Ethnic differences in common carotid intima-media thickness, and the relationship to cardiovascular risk factors and peripheral arterial disease: the Ethnic-Echocardiographic Heart of England Screening Study

Regional and demographic variations of Carotid artery Intima and Media Thickness (CIMT): A Systematic review and meta-analysis

Background and objective

Carotid artery intima media thickness (CIMT) is a strong predictor of Coronary Heart Disease (CHD) and independent phenotype of early atherosclerosis. The global variation of CIMT and its demographic association is yet unclear. We evaluated regional variations of CIMT based on WHO regions and assessed the differences by age and sex.

Methods

A systematic search was conducted on studies published between 1980 January up to December 2020. PubMed, Oxford Medicine Online, EBSCO, Taylor & Francis, Oxford University Press and Embase data bases were used for searching. Supplementary searches were conducted on the Web of Science and Google Scholar. Grey literature was searched in “Open Grey” website. The two major criteria used were “adults” and “carotid intima media”. The search strategy for PubMed was created first and then adapted for the Oxford Medicine Online, EBSCO, Taylor & Francis, Oxford University Press and Embase databases. Covidence software (Veritas Health Innovation, Melbourne, Australia; http://www.covidence.org) was used to manage the study selection process. Meta-analyses were done using the random-effects model. An I2 ≥ 50% or p< 0:05 were considered to indicate significant heterogeneity.

Results

Of 2847 potential articles, 46 eligible articles were included in the review contributing data for 49 381 individuals (mean age: 55.6 years, male: 55.8%). The pooled mean CIMT for the non-CHD group was 0.65mm (95%CI: 0.62–0.69). There was a significant difference in the mean CIMT between regions (p = 0.04). Countries in the African (0.72mm), American (0.71mm) and European (0.71mm) regions had a higher pooled mean CIMT compared to those in the South East Asian (0.62mm), West Pacific (0.60mm) and Eastern Mediterranean (0.60mm) regions. Males had a higher pooled mean CIMT of 0.06mm than females in the non CHD group (p = 0.001); there were also regional differences. The CHD group had a significantly higher mean CIMT than the non-CHD group (difference = 0.23mm, p = 0.001) with regional variations. Carotid artery segment-specific-CIMT variations are present in this population. Older persons and those having CHD group had significantly thicker CIMTs.

Conclusions

CIMT varies according to region, age, sex and whether a person having CHD. There are significant regional differences of mean CIMT between CHD and non-CHD groups. Segment specific CIMT variations exist among regions. There is an association between CHD and CIMT values.

Cardiovascular and cerebrovascular risk markers in Parkinson's disease: Results from a case-control study

BACKGROUND

The relationship between Parkinson's disease (PD) and cardiovascular and cerebrovascular disease is not yet well established. Recent data suggest an increased risk of myocardial infarction and stroke in PD patients. Therefore, we designed a study to assess surrogate markers of cardiovascular and cerebrovascular risk in PD.

METHODS

We conducted a case-control study comparing PD patients recruited from a Movement Disorders Unit with controls randomly invited from a primary healthcare center. All participants underwent a detailed clinical evaluation, including medical history, physical assessment, carotid ultrasound, blood and urine analysis, and 24-h ambulatory blood pressure monitoring. The primary outcome was the carotid intima-media thickness (CIMT).

RESULTS

We included 102 participants in each study arm. No significant difference was found in the CIMT among groups (MD: 0.01, 95% CI: -0.02, 0.04). Carotid plaques were more frequent in PD patients (OR: 1.90, 95% CI: 1.02, 3.55), although the lipid profile was more favorable in this group (LDL MD: -18.75; 95% CI: -10.69, -26.81). Nocturnal systolic blood pressure was significantly higher in PD patients (MD: 4.37, 95% CI: 0.27, 8.47) and more than half of the PD patients were non-dippers or reverse dippers (OR: 1.83, 95% CI: 1.04, 3.20).

CONCLUSION

We did not find a difference in CIMT between PD and controls. A higher frequency of carotid plaques and abnormal dipper profile supports the hypothesis that PD patients are not protected from cardiovascular and cerebrovascular disease.

The effect of HIV infection, antiretroviral therapy on carotid intima-media thickness: A systematic review and meta-analysis

AIMS

We performed a systematic review and meta-analysis on the effect of HIV infection and antiretroviral therapy (ART) on carotid intima-media thickness (cIMT) to elucidate the role of HIV infection and ART. Also, an analysis on the role of ethnicity and gender on cIMT in HIV-infected populations was performed.

MAIN METHODS

We searched the PubMed, Web of Science, the WHO websites and International AIDS Society for published observational studies were conducted by two independent reviewers for studies comparing HIV-infected antiretroviral-experienced patients and/or inexperienced with healthy controls on cIMT. The primary outcome was the standardized mean difference (SMD) of cIMT.

FINDINGS

Twenty studies (five cohort, 15 cross-sectional, and two both cohort and cross-sectional studies) were identified comprising 7948 subjects (4656 HIV-infected; 3292 controls). In cohort studies, the standardized mean 1-year change in cIMT between HIV-infected patients and uninfected controls was not significantly different (0.16 mm/yr; 95% CI, -0.16, 0.49; p = 0.326). In 17 cross-sectional studies, the SMD in cIMT was significantly higher in HIV-infected than uninfected persons (0.27 mm; 95% CI, 0.04, 0.49; p = 0.027). HIV-infected patients on ART exhibited significantly higher SMD in cIMT compared to those not on ART (0.75 mm; 95% CI, 0.30, 1.19; p = 0.001). No confounding effect of gender and ethnicity could be established using meta-regression p > 0.05.

SIGNIFICANCE

HIV infection itself and ART appear to influence the progression of cIMT and hence may be risk factors for cardiovascular events. No firm conclusions could be drawn on the effect of ethnic/race and gender differences on cIMT in HIV-infected populations.

Research Toolbox for Peripheral Arterial Disease - Minimally Invasive Assessment of the Vasculature and Skeletal Muscle

In 2010, more than 200 million people were afflicted with peripheral arterial disease (PAD). Because it is atherosclerotic in etiology, it is not surprising that PAD is a leading cause of cardiovascular morbidity. Cardiovascular disease (CVD) risk can be decreased if ambulatory physical function is improved. However, physical function is limited by a mismatch between oxygen supply and demand in the legs, which results in exertional pain, leg weakness, and balance problems. Therefore, a key factor for improving physical function, and decreasing CVD outcomes, is ensuring oxygen supply meets the oxygen demand. The purpose of this review is to highlight and evaluate practical and minimally invasive tools for assessing PAD etiology, with a specific focus on tools suited to studies focusing on improving physical function and CVD outcomes. Specifically, the macrovascular, microvascular, and skeletal muscle pathology of PAD is briefly outlined. Subsequently, the tools for assessing each of these components is discussed, including, where available, the evidence to contextualize these tools to PAD pathology as well as physical function and CVD outcomes. The goal of this review is to guide researchers to the appropriate tools with respect to their methodological design.

Power spectral estimation of high-harmonics in echoes of wall resonances to improve resolution in non-invasive measurements of wall mechanical properties in rubber tube and ex-vivo artery

The aim of this work is to develop a new type of ultrasonic analysis of the mechanical properties of an arterial wall with improved resolution, and to confirm its feasibility under laboratory conditions.

MOTIVATION

it is expected that this would facilitate a non-invasive path for accurate predictive diagnosis that enables an early detection & therapy of vascular pathologies. In particular, the objective is to detect and quantify the small elasticity changes (in Young's modulus E) of arterial walls, which precede pathology. A submicron axial resolution is required for this analysis, as the periodic widening of the wall (under oscillatory arterial pressure) varies between ±10 and 20 μm. This high resolution represents less than 1% of the parietal thickness (e.g., << 7 μm in carotid arteries). The novelty of our proposal is the new technique used to estimate the modulus E of the arterial walls, which achieves the requisite resolution. It calculates the power spectral evolution associated with the temporal dynamics in higher harmonics of the wall internal resonance f₀. This was attained via the implementation of an autoregressive parametric algorithm that accurately detects parietal echo-dynamics during a heartbeat. Thus, it was possible to measure the punctual elasticity of the wall, with a higher resolution (> an order of magnitude) compared to conventional approaches. The resolution of a typical ultrasonic image is limited to several hundred microns, and thus, such small changes are undetected. The proposed procedure provides a non-invasive and direct measure of elasticity by doing an estimation of changes in the Nf₀ harmonics and wall thickness with a resolution of 0.1%, for first time. The results obtained by using the classic temporal cross-correlation method (TCC) were compared to those obtained with the new procedure. The latter allowed the evaluation of alterations in the elastic properties of arterial walls that are 30 times smaller than those being detectable with TCC; in fact, the depth resolution of the TCC approach is limited to ≈20 μm for typical SNRs. These values were calculated based on echoes obtained using a reference pattern (rubber tube). The application of the proposed procedure was also confirmed via "ex-vivo" measurements in pig carotid segments.

Admixture Mapping of Subclinical Atherosclerosis and Subsequent Clinical Events Among African Americans in 2 Large Cohort Studies

BACKGROUND

Local ancestry may contribute to the disproportionate burden of subclinical and clinical cardiovascular disease among admixed African Americans compared with other populations, suggesting a rationale for admixture mapping.

METHODS AND RESULTS

We estimated local European ancestry (LEA) using Local Ancestry inference in adMixed Populations using Linkage Disequilibrium method (LAMP-LD) and evaluated the association with common carotid artery intima-media thickness (cCIMT) using multivariable linear regression analysis among 1554 African Americans from MESA (Multi-Ethnic Study of Atherosclerosis). We conducted secondary analysis to examine the significant cCIMT-LEA associations with clinical cardiovascular disease events. We observed genome-wide significance in relation to cCIMT association with the SERGEF gene (secretion-regulating guanine nucleotide exchange factor; β=0.0137; P=2.98×10-4), also associated with higher odds of stroke (odds ratio=1.71; P=0.02). Several regions, in particular CADPS gene (Ca2+-dependent secretion activator 1) region identified in MESA, were also replicated in the ARIC cohort (Atherosclerosis Risk in Communities). We observed other cCIMT-LEA regions associated with other clinical events, most notably the regions harboring CKMT2 gene (creatine kinase, mitochondrial 2) and RASGRF2 gene (Ras protein-specific guanine nucleotide-releasing factor 2) with all clinical events except stroke, the LRRC3B gene (leucine-rich repeat containing 3B) with myocardial infarction, the PRMT3 gene (protein arginine methyltransferase 3) with stroke, and the LHFPL2 gene (lipoma high mobility group protein I-C fusion partner-like 2) with hard and all coronary heart disease.

CONCLUSIONS

We identified several novel LEA regions, in addition to previously identified genetic variations, associated with cCIMT and cardiovascular disease events among African Americans.

Carotid Intima-media Thickness and its Association with Conventional Risk Factors in Low-income Adults: A Population-based Cross-Sectional Study in China

Carotid intima-media thickness (CIMT) is an established predictor of cardiovascular disease and stroke. However, risk factors associated with CIMT remain unclear. Therefore, we aimed to identify factors associated with CIMT in a low-income Chinese population. Stroke-free and cardiovascular disease-free residents aged ≥45 years were recruited. B-mode ultrasonography was performed to measure CIMT. The mean age of participants (n = 3789) was 59.92 years overall, 61.13 years in men, and 59.07 years in women (P < 0.001). Male sex, older age, low education level, smoking, hypertension, and high systolic blood pressure, fasting blood glucose, and low-density lipoprotein cholesterol levels were independent determinants of mean CIMT. Mean CIMT was higher by 18.07 × 10⁻³ mm in hypertensive compared to normotensive participants (P < 0.001), by 19.03 × 10⁻³ mm in men compared to women (P < 0.001), and by 9.82 × 10⁻³ mm in smokers compared to never smokers (P < 0.001). However, mean CIMT decreased by 1.07, 0.37, and 2.36 × 10⁻³ mm per 1-unit increase in education level, diastolic blood pressure, and triglycerides, respectively. It is important to manage conventional risk factors in low-income populations to decrease stroke incidence.

Growth of Carotid Intima-Media Thickness in Black and White Young Adults

Background

There are few longitudinal studies that have comprehensively examined the intima‐media thickness (IMT) growth pattern and its determinants among racial population groups.

Methods and Results

Mean and maximum IMT were measured by B‐mode ultrasonography up to 3 times in 253 white and 268 black participants, aged 13 to 36 years (mean age±standard deviation 24±3.2 years old). The development of IMT was assessed using individual growth curve modeling. A total of 521 participants with 1015 IMT measurements were eligible for this study. We found higher IMT in both left and right sides in blacks compared to whites (P<0.001) in young adulthood. Both whites and blacks showed a strong linear increase in mean IMT with age. Body mass index and father's education level were associated with mean IMT, and only body mass index was associated with maximum IMT (P<0.05). We did not observe an interaction between age and race/ethnicity on the growth of IMT, suggesting that blacks and whites developed IMT in similar patterns. Interestingly, we found a faster increase in mean left‐side IMT than mean right‐side IMT (χ²=11.5, P<0.001) in both black and white subjects as well as in males and females.

Conclusions

Our findings provide compelling prospective evidence that blacks may have thicker IMT compared to whites as young adults. These racial differences could not be explained by traditional risk factors. This implies that differences in this precursor of atherosclerosis may explain racial disparity in cerebrovascular disease.

Estimation of PSD shifts for high-resolution metrology of thickness micro-changes with possible applications in vessel walls and biological membrane characterization

Achieving accurate measurements of inflammation levels in tissues or thickness changes in biological membranes (e.g., amniotic sac, parietal pleura) and thin biological walls (e.g., blood vessels) from outside the human body, is a promising research line in the medical area. It would provide a technical basis to study the options for early diagnosis of some serious diseases such as hypertension, atherosclerosis or tuberculosis. Nevertheless, achieving the aim of non-invasive measurement of those scarcely-accessible parameters on patient internal tissues, currently presents many difficulties. The use of high-frequency ultrasonic transducer systems appears to offer a possible solution. Previous studies using conventional ultrasonic imaging have shown this, but the spatial resolution was not sufficient so as to permit a thickness evaluation with clinical significance, which requires an accuracy of a few microns. In this paper a broadband ultrasonic technique, that was recently developed by the authors to address other non-invasive medical detection problems (by integrating a piezoelectric transducer into a spectral measuring system), is extended to our new objective; the aim is its application to the thickness measurement of sub-millimeter membranes or layers made of materials similar to some biological tissues (phantoms). The modeling and design rules of such a transducer system are described, and various methods of estimating overtones location in the power spectral density (PSD) are quantitatively assessed with transducer signals acquired using piezoelectric systems and also generated from a multi-echo model. Their effects on the potential resolution of the proposed thickness measuring tool, and their capability to provide accuracies around the micron are studied in detail. Comparisons are made with typical tools for extracting spatial parameters in laminar samples from echo-waveforms acquired with ultrasonic transducers. Results of this advanced measurement spectral tool are found to improve the performance of typical cross-correlation methods and provide reliable and high-resolution estimations.

Measurement of intima media thickness of carotid artery by B-mode ultrasound in healthy people of India and Bangladesh, and relation of age and sex with carotid artery intima media thickness: An observational study

Background:

Carotid artery intima media is a surrogate marker of atherosclerosis and related with ethnicity, age, sex, traditional and non-traditional risk factors. Black ethnicity is related to greater mean and maximum carotid artery intima media thickness when compared to South Asians. Our study was done to find out the mean carotid artery intima media thickness (CAIMT) of normal healthy people of India and Bangladesh, and the relationship of non-modifiable risk factors such as age and sex with CAIMT.

Materials and Methods:

In this observational study, CAIMT of 93 people were examined by B-mode ultrasonography. All subjects underwent a careful interview and clinical, radiological, biochemical examination. Data was analyzed by software statistical package for social sciences (SPSS) (17^th version for window).

Results:

In our study, the mean CAIMT of healthy subjects including all age group was (754.94 ± 11.96 micron.). Mean CAIMT was higher in age group of 61-80 years (908.75 ± 39.02 micron) than age group of 20-40 years (713.62 ± 16.59 micron) and 41-60 years (745.55 ± 13.05 micron). CAIMT was positively correlated with age (P value <0.001) and sex (P value=0.001).

Conclusion:

An aggregated analysis based on this study in different age groups of healthy people may be useful for assessing carotid artery abnormalities as an aid to defining abnormalities and predicting risk of atherosclerosis in individual healthy people living in India and Bangladesh.

Predictors of carotid intima-media thickness and carotid plaque in young Indian adults: the New Delhi birth cohort

BACKGROUND

Carotid intima-media thickness (CIMT) and carotid plaques represent preclinical markers of atherosclerosis. We sought to describe predictors of CIMT and carotid plaques, including early life growth, in a young urban Indian cohort free of clinical cardiovascular disease (CVD).

METHODS

In 2006-2009, we performed B-mode carotid ultrasound on 600 participants (mean [SD] age 36 [1.1] years; 45% women) from the New Delhi Birth Cohort to evaluate CIMT and carotid plaques (>1mm). Height and weight were recorded at birth, 2 and 11 years of age. Data on CVD risk factors, anthropometry, medical history, socio-economic position, and lifestyle habits were collected in 1998-2002.

RESULTS

Mean (SD) CIMT for men and women was 0.91 (0.12) and 0.86 (0.13) mm, respectively. Carotid plaque was present in 33% of men and 26% of women. Waist circumference in 1998-2002 was positively associated with CIMT (β coefficient 0.26 mm [0.17, 0.36] per SD) and carotid plaque (OR 1.27 [1.06,1.52] per SD) in 2006-2009. Higher triglycerides, PAI-1, insulin resistance, and diastolic blood pressure, metabolic syndrome, and lower HDL-cholesterol and physical activity predicted higher CIMT and/or plaque (p<0.05). Longer length at 2 years was associated with higher CIMT (p<0.05). These associations were attenuated after adjusting for adult waist circumference.

CONCLUSIONS

These are the first prospective data from India showing that early life growth, adult socio-demographics, and CVD risk factors predict future CIMT and/or carotid plaque. These relationships appear primarily mediated through central adiposity, highlighting the importance of maintaining a healthy weight in early adulthood to prevent CVD.

Carotid artery intima-media thickness in college students: race/ethnicity matters

OBJECTIVE

Racial/ethnic differences in common carotid artery intima-media thickness (CIMT) and in risk factors associated with CIMT have been predominantly observed in middle-aged and older individuals. We aimed to characterize racial/ethnic differences CIMT and other cardiovascular risk factors in a healthy, young-adult population.

METHODS

College students were recruited as part of a study to characterize determinants of atherogenesis. Students were eligible if they were lifetime non-smokers, lived in the United States since six months of age, and attended high school in the United States. Blood pressure, heart rate, height, and weight were measured, B-mode carotid ultrasound was performed, questionnaires were administered and a 12-h fasting blood sample was collected. Associations between CIMT and other variables were assessed in 768 students aged 18-25 years using linear regression analysis.

RESULTS

In models adjusted for common cardiovascular risk factors, sex exhibited the strongest influence on CIMT, with men having 15.4 μm larger CIMT compared to women (95%CI 6.6, 24.2). Race/ethnicity was also strongly associated with CIMT. African Americans had 17.3 μm greater CIMT (95%CI -0.3, 34.8) compared to non Hispanic Whites, whereas Asians and Hispanic Whites had 14.3 (95%CI -24.3, -4.4) and 15.4 (95%CI -26.2, -4.7) μm smaller CIMT, respectively. BMI and systolic blood pressure were positively associated with CIMT.

CONCLUSION

The risk factors associated with atherogenesis later in life are already present and observable in college-aged young adults, so targeted campaigns to reduce life-long cardiovascular disease burden should be initiated earlier in life to improve public health.