohort during their adulthood. IMT data were available for 224 ACE I/D genotyped individuals and 202 AGT m235t genotyped individuals. Systolic and diastolic blood pressure values did not differ between ACE and AGT genotypes. Age and BMI adjusted mean IMT was 0.02 (95% CI: -0.05 to 0.02, p=0.33) and 0.03 mm (95% CI: -0.07 to 0.001, p=0.06) lower among the ID and DD genotype groups, respectively, compared to the II genotype group. MT and TT genotype groups had 0.02 mm (95% CI: -0.01 to 0.05, p=0.17) higher and 0.01 mm (95% CI: -0.04 to 0.02, p=0.59) lower mean IMT, respectively, compared to the MM genotype group. We conclude that ACE I/D and AGT m235t polymorphisms are not associated with carotid IMT in healthy young Finnish adults.

Plasma levels of adiponectin and soluble thrombomodulin in hypothyroid patients with normal thyroid function following levothyroxine replacement therapy

Hypothyroidism is associated with increased morbidity from cardiovascular disease, and adiponectin (ApN) is a newly-identified adipocytokine, which is expressed in human adipose cells and may have a protective effect against the development of coronary artery disease. The aim of the study was to evaluate the involvement of ApN secretion in hypothyroid patients with normal thyroid function following levothyroxine (L-T(4)) replacement therapy, and to associate plasma ApN levels with intima-media thickness (IMT) in the common carotid artery (CCA), an indicator of early atherosclerosis, and cardiovascular parameters including soluble thrombomodulin (sTM), a plasma endothelial injury marker. The CCA IMT and plasma levels of ApN and sTM were measured in 52 hypothyroid patients and in age-, sex- and body mass index (BMI)-matched normal control subjects. Thirty-six of the hypothyroid patients were further monitored for changes in these markers during 1 year in a euthyroid state induced by L-T(4) replacement therapy. Although the basal CCA IMT was significantly higher in hypothyroid patients [0.633 +/- 0.018 mm (mean +/- S.E.)] than in control subjects (0.552 +/- 0.022 mm, P < 0.005), both groups had similar baseline ApN and sTM levels [10.23 +/- 0.76 vs. 10.10 +/- 0.93 microg/ml: NS; and 2.58 +/- 0.14 vs. 2.68 +/- 0.20 ng/ml: NS, respectively]. Simple regression analysis revealed that plasma ApN was significantly correlated in a positive manner with age (r = 0.339, P = 0.015), HDL-cholesterol (r = 0.295, P = 0.048), and sTM (r = 0.490, P = 0.0005), but not with CCA IMT (r = 0.059, P = 0.742). In multivariate analysis, the plasma ApN level was significantly associated with that of sTM (r = 0.546, P = 0.0001) and with serum high-density lipoprotein (HDL)-cholesterol levels (r = 0.291, P = 0.029) in hypothyroid patients. During 1 year of L-T(4) replacement therapy, hypothyroid patients showed a significant decrease in CCA IMT, to 0.553 +/- 0.016 mm (P < 0.0001), a level comparable to normal controls, but no significant change in ApN (from 10.79 +/- 1.07 to 10.6 9+/- 1.14 microg/ml, NS) or sTM (from 2.59 +/- 0.15 to 2.74 +/- 0.18 ng/ml, NS). Hence, we provide evidence that ApN and sTM might not contribute to enhanced atherosclerosis, as reflected by increased CCA IMT in hypothyroid patients. However, this is the first report to demonstrate a positive and significant association of sTM with ApN. These data support the hypothesis that sTM is one of the determinant of ApN and thus suggest the presence of an sTM-associated regulatory mechanism for ApN secretion in hypothyroid patients.

Associations between physical activity, peripheral atherosclerosis and bone status in healthy Japanese women

The aim of this cross-sectional study was to investigate whether physical activity and bone status may affect arterial thickening and stiffening in healthy Japanese women. Healthy women (n = 149; mean age, 54 years) were recruited from those who participated in a local health check program at the Osaka City University Hospital. Physical activity was assessed by physical functioning score of SF-36, and bone status by bone mineral density (BMD) in lumbar spine and calcaneus osteo-sono index (OSI). Arterial wall thickening assessed by intima-media thickness (IMT) in common carotid artery (CA) and femoral artery (FA), and arterial wall stiffening by peak wave velocity (PWV) in heart-carotid (hc) and heart-femoral (hf) as central segment and in heart-brachial (hb) and femoral-ankle (fa) as peripheral segment, respectively. By Spearman Rank correlation, lumbar spine BMD was correlated negatively with CA IMT (rho = -0.225, p < 0.05) and FA IMT (rho = -0.215, p < 0.05), and calcaneus OSI with FA IMT (rho = -0.330, p < 0.0001) but not CA IMT (rho = -0051, p = 0.5335). Both lumbar spine BMD and calcaneus OSI correlated negatively with PWV in all segments (all p < 0.05). Physical functioning score correlated weakly but significantly in a negative manner with all PWV segments (all p < 0.05) but not IMT. Multiple regression analyses revealed a significant association of calcaneus OSI (beta = -0.240, p = 0.0039) but not lumbar spine BMD (beta = -0.067, p = 0.4541) with FA IMT, although neither lumbar spine BMD nor calcaneus OSI was associated with CA IMT. Furthermore, physical functioning score was independently associated with hb and fa PWV but not hc and hf PWV, suggesting the preferential association with peripheral segment including lower extremities. Neither lumbar spine BMD nor calcaneus OSI was associated with any segment of PWV. In conclusion, it was suggested that calcaneus OSI might be associated with arterial wall thickening preferentially in femoral artery, and that physical activity may be associated with arterial wall stiffening in peripheral segment including lower extremity but not in central segment in healthy Japanese women.

Cross-sectional association of serum phosphate with carotid intima-medial thickness in hemodialysis patients

BACKGROUND

Although an increased serum phosphate concentration is a significant risk factor for vascular calcification, it is unclear whether serum phosphate level is a risk factor for increased arterial wall thickness in hemodialysis patients.

METHODS

Using B-mode ultrasonography, we examined intima-medial thickness (IMT) of the carotid artery of hemodialysis patients and analyzed risk factors for increased IMT with regard to the effect of serum phosphate. Seven hundred sixteen hemodialysis patients were enrolled (547 patients without diabetes, 169 patients with diabetes; 441 men, 275 women; age, 60 +/- 8.5 years).

RESULTS

IMT of patients with diabetes was significantly greater than that of patients without diabetes (0.859 +/- 0.250 versus 0.783 +/- 0.178 mm; P < 0.0001). For the group of all patients, IMT correlated weakly, but significantly, with serum phosphate level (r = 0.093; P = 0.0127). In multiple regression analysis of the group of all patients, greater serum phosphate level (beta = 0.166; P < 0.0001) was shown to be a significant independent risk factor for increased carotid IMT, in addition to other significant independent risk factors, including advanced age, higher blood pressure, greater non-high-density lipoprotein cholesterol level, and the presence of diabetes (R2 = 0.1119; P < 0.00001). In multiple regression analyses performed separately for hemodialysis patients without and with diabetes, greater phosphate level and advanced age were significant independent risk factors for increased IMT, independent of other confounding risk factors.

CONCLUSION

These results show that in addition to advanced age, greater serum phosphate level is a significant and independent factor associated with advanced arteriosclerosis in hemodialysis patients with and without diabetes, suggesting that phosphate levels should be controlled appropriately to prevent an increase in arterial wall thickness in hemodialysis patients.

POLYMORPHISMS OF APOLIPOPROTEIN E AND ANGIOTENSIN-CONVERTING ENZYME GENES AND CAROTID ATHEROSCLEROSIS IN HEAVY DRINKERS

AIMS

To investigate the influence of apolipoprotein E (APOE) and angiotensin-converting enzyme (ACE) gene polymorphisms on carotid artery atherosclerosis in alcoholism.

METHODS

Polymorphism of both genes was identified by DNA analysis in 130 male alcohol-dependent patients. Intima-media thickness (IMT) was measured ultrasonographically.

RESULTS

Multivariate regression analysis showed that of all the known risk factors the greatest impact on carotid atherosclerosis in alcoholics was exerted by age, hypertension, LDL cholesterol and fasting plasma glucose levels. Subjects carrying the APO E epsilon4 allele were more liable to develop atherosclerotic changes in carotid arteries compared with subjects with the epsilon3/3 genotype, which showed statistical significance in patients under 50 years of age. No association was shown between ACE I/D polymorphism and carotid atherosclerosis.

CONCLUSIONS

APO E polymorphism can increase the risk of carotid atherosclerosis development in an alcoholic subject. The association of the APO E epsilon4 allele with carotid atherosclerosis was significant in younger patients. Since the elevated carotid IMT is considered to be a good marker of increased risk of generalized atherosclerosis the consequences could involve both cardiac and cerebrovascular events.

The genetics of stroke

PURPOSE OF REVIEW

Ischaemic stroke is a heterogeneous disease caused by different pathogenic mechanisms, of which small artery and large artery stroke are the most common. The identification of the genes involved is unclear. The likely candidate genes associated with stroke are those that are associated with matrix deposition (stromelysin-1, MMP3), inflammation (IL-6), and lipid metabolism (hepatic lipase, APOE, PON1) and clotting (factor V Leiden, fibrinogen).

RECENT FINDINGS

In this review we will only discuss those genes in which there has been a significant contribution to the understanding of stroke since October 2003.

SUMMARY

The published data were reviewed to determine the robustness of these associations and to examine whether there is any evidence of risk modification by factors such as smoking habit, known to be associated with stroke.

Significance of intima-media thickness in femoral artery in the determination of calcaneus osteo-sono index but not of lumbar spine bone mass in healthy Japanese people

The aim of this cross-sectional study was to investigate whether physical activity and local arterial thickening may affect bone metabolism. To analyze the effects of physical activity and atherosclerosis on bone in healthy Japanese people, health-related quality of life (HRQL) and local arterial thickening were assessed by means of the Medical( )Outcomes Study 36-item Short Form (SF-36), and intimal-medial thickness (IMT) in common carotid artery (CA) and femoral artery (FA), respectively. Bone mineral density (BMD) in lumbar spine was measured by dual X-ray absorptiometry and the osteo-sono assessment index (OSI) of the calcaneus by ultrasound. Healthy subjects (106 male and 154 female) were recruited from those who participated in a local health check program at the Osaka City University Hospital. A significant correlation existed between lumbar spine BMD and calcaneus OSI (r=0.551, P<0.0001). Among various scores in SF-36, only physical functioning score correlated weakly but significantly in a positive manner with lumbar spine BMD (rho=0.156, P=0.0147) and calcaneus OSI (rho=0.190, P=0.0024). Lumbar spine BMD correlated negatively with FA IMT (rho=-0.191, P=0.0027) whereas calcaneus OSI with FA IMT (rho=-0.199, P=0.0014). Multiple regression analyses revealed a significant association between FA IMT and calcaneus OSI, whereas lumbar spine BMD did not correlate significantly with FA or CA IMT. When subjects were restricted to female, FA IMT, but not CA IMT, still showed tendency against independent factors negatively associated with calcaneus OSI. Furthermore, lumbar spine BMD, but not calcaneus OSI, was weakly but significantly associated with increased physical functioning score independently. In conclusion, it was suggested that physical activity may affect bone strength in lumbar spine and calcaneus and that FA IMT might be a significant determinant of bone strength in calcaneus, but not in lumbar spine, in healthy Japanese subjects.

Decrease of arterial stiffness at common carotid artery in hypothyroid patients by normalization of thyroid function

This study examined the effect of hypothyroidism on arterial stiffening and the effect of levothyroxine (l-T(4)) replacement. The arterial stiffness index beta (stiffness beta) and intima-media thickness (IMT), a parameter of arterial stiffening and thickening, respectively, were determined in common carotid artery (CCA) by ultrasonography in 30 hypothyroid patients before and after 1 year of normalization of thyroid function by l-T(4) replacement. Baseline CCA stiffness beta and IMT was significantly higher in the hypothyroid patients than in age- and sex-matched normal controls [9.46 +/- 0.93 vs. 8.02 +/- 0.91 (mean +/- SE); P < 0.05, 0.635 +/- 0.018 mm vs. 0.541 +/- 0.019 mm; P < 0.005, respectively]. In multivariate analysis, baseline stiffness beta was significantly associated with baseline levels of IMT (r = 0.457, P = 0.0311), FT(4) (r = -0.413, P = 0.0169), and a plasma vascular injury marker, von Willebrand factor (vWF) (r = 0.412, P = 0.0261). During 1 year of euthyroidism, 22 and 29 out of 30 patients showed significant decreases of stiffness beta and IMT to normal respective level, from 9.46 +/- 0.93 to 7.58 +/- 0.34 and from 0.635 +/- 0.018 to 0.552 +/- 0.015 mm, respectively. Change in stiffness beta during l-T(4) therapy correlated significantly in a negative manner with baseline levels of age (r = -0.465, P = 0.011) and IMT (r = -0.406, P = 0.029). Stiffness beta after but not before l-T(4) therapy showed a tendency towards a positive correlation with age. This study suggested that increases of arterial thickening, and plasma vWF, and a reduction in serum FT(4) might have an important role independently in the increased arterial stiffening in hypothyroid patients. Furthermore, it was demonstrated that sustained euthyroidism might have the potential to reverse arterial stiffening in addition to thickening in hypothyroid patients.

Genetic risk factors for stroke and carotid atherosclerosis: insights into pathophysiology from candidate gene approaches

Ischaemic stroke is the most common form of stroke and is caused by atherosclerosis in most patients. Several genetic determinants contribute to stroke risk. Of these, carotid intimal-medial wall thickness (IMT) is particularly relevant, because it is a surrogate measure of subclinical atherosclerosis and a strong predictor of future ischaemic stroke. Studies of twins, siblings, and families have provided significant evidence for heritability, but the genes involved have not been identified. Some researchers have reported that IMT is high in people with functional variants of genes related to matrix deposition (MMP3), inflammation (interleukin 6), and lipid metabolism (hepatic lipase, APOE, CETP, and PON1). In this review, we assess the robustness of these associations and examine whether there is any evidence of risk modification by factors, such as smoking.

Arterial wall thickness is associated with insulin resistance in type 2 diabetic patients

The aim of the present study was to investigate the independent association of the intimal-medial thickness of carotid and femoral arteries (CA-IMT and FA-IMT), a marker of atheroscelosis, with insulin resistance in type 2 diabetic patients. We evaluated CA-IMT and FA-IMT by high-resolution ultrasonography and insulin resistance determined by euglycemic hyperinsulinemic clamp in 119 type 2 diabetic subjects, 71 males and 48 females (age, 54 +/- 12 (SD) years). In simple regression analyses, CA-IMT and FA-IMT were significantly inversely correlated with insulin sensitivity index (CA-IMT, r = -0.225, p = 0.010; FA-IMT, r = -0.186, p = 0.043, respectively). Multiple regression analysis was performed with the logarithm of CA-IMT or FA-IMT as a dependent variable and insulin sensitivity index as an independent variable along with known clinical risk factors. Insulin sensitivity index exhibited a significant independent contribution to log (CA-IMT) (beta = -0.204, p = 0.033) and to log (FA-IMT) (beta = -0.237, p = 0.010) in these models (CA-IMT, R(2) = 0.347, p < 0.0001; FA-IMT, R(2) = 0.398, p < 0.0001, respectively). In conclusion, insulin resistance is associated with both CA-IMT and FA-IMT in type 2 diabetic patients, suggesting that it is an independent risk factor for the development of atherosclerosis in type 2 diabetes.

A study of gene--environment interaction on the gene for angiotensin converting enzyme: a combined functional and population based approach

INTRODUCTION

Studies on the role of the insertion/deletion (I/D) polymorphism of the gene coding for angiotensin converting enzyme (ACE) in atherosclerosis have been inconsistent. In a meta-analysis, we recently showed that this relationship is stronger in high risk populations. In this paper, we used a combined functional and population based approach to investigate the gene-environment interaction of the ACE I/D polymorphism in relation to carotid artery wall thickness.

METHODS

The study was part of the Rotterdam Study, a prospective population based cohort study. In 5321 subjects, IMT was measured in the carotid arteries by ultrasonography and ACE genotype was determined by size analysis of polymerase chain reaction products.

RESULTS

In multiple regression analysis, I/D polymorphism and smoking were the main determinants for plasma ACE activity (r(2) = 0.28). There was a positive association between the D allele of the I/D polymorphism and carotid artery thickness among current smokers (p = 0.03). Subjects carrying only one of the risk factors (smoking or the D allele) did not show significant differences in IMT compared with the non-/former smokers group carrying two II alleles, while carriers of both risk factors had significant higher IMT. The association was not present in non-/former smokers.

DISCUSSION

The results provide further evidence that genetic and environmental factors interact in the formation of the arterial lesions. This study shows that large population based studies can be extremely helpful in unravelling the genetic origin of complex diseases such as atherosclerosis.

Inflammation and bone resorption as independent factors of accelerated arterial wall thickening in patients with rheumatoid arthritis

OBJECTIVE

We recently reported that rheumatoid arthritis (RA) patients had increased intima-media thickness (IMT) of the common carotid artery (CCA). The present longitudinal study was performed to determine whether the change in arterial thickness was accelerated in RA patients and to determine which factor was important in the progression of arterial wall changes.

METHODS

We studied 62 female RA patients with stable disease activity and 63 healthy female controls. IMT of the CCA was measured twice by high-resolution B-mode ultrasonography. The second examination was performed 18-36 months after the first, and changes were expressed as millimeters of increase per year. Baseline examinations included blood markers of inflammation and urinary calcium excretion (expressed as the calcium-to-creatinine ratio).

RESULTS

RA patients showed a significantly greater increase in IMT of the CCA compared with controls. In univariate analyses of the RA patient data, the C-reactive protein (CRP) level correlated with the increase in CCA IMT. Other markers of inflammation (the erythrocyte sedimentation rate and white blood cell and platelet counts) also showed significant positive associations with the annual increase in CCA IMT in multiple regression models when adjusted for age, smoking status, blood pressure, and serum cholesterol level. The urinary calcium-to-creatinine ratio was also significantly associated with an increase in CCA IMT. Moreover, both the CRP level and the urinary calcium-to-creatinine ratio were significantly and independently associated with the increase in IMT of the CCA.

CONCLUSION

Patients with RA have a higher rate of increase in thickening of the arterial wall. Inflammation and calcium mobilization are factors closely associated with the accelerated arterial wall changes.

Decrease in carotid intima-media thickness in hypothyroid patients after normalization of thyroid function

OBJECTIVE

This case-control study was carried out to assess whether levothyroxine (L-T4) replacement might cause regression of the enhanced atherosclerosis seen in hypothyroid patients.

PATIENTS AND METHODS

Intima-media thickness (IMT) in the common carotid artery (CCA) was measured from digitalized still images taken during scanning by high-resolution ultrasonography as an indicator of early atherosclerosis. Thirty-five hypothyroid patients were examined for their CCA IMT before and 1 year after normalization of thyroid function by L-T4 replacement. As control, 35 healthy subjects were enrolled from among the participants in a local health-check programme conducted at the Osaka City University Hospital.

RESULTS

Basal CCA IMT was significantly higher in hypothyroid patients [0.635 +/- 0.018 (mean +/- SE) mm] than in control subjects (0.559 +/- 0.021 mm, P < 0.005). After 1 year of euthyroidism, 34 out of 35 patients showed a significant decrease of CCA IMT, to 0.552 +/- 0.015 mm (P < 0.0001), a level comparable to normal controls. CCA IMT change was closely associated with basal levels of total cholesterol (r = -0.472, P= 0.0031), low-density lipoprotein (LDL) cholesterol (r = -0.441, P= 0.0076) and the total/HDL cholesterol ratio (r =-0.435, P= 0.0057), but not with any of the other variables measured except for age (r = -0.353, P= 0.0296).

CONCLUSIONS

This study demonstrated that L-T4 treatment might have the potential to reverse the progression of atherosclerosis in hypothyroid patients. Furthermore, it suggests that increased levels of LDL cholesterol and the total/HDL cholesterol ratio have an important role in the increased common carotid intima-media thickness in hypothyroid patients.

Genetics of intima-media thickness

PURPOSE OF REVIEW

Increased carotid artery intima-media thickness is associated with an increased risk of coronary heart disease or cerebrovascular disease and is a powerful predictor of cardiovascular and cerebrovascular outcomes. Consequently, the measurement is now used in a number of case control, cohort and familial and linkage studies as an intermediate phenotype for the investigation of the genetic and environmental determinants of atherosclerosis. The aim of this paper is to review the most recent available data on the genetic determinants of carotid intima-media thickness.

RECENT FINDINGS

Genes could account for a significant amount of variation in carotid intima-media thickness: up to 30-66%. Carotid intima-media thickness progressed more rapidly with age in familial hypercholesterolemia patients than in patients without his condition. Familial hypercholesterolemia patients with a null LDL receptor allele tended to have higher carotid intima-media thickness than patients carrying the LDL receptor defective allele. Small association studies showing positive or negative results with the angiotensinogen gene variants as well as with the angiotensin converting enzyme I/D polymorphism add to the confusion in this largely controversial area. Differing results may depend on the vascular territory and genetic background. New associations have been described in small studies.

SUMMARY

Studies on the association of polymorphisms and intima-media thickness are frequently disappointing and lead occasionally to conflicting results. Among study limitations is the fact that mostly single gene effects are considered; longitudinal cohort studies may be more appropriate than case control studies. Ongoing large prospective population studies and clinical trials have integrated the measurements of intima-media thickness and genotype determination with a genomic approach. As a result, in the near future we may see more important and robust results with significant consequences on our understanding of genetic determinants of atherosclerotic cardiovascular disease.

Effect of polymorphism of the endothelial nitric oxide synthase and apolipoprotein E genes on carotid atherosclerosis in hemodialysis patients

BACKGROUND

Decreased synthesis of nitric oxide (NO) and dyslipidemia are implicated in the development of atherosclerosis.

METHODS

We investigated the relationship between endothelial NO synthase (eNOS) gene polymorphism, apolipoprotein E (apoE) polymorphism, and carotid atherosclerosis in 163 hemodialysis patients with nondiabetic nephropathy. Intima media thickness of the carotid artery was measured by ultrasonography, and subjects were classified according to the presence or absence of carotid plaque. Multivariate odds ratios were calculated to assess the combined influence of several variables on the existence of carotid plaque, with clinical factors, the intron 4 polymorphism, T(-786)-->C polymorphism, and Glu298Asp polymorphism of eNOS and the apoE polymorphism tested as independent predictors. We also investigated the combined effect of these polymorphisms on risk for plaque.

RESULTS

The odds ratio for carotid plaque positivity was increased to 3.72 by the a allele of the intron 4 polymorphism and increased to 3.36 by the C allele of the T(-786)-->C polymorphism, but was not increased in subjects with the T allele of the Glu298Asp polymorphism or those with the epsilon4 allele of the apoE polymorphism. However, the odds ratio for plaque positivity was significantly increased to 4.00 by possession of the a allele and/or epsilon4 allele and also increased to 4.04 by the C allele and/or epsilon4 allele.

CONCLUSION

This cross-sectional study showed a synergistic effect between the intron 4 polymorphism or T(-786)-->C polymorphism of the eNOS gene and the apoE polymorphism with respect to risk for carotid atherosclerosis in nondiabetic hemodialysis patients.

Intima-media thickness of carotid artery predicts cardiovascular mortality in hemodialysis patients

BACKGROUND

Cardiovascular disease is the leading cause of death in patients with end-stage renal disease (ESRD). Previous studies showed that patients with ESRD had increased intima-media thickness of the carotid artery (CA-IMT). In the present study, we examined whether CA-IMT would predict cardiovascular mortality in patients with ESRD.

METHODS

The cohort consisted of 438 patients with ESRD treated with hemodialysis. CA-IMT was measured by high-resolution B-mode ultrasonography.

RESULTS

During the follow-up period of 30 months, 82 deaths, including 44 cardiovascular fatal events, occurred. Compared with those with CA-IMT less than 1.0 mm, those with moderately increased CA-IMT (1.0 to 2.0 mm) and those with severely increased CA-IMT (>or=2.0 mm) showed a significantly greater risk for death from cardiovascular causes; odds ratios were 3.17 (95% confidence interval [CI], 1.41 to 7.17; P = 0.005) and 10.20 (95% CI, 3.67 to 28.3; P < 0.0001), respectively, in a multivariate Cox analysis including age, sex, duration of hemodialysis therapy, presence of diabetes mellitus, blood pressure, body mass index, and high-density lipoprotein and non-high-density lipoprotein cholesterol levels as covariates. Conversely, CA-IMT was not significantly associated with noncardiovascular mortality.

CONCLUSION

These results indicate that increased CA-IMT is an independent predictor of cardiovascular mortality in the hemodialysis population.

An interaction between systolic blood pressure and angiotensin-converting enzyme gene polymorphism on carotid atherosclerosis

The insertion/deletion (I/D) polymorphism of the human angiotensin-converting enzyme (ACE) gene is a major determinant of circulating ACE activity, with the D allele being associated with higher ACE levels than the I allele. Thus, chronic exposure to high levels of circulating and tissue ACE may well predispose to vascular wall thickening and atherosclerosis. However, the effect of the ACE gene on carotid atherosclerosis remains controversial. We investigated the association between ACE gene I/D polymorphism and risk factor-dependent augmentation of carotid arterial remodeling in subjects with several risk factors for atherosclerosis. We evaluated sclerotic lesions of the common carotid artery with intima-media thickness (IMT) by ultrasonography in 184 patients (mean age +/- SD, 67 +/- 14 years old) and studied whether any risk factor-gene interactions were associated with carotid atherosclerosis. Out of the 184 subjects, 71 had the ACE II genotype, 87 the ID genotype and 26 the DD genotype. There was no significant difference in IMT among the three ACE genotypes. In total subjects, multiple regression analysis showed that age, total-cholesterol (T-C), and HDL-cholesterol (HDL-C) were significantly associated with IMT. However, the association between risk factors and IMT was genotype-specific. Systolic blood pressure (SBP) and HDL-C were significantly associated with IMT in ACE D carriers (DD+ID), but not in subjects with the ACE II genotype. Similarly, T-C was significantly associated with IMT only in subjects with the ACE II genotype. A general linear model of the interaction between the ACE genotype and the conventional risk factors showed that the SBP-ACE genotype interaction were significantly associated with IMT (F = 7.915; p = 0.005). This finding further supports the idea that analysis of risk factor-gene interaction could be a useful tool for deriving specific predictive information about the development of atherosclerosis.

Influence of hypertension and smoking as the single vascular risk factors on the intima-media thickness

In order to compare the extent of early carotid atherosclerosis between patients with single vascular risk factors (smoking = SMO or hypertension = HYP) and risk-free normal subjects (= HCS), we used intimal-medial wall thickness (IMT) measurements of the common carotid artery. The age- and sex-adjusted mean IMTs were significantly higher in the HYP and SMO groups than in the HCS control group (p < 0.005 and p < 0.001, respectively). The estimated yearly progression rate of IMT (average difference in IMT/year age difference) was significantly higher in the HYP and SMO groups than in the HCS group (p < 0.05). In the total group, the age, hypertension, smoking and sex accounted for 52% of the variability of IMT. Our results show that the estimated yearly progression rate of IMT is slower in healthy and risk-free volunteers than previously detected and that the smoking and hypertension have a similar effect to the progression of early atherosclerosis. This also emphasises the influence of smoking in initial vascular remodelling process.

Carotid and femoral intima-media thickness in relation to three candidate genes in a Caucasian population

BACKGROUND

In a Caucasian population, the prevalence and incidence of hypertension, renal function and large artery stiffness were significantly correlated with polymorphisms in the genes encoding the angiotensin-converting enzyme (ACE I/D), aldosterone synthase (-C344T) and the cytoskeleton protein alpha-adducin (Gly460Trp).

OBJECTIVE

This study investigated intima-media thickening, a precursor of atherosclerosis, in relation to these genetic polymorphisms.

METHODS

Carotid and femoral intima-media thickness were assessed with a wall-track system in 380 subjects enrolled in a population study. Subjects were genotyped for the presence of the ACE D, aldosterone synthase -344T and alpha-adducin 460Trp alleles. The statistical analysis allowed for confounders, interactions among genes, and the non-independence of the phenotypes within families.

RESULTS

The sample included 188 men (49.5%). Mean age was 39.8 years. Intima-media thickness of the carotid and femoral arteries averaged 575 and 719 microm, respectively. Intima-media thickness of the femoral-but not carotid-artery increased with the number of ACE D alleles. The effect of ACE genotype on femoral intima-media thickness was confined to carriers of the 460Trp allele and the -344T allele. Expressed as a percentage of the population mean, the mean differences between II and DD homozygotes averaged 13.4% (95% CI 5.6-21.2%) in all subjects, 21.2% (8.0-34.5%) in carriers of the 460Trp allele, 15.4% (4.1-26.8%) in carriers of the -344T allele, and 25.2% (10.7-39.7%) if the 460Trp and -344T alleles were both present.

CONCLUSION

This study shows that a relationship exists between the intima-media thickness of the large muscular femoral artery and the ACE gene. This relationship is only apparent in the presence of either the alpha-adducin 460Trp or the aldosterone synthase -344T allele. These findings may have clinical implications for the assessment of genetic cardiovascular risk.

Genetic aspects of stroke: human and experimental studies

As one of the leading causes of death within both the developed and developing world, stroke is a worldwide problem. Risk factors can be identified and controlled at the level of lifestyle changes; however, genetic components of stroke have yet to be identified. The identification of such genetic components is critical in the understanding, diagnosis, and treatment of stroke in the future. This review focuses on the genetic determinants of stroke in both human and experimental systems. Mendelian disorders, candidate genes, and twin studies provide evidence for a strong genetic component of stroke. Genome-wide scanning in both human and animal models has led to the identification of regions of the genome that contain genes for stroke susceptibility and sensitivity. Animal models of stroke allow for environmental control and genetic homogeneity, not possible within a human population, and therefore are essential for the dissection of this complex, multifactorial disorder. Future genetic and genomic strategies and their role in ultimate causative gene identification are discussed.

Advanced atherosclerosis in predialysis patients with chronic renal failure

BACKGROUND

Atherosclerosis is advanced in hemodialysis patients as shown by increased intima-media thickness of carotid arteries (CA-IMT), although it is not established whether the advanced atherosclerosis results from hemodialysis treatment or from chronic renal failure. The purpose of this study was to evaluate the effects of hemodialysis and renal failure on CA-IMT in patients with chronic renal failure.

METHODS

CA-IMT was measured by high-resolution B-mode ultrasonography in 110 patients with chronic renal failure before starting dialysis (CRF group), and compared with CA-IMT of 345 hemodialysis patients (HD group) and 302 healthy control subjects. They were all nondiabetic and the three groups were comparable in age and gender.

RESULTS

As compared with the healthy control subjects, the CRF and HD groups had greater CA-IMTs, whereas CA-IMTs of the CRF and HD groups were not statistically different. There was no significant correlation between duration of hemodialysis and CA-IMT in the HD group. Multiple regression analysis in the total subjects indicated that presence of renal failure, but not being treated with hemodialysis, was a significant factor associated with increased CA-IMT independent of age, gender, blood pressure, smoking, high-density lipoprotein (HDL) and non-HDL cholesterol levels.

CONCLUSIONS

These results demonstrate that thickening of arterial wall is present in patients with chronic renal failure before starting hemodialysis treatment, and support the concept that advanced atherosclerosis in hemodialysis patients is due not to hemodialysis treatment, but to renal failure and/or metabolic abnormalities secondary to renal failure.

Increased thickness of the arterial intima-media detected by ultrasonography in patients with rheumatoid arthritis

OBJECTIVE

To determine whether arterial wall thickening is advanced in rheumatoid arthritis (RA) patients compared with healthy controls by measuring the intima-media thickness (IMT) of the common carotid and femoral arteries, and to evaluate the factors associated with arterial IMT in patients with RA.

METHODS

We studied 138 RA patients and 94 healthy controls (matched for age, sex, and other major risk factors for atherosclerosis). IMT was measured on digitized still images of the common carotid and femoral arteries obtained by high-resolution ultrasonography (10-MHz in-line Sectascanner). Laboratory variables relevant to RA activity were measured by routine methods. The degree of RA progression was assessed by scoring (Larsen method) metacarpophalangeal (MCP) joints on hand radiographs. Activities of daily living were determined by a modified Health Assessment Questionnaire (M-HAQ) score, and physical activity levels were assessed by ultrasound measurement of the calcaneus (expressed as the osteo-sono assessment index [OSI] Z score).

RESULTS

Common carotid and femoral artery IMTs were significantly higher (P < 0.05) in RA patients (mean +/- SD 0.641 +/- 0.127 and 0.632 +/- 0.125 mm, respectively) compared with controls (0.576 +/- 0.115 and 0.593 +/- 0.141 mm, respectively). Multiple regression analysis revealed a significant association between RA and the common carotid artery IMT. Moreover, the common carotid artery IMT in RA patients was positively associated with disease duration, the MCP joint Larsen score, and the M-HAQ score, and was negatively associated with the calcaneus OSI Z score. No significant association was found between corticosteroid treatment and common carotid artery IMT.

CONCLUSION

RA patients exhibited greater thickness of the common carotid and femoral arteries than healthy controls. The duration and severity of RA and decreased activities of daily living, but not corticosteroid treatment, were independently associated with the increased arterial wall thickness.

The 807T allele in alpha2 integrin is protective against atherosclerotic arterial wall thickening and the occurrence of plaque in patients with type 2 diabetes

Polymorphism of alpha2 integrin (C807T) is shown to be associated with an increased incidence of thrombotic cardiovascular events. However, it is not clear whether this polymorphism is associated with atherosclerotic arterial wall thickening. In this study, we examined the association of C807T polymorphism with arterial wall thickness in 265 control subjects and 272 patients with type 2 diabetes. In all subjects, intima-media thickness of the right carotid artery in the 807TT group (0.649 +/- 0.028 mm [SE]) was significantly (P = 0.0228, Scheffe's F test) less than in the 807CC group (0.767 +/- 0.033). This effect of polymorphism is gene dose dependent (P = 0.0227, ANOVA). The similar association was also observed in patients with diabetes but not in control subjects. Multiple regression analysis in all subjects revealed that the T allele was inversely (beta = -0.095, P = 0.021) associated with intima-media thickness independent of age, HbA(1c), and HDL cholesterol. Finally, an inverse relation between the occurrence of carotid plaque and the T allele was observed in patients with diabetes with an adjusted odds ratio of 0.487 (P = 0.031) in multiple logistic regression analyses. These results suggest that the number of 807T alleles in alpha2 integrin is protective against atherosclerotic arterial wall thickening and the occurrence of plaque in patients with type 2 diabetes.

Intima-media thickness: a new tool for diagnosis and treatment of cardiovascular risk

Increased intima-media thickness (IMT) is a non-invasive marker of early arterial wall alteration, which is easily assessed in the carotid artery by B-mode ultrasound, and more and more widely used in clinical research. Methods of IMT measurement can be categorized by two approaches: (i) measurement at multiple extracranial carotid sites in near and far walls and (ii) computerized measurement restricted to the far wall of the distal common carotid artery. Because IMT reflects global cardiovascular risk, its normal value might be better defined in terms of increased risk rather than in terms of statistical distribution within a healthy population. The available epidemiological data indicate that increased IMT (at or above 1 mm) represents a risk of myocardial infarction and/or cerebrovascular disease. Close relationships have been shown between: (i) most traditional cardiovascular risk factors; (ii) certain emerging risk factors such as lipoproteins, psychosocial status, plasma viscosity, or hyperhomocysteinemia; and (iii) various cardiovascular or organ damages such as white matter lesion of the brain, left ventricular hypertrophy, microalbuminuria or decreased ankle to brachial systolic pressure index. Thus, IMT gives a comprehensive picture of the alterations caused by multiple risk factors over time on arterial walls. Prospective primary and secondary prevention studies have also shown that increased IMT is a powerful predictor of coronary and cerebrovascular complications (risk ratio from 2 to 6) with a higher predictive value when IMT is measured at multiple extracranial carotid sites than solely in the distal common carotid artery. Therapeutic double-blind trials have shown that lipid-lowering drugs, such as resin and overall statines, and to a lesser extent antihypertensive drugs, such as calcium antagonists, may have a beneficial effect on IMT progression in asymptomatic or in coronary patients. However, methodological standardization of IMT measurement still needs to be implemented before routine measurement of IMT can be proposed in clinical practice as a diagnostic tool for stratifying cardiovascular risk in primary prevention and for aggressive treatment decision. It can be anticipated however, that the presence of increased carotid IMT in one individual with intermediate cardiovascular risk would lead to his classification into the high-risk category and thus influence the aggressiveness of risk factor modifications.

Relationship of angiotensin converting enzyme genotype with serum triglyceride concentration in stroke patients

The Objective of this research was to study the relationship of angiotensin converting enzyme (ACE) genotype with serum triglycerides concentration in stroke patients. The insertion/deletion (I/D) ACE polymorphism was identified by using polymerase chain reaction in 122 prospectively studied ischemic stroke patients (age 45-91 years). Serum triglycerides concentration was determined at admission and 3 months after the stroke, and compared between the ACE genotype groups (37 D/D, 68 D/I, 17 I/I). All clinical characteristics were similar in the three groups. Patients with D/D genotype had mean serum triglycerides concentration significantly higher in acute (179.0+/-111.8 mg/dl) and chronic phase (176.4+/-121.6 mg/dl) than those with I/I genotype (acute phase: 108.7+/-36.1 mg/dl, P=0.019; chronic phase: 116.0+/-44.3 mg/dl, P=0.021). The results showed that serum triglycerides concentration is elevated in stroke patients with the DD ACE genotype and it may be related to the risk of cerebrovascular disease associated with this polymorphism.

Renal insufficiency accelerates atherosclerosis in patients with type 2 diabetes mellitus

Diabetes mellitus is a strong risk factor for the progression of atherosclerosis. In patients with chronic renal failure on hemodialysis, advanced atherosclerosis is reported to be present. We examined how renal insufficiency affects intima-medial thickness (IMT) of the carotid and femoral arteries in patients with type 2 diabetes mellitus. IMT was measured by B-mode ultrasonography in 115 patients with type 2 diabetes mellitus (65 men, 50 women; 58 +/- 13 years old). The IMT of the carotid and the femoral artery of patients with creatinine clearance less than 80 mL/min (n = 55) were significantly greater than those of patients with creatinine clearance 80 mL/min or greater (n = 60; P < 0.01 and P < 0.05). Linear regression analyses showed that there was a significant negative correlation between creatinine clearance and IMT of the carotid artery (r = -0.330; P < 0.001) and femoral artery (r = -0.336; P < 0.001). Multiple regression analyses revealed that age and creatinine clearance significantly and independently affected the IMT of the carotid artery (R(2) = 0.176; P < 0.0001), and age, duration of diabetes, and smoking affected the IMT of the femoral artery (R(2) = 0.287; P < 0.0001). These findings show that decreased renal function accelerates atherosclerosis in patients with type 2 diabetes mellitus and that chronic renal failure is a significant, independent risk factor for carotid atherosclerosis in these patients.

Diabetes mellitus, aortic stiffness, and cardiovascular mortality in end-stage renal disease

Cardiovascular mortality is elevated in patients with end-stage renal disease (ESRD), especially in those with diabetes mellitus. Although the higher cardiovascular death rate in diabetic ESRD patients may be the result of more advanced atherosclerotic changes of the arterial wall, this has not been documented previously. Aortic stiffness was compared between ESRD patients with and without diabetes, and the impact of aortic stiffness on cardiovascular mortality was examined in a prospective, observational cohort study. The cohort consisted of 265 ESRD patients on hemodialysis, including 50 diabetic patients studied between June 1992 and December 1998. At baseline, the diabetic ESRD patients had significantly higher aortic pulse wave velocity (PWV), a noninvasive measure of aortic stiffness, than the nondiabetic patients. During a mean follow-up period of 63 mo, 81 deaths, including 36 cardiovascular deaths, were recorded. Kaplan-Meier analysis revealed higher all-cause or cardiovascular mortality rates in the diabetic as compared with the nondiabetic patients and also in those with higher aortic PWV than those with lower aortic PWV. The effect of diabetes on cardiovascular death was significant in the Cox model, including age, years on hemodialysis, gender, smoking, C-reactive protein, hematocrit, and body mass index as covariates. However, when aortic PWV was included as a covariate, the impact of diabetes was no longer significant, whereas aortic PWV was a significant predictor. In a model including 13 covariates, aortic PWV remained a significant predictor for cardiovascular and overall mortality but not for non-cardiovascular death. These results demonstrate that the increased aortic stiffness of the ESRD patients with diabetes mellitus contributed to the higher all-cause and cardiovascular mortality rates.

Relations between ACE gene and ecNOS gene polymorphisms and resistive index in type 2 diabetic patients with nephropathy

OBJECTIVE

ACE and endothelial cell nitric oxide synthase (ecNOS) genotypes have been reported to be related to the incidence of renal diseases and coronary artery diseases. In order to assess the effect of the gene polymorphism of both ACE and ecNOS on renal hemodynamic abnormality, we examined 155 Japanese patients with type 2 diabetes with various stages of nephropathy.

RESEARCH DESIGN AND METHODS

The patients ranged in age from 40 to 72 years (92 men and 63 women). They were divided into four groups: group 1 consisted of patients with urinary albumin excretion (UAE) <30 mg/day (n = 69), group 2 had 30 < or = UAE < 300 mg/day (n = 44), group 3 had UAE > or =300 mg/day and serum creatinine <1.5 mg/dl (n = 22), and group 4 had serum creatinine >1.5 mg/dl (n = 20). Intrarenal hemodynamics were studied by duplex Doppler sonography in patients with type 2 diabetes. The ACE and ecNOS gene polymorphisms were examined by polymerase chain reaction.

RESULTS

There were no significant differences in sex, BMI, and blood glucose level, but there were differences in HbA(1c) and lipoprotein profiles among the four groups. There were no significant differences in the distribution of ACE genotype or in the frequency of the ecNOS 4a allele among the four groups. Resistive index (RI) values of the interlobar arteries of group 4 were significantly higher than those of groups 1, 2, and 3, whereas the RI values were not significantly different among groups 1, 2, and 3. Multiple regression analysis showed that age, duration of diabetes, systolic and diastolic blood pressure, and creatinine clearance were significantly associated with the increased RI values, but that there was no significant association between RI values and the ecNOS genotype (R(2) = 0.613, P < 0.0001).

CONCLUSIONS

These results suggest that intrarenal hemodynamic abnormalities are present as a feature of the progression of nephropathy in type 2 diabetes, and that they are associated with age, duration of diabetes, decreased creatinine clearance, and blood pressure, but not with the genetic factors of the ACE and ecNOS gene polymorphism in nephropathy of type 2 diabetes.

Femoral artery wall thickness and stiffness in evaluation of peripheral vascular disease in type 2 diabetes mellitus

Stiffening and thickening of arterial wall are two important components of atherosclerosis. The purpose of this study was to evaluate the effects of femoral artery wall stiffness on clinical manifestation of peripheral vascular disease (PVD) in type 2 diabetes mellitus. The subjects were 315 patients with type 2 diabetes. Presence of intermittent claudication and/or leg pain at rest and reduced ankle-brachial blood pressure index (ABI<0.9) were used as a subjective and an objective index of PVD, respectively. Femoral artery intima-media thickness (FA-IMT) and stiffness parameter beta (FA-stiffness beta) were measured by ultrasound methods. Symptomatic patients (N=58) showed greater values for both FA-IMT and FA-stiffness beta than those without symptom (N=257). Similarly, patients with reduced ABI (N=56) had greater FA-IMT and FA-stiffness beta than those without (N=259). However, correlation between FA-IMT and FA-stiffness beta was not impressive, especially in the symptomatic patients. To evaluate the effect of FA-stiffness beta on PVD symptoms, the subjects were divided into three subgroups according to FA-IMT, and then FA-stiffness beta was compared between those with and without PVD symptoms in each subgroup. The symptomatic patients had greater FA-stiffness beta values than the asymptomatic subjects in all the three subgroups. Multiple logistic regression analysis indicated that the presence of PVD symptoms was associated more closely with increased FA-stiffness beta than with increased FA-IMT, whereas reduced ABI was associated more closely with FA-IMT than with FA-stiffness beta. These data suggest that stiffening of arterial wall has a significant impact on PVD manifestations, particularly on the leg symptoms, in patients with type 2 diabetes.

Abdominal Aortic Aneurysm in Normotensive Patients: Association with Angiotensin-converting Enzyme Gene Polymorphism

OBJECTIVE AND DESIGN

to assess if deletion of the angiotensin-converting enzyme (ACE) gene is a risk factor for abdominal aortic aneurysms (AAAs) in normotensive patients.

MATERIALS AND METHODS

ACE gene polymorphism was examined by polymerase chain reaction in 124 subjects with AAA and in 112 control subjects. AAA normotensive patients (group A, n=56) were compared to normotensive control subjects (group B, n =112) and to AAA hypertensive patients (group C, n =68). All subjects enrolled in this study were Caucasian and from central and southern Italy.

RESULTS

the distribution of ACE genotypes was: normotensive patients with AAAs (group A): 3 II, 14 ID, 39 DD; normotensive control subjects (group B): 36 II, 48 ID, 28 DD; hypertensive patients with AAAs (group C): 14 II, 32 ID, 22 DD. The DD genotype was more common in group A than in control groups (A vs B p<0.001; A vs C p <0.001). The ID genotype was more common in group A as well (A vs B p <0.05; A vs C p <0.005).

CONCLUSIONS

our data suggest a role for ACE I/D gene polymorphism in the pathogenesis of AAA in normotensive patients.