Association of Social Networks and Physical Activity in South Asians: The Mediators of Atherosclerosis in South Asians Living in America Cohort Study

Percutaneous Coronary Intervention Outcomes by 5 Major Race and Ethnic Subgroups

BACKGROUND

Racial and ethnic disparities in cardiovascular disease outcomes, including percutaneous coronary intervention (PCI), are well-documented. However, studies do not stratify certain subgroups, such as separating South Asian and East Asian patients, who exhibit varying burdens of cardiovascular disease and PCI outcomes. Additionally, socioeconomic status (SES) further complicates outcomes, with low SES serving as an independent predictor of adverse outcomes post-PCI.

OBJECTIVES

This study aimed to analyze PCI outcomes across 5 racial and ethnic groups-White, Black, Hispanic, South Asian, and East Asian populations-while accounting for comorbidities and SES to better understand how race and ethnicity influence cardiovascular outcomes.

METHODS

We conducted a retrospective cohort study of patients undergoing PCI from 2012 to 2022. Patients were stratified by race/ethnicity and matched to median household income based on U.S. Census Zone Improvement Plan code data. The primary endpoint was 1-year major adverse cardiovascular events (MACE). Multivariable Cox regression models were used to assess outcomes, adjusting for comorbidities and SES.

RESULTS

A total of 21,236 patients were included: 47.8% White, 11.3% Black, 18.0% Hispanic, 20.7% South Asian, and 2.2% East Asian. South Asian patients had significantly lower MACE (adjusted HR: 0.62; P < 0.001) compared with White patients. Black patients, in contrast, had a higher risk of MACE (adjusted HR: 1.27; P = 0.032).

CONCLUSIONS

Significant racial and ethnic disparities exist in 1-year PCI outcomes, with South Asian patients exhibiting favorable outcomes compared with White patients, and Black patients experiencing worse outcomes. Baseline comorbidities and estimated SES do not fully explain these disparities, suggesting that targeted strategies are needed to address the multifactorial influences on PCI outcomes across racial and ethnic groups.

Social capital and physical activity: a literature review up to March 2024

Background

Social capital, as a multidimensional social science concept, plays a crucial role in promoting physical activity. Despite numerous studies exploring the relationship between social capital and physical activity, there is still a lack of systematic understanding of how different dimensions of social capital influence physical activity levels. This study aims to systematically review the literature up to 2024 on the relationship between social capital and physical activity, uncover the role of social capital in promoting physical activity, and identify its multidimensional impacts.

Methods

We used a combination of search terms including "social capital" and "physical activity" to search the Web of Science, PubMed, Scopus, SportDiscus, and PsychINFO databases for English literature published up to March 1, 2024.

Results

We identified 2,021 unique articles and reviewed 115 studies that met our inclusion criteria. These studies evaluated various dimensions of social capital, with key dimensions including social participation (34%), social networks (30%), social cohesion (30%), social trust (29%), overall social network (26%), social support (19%), safety (19%), norms of reciprocity (13%), social control (10%), satisfaction with the environment (8%), collective efficacy (4%), norms for physical activity (3%), and voting (1%). In studies exploring the relationship between social capital and physical activity, the majority of positive results in the hypothesized direction were observed in dimensions such as social cohesion, trust, participation, reciprocity, satisfaction with the environment, and overall social networks. In contrast, dimensions such as voting, collective efficacy, safety, control, and physical activity norms predominantly showed null or negative results. The results for social support were mixed, displaying positive, negative, and null outcomes, while findings for social networks were also predominantly mixed.

Conclusion

This study reveals the significant role of social capital in promoting physical activity, particularly in the dimensions of social cohesion, social trust, social participation, norms of reciprocity, satisfaction with environment, and overall social network. When designing public health interventions in the future, it is crucial to tailor strategies to different populations and contexts to better leverage social capital in promoting physical activity.

Social networks as facilitators and barriers to behavior change among U.S. South Asian adult participants of a culturally adapted, group lifestyle intervention

OBJECTIVES

This qualitative study aimed to characterize how social networks influence cardiovascular health behaviors among U.S. South Asian adults in a culturally adapted, group lifestyle intervention.

METHODS

A purposive sample of participants (n = 24) from the South Asian Healthy Lifestyle Intervention (SAHELI) randomized trial's intervention arm participated in semi-structured process evaluation interviews. Specific open-ended questions were used to probe participants' behavior changes, personal social networks, and social support for behavior change. The team transcribed interviews and identified themes using inductive and deductive coding, based on a theoretical model of social influence.

RESULTS

Among 24 participants (67 % female, mean age 50.5 years, 88 % foreign-born, 50 % with limited English proficiency), three themes emerged: 1) SAHELI participants and their family members provided bidirectional social support for behavior change; 2) intervention participants provided social support to one another; and 3) participants faced resistance to change from some community members.

CONCLUSIONS

Behavior changes initiated during SAHELI diffused to participants' close family members. Several social network influences varied by participant gender, English language proficiency, and network member type.

PRACTICE IMPLICATIONS

Health professionals should ask patients about how their social networks facilitate or hinder behavior changes. Gender and cultural factors may modify how social networks influence behavior change.

Social Determinants of Cardiovascular Health in Asian Americans: A Scientific Statement From the American Heart Association

To achieve cardiovascular health (CVH) equity in the United States, an understanding of the social and structural factors that contribute to differences and disparities in health is necessary. The Asian American population is the fastest-growing racial group in the United States but remains persistently underrepresented in health research. There is heterogeneity in how individual Asian American ethnic groups experience CVH and cardiovascular disease outcomes, with certain ethnic groups experiencing a higher burden of adverse social conditions, disproportionately high burden of suboptimal CVH, or excess adverse cardiovascular disease outcomes. In this scientific statement, upstream structural and social determinants that influence CVH in the Asian American population are highlighted, with particular emphasis on the role of social determinants of health across disaggregated Asian American ethnic groups. Key social determinants that operate in Asian American communities include socioeconomic position, immigration and nativity, social and physical environments, food and nutrition access, and health system-level factors. The role of underlying structural factors such as health, social, and economic policies and structural racism is also discussed in the context of CVH in Asian Americans. To improve individual-, community-, and population-level CVH and to reduce CVH disparities in Asian American ethnic subgroups, multilevel interventions that address adverse structural and social determinants are critical to achieve CVH equity for the Asian American population. Critical research gaps for the Asian American population are given, along with recommendations for strategic approaches to investigate social determinants of health and intervene to reduce health disparities in these communities.

Profiles of cardiometabolic risk and acculturation indicators among South Asians in the US: latent class analysis of the MASALA study

Background

South Asians (SA) represent the fastest growing US immigrant group, and previous studies have indicated that they face disproportionately high burden of cardiometabolic disease. Cardiometabolic disease manifests as a syndemic or synergistic epidemic encompassing multiple disease clusters influenced by biological, social, and psychological factors stemming from the acculturative process. This process may exacerbate morbidity within immigrant subgroups. Our aim was to identify cardiometabolic risk profiles among SA using indicators of acculturation.

Methods

We conducted a latent class analysis on data from the Mediators of Atherosclerosis in South Asians Living in America study (N=771). A composite cardiometabolic disease outcome was constructed using prevalent hypertension, type 2 diabetes, and body mass index. Acculturation indicators included years living in the US, English language proficiency, dietary behaviors, preservation of cultural traditions, social and neighborhood support, maintenance of social relationships (i.e., friendships), and experiences of discrimination, along with proxies of acculturative stress (i.e., depressive symptomology, trait anxiety and anger). Social and environmental determinants of health, health behaviors, religiosity and spirituality served as covariates to further assess latent class membership.

Results

Four cardiometabolic risk profiles emerged: (1) lowest risk [73.8% of sample] characterized by high integration into both SA and US cultures; (2) the modest risk [13.4% of sample], exhibiting elevated levels of mental health distress and experiences of discrimination, and distancing themselves from both cultures; and the (3) moderate risk [8.9% of sample] and (4) highest risk [3.9% of sample], demonstrating greater assimilation into US culture. Compared to the lowest risk profile: the modest risk profile was associated with low-income and conflicting attitudes about religion/spirituality, while the moderate risk profile was characterized by lower income and educational attainment with positive behaviors and attitudes toward religion/spirituality.

Conclusion

Findings expand our understanding of immigrant cardiometabolic health as a syndemic issue wherein multiple co-occurring and interacting processes synergize to produce negative outcomes in already at-risk subpopulations. Furthermore, acculturation emerges as a crucial factor in understanding health disparities among immigrant and refugee groups in the US.

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.

The Effect of Social Support on Social Media on Asian College Students' Intention to Participate in Physical Activity in the United States

Background

College students who identified themselves as Asians in the United States (i.e., Asian college students) are facing health inequalities and engaging in increasingly low levels of physical activity (PA). Although social support was found to be effective in increasing college students' PA and social media is an important channel for social support for Asian students, few studies have explored how to provide social support through social media interventions to promote Asian students' PA level. Thus, this study aimed to explore the effects of social support on social media on Asian college students' intention to participate in PA based on the theory of planned behavior.

Methods

We conducted an online Qualtrics survey among all undergraduate students at a university on the West Coast of the United States. Among 936 respondents, 337 (36%) were Asian college students. Descriptive analysis, regression models, and mediating effect tests were performed using SPSS 28.

Results

For Asian students, social support on social media has both direct effects and indirect effects through perceived behavioral control (PBC) on their intention to participate in PA.

Conclusion

Future interventions could consider encouraging Asian students to provide support to each other and form support groups using social media to increase their PBC.

The Role of Family Social Networks in Cardiovascular Health Behaviors Among Asian Americans, Native Hawaiians, and Pacific Islanders

Asian American, Native Hawaiians, and Other Pacific Islander (AANHPI) populations experience significant disparities in cardiovascular health. AANHPI populations also have strong, family-centered social relationships and networks. Since social networks may influence health behaviors, this review aimed to summarize research on the relationship between family social networks and cardiovascular health behaviors among AANHPI individuals. Current evidence suggests that family social network structures may play a particularly important role in smoking, dietary pattern, and physical activity behaviors among AANHPI individuals. Family networks may hinder or promote healthy behaviors through several social network mechanisms including social support, social influence, and social control. These effects vary across different AANHPI subgroups. Recommendations for future research on the role of social networks in health behaviors among AANHPI individuals are provided. Drawing on methodological advances and interventions that leverage social networks in AANHPI populations may be an avenue to improve health and reduce disparities.

Risk Amplifiers for Vascular Disease and CKD in South Asians: When Intrinsic β-Cell Dysfunction Meets a High-Carbohydrate Diet

South Asians, comprising almost one fourth of the world population, are at higher risk of type 2 diabetes mellitus, hypertension, cardiovascular disease, and CKD compared with other ethnic groups. This has major public health implications in South Asia and in other parts of the world to where South Asians have immigrated. The interplay of various modifiable and nonmodifiable risk factors confers this risk. Traditional models of cardiometabolic disease progression and CKD evaluation may not be applicable in this population with a unique genetic predisposition and phenotype. A wider understanding of dietary and lifestyle influences, genetic and metabolic risk factors, and the pitfalls of conventional equations estimating kidney function in this population are required in providing care for kidney diseases. Targeted screening of this population for metabolic and vascular risk factors and individualized management plan for disease management may be necessary. Addressing unhealthy dietary patterns, promoting physical activity, and medication management that adheres to cultural factors are crucial steps to mitigate the risk of cardiovascular disease and CKD in this population. In South Asian countries, a large rural and urban community-based multipronged approach using polypills and community health workers to decrease the incidence of these diseases may be cost-effective.

Physical Activity in South Asian Indians: A Systematic Review of Randomized Controlled Trials

This review systematically examines the characteristics and effectiveness of randomized controlled trials with aerobic physical activity (PA) interventions tailored to South Asian Indians (SAIs). PubMed/MEDLINE, Scopus, Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, CINAHL, and Google Scholar were searched. The search yielded 1,842 studies; 11 met the criteria. The Center for Evidence-Based Medicine's critical appraisal tool was used to assess the quality of studies. Studies that used supervised structured PA sessions, educational material in SAI languages, motivational strategies, and positive reinforcement for goal setting, reported significant improvement in PA (p < .05; Cohen's d ≤ 0.3 to >0.8). Future PA studies in India featuring SAIs would benefit from clinic-based one-on-one structured aerobic PA interventions. In contrast, SAI immigrants in Western countries would benefit from community-based structured aerobic PA interventions that are offered in groups and culturally adapted.

Obesity and Cardiovascular Risk among South Asian Americans

Purpose of review

South Asian Americans experience higher cardiometabolic risk and disproportionately high rates of cardiovascular disease (CVD) compared to other racial and ethnic groups in the United States. The purpose of this review is to summarize recent evidence about the role of obesity in CVD risk in South Asian Americans and identify key evidence gaps and future directions for research and interventions for obesity in this group.

Recent findings

South Asian Americans are predisposed to abdominal obesity and have a higher distribution of visceral fat, intermuscular fat, and intrahepatic fat compared to adults of other race and ethnic groups. In this population, the risk for cardiometabolic disease appears to be elevated even at a normal body mass index. Social, cultural, religious, interpersonal, and environmental factors are related to obesity and obesity-related behaviors among South Asian Americans.

Summary

There is a relatively high prevalence of obesity in South Asian-origin populations in the United States, who have unique socio-cultural determinants of overweight and obesity. Future research should clarify why the risk for metabolic disease and CVD is elevated at normal BMI in the South Asian American population, and environmental and other structural factors that may influence obesity in this group. Interventions must be adapted to the social and cultural context of South Asian Americans to improve effectiveness and implementation.

Identification and Management of Atherosclerotic Cardiovascular Disease Risk in South Asian Populations in the U.S

South Asians (SAs, individuals with ancestry from Bangladesh, Bhutan, India, Maldives, Nepal, Pakistan, and Sri Lanka) are among the fastest growing ethnic subgroups in the United States. SAs typically experience a high prevalence of diabetes, abdominal obesity, and hypertension, among other cardiovascular disease risk factors, which are often under recognized and undermanaged. The excess coronary heart disease risk in this growing population must be critically assessed and managed with culturally appropriate preventive services. Accordingly, this scientific document prepared by a multidisciplinary group of clinicians and investigators in cardiology, internal medicine, pharmacy, and SA-centric researchers describes key characteristics of traditional and nontraditional cardiovascular disease risk factors, compares and contrasts available risk assessment tools, discusses the role of blood-based biomarkers and coronary artery calcium to enhance risk assessment and prevention strategies, and provides evidenced-based approaches and interventions that may reduce coronary heart disease disparities in this higher-risk population.

Barriers and facilitators to healthy active living in South Asian families in Canada: a thematic analysis

OBJECTIVES

The study objective was to understand the barriers and facilitators to healthy active living in South Asian families living in Canada.

DESIGN

Semi-structured interviews of 30-60-minute duration with South Asian women with young families, and analysed using a thematic analytical approach.

SETTING

Community-dwelling South Asian women interviewed in the home environment or by phone.

PARTICIPANTS

Fifteen married South Asian women (mean age=34.2 years) living in the Peel region of Ontario, Canada, with at least 1 child under the age of 5 years. The majority of women had immigrated to Canada (13/15), during a 5-10-year interval preceding interviews.

RESULTS

57 different codes were derived from 18 interview hours, and further evaluated through member checking. The top three barriers to healthy eating were: (1) not having enough time for healthy food preparation, (2) lack of knowledge about what is healthy eating and (3) viewing healthy eating as a matter of engaging in time limited dieting. These barriers were addressed with: (1) knowledge and awareness of healthy eating, (2) clear goal setting, (3) access to fresh vegetables and fruits and (4) better arrangements and more time for food preparation. The top five barriers to physical activity were: (1) not enough time and energy, (2) competing priorities, (3) lack of childcare, (4) lack of family-engaging exercise and (5) limited access to interesting exercise programming. These barriers were addressed by: (1) experiencing exercise as enjoyable and stress releasing, (2) commitments to walking exercise, (3) use of an electronic exercise-tracking device, (4) offspring exercise supported by spouse and family and (5) success stories about exercise from others.

CONCLUSIONS

Barriers to healthy active living in South Asian women with young families can be addressed with facilitators that stimulate clear goal setting and healthy food preparation skills, and exercise formats that engage mothers and offspring, with or without exercise tracking.

Low Amount and Intensity of Leisure-time Physical Activity in Asian Indian Adults

PURPOSE

We sought to describe leisure-time, aerobic, and muscle strengthening physical activity (PA) patterns in U.S. Asian Indians, in comparison to other races/ethnicities.

DESIGN, SETTING, AND SAMPLE

We utilized the 2011-2018 National Health Interview Surveys, a set of cross-sectional, nationally representative surveys of the U.S. noninstitutionalized population. Our study population included 257 652 adults who answered PA questions.

MEASURES

PA was classified per 2008 U.S. guidelines and continuously per estimated metabolic equivalents (METs). Race was classified into White, Black, Asian Indian, Other Asian, and American Indian/Alaskan Native/Multiracial.

ANALYSIS

We used survey design-adjusted, multivariable logistic regression to determine odds of sufficient and highly active physical activity levels, adjusting for predisposing, enabling, need, and health care service factors as guided by the Anderson Model. We also used linear regression to determine racial differences in average MET-minutes/week. Analysis was additionally stratified by comorbidity status.

RESULTS

While Asian Indians (N = 3049) demonstrated similar odds of sufficient aerobic PA as Whites (aOR [95% CI]: .97 [.88,1.07]), Asian Indians had 22% lower odds of meeting highly active aerobic PA levels (.78 [.71,0.87]) and 18% lower odds of meeting sufficient muscle strengthening PA levels (.82 [.73,0.91]). This translated to an average 172 (95% CI: 45 300) fewer MET-minutes. Furthermore, this decrease in MET-minutes/week was especially apparent in those without hypertension (β[95% CI]: -164 [-314,-15]) without diabetes (-185 [-319,-52]), and low/normal BMI (-422 [-623,-222]).

CONCLUSION

Asian Indians, especially those without comorbidities, are less likely to engage in high-intensity physical activity than Whites.

Assessing Social Network Influences on Adult Physical Activity Using Social Network Analysis: A Systematic Review

OBJECTIVE

Social network analysis (SNA) can measure social connectedness and assess impact of interpersonal connections on health behaviors, including physical activity (PA). This paper aims to systematically review adult PA studies using SNA to understand important social network concepts relative to PA.

DATA SOURCE

A search was performed using PsycINFO, MEDLINE, PubMed, and Web of Science.

STUDY INCLUSION AND EXCLUSION CRITERIA

To be included in the search, articles needed to 1) include a measure of PA, 2) conduct an SNA in which specific relationships were measured, and 3) conduct an analysis between social network measures and PA.

DATA EXTRACTION

Key study elements including network design and results were extracted.

DATA SYNTHESIS

Data were synthesized to answer 2 questions: 1) how has adult PA been investigated using SNA approaches and 2) how is an adult's social network associated with PA behaviors?

RESULTS

A final sample of 28 articles remained from an initial 11 085 articles. Network size, homophily, network composition, and network exposure to PA were all associated with individual level PA across studies. Lastly, longitudinal and intervention studies showed a more complex picture of social influence and diffusion of PA behavior.

CONCLUSIONS

Adults' PA behaviors are influenced by their networks. Capitalizing on this influence, researchers should engage not just individual behavior change but also the social influences present within the person's life.

Epidemiology of diabetes among South Asians in the United States: lessons from the MASALA study

South Asian individuals in the United States are at an increased risk of type 2 diabetes (T2DM); however, the mechanisms behind this are not well understood. The Mediators of Atherosclerosis in South Asians Living in America (MASALA) study is the only longitudinal cohort of South Asians in the United States and provides key insights as to the epidemiology of T2DM in South Asians. Evidence from the MASALA study suggests that South Asians experience a disproportionately high burden of prevalent and incident T2DM compared with members of other race/ethnic groups. Higher insulin resistance in South Asians, even with low body mass index (BMI), more impairment in insulin secretion, and greater deposition of ectopic fat likely play a role in T2DM etiology. Furthermore, South Asian migrants to the United States experience a range of factors related to acculturation, social networks, and religious beliefs, which may impact physical activity and dietary practices. Interventions to prevent T2DM in South Asians should include a focus on cultural factors related to health and should consider the complete mechanistic pathway and the relative contributions of insulin resistance, β cell dysfunction, and ectopic fat deposition on T2DM development in South Asians, particularly in those with lower BMI.

Association of Social Network Characteristics With Cardiovascular Health and Coronary Artery Calcium in South Asian Adults in the United States: The MASALA Cohort Study

Background

South Asian adults have worse cardiovascular health (CVH) and more coronary artery calcium compared with other race/ethnicities. The impact of the social environment has not been examined as a potential driver of CVH or coronary artery calcium in this population. We evaluated associations of social network characteristics with CVH and coronary artery calcium in South Asian American adults to inform strategies for CVH promotion in this at‐risk population.

Methods and Results

Using data from the MASALA (Mediators of Atherosclerosis in South Asians Living in America) cohort study, multinomial and multivariable logistic regression were used to evaluate associations of participant social network size and density, proportion of network who are kin or South Asian ethnicity and reported health of participant's identified social network members (“alters”), with participant CVH and presence of coronary artery calcium. The 699 MASALA participants included were mean age 59.2 (SD, 9.2) years and 42.9% women. After adjustment, a 1‐person larger social network size was associated with 13% higher odds of ideal CVH (odds ratio [OR], 1.13; 95% CI, 1.01–1.27). Reporting an alter with high blood pressure was associated with lower odds of ideal CVH (OR, 0.51; 95% CI, 0.29–0.88), and reporting an alter with high cholesterol was associated with lower odds of ideal CVH (OR, 0.54; 95% CI, 0.30–0.94).

Conclusions

Social network characteristics are associated with CVH in South Asian American adults. Engaging social networks may help promote CVH in this population.

Associations of Neighborhood Factors and Activity Behaviors: The Mediators of Atherosclerosis in South Asians Living in America (MASALA) Study

Social and built environments may influence physical activity (PA). However, evidence for South Asian Americans (SAA), a group with low PA levels and high cardiometabolic risk, is lacking. We assessed the association between five neighborhood factors and PA behaviors in a community-based cohort of SAA. Data were from the Mediators of Atherosclerosis in South Asians Living in America (MASALA) Study 2010-2013 (n = 906). Adjusted multivariable models stratified by sex regressing PA behaviors on neighborhood factors were run. Higher neighborhood social cohesion was associated with 17% more PA MET minutes/week in men (p < 0.01), but not in women. Having a park/playground near home was associated with meeting PA guidelines (odds ratio (95% CI): men: 3.14 (1.20-8.24); women: 3.67 (1.17-11.52). Neighborhood factors were associated with favorable PA behaviors in SAA. PA interventions for SAA that increase neighborhood social cohesion or focus on linking individuals with local resources may be effective.