Can traditional risk factors explain the higher risk of cardiovascular disease in South Asians compared to Europeans in Norway and New Zealand? Two cohort studies

Trends in incidence rates of acute myocardial infarction and stroke among immigrant groups in Norway, 1999-2019: the NCDNOR project

AIMS

We aimed to study time trends of acute myocardial infarction (AMI) and stroke incidence rates among immigrant groups living in Norway, with a special focus on immigrants from South Asia and former Yugoslavia.

METHODS

All incident AMI and stroke events were identified in Norwegian residents aged 35-79 years during 1996-2019 using hospital and cause of death registry data. A 3-year wash-out period was used to identify incident events. Thus, cases were counted from 1999 onwards. We calculated annual age-standardised incidence rates using direct standardisation. Poisson regression was used to calculate the average annual change in incidence rates of AMI and stroke and to study differences between immigrant groups and the Norwegian-born population.

RESULTS

Age-standardised incidence rates of AMI were higher in immigrants from South Asia and former Yugoslavia than in the Norwegian-born population. For Norwegian-born men and women, and former Yugoslavian women, the annual age-standardised AMI incidence rates declined over the study period by 2.4%, 2.0% and 2.3%, respectively. South Asian men and women and former Yugoslavian men did not experience such a decline, although there was an apparent decline in the last 3 years of the period for South Asian men. For former Yugoslavian men, this resulted in increasing differences compared with Norwegian-born men. For stroke, all these groups had declining trends in incidence rates, and former Yugoslavian women had the strongest decline of 4.3% annually.

CONCLUSION

During 1999-2019, immigrants from South Asia and former Yugoslavia did not experience the same beneficial decline in AMI incidence as the Norwegian-born population. However, both immigrant groups experienced similar or larger declines in the incidence of stroke as Norwegian-born men and women.

Effects of Metformin on CIMT and FMD in PCOS patients: a systematic review and meta-analysis

BACKGROUND

This study aims to analyze the efficacy of metformin on carotid intima media thickness (CIMT) and flow-mediated dilation (FMD) for patients with polycystic ovary syndrome (PCOS).

METHODS

A literature search of PubMed, Embase, and the Cochrane Library from inception to December 2023 was conducted. Then, after studies selection and data extraction, the mean difference (MD) with a 95% confidence interval (CI) was used to evaluate metformin efficacy in CIMT and FMD for PCOS patients. Heterogeneity was investigated through subgroup and sensitivity analysis. The protocol of our study has been registered in PROSPERO (CRD42024497239).

RESULTS

A total of 12 studies with 248 patients were included. CIMT was lower in the endpoint group (after metformin) compared with the baseline group (before metformin) (MD = -0.11, 95% CI = -0.21 to -0.01, p = 0.04). FMD was higher in the endpoint group compared with the baseline group (MD = 3.25, 95% CI = 1.85 to 4.66, p < 0.01). No statistically significant difference was observed in nitroglycerin-mediated dilation (NMD) between the two groups (MD = 0.65, p = 0.51). Subgroup analysis showed that a relatively lower MD of CIMT in PCOS patients from Europe in the endpoint group compared with the baseline group (MD = -0.09, 95% CI = -0.14 to -0.04, p < 0.001). However, the MD in CIMT was not significantly different between the endpoint group and baseline group in PCOS patients from Asia (p = 0.270).

CONCLUSION

Metformin may have a beneficial effect on CIMT and FMD, but not on NMD, suggesting that metformin may help reduce cardiovascular events in PCOS patients. Notably, the clinical efficacy of metformin can be influenced by regional differences and study types.

International Migration and Cardiovascular Health: Unraveling the Disease Burden Among Migrants to North America and Europe

Europe and North America are the 2 largest recipients of international migrants from low-resource regions in the world. Here, large differences in cardiovascular disease (CVD) morbidity and death exist between migrants and the host populations. This review discusses the CVD burden and its most important contributors among the largest migrant groups in Europe and North America as well as the consequences of migration to high-income countries on CVD diagnosis and therapy. The available evidence indicates that migrants in Europe and North America generally have a higher CVD risk compared with the host populations. Cardiometabolic, behavioral, and psychosocial factors are important contributors to their increased CVD risk. However, despite these common denominators, there are important ethnic differences in the propensity to develop CVD that relate to pre- and postmigration factors, such as socioeconomic status, cultural factors, lifestyle, psychosocial stress, access to health care and health care usage. Some of these pre- and postmigration environmental factors may interact with genetic (epigenetics) and microbial factors, which further influence their CVD risk. The limited number of prospective cohorts and clinical trials in migrant populations remains an important culprit for better understanding pathophysiological mechanism driving health differences and for developing ethnic-specific CVD risk prediction and care. Only by improved understanding of the complex interaction among human biology, migration-related factors, and sociocultural determinants of health influencing CVD risk will we be able to mitigate these differences and truly make inclusive personalized treatment possible.

Prevalence of cardiovascular risk factors among Asian migrant workers in South Korea

BACKGROUND

The burden of non-communicable diseases is rapidly increasing among young adults in middle- and low-income countries. Asian migrant workers continue to be a significant contributor to South Korea's economy; however, their cardiovascular health is neglected. We explored the prevalence of cardiovascular risk factors among Asian migrant workers in South Korea.

METHODS

Cross-sectional survey, anthropometric measurements, blood pressure measurements, and biochemical tests including triglyceride, high-density lipoprotein, low-density lipoprotein, total cholesterol, fasting blood sugar, HbA1c, and C-reactive protein levels were conducted in 141 Asian migrant workers in South Korea.

RESULTS

The mean age of the participants was 31.3 (5.6) years. Of the participants, 14.8% were current smokers, and 47.5% consumed alcohol. The prevalence of overweight/obesity was 32.4%. The prevalence of hypertension and dyslipidemia were 51.2% and 64.6%, respectively. Of the participants, 98.5% had an increased waist circumference; elevated HbA1C and C-reactive protein was seen in 20.9% and 4.3%, respectively. The prevalence of metabolic syndrome was 5.5%. Clustering of two or more risk factors was seen in 45% of the participants. Factors associated with a high risk of cardiovascular diseases (clustering of two or more risk factors) were age (odds ratio 1.16, p < 0.01) and smoking (4.98, p < 0.05).

CONCLUSION

The prevalence of cardiovascular risk factors was alarmingly high among Asian migrant workers employed in South Korea. Efforts to mitigate and eliminate those risk factors are urgently required.

SCORE2 cardiovascular risk prediction models in an ethnic and socioeconomic diverse population in the Netherlands: an external validation study

Background

Socioeconomic status and ethnicity are not explicitly incorporated as risk factors in the four SCORE2 cardiovascular disease (CVD) risk models developed for country-wide implementation across Europe (low, moderate, high and very-high model). The aim of this study was to evaluate the performance of the four SCORE2 CVD risk prediction models in an ethnic and socioeconomic diverse population in the Netherlands.

Methods

The SCORE2 CVD risk models were externally validated in socioeconomic and ethnic (by country of origin) subgroups, from a population-based cohort in the Netherlands, with GP, hospital and registry data. In total 155,000 individuals, between 40 and 70 years old in the study period from 2007 to 2020 and without previous CVD or diabetes were included. Variables (age, sex, smoking status, blood pressure, cholesterol) and outcome first CVD event (stroke, myocardial infarction, CVD death) were consistent with SCORE2.

Findings

6966 CVD events were observed, versus 5495 events predicted by the CVD low-risk model (intended for use in the Netherlands). Relative underprediction was similar in men and women (observed/predicted (OE-ratio), 1.3 and 1.2 in men and women, respectively). Underprediction was larger in low socioeconomic subgroups of the overall study population (OE-ratio 1.5 and 1.6 in men and women, respectively), and comparable in Dutch and the combined "other ethnicities" low socioeconomic subgroups. Underprediction in the Surinamese subgroup was largest (OE-ratio 1.9, in men and women), particularly in the low socioeconomic Surinamese subgroups (OE-ratio 2.5 and 2.1 in men and women). In the subgroups with underprediction in the low-risk model, the intermediate or high-risk SCORE2 models showed improved OE-ratios. Discrimination showed moderate performance in all subgroups and the four SCORE2 models, with C-statistics between 0.65 and 0.72, similar to the SCORE2 model development study.

Interpretation

The SCORE 2 CVD risk model for low-risk countries (as the Netherlands are) was found to underpredict CVD risk, particularly in low socioeconomic and Surinamese ethnic subgroups. Including socioeconomic status and ethnicity as predictors in CVD risk models and implementing CVD risk adjustment within countries is desirable for adequate CVD risk prediction and counselling.

Funding

Leiden University Medical Centre and Leiden University.

The Lancet women and cardiovascular disease Commission: reducing the global burden by 2030

Cardiovascular disease is the leading cause of death in women. Decades of grassroots campaigns have helped to raise awareness about the impact of cardiovascular disease in women, and positive changes affecting women and their health have gained momentum. Despite these efforts, there has been stagnation in the overall reduction of cardiovascular disease burden for women in the past decade. Cardiovascular disease in women remains understudied, under-recognised, underdiagnosed, and undertreated. This Commission summarises existing evidence and identifies knowledge gaps in research, prevention, treatment, and access to care for women. Recommendations from an international team of experts and leaders in the field have been generated with a clear focus to reduce the global burden of cardiovascular disease in women by 2030. This Commission represents the first effort of its kind to connect stakeholders, to ignite global awareness of sex-related and gender-related disparities in cardiovascular disease, and to provide a springboard for future research.

Validation of the cardiovascular risk model NORRISK 2 in South Asians and people with diabetes

OBJECTIVES

To evaluate the predictive ability of the previously published NORRISK 2 cardiovascular risk model in Norwegian-born and immigrants born in South Asia living in Norway, and to add information about diabetes and ethnicity in an updated model for South Asians and diabetics (NORRISK 2-SADia). Design. We included participants (30-74 years) born in Norway (n = 13,885) or South Asia (n = 1942) from health surveys conducted in Oslo 2000-2003. Cardiovascular disease (CVD) risk factor information including self-reported diabetes was linked with information on subsequent acute myocardial infarction (AMI) and acute cerebral stroke in hospital and mortality registry data throughout 2014 from the nationwide CVDNOR project. We developed an updated model using Cox regression with diabetes and South Asian ethnicity as additional predictors. We assessed model performance by Harrell's C and calibration plots. Results. The NORRISK 2 model underestimated the risk in South Asians in all quintiles of predicted risk. The mean predicted 13-year risk by the NORRISK 2 model was 3.9% (95% CI 3.7-4.2) versus observed 7.3% (95% CI 5.9-9.1) in South Asian men and 1.1% (95% CI 1.0-1.2) versus 2.7% (95% CI 1.7-4.2) observed risk in South Asian women. The mean predictions from the NORRISK 2-SADia model were 7.2% (95% CI 6.7-7.6) in South Asian men and 2.7% (95% CI 2.4-3.0) in South Asian women. Conclusions. The NORRISK 2-SADia model improved predictions of CVD substantially in South Asians, whose risks were underestimated by the NORRISK 2 model. The NORRISK 2-SADia model may facilitate more intense preventive measures in this high-risk population.

Cardiovascular risk assessment in South and Middle-East Asians living in the Western countries

Nearly a quarter of the world population lives in the South Asian region (India, Pakistan, Bangladesh, Sri Lanka, Nepal, Bhutan, and the Maldives). Due to rapid demographic and epidemiological transition in these countries, the burden of non-communicable diseases is growing, which is a serious public health concern. Particularly, the prevalence of pre-diabetes, diabetes and atherosclerotic cardiovascular disease (CVD) is increasing. South Asians living in the West have also substantially higher risk of CVD and mortality compared with white Europeans and Americans. Further, as a result of global displacement over the past three decades, Middle-Eastern immigrants now represent the largest group of non-European immigrants in Northern Europe. This vulnerable population has been less studied. Hence, the aim of the present review was to address cardiovascular risk assessment in South Asians (primarily people from India, Pakistan and Bangladesh), and Middle-East Asians living in Western countries compared with whites (Caucasians) and present results from some major intervention studies. A systematic search was conducted in PubMed to identify major cardiovascular health studies of South Asian and Middle-Eastern populations living in the West, relevant for this review. Results indicated an increased risk of CVD. In conclusion, both South Asian and Middle-Eastern populations living in the West carry significantly higher risk of diabetes and CVD compared with native white Europeans. Lifestyle interventions have been shown to have beneficial effects in terms of reduction in the risk of diabetes by increasing insulin sensitivity, weight loss as well as better glycemic and lipid control.

Diet quality and risk factors for cardiovascular disease among South Asians in Alberta

South Asians have a higher prevalence of early onset cardiovascular disease risk compared with other populations. Dietary intake is a modifiable risk factor for cardiovascular disease. Dietary patterns in immigrants and successive generations of South Asians settled in Western countries undergo adaptions. Little is known about the dietary intake of South Asians in Alberta, thus the objective of the present study was to describe the dietary patterns among South Asians and their risks for cardiovascular diseases. A retrospective analysis of data collected from 140 South Asian adults participating in the Alberta’s Tomorrow Project was conducted. Dietary intake was assessed using a food frequency questionnaire and the Healthy Eating Index (HEI) was used an indicator of overall diet quality and adherence to dietary recommendations made by Health Canada. Central obesity (70%), hypercholesterolemia (27%), and hypertension (14%) were predominant health conditions observed in the study participants. About 56% and 44% of participants obtained moderate and poor HEI scores, respectively. The diet quality of the majority of participants was inadequate to meet macro- and micronutrient intake recommendations. The high prevalence of poor/moderate diet quality and pre-existing chronic health conditions across all body mass index groups is a cause for concern in this population.

Epidemiology, risk factors, and opportunities for prevention of cardiovascular disease in individuals of South Asian ethnicity living in Europe

South Asian (SA) individuals represent a large, growing population in a number of European countries. These individuals, particularly first-generation SA immigrants, are at higher risk of developing type 2 diabetes, atherogenic dyslipidaemia, and coronary heart disease than most other racial/ethnic groups living in Europe. SAs also have an increased risk of stroke compared to European-born individuals. Despite a large body of conclusive evidence, SA-specific cardiovascular health promotion and preventive interventions are currently scarce in most European countries, as well as at the European Union level. In this narrative review, we aim to increase awareness among clinicians and healthcare authorities of the public health importance of cardiovascular disease among SAs living in Europe, as well as the need for tailored interventions targeting this group - particularly, in countries where SA immigration is a recent phenomenon. To this purpose, we review key studies on the epidemiology and risk factors of cardiovascular disease in SAs living in the United Kingdom, Italy, Spain, Denmark, Norway, Sweden, and other European countries. Building on these, we discuss potential opportunities for multi-level, targeted, tailored cardiovascular prevention strategies. Because lifestyle interventions often face important cultural barriers in SAs, particularly for first-generation immigrants; we also discuss features that may help maximise the effectiveness of those interventions. Finally, we evaluate knowledge gaps, currently available risk stratification tools such as QRISK-3, and future directions in this important field.

Performance of a Framingham cardiovascular risk model among Indians and Europeans in New Zealand and the role of body mass index and social deprivation

Objectives

To evaluate a Framingham 5-year cardiovascular disease (CVD) risk score in Indians and Europeans in New Zealand, and determine whether body mass index (BMI) and socioeconomic deprivation were independent predictors of CVD risk.

Methods

We included Indians and Europeans, aged 30–74 years without prior CVD undergoing risk assessment in New Zealand primary care during 2002–2015 (n=256 446). Risk profiles included standard Framingham predictors (age, sex, systolic blood pressure, total cholesterol/high-density lipoprotein ratio, smoking and diabetes) and were linked with national CVD hospitalisations and mortality datasets. Discrimination was measured by the area under the receiver operating characteristics curve (AUC) and calibration examined graphically. We used Cox regression to study the impact of BMI and deprivation on the risk of CVD with and without adjustment for the Framingham score.

Results

During follow-up, 8105 and 1156 CVD events occurred in Europeans and Indians, respectively. Higher AUCs of 0.76 were found in Indian men (95% CI 0.74 to 0.78) and women (95% CI 0.73 to 0.78) compared with 0.74 (95% CI 0.73 to 0.74) in European men and 0.72 (95% CI 0.71 to 0.73) in European women. Framingham was best calibrated in Indian men, and overestimated risk in Indian women and in Europeans. BMI and deprivation were positively associated with CVD, also after adjustment for the Framingham risk score, although the BMI association was attenuated.

Conclusions

The Framingham risk model performed reasonably well in Indian men, but overestimated risk in Indian women and in Europeans. BMI and socioeconomic deprivation could be useful predictors in addition to a Framingham score.