Can arterial wave augmentation in young adults help account for variability of cardiovascular risk in different British ethnic groups?

Association between perceived discrimination and pulse wave velocity: a scoping review

Racial discrimination is a chronic stressor that may contribute to cardiovascular disease (CVD) disparities in non-Hispanic Black (NHB) adults. NHB adults experience greater perceived discrimination (PD) and CVD risk compared with non-Hispanic White adults. Although the association between PD and some subclinical CVD markers has been examined, the relationship between PD and arterial stiffness has not been established, limiting our understanding of the impact of PD on CVD.

Objective

The objective of this review was to summarise the literature on the relationship between PD and arterial stiffness.

Design

Systematic scoping review.

Data sources

PubMed, Embase, SPORTDiscus with full text and CINALH+ with full text databases were searched from inception to 10 July 2023.

Eligibility criteria

Adults (≥18 years), arterial stiffness measured as pulse wave velocity (PWV), PD assessment, and randomised control trial or observational study designs.

Data extraction and synthesis

Of 453 articles identified, four studies were included. Two studies were cross-sectional (United States, Brazil), one was longitudinal (United Kingdom), and another was a randomized control trial (United States).

Results

The age of the study populations ranged from 18 years to 75 years and one study evaluated a clinical population. All studies used different PWV devices and PD assessments. Associations between PD and PWV varied by geographical region, sex, clinical status and study design.

Conclusion

Research evaluating the association between PD and PWV is scarce and heterogeneous in PD and PWV assessments. There is an inconclusive association between PD and PWV.

Ethnic differences in subclinical vascular function in South Asians, Whites, and African Americans in the United States

BACKGROUND

South Asians are a high-risk ethnic group for cardiovascular disease despite having lower levels of conventional cardiovascular risk factors such as obesity and smoking. Ethnic differences in pulse wave reflections, arterial stiffness, and subclinical atherosclerosis as measured using augmentation index (AIX), pulse wave velocity (PWV), and carotid intima-media thickness (CIMT) may reflect some of this excess risk.

METHODS

We conducted a cross-sectional analysis of pooled data from three community-based sources in Atlanta, Georgia, USA. Data on 530 South Asians collected from local health fairs was compared with data on 507 White and 192 African Americans from the Emory Predictive Health Initiative and 351 White and 382 African Americans from the Morehouse and Emory Team up to Eliminate Health Disparities Study.

RESULTS

Linear regression models adjusted for age, sex, smoking, MAP, fasting glucose, TC, HDL-C, creatinine, and body mass index were used to assess the relationship between ethnicity and vascular function measures. In fully adjusted models, South Asians had higher heart rate corrected AIX as compared with Whites and African Americans (by 5.47%, p < 0.01 and 3.50%, p < 0.01; respectively), but lower PWV (by 0.51 m/s, p < 0.01 and 0.72 m/s, p < 0.01; respectively) and lower CIMT (by 0.02 mm p = 0.03 and 0.04 mm p < 0.01; respectively).

CONCLUSIONS

Systemic pulse wave reflections, independent of other risk factors, are higher in South Asians as compared with Whites and African Americans. Future research is needed to determine whether higher AIX explains the increased cardiovascular risk among South Asians.

Ethnicity and Arterial Stiffness

Early vascular aging reflects increased arterial stiffness of central blood vessels at young chronological ages and powerfully predicts cardiovascular events and mortality, independent of routine brachial blood pressure and other risk factors. Since ethnic disparities exist in routine blood pressure, in hypertension and cardiovascular outcomes, this review evaluates major studies comparing arterial stiffness through the life course between different ethnic groups or races (which have no biological definition)-in children, adolescents, young, and middle-aged adults and the very elderly. Most report that compared with white European-origin samples, populations of black African descent have increased central arterial stiffness throughout different life stages, as well as a more rapid increase in arterial stiffness at young ages. Exceptions may include African Caribbean origin people in Europe. Differences in vascular structure and function are clearest, where obesity, socioeconomic, and psychosocial factors are most marked. Few studies evaluate a wider spectrum of ethnic groups or factors contributing to these ethnic disparities. Genetic effects are not obvious; maternal risk and intergenerational studies are scarce. Nevertheless, across all ethnic groups, for given levels of blood pressure and age, some people have stiffer central arteries than others. These individuals are most at risk of vascular events and mortality and, therefore, may benefit from early, as yet untested, preventive action and treatment.

Association of Endothelial Function with Parental Hypertension in Normotensive-Obese African-American Women: A Pilot Study

Obese African-American (AA) women are at high risk of hypertension (HT) and cardiovascular disease (CVD). Flow-mediated dilation (FMD) and arterial augmentation index (AI) are measures of endothelial function and arterial stiffness. Whether endothelial function and arterial stiffness predict risk of HT or CVD in obese African-American women with, versus without, parental histories of HT and whether aerobic exercise is an effective countermeasure remain unclear. The capacity for FMD is partly heritable. Therefore, we tested the hypotheses that less FMD and greater AI may be found in normotensive-obese, young-adult (18-26 year-old) AA women with hypertensive parents (n=10) than in a matched control group with normotensive parents (n=10) and that a single bout of aerobic exercise improves both endothelial function and arterial stiffness, with less improvement in the women with hypertensive parents. We studied each subject while at rest, 20 min before and 20 min after, 30 min of aerobic exercise. The exercise-induced changes and parental hypertension-related differences in AI were not significant. The exercise increased FMD in both of the groups with no significant difference in magnitude between the women with hypertensive and normotensive parents. FMD was significantly less in the women with hypertensive parents than in the women with normotensive parents after, but not before, the exercise (mean ±95% confidence interval of 11.3 ± 4.9% vs. 15.6 ± 4.9%, P=0.05). These findings suggest that a 30-min bout of aerobic exercise may improve FMD and unmask endothelial dysfunction in normotensive-obese, young-adult AA women with parental histories of HT. Future studies should determine whether regular aerobic exercise protects obese AA women from the endothelial dysfunction associated with diabetes and prevents CVD in this high-risk population.

Why are there ethnic differences in cardio-metabolic risk factors and cardiovascular diseases?

Europe's population is becoming increasingly ethnically diverse, and epidemiological studies indicate that there are remarkable differences in cardio-metabolic risk factors between ethnic groups living in the same area. Variations observed in the distribution of cardiovascular risk factors in these communities may therefore help explain-at least in part-the different burdens on cardiovascular diseases. So far, the underlying pathophysiology leading to ethnic variations in the prevalence of cardio-metabolic risk factors is still poorly understood but it is likely to represent the complex interactions from several innate and environmental factors. Tailored prevention and treatment strategies should therefore be implemented in those "high-risk populations," but data derived from randomized clinical trials are still limited. This article will provide an overview on the role of ethnicity on cardio-metabolic risk factors and cardiovascular diseases, focusing on type 2 diabetes and dyslipidemia based mainly on Dutch and British data.

Longitudinal study of the influence of lung function on vascular health from adolescence to early adulthood in a British multiethnic cohort

Background:

Vascular and lung function develop and decline over the life course; both predict cardiovascular events and mortality but little is known of how they develop over time. We analysed their relationship in a multiethnic cohort study to test whether lung function from early adolescence to young adulthood affected vascular indices.

Methods:

‘DASH’ (http://dash.sphsu.mrc.ac.uk) included 6643 children aged 11–13 years in 2003; a representative 10% sample (n = 665) participated in a pilot follow-up in 2013. Psychosocial, anthropometric, blood pressure (BP), and lung function measures were collected in both surveys; aortic pulse wave velocity (PWV) and augmentation index (AIx) were measured at aged 21–23 years. Relationships between forced expiratory volume Z-scores in 1 s (zFEV₁), after global initiative-ethnic adjustments and BP, PWV, and AIx were tested in linear regression and general estimating statistical models.

Results:

In total, 488 people with complete data were included. At 11–13 years, SBP was positively associated with zFEV₁ (coefficient = 1.90, 95% confidence interval 1.11–2.68, P < 0.001); but not at 21–23 years. The 10-year increase in zFEV₁ was associated with rise in SBP (1.38, 0.25–1.51, P < 0.05) in mixed effect models adjusted for age, sex, ethnicity, waist to height ratio, employment, reported racism, smoking, and alcohol use but DBP change was unrelated. In fully adjusted models, neither PWV nor central AIx were associated with zFEV₁ at 11–13 years or 21–23 years (P > 0.05).

Conclusion:

Forced expiratory volume change is positively and independently associated with SBP change from adolescence to young adulthood, suggesting earlier lung function plays important roles in SBP development. Vascular indices were unrelated to lung function or its change.

Long-Term Improvement in Aortic Pulse Wave Velocity After Weight Loss Can Be Predicted by White Adipose Tissue Factors

BACKGROUND

Arterial stiffness, measured by pulse wave velocity (PWV), is linked to obesity, cardiovascular disease, and all-cause mortality. Short-term weight loss improves PWV, but the long-term effects are unknown. We investigated the effect of pronounced long-term weight loss on PWV and whether anthropometric/metabolic parameters and/or white adipose tissue (WAT) phenotype could predict this change in PWV.

METHODS

Eighty-two obese subjects were examined before and 2 years after Roux-en-Y gastric bypass. Analyses included anthropometrics, routine clinical chemistry, and hyperinsulinemic-euglycemic clamp. Arterial stiffness was measured as aortic PWV (aPWV) using the Arteriograph device. WAT mass and distribution were assessed by dual-X-ray absorptiometry. Baseline visceral and subcutaneous WAT samples were obtained to measure adipocyte cell size. Transcriptomic profiling of subcutaneous WAT was performed in a subset of subjects (n = 30).

RESULTS

At the 2-year follow-up, there were significant decreases in body mass index (39.4 ± 3.5 kg/m2 vs. 26.6 ± 3.4 kg/m2; P < 0.0001) and aPWV (7.8 ± 1.5 m/s vs. 7.2 ± 1.4 m/s; P = 0.006). Multiple regression analyses showed that baseline subcutaneous adipocyte volume was associated with a reduction in aPWV (P = 0.014), after adjusting for confounders. Expression analyses of 52 genes implicated in arterial stiffness showed that only one, COL4A1, independently predicted improvements in aPWV after adjusting for confounders (P = 0.006).

CONCLUSIONS

Bariatric surgery leads to long-term reduction in aPWV. This improvement can be independently predicted by subcutaneous adipocyte volume and WAT COL4A1 expression, which suggests that subcutaneous WAT has a role in regulating aPWV.

CLINICAL TRIALS REGISTRATION

Trial Number NCT01727245 (clinicaltrials.gov).