Excess coronary artery disease risk in South Asian immigrants: can dysfunctional high-density lipoprotein explain increased risk?

Cardiovascular risk profile in two cohorts of young apparently healthy South Asian descendants in the Netherlands: still a long way to go!

BACKGROUND

Cardiovascular disease (CVD) imposes a major healthcare burden on young descendants of South Asian migrants living in the western world. In comparison to the native population, the prevalence is significantly higher and the prevalence of CVD risk factors is increasing rapidly. The cardiovascular risk profile and 10-year risk scores of South Asian descendants were evaluated in two cohorts with a 10-year time difference.

METHODS

Two cross-sectional studies, conducted in 2004 and 2014, focused on asymptomatic South Asian descendants aged 18-59 years were performed. A short questionnaire, BMI, waist circumference, blood pressure, and nonfasting blood tests were obtained. The cohort of 2014 was matched with the cohort of 2004, based on age, gender, and family history of CVD.

RESULTS

In 2014, 674 South Asians (44% men, age 38.2 ± 12.0 years) were matched with 674 South Asians (44% men, age 38.3 ± 12.1 years) included in 2004. Notably, hypertension prevalence decreased significantly in 2014 (10.6% vs 23.1% in 2004, P  < 0.001), while mean BMI increased (26.1 vs 24.9, P  < 0.001). The mean Framingham risk score was lower in 2014 (5.31 ± 6.19%) than in 2004 (6.45 ± 8.02%, P  < 0.05).

CONCLUSION

This study demonstrates that South Asian descendants in 2014 have a lower but still high absolute risk for coronary events compared to 2004. Important differences in cardiovascular risk profile exist. Despite improvements, South Asian descendants in 2014 still face a high absolute risk for coronary events compared to 2004, indicating the necessity for continued primary prevention and lifestyle interventions.

Control of cardiometabolic risk factors and their association with carotid intima media thickness among patients with type 2 diabetes mellitus-single center experience in a developing country

Background/aim

Type 2 diabetes mellitus (T2DM) is closely associated with atherosclerotic cardiovascular diseases (ASCVD). The objective of this study was to describe the degree of ASCVD risk factor control and their association with carotid intima-media thickness (CIMT) in T2DM patients followed up at a diabetes clinic in Southern, Sri Lanka.

Materials and methods

A crosssectional study was conducted to examine the association between CIMT and nonalcoholic fatty liver disease (NAFLD)in 300 T2DM patients. Both CIMT and its associations with modifiable cardiometabolic risk factors were examined using ultrasonography. The recommended optimal targets for risk factors were defined as glycated hemoglobin (HbA1C) < 7 %, absence of NAFLD, albumin-to-creatinine ratio (ACR) < 30 mg, triglyceride (TG) < 150 mg/dL, low-density lipoprotein cholesterol (LDL-C) < 100 mg/dL, high-density lipoprotein cholesterol (HDL-C) in men > 40 and in women > 50 mg/dL, systolic blood pressure (SBP) < 130 mmHg, and diastolic blood pressure (DBP) < 80 mmHg.

Results

SBP, DBP, LDL-C, TG, HDL-C, HbA1C, and ACR were optimally controlled in 59.3%, 75.0%, 46.7%, 84.3%, 46.0%, 33.0%, and 18.7% of patients, respectively. Notably, nearly half of the study subjects did not have NAFLD. Only three patients (1%) had achieved all therapeutic targets. There were statistically significant differences in CIMT between optimally controlled TG and suboptimally controlled TG group (p = 0.027) and between the groups with and without NAFLD (p = 0.045) when adjusted for age and duration of diabetes. CIMT showed significant and positive associations with LDL-C (p = 0.024), TG (p = 0.026), and NAFLD (p = 0.005). Among these, the presence of NAFLD had the highest odds of having higher CIMT when compared to LDL-C and TG.

Conclusion

The majority of patients have not achieved the recommended targets for ASCVD risk factors and are at high risk of ASCVD. It is therefore necessary to identify the reasons for not achieving the treatment targets in order to reduce the ASCVD burden by controlling LDL-C, TG, and NAFLD.

The impact of the Sri Lankan economic crisis on medication adherence: An online cross-sectional survey

Background

The economic crisis in Sri Lanka has disarrayed the country's healthcare services, posing a challenge to people with chronic diseases on routine care. This study investigated the changes in medication adherence during the economic crisis.

Methods

A web-based cross-sectional survey was undertaken in July-August 2022. It assessed socio-demographics, diseases, medication adherence, and reasons for changes in compliance of respondents and their family members during the economic crisis. Descriptive statistics and multivariable logistic regression analysis were used.

Findings

A total of 1214 respondents, aged ≥18 years were included in the survey. The majority were females (60%). The main finding was that 39%, 41%, and 37% of participants, their family members, or children respectively have changed medication use during the crisis. Among those who changed their medication practices, the most significant change was the change in the brand, reported by 44.7% of the respondents. A similar pattern was observed among other family members, with 61.3% of adults and 53.8% of children switching brands. Respondents who lived outside the Colombo district had a significantly increased risk of changing medication (OR = 1.425, 95% CI = 1.020-1.992, P = 0.038). Respondents with monthly incomes of less than 100,000 LKR had a twofold greater risk of medication nonadherence compared to participants who earned more than 100,000 LKR per month (OR = 2.278, 95% CI = 1.37-3.78, P = 0.001). The most stated reason for changing medication among adults was the high cost of drugs, whereas among, children, the lack of access to drugs in the public or private sector was the leading cause of non-compliance.

Interpretation

The population's adherence to medication is negatively impacted by the economic crisis in Sri Lanka.

Cardiovascular Disease in South Asian Immigrants: a Review of Dysfunctional HDL as a Potential Marker

South Asians (SAs) account for a quarter of the world's population and are one of the fastest-growing immigrant groups in the United States (US). South Asian Immigrants (SAIs) are disproportionately more at risk of developing cardiovascular disease (CVD) than other ethnic/racial groups. Atherosclerosis is a chronic inflammatory disorder and is the major cause of CVD. Traditional CVD risk factors, though important, do not fully explain the elevated risk of CVD in SAIs. High-density lipoproteins (HDLs) are heterogeneous lipoproteins that modify their composition and functionality depending on physiological or pathological conditions. With its cholesterol efflux, anti-inflammatory, and antioxidant functions, HDL is traditionally considered a protective factor for CVD. However, its functions can be compromised under pathological conditions, such as chronic inflammation, making it dysfunctional (Dys-HDL). SAIs have a high prevalence of type 2 diabetes and metabolic syndrome, which may further promote Dys-HDL. This review explores the potential association between Dys-HDL and CVD in SAIs and presents current literature discussing the role of Dys-HDL in CVD.

Lipid accumulation product (LAP) as a potential index to predict risk of insulin resistance in young, non-obese Asian Indian males from Southern India: observations from hyperinsulinemic-euglycemic clamp studies

INTRODUCTION

We aimed to compare the predictive accuracy of surrogate indices namely the lipid accumulation product (LAP) index, homeostatic model of assessment of insulin resistance (HOMA-IR), fasting glucose-insulin ratio (FG-IR) and the quantitative-insulin sensitivity check index (QUICKI), against the M value of hyperinsulinemic-euglycemic clamp (HEC), and to determine a cut-off value for the LAP index to predict risk of insulin resistance in non-obese (body mass index <21 kg/m²), normoglycemic, Asian Indian males from Southern India.

RESEARCH DESIGN AND METHODS

Data of HEC studies performed in 108 non-obese, normoglycemic, Asian Indian males was obtained retrospectively and the M value (a measure of whole-body insulin sensitivity) was calculated. The M value is the rate of whole-body glucose metabolism at the hyperinsulinemic plateau (a measure of insulin sensitivity) and is calculated between 60 and 120 min after the start of the insulin infusion in the HEC procedure. The LAP index, the HOMA-IR, FG-IR and QUICKI were calculated. Spearman's correlation and logistic regression analysis were performed. Cut-off value for the LAP index was obtained using receiver operating characteristics with area under curve (AUC) analysis at 95% CI. P value <0.05 was considered to be statistically significant.

RESULTS

Significant negative correlation was observed for the M value with LAP index (r=-0.39, p<0.001) while significant positive correlation was noted with FG-IR (r=0.25; p<0.01) and QUICKI (r=0.22; p<0.01). The LAP index cut-off value ≥33.4 showed 75% sensitivity and 75% specificity with AUC (0.72) to predict risk of insulin resistance in this cohort.

CONCLUSION

The LAP index showed higher predictive accuracy for the risk of insulin resistance as compared with HOMA-IR, QUICKI and FG-IR in non-obese, normoglycemic Asian Indian males from Southern India.

Genetic and Non-genetic Determinants of Cardiovascular Disease in South Asians

South Asians (SAs), people from the Indian subcontinent (e.g., India, Pakistan, Bangladesh, Sri Lanka, and Nepal) have a higher prevalence of cardiovascular disease (CVD) and suffer from a greater risk of CVD-associated mortality compared to other global populations. These problems are compounded by the alterations in lifestyles due to urbanization and changing cultural, social, economic, and political environments. Current methods of CV risk prediction are based on white populations that under-estimate the CVD risk in SAs. Prospective studies are required to obtain actual CVD morbidity/mortality rates so that comparisons between predicted CVD risk can be made with actual events. Overwhelming data support a strong influence of genetic factors. Genome-Wide Association Studies (GWAS) serve as a starting point for future genetic and functional studies since the mechanisms of action by which these associated loci influence CVD is still unclear. It is difficult to predict the potential implication of these findings in clinical settings. This review provides a systematic assessment of the risk factors, genetics, and environmental causes of CV health disparity in SAs, and highlights progress made in clinical and genomics discoveries in the rapidly evolving field, which has the potential to show clinical relevance in the near future.

Genetic, clinical, molecular, and pathogenic aspects of the South Asian-specific polymorphic MYBPC3Δ25bp variant

Hypertrophic cardiomyopathy (HCM) is a cardiac genetic disease characterized by ventricular enlargement, diastolic dysfunction, and increased risk for sudden cardiac death. Sarcomeric genetic defects are the predominant known cause of HCM. In particular, mutations in the myosin-binding protein C gene (MYBPC3) are associated with ~ 40% of all HCM cases in which a genetic basis has been established. A decade ago, our group reported a 25-base pair deletion in intron 32 of MYBPC3 (MYBPC3Δ25bp) that is uniquely prevalent in South Asians and is associated with autosomal dominant cardiomyopathy. Although our studies suggest that this deletion results in left ventricular dysfunction, cardiomyopathies, and heart failure, the precise mechanism by which this variant predisposes to heart disease remains unclear. Increasingly appreciated, however, is the contribution of secondary risk factors, additional mutations, and lifestyle choices in augmenting or modifying the HCM phenotype in MYBPC3Δ25bp carriers. Therefore, the goal of this review article is to summarize the current research dedicated to understanding the molecular pathophysiology of HCM in South Asians with the MYBPC3Δ25bp variant. An emphasis is to review the latest techniques currently applied to explore the MYBPC3Δ25bp pathogenesis and to provide a foundation for developing new diagnostic strategies and advances in therapeutics.

Lipids in South Asians: Epidemiology and Management

Purpose of Review

This review focuses on lipoprotein abnormalities in South Asians (SA) and addresses risk stratification and management strategies to lower atherosclerotic cardiovascular disease (ASCVD) in this high-risk population.

Recent Findings

South Asians (SAs) are the fastest growing ethnic group in the United States (U.S) and have an increased risk of premature coronary artery disease (CAD). While the etiology may be multifactorial, lipoprotein abnormalities play a key role. SAs have lower low-density lipoprotein cholesterol (LDL-C) compared with Whites and at any given LDL-C level, SA ethnicity poses a higher risk of myocardial infarction (MI) and coronary artery disease (CAD) compared with other non-Asian groups. SAs have lower high-density lipoprotein cholesterol (HDL-C) with smaller particle sizes of HDL-C compared with Whites. SAs also have higher triglycerides than Whites which is strongly related to the high prevalence of metabolic syndrome in SAs. Lipoprotein a (Lp(a)) levels are also higher in SAs compared with many other ethnic groups. This unique lipoprotein profile plays a vital role in the elevated ASCVD risk in SAs. Studies evaluating dietary patterns of SAs in the U.S show high consumption of carbohydrates and saturated fats.

Summary

SAs have a high-risk lipoprotein profile compared with other ethnicities. Lipid abnormalities play a central role in the pathogenesis of CAD in SAs. More studies are needed to understand the true impact of the various lipoproteins and their contribution to increasing ASCVD in SAs. Aggressive lowering of LDL-C in high-risk groups using medications, such as statins, and lifestyle modification including dietary changes is essential in overall CAD risk reduction.

Investigating apolipoproteins of human high-density lipoprotein by cyclodextrin-micellar electrokinetic chromatography

A cyclodextrin-micellar electrokinetic chromatography (CD-MEKC) method has been developed to determine the apolipoproteins (apos) of human high-density lipoprotein (HDL). The optimal CD-MEKC conditions included a separation buffer mixture of 5 mM sodium phosphate, 40 mM bile salts (50% sodium cholate and 50% sodium deoxycholate), 25 mM carboxymethyl-β-CD (CM-β-CD) and pH 7.0. The separation voltage was 15 kV, and the capillary temperature was 15℃. The CD-MEKC profiles of human HDL apolipoproteins showed good repeatability and sensitivity. Linear analysis has been performed for human apolipoprotein standards including apos AI, AII, CI, CII, CIII and E. Linear regression lines with coefficients of determination (R²) greater than 0.99 were obtained for apos AI, AII, CI, CII and E. The linear ranges for the six apolipoproteins were within 0.18-0.70 mg/mL, and the concentration limits of detection (LOD) were lower than 0.0617 mg/mL. Apos AI, AII, CI and CIII were identified and quantified in human HDL by comparing with apolipoprotein standards. Furthermore, the CD-MEKC profiles of uremic patients differed significantly from healthy subjects. The concentration ratios of apo AI/apo CIII were significantly lower for uremic patients than healthy subjects. This study demonstrated the feasibility of determining human HDL apolipoproteins by CD-MEKC. In the future, it might help monitor the progression of uremia and cardiovascular disease.

Caucasian and south Asian men show equivalent improvements in surrogate biomarkers of cardiovascular and metabolic health following 6-weeks of supervised resistance training

Background: The South Asian population have greater cardiovascular risk than their age-matched Caucasian counterparts, characterized by unfavorable biomarkers. South Asians may also be partially resistant to the pleiotropic benefits of physical activity on cardiovascular health. There is a current absence of studies that compare markers of cardio-metabolic health between Caucasians and South Asians employing resistance exercise. This study set out to compare the response in biomarkers of cardio-metabolic health in Caucasians and South Asians in response to resistance exercise. Methods: Caucasian (n=15, 25.5 ± 4.8 yrs) and South Asian (n=13, 25.4 ± 7.0 yrs) males completed a 6-week progressive resistance exercise protocol. Fasting blood glucose, insulin, and their product insulin resistance (HOMA-IR), triglycerides (TRIGS), low density lipoprotein (LDL), high density lipoprotein (HDL), total cholesterol (TC), vascular endothelial growth factor (VEGF), asymmetric dimythylarginine (ADMA), L-arginine (L-ARG) and C-reactive protein (CRP) were established at baseline and following resistance exercise. Results: There were significant improvements in fasting glucose, TC, LDL, HDL and VEGF in both groups following resistance exercise ( p<0.05, for all). No change was observed in insulin, HOMA-IR, TRIGS, ADMA, L-ARG following resistance exercise ( p>0.05, in both groups). CRP increased in the South Asian group ( p<0.05) but not the Caucasian group ( p>0.05) Conclusions: The cardio-metabolic response to resistance exercise is comparable in young Caucasian and South Asian males though inflammatory response to exercise may be prolonged in South Asians.

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.

The effect of tranexamic acid in unilateral and bilateral total knee arthroplasty in the South Asian population: A retrospective cohort study

INTRODUCTION

Together with evidence of higher bleeding tendencies, the vulnerability of the South-Asian population to anemia secondary to a higher prevalence of hemoglobinopathies and micronutrient deficiencies merits further exploration of the effects of tranexamic acid on this population. Additionally, limited access to self-care facilities and certain sociocultural beliefs and practices may not be conducive to a speedy recovery from surgical complications. The aim of this study is to investigate the effects of intraoperative administration of tranexamic acid during total knee arthroplasty when considering the South-Asian population.

METHODOLOGY

Medical record files of 355 patients who underwent total knee arthroplasty (2007-2015) were reviewed to collect data regarding patient characteristics, surgical variables and post-operative complications. Unilateral and Bilateral total knee arthroplasty were studied separately. Analysis was done using t-test, Mann-Whitney U test, chi-square and Fisher's exact square where appropriate. The threshold for significance was p < 0.05.

RESULTS

The study showed that for unilateral surgery, tranexamic acid caused a significant reduction in estimated blood loss (p-value=0.011), total operative time, calculated blood loss, and hemoglobin change (p-value<0.001) whereas in bilateral surgery, tranexamic acid only caused a significant reduction in calculated blood loss (p-value < 0.001) and hemoglobin change (p-value=0.001). Interestingly, in those who received tranexamic acid vs. those who did not, there was a significant increase in length of hospital stay (p<0.001) and special care unit admissions (p-value=0.033) in unilateral and bilateral surgery respectively.

CONCLUSIONS

Although tranexamic acid effectively reduces intraoperative blood loss, it does not have an effect on the need for post-operative blood transfusions. The increased length of stay and special care unit admissions associated with tranexamic acid use should be explored further to reveal the complete safety profile of tranexamic acid administration in the South-Asian population during total knee arthroplasty.

Total knee Arthroplasty: risk factors for allogeneic blood transfusions in the South Asian population

BACKGROUND

Total knee arthroplasty (TKA) is the recommended treatment for end-stage knee osteoarthritis. Considering the various risks associated with intra and postoperative blood transfusions, better understanding is required with respect to the risk factors contributing to a greater possibility of blood transfusion during or after surgery. Although literature highlights several such factors, our study is among the first to identify these risk factors in the South Asian population which differs from other populations in several ways.

METHODS

The study consists of a review of 658 patients undergoing TKA from 2005 to 2015. Data was obtained from patient medical records and was analysed using logistic regression analysis. The relationship between each predictor and the outcome variable was calculated as an Odds ratio (OR), the threshold of significance for which was p = 0.25 and p = 0.05 for univariate and multivariable analysis respectively.

RESULTS

The mean age of the patient population was 63 years (78% female), 25% of whom received one or more blood transfusions. Multivariable analysis revealed 5 significant independent predictors for increased risk of blood transfusions including bilateral knee surgery (OR:5.51), preoperative anemia (OR:4.15), higher ASA (American Society of Anaesthesiologists) status (3-4) (OR:1.92), female sex (OR:3.44) and BMI (Body mass index) ≤30 (OR:1.79) while increasing co-morbidities and age (>60) were found to be insignificant.

CONCLUSIONS

The factors identified for the South Asian population are largely similar to those for other populations. Identification of high risk patients will permit the application of an international multipronged approach which not only targets the modifiable risk factors but also the decision making process and blood management protocols in order to minimize the transfusion associated risks for a patient undergoing a TKA.

Coronary artery disease in women

BACKGROUND

Despite the importance of CAD for women, there is persistent perception that CAD is a man's disease. Contributing to this notion is the observation of differences in incidence rates according to age; the incidence of CAD in women is lower than men, but rises steadily after fifth decade. The distribution of CAD risk factors varies between men and women across age ranges and failure to consider these differences may have contributed to the belief that women are at lower risk of CAD compared with men. In addition, women are more likely to have symptoms considered atypical compared with men. There is an urgent need to better understand the presentation of cardiac symptoms in women, in order to facilitate diagnosis and treatment, to initiate aggressive risk factor intervention and to improve the quality of life.

METHODS

We studied clinical and angiographic profile of women undergoing coronary angiogram over a period of 6 years at Nanavati Hospital, Mumbai. The objectives were to examine the distribution of risk factor and coronary angiographic patterns of CAD in women.

RESULTS

It was observed that coronary artery disease is most commonly involving females between the age 60 to 80 years. Raised LDL-C was found to be most common risk factor involved in development of coronary artery disease in females. Most common presentation of CAD in women is unstable angina or non-ST segment elevation MI. Most common coronary angiography finding was single vessel disease.

CONCLUSION

Though coronary artery disease is late to present in women it significantly hamper quality of life. The clinical presentation of coronary artery disease in women varies from asymptomatic to severe unstable angina to myocardial infarction. Stress testing and 2D-ECHO helps to some extent for prediction of coronary artery disease but false positive as well as false negative test results are not negligible. Coronary angiography is the conclusive test to determine spectrum and characterization of coronary artery anatomy in women. As this study is based on experience at single center, various biases may be possible. Widespread data collection involving multiple center and multiple operators will be helpful.

Algorithm for predicting CHD death risk in Turkish adults: conventional factors contribute only moderately in women

OBJECTIVE

To assist the management strategy of individuals, we determined an algorithm for predicting the risk of coronary heart disease (CHD) death in Turkish adults with a high prevalence of metabolic syndrome (MetS).

METHODS

The risk of CHD death was estimated in 3054 middle-aged adults, followed over 9.08±4.2 years. Cox proportional hazard regression was used to predict risk. Discrimination was assessed using C-statistics.

RESULTS

CHD death was identified in 233 subjects. In multivariable analysis, the serum high-density lipoprotein-cholesterol (HDL-C) level was not predictive in men and the non-HDL-C level was not predictive in women. Age, presence of diabetes, systolic blood pressure ≥160 mm Hg, smoking habit, and low physical activity were predictors in both sexes. The exclusion of coronary disease at baseline did not change the risk estimates materially. Using an algorithm of the 7 stated variables, individuals in the highest category of risk score showed a 19- to 50-fold higher spread in the absolute risk of death from CHD than those in the second lowest category. C-index of the model using age alone was as high as 0.774 in men and 0.836 in women (p<0.001 each), while the incorporation of 6 conventional risk factors contributed to a C-index of 0.058 in males and 0.042 in females.

CONCLUSION

In a middle-aged population with prevalent MetS, men disclosed anticipated risk parameters (except for high HDL-C levels) as determinants of the risk of CHD death. On the other hand, serum non-HDL-C levels and moderate systolic hypertension were not relevant in women. The moderate contribution of conventional risk factors (beyond age) to the estimation of the risk of CHD death in women is consistent with the operation of autoimmune activation.

Little contribution of conventional factors in an algorithm to predicting death risk in Turkish adults

OBJECTIVE

Determinants of risk of death are highly relevant for the management strategy of individuals. We aimed to determine an algorithm for predicting risk of death in Turkish adults who have a high prevalence of metabolic syndrome (MetS).

METHODS

Nine-year risk of death was estimated in 3348 middle-aged adults, followed over 8.81±4.2years. Cox proportional hazard regression was used to predict risk of death. Discrimination was assessed using C-statistics.

RESULTS

Death occurred in 565 subjects. In multivariable analysis, high-density lipoprotein (HDL) and non-HDL cholesterol levels were not predictive in either sex; in women, current smoking was also not predictive. Age, presence of diabetes, systolic blood pressure ≥160mmHg and low physical activity were predictors in both sexes, beyond smoking status in men. Exclusion of coronary disease at baseline did not change risk estimates materially. Using an algorithm of the stated 7 variables showed an 11- to 18-fold spread in the absolute risk of dying among individuals in the highest than in the lowest of 4 risk score categories. C-statistics of the model using age alone was 0.790 in men, 0.808 in women (p<0.001 each), while the incorporation of 6 conventional risk factors contributed to C-index was >0.020 in males and 0.009 in females.

CONCLUSIONS

In a middle-aged population with prevalent MetS, serum lipoproteins and, in women, smoking status, were not relevant for the risk of death. The contribution of conventional risk factors beyond age to estimating risk of death was modest among Turkish men, and little in women in whom autoimmune activation is operative.

Genetic epidemiology of coronary artery disease: an Asian Indian perspective

Coronary artery disease (CAD) has emerged as a major cause of morbidity and mortality worldwide. Recent findings on the role of genetic factors in the aetiopathology of CAD have implicated novel genes and variants in addition to those involved in lipid and lipoprotein metabolism. However, our present knowledge is limited due to lack of clarity on their exact identity and the quantum of impact on disease susceptibility, and incident risk. It is a matter of great interest to understand the role of genetic factors in ethnic populations that have a strong underlying predisposition to CAD such as the South Asian populations, particularly among Asian Indians living in India and abroad. Although, a number of isolated studies do implicate certain gene polymorphisms towards enhanced disease susceptibility, the available data remains scanty and inconclusive as they have not been validated in large, prospective cohorts. The present review aims to consolidate the available literature on the genetics of CAD in Asian Indians and seeks to provide insights on the concerns that need to be addressed in future studies to generate information having clinical value.

The association between fasting serum insulin, apo-lipoproteins level, and severity of coronary artery involvement in non-diabetic patients

BACKGROUND

In the previous studies, fasting insulin and apo-lipoproteins are considered as one of the risk-factor of coronary artery disease (CAD) but did not have the same results. In this study, we attempted to define the association of high fasting insulin and apo-lipoproteins of serum in non-diabetic patients who were afflicted with coronary arteries disease with severity of coronary arteries involvement.

MATERIALS AND METHODS

This study was conducted between September 2011 and February 2012 on three groups, each one consisting of 100 members while using angiographic scores of Gensini with three equal groups with low, medium, and high stenosis of coronary arteries. The evaluation of non-diabetic patients afflicted with CADs, included the fasting glucose level less than 126 mg/dl or non-consumption of blood glucose reduction drugs or negativity history of diabetes.

RESULTS

In this study, there were 300 non-diabetic patients afflicted with CAD in three groups of low, medium, and high extremity. Due to attained results, the patients afflicted with high CAD had a higher level of insulin (18.3 ± 0.8) in relation with low and medium groups (P < 0.001). As it was observed, the level of serum apo-lipoproteins of A1 (APO-A1) in low group of CAD (175 ± 36.4) is meaningfully higher than its quantity in high-CAD group (158 ± 42.4, P < 0.001). Furthermore, the quantity of serum apo-lipoproteins of B (APO-B) in mild CAD group (139 ± 30.4) is meaningfully less than severe CAD group (155.21 ± 29.7, P < 0.001).

CONCLUSION

Our findings show that insulin, APO-A1, APO-B, and total cholesterol measurement is a good case for defining the severity of coronary artery involvement, while high-density lipoprotein, low-density lipoprotein, and triglyceride are not important risk-factors.

One size does not fit all: cardiovascular health disparities as a function of ethnicity in Asian-American women

OBJECTIVE

Although few studies have examined cardiovascular disease in Asian-American subgroups separately, limited data in Asian Americans strongly suggest that some subgroups are at increased risk. The present study examined modifiable cardiovascular risk factor profiles as a function of Asian ethnicity.

METHODS

This descriptive cross-sectional pilot study recruited Asian-American women (N=147) in northeast Florida including Cambodians (n=39), Chinese (n=36), Filipinos (n=49), and Vietnamese (n=23). Risk factors included blood pressure, body mass index, waist circumference and blood lipids.

RESULTS

Filipino participants (41%) had ≥4 risk factors compared to 21% Cambodian, 13% Vietnamese and 0% Chinese. The Chinese had significantly more participants (44%) with the absence of CVD risk factors compared to all other subgroups. Obesity rate (18%), mean BMI: 26 ± 5 kg/m(2) and mean triglycerides (173 ± 103 mg/dL) were highest in Filipinas (n=49). The Chinese (n=36) had a low rate (4%) of obesity with a mean BMI of 23 ± 3 kg/m(2) and the least risk factors along with the lowest triglycerides (88 ± 44 mg/dL). Cambodians (n=39; BMI of 24 ± 3 kg/m(2)) and Vietnamese (n=23; BMI: 22 ± 3 kg/m(2)) had low rates of obesity with comparable rates of unhealthy lipids and hypertension as the Filipinas.

CONCLUSIONS

Modifiable CVD risk factor profiles significantly differed as a function of ethnicity supporting the premise that Asian-American women cannot be categorized as one group and the traditional "one size fits all" prevention or treatment of CVD risk factors should be re-considered.

Racial/ethnic differences in dyslipidemia patterns

BACKGROUND

No studies have comprehensively examined the prevalence of dyslipidemia, a major risk factor for cardiovascular disease, among diverse racial/ethnic minority groups. The primary aim of this study was to identify racial/ethnic differences in dyslipidemia among minorities including Asian Americans (Asian Indian, Chinese, Filipino, Japanese, Korean, or Vietnamese), Mexican Americans, and blacks compared with non-Hispanic whites.

METHODS AND RESULTS

Using a 3-year cross section (2008-2011), we identified 169 430 active primary care patients (35 years or older) from an outpatient healthcare organization in northern California. Age-standardized prevalence rates were calculated for 3 dyslipidemia subtypes: high triglycerides (fasting laboratory value ≥150 mg/dL), low levels of high-density lipoprotein cholesterol (fasting laboratory value <40 mg/dL [men] and <50 mg/dL [women]), and high levels of low-density lipoprotein cholesterol (fasting laboratory value ≥130 mg/dL or taking low-density lipoprotein-lowering agents). Odds ratios were calculated by multivariable logistic regression, with adjustment for patient characteristics (age, measured body mass index, smoking). Compared with non-Hispanic whites, every minority subgroup had an increased prevalence of high triglycerides except blacks. Most minority groups had an increased prevalence of low high-density lipoprotein cholesterol, except for Japanese and blacks. The prevalence of high low-density lipoprotein cholesterol was increased among Asian Indians, Filipinos, Japanese, and Vietnamese compared with non-Hispanic whites.

CONCLUSIONS

Minority groups, except for blacks, were more likely to have high triglyceride/low high-density lipoprotein cholesterol dyslipidemia. Further research is needed to determine how racial/ethnic differences in dyslipidemia affect racial/ethnic differences in cardiovascular disease rates.

Culturally Specific Tobacco Use and South Asians in the United States

Over the past two decades, the United States has attracted large South Asian populations, who have imported tobacco products previously unique to the native subcontinent. South Asian cigarette use prevalence is consistently lower than other U.S. Asian subgroups; however, most surveys fail to capture smokeless products accurately. In part because of the pervasive use of popular smokeless cultural products resulting in greater population attributable risk of oral malignancies, many countries outside the United States have developed surveillance systems to capture these products and implemented effective population-level or community-based intervention strategies. This minority population in the United States continues to be “at risk” of suffering from a disproportionate burden of diseases, which are plausibly linked to the use of these products. The primary focus of this article is to provide an exhaustive literature review of tobacco use patterns and existing tobacco control strategies among South Asians in the United States. Framed within the social ecological model, the article suggests that there needs to be more detailed assessment of cultural tobacco products, a concurrent increase in cultural competencies of health care providers and provision of cessation resources outside the clinical setting. At the policy level, future efforts should adequately regulate these products and oversight must include such products in efforts to reduce rates of use. Concurrently, community-based efforts are needed to change social norms related to perceived health benefit and lack of stigma. This will help ensure that appropriately framed messages around use rates and burden of disease are addressed through culturally valued institutions and leaders.

Coronary disease risk prediction algorithm warranting incorporation of C-reactive protein in Turkish adults, manifesting sex difference

BACKGROUND AND AIM

An algorithm is needed for predicting coronary heart disease (CHD) risk in Turkish adults who have a high prevalence of metabolic syndrome (MetS).

METHODS AND RESULTS

Ten-year risk of CHD was estimated in 2232 middle-aged adults free of CHD at baseline, followed over 7.6-years. Cox proportional hazard regression was used to predict CHD. Discrimination was assessed with area under receiver operating characteristics curve (AROC). CHD developed in 302 subjects. In multivariable analysis, high-density lipoprotein (HDL)-cholesterol levels were borderline predictive in men; smoking status and HDL-and low-density lipoprotein (LDL)-cholesterol levels were not predictive in women. Age, presence of diabetes, systolic blood pressure and C-reactive protein (CRP) were predictors in both sexes, while smoking status and LDL-cholesterol were so in men only. AROC of the model was 0.789 in men, and 0.806 in women (p < 0.001 each). An algorithm using the stated seven variables was derived separately for each sex. After age adjustment, men and women in the highest quintile of risk score were significantly and 20-27-fold more likely to develop CHD than those in the lowest quintile.

CONCLUSIONS

In a population with prevalent MetS, low-grade inflammation is independently relevant for CHD, as are serum lipoproteins and smoking status. The derived algorithm is effective in estimating CHD risk among Turkish adults.

Metabolic syndrome among Sri Lankan adults: prevalence, patterns and correlates

Metabolic Syndrome (MS) increases the risk for Coronary Artery Disease, stroke and diabetes. MS is twice more common amongst South Asian immigrants in US compared to native Caucasians. There are no nationally representative studies on prevalence of MS from any of the South Asian countries. The present study aims to evaluate the prevalence of MS among Sri Lankan adults and investigates its relationships with socio-demographic, clinical and biochemical parameters. Data on MS and its associated details were obtained from a population-based cross-sectional study conducted between years 2005-2006. MS was defined according to the International Diabetes Federation criteria. A binary logistic regression analysis was performed using the dichotomous variable MS (0 = absent, 1 = present). The independent co-variants were: gender, age category, area of residence, ethnicity, level of education, income and physical activity. Sample size was 4,485 (Response rate-89.7%), 39.5% were males and mean age was 46.1 ± 15.1 years. The crude prevalence of MS was 27.1% (95% CI: 25.8-28.5), and age-adjusted prevalence was 24.3% (95% CI: 23.0-25.6). Prevalence in males and females were 18.4% (95% CI: 16.5-20.3) and 28.3% (95% CI: 26.6-30.0) respectively (p < 0.001). Urban adults (34.8% [95% CI: 31.8-37.9]) had a significantly higher prevalence than rural adults (21.6% [95% CI: 20.2-23.0]). Among ethnic groups, the highest prevalence of MS was observed in Sri Lankan Moors (43.0% [95% CI: 37.2-48.9]). In all adults, MS was observed in those with the highest level of education and monthly household income. Prevalence of MS in the different physical activity categories of the IPAQ were; 'inactive'-38.8% (95% CI 34.5-43.2), 'moderately active'-33.5% (95% CI 30.9-36.1) and 'active'-21.1% (95% CI 19.6-22.7). The results of the binary logistic regression analysis indicates that female gender (OR:1.7), increasing age, urban living (OR:1.7), Moor ethnicity (OR:2.6), secondary (OR:1.5) and tertiary levels of education (OR:2.3), monthly household income LKR 7,000-24,999 (OR:1.5) and >50,000 (OR:2.1), and physical inactivity (OR:1.6), all significantly increased risk of developing MS. MS is common among Sri Lankan adults affecting nearly one-fourth of the population. Female gender, increasing age, urban living, higher socio-economical status and physical inactivity were important associated factors.

Epidemiology and risk factors of cerebral ischemia and ischemic heart diseases: similarities and differences

Cerebral ischemia and ischemic heart diseases, common entities nowadays, are the main manifestation of circulatory diseases. Cardiovascular diseases, followed by stroke, represent the leading cause of mortality worldwide. Both entities share risk factors, pathophisiology and etiologic aspects by means of a main common mechanism, atherosclerosis. However, each entity has its own particularities. Ischemic stroke shows a variety of pathogenic mechanisms not present in ischemic heart disease. An ischemic stroke increases the risk of suffering a coronary heart disease, and viceversa. The aim of this chapter is to review data on epidemiology, pathophisiology and risk factors for both entities, considering the differences and similarities that could be found in between them. We discuss traditional risk factors, obtained from epidemiological data, and also some novel ones, such as hyperhomocisteinemia or sleep apnea. We separate risk factors, as clasically, in two groups: nonmodifiables, which includes age, sex, or ethnicity, and modifiables, including hypertension, dyslipidemia or diabetis, in order to discuss the role of each factor in both ischemic events, ischemic stroke and coronary heart disease.

Incorporation of whole, ancient grains into a modern Asian Indian diet to reduce the burden of chronic disease

Refined carbohydrates, such as white rice and white flour, are the mainstay of the modern Asian Indian diet, and may contribute to the rising incidence of type 2 diabetes and cardiovascular disease in this population. Prior to the 1950s, whole grains such as amaranth, barley, brown rice, millet, and sorghum were more commonly used in Asian Indian cooking. These grains and other non-Indian grains such as couscous, quinoa, and spelt are nutritionally advantageous and may be culturally acceptable carbohydrate substitutes for Asian Indians. This review focuses on practical recommendations for culturally sensitive carbohydrate modification in a modern Asian Indian diet to reduce type 2 diabetes and cardiovascular disease in this population.

Low-grade inflammation, and dysfunction of high-density lipoprotein and its apolipoproteins as a major driver of cardiometabolic risk

Dysfunction of high-density lipoprotein (HDL) particles that even become proinflammatory or lose atheroprotective properties is known through analyses of HDL isolated from diabetic subjects. Recently, high concentrations of HDL or apolipoprotein (apo) A-I in individuals with diabetes or coronary heart disease were found to reveal dysfunction in some population-based studies. Such dysfunction of HDL and its apos A-I, A-II, and C-III has been observed in a general population for the first time among Turkish adults. Functional defectiveness manifested itself by unexpected correlations with inflammatory biomarkers and, in long-term follow-up, by lack of protection against diabetes and coronary heart disease, accounting for the excess incidences in Turks. Female sex was more pronouncedly affected by this process that presumably exists in other ethnicities in South Asia, East Europe, and the Middle East. In contradistinction, in Western and East Asian population, only individuals with glucose intolerance or those at risk for cardiometabolic disease are considered to be or were documented in a review of clinical trials to have been affected by impaired function of HDL. High-density lipoprotein dysfunctionality is closely linked to obesity and low-grade inflammation yet seems to act partly independently of them. Cigarette smoking in overweight women with low-grade inflammation appears to offer limited protection against cardiometabolic risk. The great impact in public health of the dysfunction of protective serum proteins requires individual clinical recognition, appropriate preventive measures, and delineation of management, including with anti-inflammatory drugs.

Prevalence of metabolic syndrome in patients with angiographically proven coronary artery disease presenting to a tertiary care hospital in Delhi, India

BACKGROUND

Coronary artery disease is fast emerging as the major concern for afflicting people across the globe. The Indian subcontinent is highly predisposed to this condition due to distinctive risk factor profile of this population. This fact has led to a condition where the current preventative and management protocols that have worked well in the non-Asian Indian Caucasian populations, have failed to bring about the anticipated control over the incidence and progression of CAD in Asian Indians. Metabolic syndrome has been identified as a major determinant of CAD in this population.

MATERIALS AND METHODS

The prevalence of metabolic syndrome was determined in 431 patients undergoing coronary angiography through various diagnostic algorithms. The Asian modified diagnostic criteria were also implemented to estimate the metabolic syndrome prevalence in patients with different levels of stenosis.

RESULTS

We observed a high incidence of metabolic syndrome in the patients with coronary artery disease. The prevalence of MS increased with increase in severity of coronary artery involvement. The IDF guideline with Asian modification was the most successful diagnostic algorithm.

CONCLUSIONS

It is now imperative to acknowledge the unique pattern of CAD and risk factor profile prevalent among South Asians. This will facilitate more focused and individualized management protocols directed to this population. Metabolic syndrome is a major syndrome prevalent in this population. Hence, effective control of MS may help in reducing the morbidity and mortality due to CAD in a great way.

Metabolic syndrome in South Asian immigrants: more than low HDL requiring aggressive management

Aggressive clinical and public health interventions have resulted in significant reduction in coronary artery disease (CAD) worldwide. However, South Asian immigrants (SAIs) exhibit the higher prevalence of CAD and its risk factors as compared with other ethnic populations. The objective of the current study is to assess the prevalence of metabolic syndrome (MS), its association with high density Lipoprotein (HDL) function, Apo lipoprotein A-I (APOA1) gene polymorphisms, and sub-clinical CAD using common carotid intima-media thickness (CCA-IMT) as a surrogate marker. A community-based cross-sectional study was conducted on SAIs aged 35-65 years. Dysfunctional/pro-inflammatory (Dys-HDL) was determined using novel cell free assay and HDL inflammatory index. Six intronic APOA1 gene polymorphisms were analyzed by DNA sequencing. According to the International Diabetes Federation definition, MS prevalence was 29.7% in SAIs without CAD and 26% had HDL inflammatory index ≥ 1 suggesting pro-inflammatory Dys-HDL. Six novel APOA1 single nucleotide polymorphisms (SNPs) were analyzed with logistic regression, three SNPs (G2, G3, and G5) were found to be significantly associated with MS (p = 0.039, p = 0.038, p = 0.054). On multi-variate analysis, MS was significantly associated with BMI > 23 (P = 0.005), Apo-A-I levels (p = 0.01), and Lp [a] (p < 0.0001). SAIs are known to be at a disproportionately high risk for CAD that may be attributed to a high burden for MS. There is need to explore and understand non-traditional risk factors with special focus on Dys-HDL, knowing that SAIs have low HDL levels. Large prospective studies are needed to further strengthen current study results.

Obesity-related non-communicable diseases: South Asians vs White Caucasians

South Asians are at higher risk than White Caucasians for the development of obesity and obesity-related non-communicable diseases (OR-NCDs), including insulin resistance, the metabolic syndrome, type 2 diabetes mellitus (T2DM) and coronary heart disease (CHD). Rapid nutrition and lifestyle transitions have contributed to acceleration of OR-NCDs in South Asians. Differences in determinants and associated factors for OR-NCDs between South Asians and White Caucasians include body phenotype (high body fat, high truncal, subcutaneous and intra-abdominal fat, and low muscle mass), biochemical parameters (hyperinsulinemia, hyperglycemia, dyslipidemia, hyperleptinemia, low levels of adiponectin and high levels of C-reactive protein), procoagulant state and endothelial dysfunction. Higher prevalence, earlier onset and increased complications of T2DM and CHD are often seen at lower levels of body mass index (BMI) and waist circumference (WC) in South Asians than White Caucasians. In view of these data, lower cut-offs for obesity and abdominal obesity have been advocated for Asian Indians (BMI; overweight >23 to 24.9 kg m(-2) and obesity ≥ 25 kg m(-2); and WC; men ≥ 90 cm and women ≥ 80 cm, respectively). Imbalanced nutrition, physical inactivity, perinatal adverse events and genetic differences are also important contributory factors. Other differences between South Asians and White Caucasians include lower disease awareness and health-seeking behavior, delayed diagnosis due to atypical presentation and language barriers, and religious and sociocultural factors. All these factors result in poorer prevention, less aggressive therapy, poorer response to medical and surgical interventions, and higher morbidity and mortality in the former. Finally, differences in response to pharmacological agents may exist between South Asians and White Caucasians, although these have been inadequately studied. In view of these data, prevention and management strategies should be more aggressive for South Asians for more positive health outcomes. Finally, lower cut-offs of obesity and abdominal obesity for South Asians are expected to help physicians in better and more effective prevention of OR-NCDs.

Impaired anti-inflammatory function of apolipoprotein A-II concentrations predicts metabolic syndrome and diabetes at 4 years follow-up in elderly Turks

BACKGROUND

We evaluated prospectively the predictive value of serum apolipoprotein (apo) A-II, the second major apolipoprotein of high-density lipoprotein (HDL), for cardiometabolic risk in Turkish adults showing abnormalities in other proteins that normally confer protection.

METHODS

Determinants of apoA-II and its associations with coronary heart disease (CHD), metabolic syndrome (MetS) and diabetes were investigated at 4 years follow-up in 193 elderly men and women.

RESULTS

ApoA-II concentrations at baseline, in addition to being significantly related to HDL-cholesterol, were directly associated with complement C3 in multivariate linear regression analyses comprising nine variables. Following adjustment for gender, age and HDL-cholesterol (>30/>33 g/L, in men and women, respectively), low serum apoA-II concentrations predicted incident MetS [relative risk (RR) 3.5 (95% CI 1.4; 8.6)] and type 2 diabetes [RR 4.5 (95% CI 1.3; 15.6)] in both genders at an increment of 1 SD. Increased apoA-II values were not associated with prevalent or incident CHD, and tended to be marginally atheroprotective only in males.

CONCLUSIONS

Serum apoA-II concentrations confer risk for MetS and diabetes and exhibit evidence of anti-inflammatory properties among Turks. These findings support the effects seen for several other HDL protein constituents. This finding may explain the increased cardiometabolic risk among Turks.

Serum apolipoprotein C-III in high-density lipoprotein: a key diabetogenic risk factor in Turks

AIMS

We studied determinants of serum apolipoprotein C-III (apoC-III) and whether levels of apoC-III or its fractions predict metabolic syndrome (MetS), Type 2 diabetes and coronary heart disease (CHD).

METHODS

The predictive value of apoC-III, measured by immunoturbimetric immunoassay in 802 tracked individuals of a Turkish general population in determining cardiometabolic risk was assessed over 4.4 +/- 1.2 years' follow-up. Patients with MetS, Type 2 diabetes and CHD at baseline were excluded.

RESULTS

Total apoC-III, as well as both fractions, was significantly, linearly and inversely related to smoking status, positively to alcohol usage and to levels of complement C3. Mid and high tertiles of total or non-high density lipoprotein (HDL) apoC-III predicted significantly and independently incident MetS; they predicted CHD with risk ratios of 1.6 [95% confidence intervals (CI) 1.02-2.5], for 1 sd increment, after adjustments that included HDL cholesterol and body mass index (BMI). The highest tertile of HDL apoC-III was a major independent predictor of new-onset diabetes with a 2.5-fold risk ratio for 1 sd increment (95% CI 1.5-4.0) in combined sexes, after adjustment for waist circumference, HDL cholesterol and other confounders and was a better predictor than waist girth.

CONCLUSIONS

Serum total apoC-III or its fractions are linearly and inversely associated with smoking, positively with alcohol usage and serum complement C3. The presumably dysfunctional HDL apoC-III is a stronger predictor of Type 2 diabetes than waist girth in Turks. Non-HDL apoC-III predicts strongly the development of MetS as well as incident CHD, independent of HDL cholesterol, BMI and non-lipid factors. The atherogenicity of apoC-III and dysfunctionality of HDL apoC-III carry huge public health implications in Turks.