A multilevel framework to investigate cardiovascular health disparities among South Asian immigrants in the United States

Variations of the Extent of Obstructive Coronary Artery Disease Among Canadian Immigrants

BACKGROUND

An increasing proportion of immigrants are residing in developed countries, but little is known about the extent of their obstructive coronary artery disease (CAD). Our objective was to evaluate the association between immigrant status and CAD among immigrants.

METHODS AND RESULTS

Initial coronary angiography performed for stable CAD from 2012 to 2021 in Ontario, Canada was examined. Immigrants were categorized by their country of birth into 7 world regions. The primary outcome was the rate of obstructive CAD, defined as the presence of left main stenosis ≥50% or major epicardial vessel stenosis ≥70%. Multivariable logistic regression analyses were conducted to compare the adjusted odds of obstructive CAD among long-term residents and immigrants, and then within immigrant groups. Our cohort included 208 363 long-term residents and 36 139 immigrants; the immigrants were substantially younger than the long-term residents (61.3 versus 66.6 years). Male immigrants had 12.0% higher adjusted odds (95% CI, 1.17-1.24) of having obstructive CAD than long-term residents, whereas no significant difference was observed among female immigrants and long-term residents. There was also substantial variation in CAD among immigrants based on their country of origin. For example, male immigrants from South Asia had 49.0% higher adjusted odds of having CAD, whereas patients from Africa (0.75) and the Caribbean (0.63) had lower adjusted odds.

CONCLUSIONS

We observed earlier presentations for cardiac catheterization among immigrants with stable CAD and higher adjusted odds of having obstructive CAD among male immigrants compared with long-term residents of Canada. Rates of obstructive CAD varied significantly by their region of birth.

Everyday Discrimination and Its Predictors in the MASALA Study

South Asians are a fast-growing, heterogeneous ethnic group in the United States. However, they remain understudied in health equity research despite experiencing a high burden of cardiovascular disease. Biased assumptions, such as the model minority myth, obscure their unique experiences of discrimination-a known contributor to cardiovascular disease-related health inequities. The form and pattern of everyday discrimination among South Asians has been largely unexamined. We addressed this gap by examining the dimensionality of the everyday discrimination scale (EDS) and its potential predictors among South Asians. Data are from the Mediators of Atherosclerosis in South Asians Living in America (MASALA; 2010-2018), a cross-sectional community sample (N = 1164, 52% male, Mage = 56.73, SDage = 9.41). Structural equation modeling (SEM) analysis was used to conduct confirmatory factor analyses to estimate a measurement model for the latent variable of everyday discrimination and a structural model to examine associations between hypothesized predictors and the latent everyday discrimination variable. Confirmatory factor analyses revealed that a six-item, unidimensional version of the EDS fit the data best. SEM analyses showed that everyday discrimination was socially patterned across individual-, health-, community-, and cultural characteristics. Findings highlight the importance of considering how social positionalities and context may shape exposure to everyday discrimination. Importantly, our results have implications for identifying South Asian individuals at an increased risk of experiencing everyday discrimination and its associated health inequities, including cardiovascular disease-related outcomes.

Blood Pressure and Heart Rate Response to Orthostasis in Somali Americans

PURPOSE

Cardiovascular health disparities are present in African Americans, but it remains unknown whether this phenomenon affects Somali Americans. Study of Somali Americans is warranted due to distinct genetic and cultural differences from African Americans of western African ancestry. Orthostatic hemodynamic responses have implications for cardiovascular risk, especially among African American females. We sought to examine race and sex differences in systolic (SAP) and diastolic (DAP) arterial pressure and heart rate (HR) responsiveness to standing. We hypothesized that SAP, DAP, and HR change from supine to standing position would be higher in Somali Americans.

METHODS

We studied blood pressure and HR responsiveness in 139 (70 Somali, age 29 ± 10 years; 69 White, age 31 ± 9 years) participants. Supine SAP, DAP, and HR were measured after at least 5 min of supine rest, and again after 1 min of standing. SAP, DAP, and HR change was compared between groups.

RESULTS

ΔSAP and ΔDAP were similar between groups (race × sex: p > 0.05). However, HR responsiveness to orthostasis varied between race and sex comparisons (race × sex: p = 0.011). Somali females exhibited an augmented HR response to orthostasis compared to White females (Δ19 ± 13 vs. 11 ± 9 beats/min, p = 0.005) and Somali males (Δ19 ± 13 vs. 12 ± 9 beats/min, p = 0.020).

CONCLUSION

ΔHR with standing is augmented in young female Somali Americans. These findings highlight an early potential impairment in hemodynamic regulation that may heighten future cardiovascular risk. Further work is warranted to identify the potential autonomic nervous system underpinnings that may contribute to potentiated orthostatic responses and cardiovascular risk in Somali American females. Trial Registration www.

CLINICALTRIALS

gov ; unique identifier, NCT04124848; NCT05411029; NCT03308578.

Blood Pressure and Heart Rate Response to Orthostasis in Somali Americans

Purpose

Cardiovascular health disparities are present in African Americans, but it remains unknown whether this phenomenon affect Somali Americans. Study of Somali Americans is warranted due to distinct genetic and cultural differences from African Americans of western African ancestry. Orthostatic hemodynamic responses have implications for cardiovascular risk, especially among African American females. We sought to examine race and sex differences in systolic (SAP) and diastolic (DAP) arterial pressure and heart rate (HR) responsiveness to standing. We hypothesized that SAP, DAP, and HR change from supine to standing position would be higher in Somali Americans.

Methods

We studied blood pressure and HR responsiveness in 139 (70 Somali; age: 29±10 years, 69 White; age: 31±9 years) participants. Supine SAP, DAP, and HR were measured after at least five minutes of supine rest, and again after one minute of standing. SAP, DAP, and HR change was compared between groups.

Results

ΔSAP and ΔDAP were similar between groups (race × sex: p>0.05). However, HR responsiveness to orthostasis varied between race and sex comparisons (race×sex: p=0.011). Somali females exhibited an augmented HR response to orthostasis compared to White females (Δ19±13 vs. 11±9 beats/min, p=0.005) and Somali males (Δ19±13 vs. 12±9 beats/min, p=0.020).

Conclusion

ΔHR to standing is augmented in young female Somali Americans. These findings highlight an early potential impairment in hemodynamic regulation that may heighten future cardiovascular risk. Further work is warranted to identify the potential autonomic nervous system underpinnings that may contribute to potentiated orthostatic responses and cardiovascular risk in Somali American females.

Clinical Trial Registration

www.clinicaltrials.gov; unique identifier, NCT04124848; NCT05411029; NCT03308578.

Paving a Path to Equity in Cardiorenal Care

Cardiorenal syndrome encompasses a dynamic interplay between cardiovascular and kidney disease, and its prevention requires careful examination of multiple predisposing underlying conditions. The unequal distribution of diabetes, heart failure, hypertension, and kidney disease requires special attention because of the influence of these conditions on cardiorenal disease. Despite growing evidence regarding the benefits of disease-modifying agents (e.g., sodium-glucose cotransporter 2 inhibitors) for cardiovascular, kidney, and metabolic (CKM) disease, significant disparities remain in access to and utilization of these essential therapeutics. Multilevel barriers impeding their use require multisector interventions that address patient, provider, and health system-tailored strategies. Burgeoning literature also describes the critical role of unequal social determinants of health, or the sociopolitical contexts in which people live and work, in cardiorenal risk factors, including heart failure, diabetes, and chronic kidney disease. This review outlines (i) inequality in the burden and treatment of hypertension, type 2 diabetes, and heart failure; (ii) disparities in the use of key disease-modifying therapies for CKM diseases; and (iii) multilevel barriers and solutions to achieve greater pharmacoequity in the use of disease-modifying therapies. In addition, this review provides summative evidence regarding the role of unequal social determinants of health in cardiorenal health disparities, further outlining potential considerations for future research and intervention. As proposed in the 2023 American Heart Association presidential advisory on CKM health, a paradigm shift will be needed to achieve cardiorenal health equity. Through a deeper understanding of CKM health and a commitment to equity in the prevention, detection, and treatment of CKM disease, we can achieve this critical goal.

Diabetes in South Asians: Uncovering Novel Risk Factors With Longitudinal Epidemiologic Data: Kelly West Award Lecture 2023

South Asian populations have a higher prevalence and earlier age of onset of type 2 diabetes and atherosclerotic cardiovascular diseases than other race and ethnic groups. To better understand the pathophysiology and multilevel risk factors for diabetes and cardiovascular disease, we established the Mediators of Atherosclerosis in South Asians Living in America (MASALA) study in 2010. The original MASALA study cohort (n = 1,164) included 83% Asian Indian immigrants, with an ongoing expansion of the study to include individuals of Bangladeshi and Pakistani origin. We have found that South Asian Americans in the MASALA study had higher type 2 diabetes prevalence, lower insulin secretion, more insulin resistance, and an adverse body composition with higher liver and intermuscular fat and lower lean muscle mass compared with four other U.S. race and ethnic groups. MASALA study participants with diabetes were more likely to have the severe hyperglycemia subtype, characterized by β-cell dysfunction and lower body weight, and this subtype was associated with a higher incidence of subclinical atherosclerosis. We have found several modifiable factors for cardiometabolic disease among South Asians including diet and physical activity that can be influenced using specific social network members and with cultural adaptations to the U.S. context. Longitudinal data with repeat cardiometabolic measures that are supplemented with qualitative and mixed-method approaches enable a deeper understanding of disease risk and resilience factors. Studying and contrasting Asian American subgroups can uncover the causes for cardiometabolic disease heterogeneity and reveal novel methods for prevention and treatment.

Cardiovascular Health by Life's Essential 8 and Associations With Coronary Artery Calcium in South Asian American Adults in the MASALA Study

South Asian Americans experience high cardiovascular disease risk. We evaluated the distribution and correlates of cardiovascular health (CVH) summarized by the Life's Essential 8 (LE8) score among South Asian adults. In participants of the MASALA (Mediators of Atherosclerosis in South Asians Living in America) study, the association of demographic, social, and cultural factors with LE8 score was evaluated with t tests and analysis of variance. The association of LE8 score with coronary artery calcium (CAC) was evaluated with adjusted logistic regression. There were 556 women (mean age 55.9 years [SD 8.7], mean LE8 score 67.2 (SD 12.6) and 608 men (mean age 57.5 years [SD 9.9], mean LE8 score 61.9 (SD 13.1). Among women and men, the LE8 CVH score was higher in participants with higher annual family income, higher educational attainment, and fewer depressive symptoms. Overall, there was 26% lower odds of any CAC for each 10-point higher LE8 score (odds ratios [OR] 0.74, 95% confidence intervals [CI] 0.66 to 0.83), with similar magnitude of association in women and men. Participants with a high LE8 CVH score had 82% lower odds of CAC (OR 0.18, 95% CI 0.09 to 0.33), and participants with an intermediate LE8 CVH score had 38% lower odds of CAC (OR 0.62, 95% CI 0.41 to 0.94) than did participants with a low LE8 CVH score, with similar findings stratified by gender. In conclusion, in this cohort of South Asian Americans, most adults had suboptimal CVH assessed by the LE8 score. Higher LE8 score correlated with lower odds of any CAC.