High total and cardiovascular disease mortality in adults of Indian descent in Trinidad, unexplained by major coronary risk factors

Barriers towards organ donor registration and consent among people of Indian origin living globally: a systematic review and integrative synthesis-protocol

INTRODUCTION

The need for organs is comparatively higher among people of Indian origin due to the higher prevalence of end-stage organ failure. In spite of the higher need, they have a lower number of organ donors. Studies have been carried out among people of Indian origin living globally to understand the reasons for the low donation rate, but there has been no systematic review that has integrated all of these studies to synthesise the current literature. Therefore, the purpose of this review is to examine the barriers towards organ donor registration and consent among Indians living globally.

METHODS AND ANALYSIS

A systematic search will be conducted using the following relevant databases namely CINHAL, MEDLINE, PsycINFO, Scopus, Web of Science, PubMed Central, Global Health and Grey literature. Studies from 1994 that satisfy our inclusion criteria will be included. Two reviewers will conduct the screening, data extraction and quality assessment of the studies; in event of any disagreement between the two reviewers at any stage, the third reviewer will reconcile any disagreements and consensus will be made.

ETHICS AND DISSEMINATION

As this study includes only secondary data, ethical approval for secondary data usage has been sought. This study will use Preferred Reporting Items for Systematic Review and Meta-Analysis guidelines to report and the study outcomes will be disseminated through a relevant peer-review publication, related conferences and also to various non-governmental organisations globally which are working with this particular community; following which further research can be developed based on this evidence and also helps in building a culturally competent strategy.

PROSPERO REGISTRATION NUMBER

CRD42019155274.

Evaluating Cardiovascular Disease (CVD) risk scores for participants with known CVD and non-CVD in a multiracial/ethnic Caribbean sample

Background

Cardiovascular Disease (CVD) risk prediction models have been useful in estimating if individuals are at low, intermediate, or high risk, of experiencing a CVD event within some established time frame, usually 10 years. Central to this is the concern in Trinidad and Tobago of using pre-existing CVD risk prediction methods, based on populations in the developed world (e.g. ASSIGN, Framingham and QRISK^®2), to establish risk for its multiracial/ethnic Caribbean population. The aim of this study was to determine which pre-existing CVD risk method is best suited for predicting CVD risk for individuals in this population.

Method

A survey was completed by 778 participants, 526 persons with no prior CVD, and 252 who previously reported a CVD event. Lifestyle and biometric data was collected from non-CVD participants, while for CVD participants, medical records were used to collect data at the first instance of CVD. The performances of three CVD risk prediction models (ASSIGN, Framingham and QRISK^®2) were evaluated using their calculated risk scores.

Results

All three models (ASSIGN, Framingham and QRISK^®2) identified less than 62% of cases (CVD participants) with a high proportion of false-positive predictions to true predictions as can be seen by positive predictabilities ranging from 78% (ASSIGN and Framingham) to 87% (QRISK^®2). Further, for all three models, individuals whose scores fell into the misclassification range were 2X more likely to be individuals who had experienced a prior CVD event as opposed to healthy individuals.

Conclusion

The ASSIGN, Framingham and QRISK^®2 models should be utilised with caution on a Trinidad and Tobago population of intermediate and high risk for CVD since these models were found to have underestimated the risk for individuals with CVD up to 2.5 times more often than they overestimated the risk for healthy persons.

National Eye Survey of Trinidad and Tobago (NESTT): prevalence, causes and risk factors for presenting vision impairment in adults over 40 years

AIM

To estimate the prevalence, causes and risk factors for presenting distance and near vision impairment (VI) in Trinidad and Tobago.

METHODS

This is a national, population-based survey using multistage, cluster random sampling in 120 clusters with probability-proportionate-to-size methods. Stage 1 included standardised, community-based measurement of visual acuity. Stage 2 invited all 4263 people aged ≥40 years for comprehensive clinic-based assessment. The Moorfields Eye Hospital Reading Centre graded fundus photographs and optical coherence tomography images independently.

RESULTS

The response rates were 84.2% (n=3589) (stage 1) and 65.4% (n=2790) (stage 2), including 97.1% with VI. The mean age was 57.2 (SD 11.9) years, 54.5% were female, 42.6% were of African descent and 39.0% were of South Asian descent. 11.88% (95% CI 10.88 to 12.97, n=468) had distance VI (logarithm of the minimum angle of resolution [logMAR] >0.30), including blindness (logMAR >1.30) in 0.73% (95% CI 0.48 to 0.97, n=31), after adjustment for study design, non-response, age, sex and municipality. The leading causes of blindness included glaucoma (31.7%, 95% CI 18.7 to 44.8), cataract (28.8%, 95% CI 12.6 to 45.1) and diabetic retinopathy (19.1%, 95% CI 4.2 to 34.0). The leading cause of distance VI was uncorrected refractive error (47.4%, 95% CI 43.4 to 51.3). Potentially avoidable VI accounted for 86.1% (95% CI 82.88 to 88.81), an estimated 176 323 cases in the national population aged ≥40 years. 22.3% (95% CI 20.7 to 23.8, n=695) had uncorrected near VI (logMAR >0.30 at 40 cm with distance acuity <0.30). Significant independent associations with distance VI included increasing age, diagnosed diabetes and unemployment. Significant independent associations with near VI included male sex, no health insurance and unemployment.

CONCLUSIONS

Trinidad and Tobago's burden of avoidable VI exceeds that of other high-income countries. Population and health system priorities are identified to help close the gap.

Prevalence of clOpidogrel 'resIstaNce' in a selected population of patients undergoing elective percutaneous coronary intervention at a tertiary cardiovascular centre in Trinidad: the POINT pilot study

Objectives

This novel, pilot study aimed to assess the estimated prevalence of high on-treatment platelet reactivity (HPR) in Trinidad and Tobago.

Methods

Patients (n=40) who were awaiting elective percutaneous coronary intervention on maintenance dual antiplatelet therapy (DAPT) with aspirin 81 mg daily and clopidogrel 75 mg or loaded at least 48 hours prior were recruited. Platelet reactivity with the VerifyNow P2Y12 assay (Accriva Diagnostics, San Diego, California, USA) was assessed prior to cardiac catheterisation.

Results

60.7% (17/28) of the South Asian (Indo-Trinidadians) patients had HPR, whereas 14.3% (1/7) of Africans and 40% (2/5) of mixed ethnicity had HPR. There was a significant association between HPR (P2Y12 reaction units >208) and ethnicity with South Asians (Indo-Trinidadians) (OR 5.4; 95% CI 1.18 to 24.66, p=0.029).

Conclusions

This pilot study serves to introduce the preliminary observation that the estimated prevalence of HPR is considerably higher within the heterogeneous population in Trinidad at 50% as compared with predominantly Caucasian studies. Furthermore, the HPR is significantly higher in South Asians (Indo-Trinidadians) (>60% of patients) which has severe clinical repercussions considering the cardiovascular disease pandemic. Clopidogrel may not be a satisfactory or optimal antiplatelet agent in this subgroup, and therefore, another more potent antiplatelet such as ticagrelor should be used instead. Further large-scale studies are imperative to confirm these findings. (Funded by the University of the West Indies, St. Augustine; POINT ClinicalTrials.gov number, NCT03667066.).

South Asian Cardiovascular Disease & Cancer Risk: Genetics & Pathophysiology

South Asians (SAs) are at heightened risk for cardiovascular disease as compared to other ethnic groups, facing premature and more severe coronary artery disease, and decreased insulin sensitivity. This disease burden can only be partially explained by conventional risk factors, suggesting the need for a specific cardiovascular risk profile for SAs. Current research, as explored through a comprehensive literature review, suggests the existence of population specific genetic risk factors such as lipoprotein(a), as well as population specific gene modulating factors. This review catalogues the available research on cardiovascular disease and genetics, anthropometry, and pathophysiology, and cancer genetics among SAs, with a geographical focus on the U.S. A tailored risk profile will hinge upon population customized classification and treatment guidelines, informed by continued research.

How much do universal anthropometric standards bias the global monitoring of obesity and undernutrition?

Each year, hundreds of articles in population health and nutrition, many in high-profile journals, use standard cutoffs based on weight and height as assessments of obesity and undernutrition. These global efforts to monitor overweight and underweight often rest on the assumption that ethnic differences in underlying body form are sufficiently small to permit universal anthropometric cutoffs for comparing excess and insufficient body fat across populations. However, a century of work in human biological variation suggests that human populations can vary dramatically in underlying body form in a way that may require population-sensitive cutoffs for monitoring. Here, we describe recently developed methods that can provide population-sensitive assessments of both excess and insufficient energy reserves in a wide range of countries. We use this approach to illustrate how worldwide variation in human body form is far more widespread than previously thought, and that it can occur at several geographic scales, including the level of world regions, countries and populations within countries. The findings also suggest that using standard cutoffs that ignore this variation can underestimate current obesity levels in adults by more than 400-500 million while also incorrectly prioritizing high-risk areas for undernutrition in children in key regions around the world.

PPAR-γ receptor agonists-a review of their role in diabetic management in Trinidad and Tobago

The PPAR-γ receptor agonists, as a relatively new and perhaps still not very widely used class of antidiabetic agent in the Caribbean and particularly the Trinidadian context, possess pharmacologic properties that certainly have been shown to have impact on many of the inflammatory, metabolic, biochemical and structural macrovascular aberrations that occur in the type 2 diabetic. Activation of PPAR(gamma) nuclear receptors regulates the transcription of insulin-responsive genes involved in the control of glucose production, transport, and utilization. PPAR(gamma)-responsive genes also participate in the regulation of fatty acid metabolism, an important contributory pathogenic factor in this subset of patients. The unique mode of action of this class of therapeutic agent addresses a range of anomalies occurring at the cellular and sub-cellular level that are injurious to the diabetic. My aim in addressing the issue of the potential impact of PPAR-γ receptor agonists on cardiovascular disease (CVD) morbidity and mortality in the diabetic, is first, to seek to enhance both an awareness of, and greater familiarity among our own physicians, with this class of drug, and secondly, to effect a timely review of the recent literature as it relates to the tremendous possibilities for the potential clinical gains that might accrue from their use, in so far as this may serve to ameliorate the ravages of the CVD disease that all too tragically attends the type 2 diabetic, and more specifically those with the insulin resistance syndrome. (Mol Cell Biochem 263: 189-210, 2004).

Human Leukocyte Antigens in Hypertrophic Cardiomyopathy Patients in South India

Hypertrophic cardiomyopathy is characterized by massive ventricular hypertrophy, reduced diastolic function, and excessive ventricular contraction. The human leukocyte antigens HLA-A, HLA-B, and HLA-DR were studied in 14 hypertrophic cardiomyopathy patients with left ventricular obstruction from South India. They were compared with 81 normal age- and sex-matched individuals from the same ethnic background. The human leucocyte antigens were identified using the standard serological assay with a longer incubation for DR antigens. The odds ratio, frequency, chi-squared value, p-value, etiological fraction, preventive fraction, and haplotype frequency estimates were calculated. The HLA-B51 and HLA-DR2 levels were significantly increased in hypertrophic cardiomyopathy patients compared to controls, whereas HLA-A19, HLA-B7, and HLA-DR4 were decreased when compared to the controls. It was noticed that haplotype B51-DR2-DQ3 was significantly associated with hypertrophic cardiomyopathy patients from South India. Hypertrophic cardiomyopathy may be associated with genes in the human leukocyte antigen region, and immunogenetic factors linked to human leukocyte antigens appear to play a major role in the pathogenesis.

Diabetes mellitus and its complications in India

India is one of the epicentres of the global diabetes mellitus pandemic. Rapid socioeconomic development and demographic changes, along with increased susceptibility for Indian individuals, have led to the explosive increase in the prevalence of diabetes mellitus in India over the past four decades. Type 2 diabetes mellitus in Asian Indian people is characterized by a young age of onset and occurrence at low levels of BMI. Available data also suggest that the susceptibility of Asian Indian people to the complications of diabetes mellitus differs from that of white populations. Management of this disease in India faces multiple challenges, such as low levels of awareness, paucity of trained medical and paramedical staff and unaffordability of medications and services. Novel interventions using readily available resources and technology promise to revolutionise the care of patients with diabetes mellitus in India. As many of these challenges are common to most developing countries of the world, the lessons learnt from India's experience with diabetes mellitus are likely to be of immense global relevance. In this Review, we discuss the epidemiology of diabetes mellitus and its complications in India and outline the advances made in the country to ensure adequate care. We make specific references to novel, cost-effective interventions, which might be of relevance to other low-income and middle-income countries of the world.

Prevalence of Diabetes, Obesity and Dyslipidaemia in Persons within High and Low Income Groups Living in North and South Trinidad

INTRODUCTION

Diabetes Mellitus, obesity and dyslipidaemia are metabolic disorders characterized by similar risk factors, complications and outcomes including stroke, insulin resistance, MI and even death. Studies have indicated that impoverished and low income areas of developing countries are more prone to increasing obesity which when uncontrolled can lead to diabetes mellitus and dyslipidaemia.

AIM

The study was aimed to compare the prevalence of diabetes mellitus, obesity and dyslipidaemia in high and low income groups of North and South Trinidad, to determine factors that contribute to its prevalence and to observe any associations between the three aforementioned diseases.

MATERIALS AND METHODS

The cross-sectional study was conducted on 200 participants who visited the two major hospitals at south and north Trinidad where the mean differences between fasting glucose, lipid profile, BMI, waist and hip ratio and blood pressure of both diabetic and non-diabetic participants were obtained via questionnaires and then analysed using SPSS.

RESULTS

Residents of south Trinidad showed a higher proportion of persons with diabetes and dyslipidaemia at 68.6% and 52% when compared to 28.6% and 27% respectively for the north population. Those from north Trinidad showed a higher prevalence of obesity at 45.9% with higher income levels. About 17.3% participants smoked or were exposed to cigarettes in north compared to 9.8% of participants whom smoked or were exposed to cigarettes in south. North had 2% of alcohol consumed daily and 3.9% consumed alcohol daily in south. In north, 21.4% of participants were stressed when compared to 18.6% from south.

CONCLUSION

A significant correlation was established between cholesterol, LDL and triglycerides which lead to the conclusion that obesity is caused by dyslipidaemia. Also, our study concluded that stress and dyslipidaemia are income related.

The Relationship of Metabolic Syndrome Traits with Beta-Cell Function and Insulin Sensitivity by Oral Minimal Model Assessment in South Asian and European Families Residing in the Netherlands

Background. There are different metabolic syndrome traits among patients with different ethnicities. Methods. We investigated this by studying 44 South Asians and 54 Europeans and classified them in three groups according to the occurrence of metabolic syndrome (MetS) and Type 2 Diabetes (T2D). Insulin sensitivity index (ISI), static, dynamic, and total beta-cell responsivity indices (Φ), and disposition indices (DIs) were calculated with the use of oral minimal model (OMM). Results. In both ethnicities, ISI was lower in the subgroup with MetS and T2D as compared to the subgroup without MetS nor T2D (P < 0.004). South Asians without MetS were more insulin resistant than Europeans without MetS (P = 0.033). In the South Asians, ISI, dynamic DI, and static DI were associated significantly (P < 0.006) with high-density lipoprotein cholesterol and triglycerides. In the Europeans, ISI was associated with waist-to-hip ratio (P = 0.005) and systolic and diastolic blood pressure (P < 0.005), while static DI was related to the systolic blood pressure (P = 0.005). Conclusions. MetS was linked with insulin resistance and reduced capacity to handle glucose regardless of ethnicity. ISI and DIs were associated with lipid traits in South Asians and with blood pressure in Europeans suggesting that insulin resistance enhances different metabolic syndrome traits among different ethnicities.

Frequency of fat mass and obesity-associated gene rs9939609 and peroxisome proliferator-activated receptor gamma 2 gene rs1801282 polymorphisms among Trinidadian neonates of different ethnicities and their relationship to anthropometry at birth

BACKGROUND

The fat mass and obesity-associated gene (FTO) rs9939609 and peroxisome proliferator-activated receptor gamma 2 gene (PPARG2) rs1801282 polymorphisms are type 2 diabetes mellitus susceptibility gene variants associated with obesity. This study examined whether these variants are associated with anthropometry at birth among a representative multi-ethnic sample of Trinidadian neonates.

METHODS

Cord blood was obtained from consecutive term live births and DNA was genotyped for FTO and PPARG2 variants using polymerase chain reaction. Associations between neonate anthropometry at birth and genotype frequency were assessed using the χ(2) test and linear regression.

RESULTS

Significant associations were observed between neonate ethnicity and PPARG2 (p = 0.005) and FTO (p = 0.017) variants: high-risk alleles were more prevalent among African than South Asian neonates for both variants. The allelic and genotypic frequencies for mixed neonates were between those for the African and those for the South Asian neonates. No significant relationship was observed between rs9939609 and rs1801282 and anthropometric measures. For both variants, the allelic and genotypic frequencies among the African and South Asian neonates mirrored those found elsewhere for similar ethnic groups.

CONCLUSIONS

Neonates of African ethnicity possess the highest frequency of rs9939609 and rs1801282 alleles and genotypes; this may be associated with ethnic differences in the risk of lifestyle diseases.

Ethnic differences in the occurrence of acute coronary syndrome: results of the Malaysian National Cardiovascular Disease (NCVD) Database Registry (March 2006 - February 2010)

BACKGROUND

The National Cardiovascular Disease (NCVD) Database Registry represents one of the first prospective, multi-center registries to treat and prevent coronary artery disease (CAD) in Malaysia. Since ethnicity is an important consideration in the occurrence of acute coronary syndrome (ACS) globally, therefore, we aimed to identify the role of ethnicity in the occurrence of ACS among high-risk groups in the Malaysian population.

METHODS

The NCVD involves more than 15 Ministry of Health (MOH) hospitals nationwide, universities and the National Heart Institute and enrolls patients presenting with ACS [ST-elevation myocardial infarction (STEMI), non-ST elevation myocardial infarction (NSTEMI) and unstable angina (UA)]. We analyzed ethnic differences across socio-demographic characteristics, hospital medications and invasive therapeutic procedures, treatment of STEMI and in-hospital clinical outcomes.

RESULTS

We enrolled 13,591 patients. The distribution of the NCVD population was as follows: 49.0% Malays, 22.5% Chinese, 23.1% Indians and 5.3% Others (representing other indigenous groups and non-Malaysian nationals). The mean age (SD) of ACS patients at presentation was 59.1 (12.0) years. More than 70% were males. A higher proportion of patients within each ethnic group had more than two coronary risk factors. Malays had higher body mass index (BMI). Chinese had highest rate of hypertension and hyperlipidemia. Indians had higher rate of diabetes mellitus (DM) and family history of premature CAD. Overall, more patients had STEMI than NSTEMI or UA among all ethnic groups. The use of aspirin was more than 94% among all ethnic groups. Utilization rates for elective and emergency percutaneous coronary intervention (PCI) and coronary artery bypass graft (CABG) were low among all ethnic groups. In STEMI, fibrinolysis (streptokinase) appeared to be the dominant treatment options (>70%) for all ethnic groups. In-hospital mortality rates for STEMI across ethnicity ranges from 8.1% to 10.1% (p = 0.35). Among NSTEMI/UA patients, the rate of in-hospital mortality ranges from 3.7% to 6.5% and Malays recorded the highest in-hospital mortality rate compared to other ethnic groups (p = 0.000). In binary multiple logistic regression analysis, differences across ethnicity in the age and sex-adjusted ORs for in-hospital mortality among STEMI patients was not significant; for NSTEMI/UA patients, Chinese [OR 0.71 (95% CI 0.55, 0.91)] and Indians [OR 0.57 (95% CI 0.43, 0.76)] showed significantly lower risk of in-hospital mortality compared to Malays (reference group).

CONCLUSIONS

Risk factor profiles and ACS stratum were significantly different across ethnicity. Despite disparities in risk factors, clinical presentation, medical treatment and invasive management, ethnic differences in the risk of in-hospital mortality was not significant among STEMI patients. However, Chinese and Indians showed significantly lower risk of in-hospital mortality compared to Malays among NSTEMI and UA patients.

Determinants of plasma triglyceride levels in a multiethnic working class Caribbean population: effect of ethnicity, diet and obesity

AIMS

Objective of the study is to identify the predictors of plasma triglycerides.

MATERIALS AND METHODS

A stratified random sample of university staff categories underwent measurements of anthropometry, blood pressure, and fasting blood glucose, insulin, lipids, CRP and homocysteine. Dietary intakes were assessed using duplicate 24h recalls. HOMA-IR was calculated. Stepwise, multivariate regression analysis was performed with TAG as the dependent variable.

RESULTS

The sample (n=251) was 55% females with a mean age of 44.9±9.7 years. African ancestry comprised 43%, followed South Asian 30% and mixed ethnicity 27%. Prevalence of obesity was 19.4%, insulin resistance 22.7% and metabolic syndrome 21.6%. Males had significantly higher (p<0.01) triglycerides and VLDL and lower HDL than females. Africans had significantly lower triglycerides and cholesterol than South Asians and Mix. Triglycerides were significantly (p<0.01) correlated with glucose, cholesterol, insulin, CRP, systolic, diastolic blood pressure, WC, BMI, age and components of MS. Glucose, cholesterol, insulin and total energy intake predicted TAG, to varying extents, in all participants (R(2)=45.1%), males (R(2)=40.3%), females (R(2)=56.0%), Africans (R(2)=35.0%), TSA (R(2)=31.5%) and mix (R(2)=51.0%).

CONCLUSIONS

Africans have lower triglycerides and cholesterol than South Asians and mix. Major predictors of triglycerides were fasting glucose and cholesterol independent of gender and ethnicity.

Endothelial Function and Carotid Intimal Medial Thickness in Asymptomatic Subjects With and Without Cardiovascular Risk Factors

BACKGROUND

The study was performed to assess endothelial function and carotid intimal-medial thickness (IMT) in asymptomatic patients, with and without risk factors for cardiovascular disease.

METHODS

A cross sectional survey of asymptomatic patients, aged 21 - 60 years, with and without risk factors for cardiovascular disease was recruited from the outpatient department of Cardiology. Endothelial function was evaluated by flow mediated dilatation (FMD) of the brachial artery and carotid IMT was determined using a high resolution B mode ultrasonography system.

RESULTS

A total of 104 patients were included in the study. The mean carotid IMT was 0.67 ± 0.05 mm in the group without risk factors and 0.78 ± 0.12 mm in the group with risk factors (P value < 0.05). Endothelial dysfunction (ED) and increased carotid IMT were more significant in the group with risk factors (P value < 0.001). Age, total cholesterol, LDL cholesterol, HDL cholesterol, triglycerides, blood pressure, body mass index and HbA1c had a significant correlation with both IMT and FMD response. A higher proportion of subjects with diabetes mellitus (87%), metabolic syndrome (86%) and family history of premature coronary artery disease (78%) had ED. In subjects with normal coronary angiogram, 71% had abnormal FMD response and 36% had increased carotid IMT.

CONCLUSION

In asymptomatic subjects, risk factors for cardiovascular disease are significantly associated with objective evidence of ED and increased carotid IMT. FMD response and carotid IMT values are likely to yield additional information beyond traditional risk factors for classifying patients in regard to the likelihood of cardiovascular event. Therapeutic measures with the aim of improving endothelial function and reducing carotid IMT may reduce the burden of cardiovascular disease.

Evaluation of the burden of type 2 diabetes mellitus in population of Puducherry, South India

AIMS

To find out the prevalence of undiagnosed diabetes mellitus and the correlates among the adult population of Puducherry, South India.

METHODS

In this population based cross-sectional study in the rural and urban field practice area of Mahatma Gandhi Medical College and Research Institute, Puducherry, by simple random sampling 1013 adults of 30 years and above, not on anti-diabetics drugs were included. Main outcome measures were the prevalence and correlates of undiagnosed diabetes mellitus among the adult population. Pre-designed and pre-tested questionnaire was used to elicit the information on family and individual socio-demographic variables. Height, weight, waist and hip circumference, blood pressure were measured and venous blood was collected to measure fasting blood glucose and blood cholesterol.

RESULTS

Overall, 10.3% study subjects were diagnosed as diabetic. In univariate analysis age, dilatory habit, tobacco addiction, body mass index, waist hip ratio, hypertension, and total blood cholesterol were found statistically significant. In multivariate logistic regression (LR method) analysis age, residence, education, dietary habit, tobacco addiction, body mass index, waist hip ratio and total blood cholesterol were statistically significant.

CONCLUSIONS

In our study adults having increased age, urban residence, illiterate, non-vegetarian diet, tobacco addiction, obese and high total blood cholesterol were important correlates.

Epidemiology of cardiovascular disease in type 2 diabetes: the Indian scenario

Noncommunicable diseases, of which coronary artery disease (CAD) and diabetes top the list, have overtaken communicable diseases with respect to overall mortality, even in developing countries like India. High prevalence rates of diabetes and CAD are seen not only in affluent migrant Indians, but also in those living within the subcontinent. Indeed the epidemic of diabetes and CAD is now spreading to the middle- and lower-income groups in India. The risk for CAD is two to four times higher in diabetic subjects, and in Indians, CAD occurs prematurely, i.e., one to two decades earlier than in the West. Thus there is an urgent need for studies on CAD in diabetic and nondiabetic subjects in India. The Chennai Urban Population Study, a population-based study in Chennai, in South India, showed a prevalence of CAD of 11%, which is 10 times more than what it was in 1970. Clustering of risk factors for CAD such as hyperglycemia, central body obesity, dyslipidemia, and hypertension tends to occur, and interplay of these risk factors could explain the enhanced CAD risk in Indians. Additionally, low-grade inflammation and a possible inherent genetic susceptibility are other contributing factors. Preventive measures such as lifestyle modification with healthy diet, adequate physical activity, and decrease in stress could help prevent the twin epidemics of diabetes and CAD.

Atheromatous plaque reflects serum total cholesterol levels: a comparative morphologic study of endarterectomy coronary atherosclerotic plaques removed from patients from the southern part of India and Caucasians from Ottawa, Canada

BACKGROUND

Natives of South India have a very high incidence of coronary artery disease, despite low calorie and fat intake.

HYPOTHESIS

This study was undertaken to determine whether morphologic features of atheromatous plaque reflect the serum total cholesterol.

METHODS

Fifty-three endarterectomy specimens from patients (mean age 47 +/- 9 years, mean cholesterol 203 +/- 47 mg/dl) obtained from one cardiac surgeon working in a single institution in South India were evaluated. Morphologic findings were compared with 40 endoarterectomy specimens obtained from age-matched Caucasians from Ottawa, Canada, with a reported mean cholesterol of 262 +/- 47 mg/dl. Morphometric measurements of the vessel size, percent stenosis, and the various components of the atherosclerotic plaque were determined by computerized planimetry.

RESULTS

The vessel size was smaller in the Indian than in the Canadian population (4.6 +/- 2.9 vs. 5.6 +/- 3.0 mm2, p = 0.07), the plaque area was less (4.3 +/- 2.3 vs. 5.3 +/- 2.8 mm2, p = 0.055) and the calculated percent stenosis was significantly less (93 vs. 96%, p = 0.028). Of all the parameters evaluated, only necrotic core in the Indian population (7.1 +/- 10.9% vs. Canadian 16.7 +/- 19.7%, p < 0.001) and proteoglycan deposition (7.9 +/- 11.2% vs. Canadian 3.7 +/- 5.3%, p < 0.023) were significantly different. Despite the Indians having low total cholesterol, there was greater diffuse double and triple-vessel disease and at a younger age than in the Caucasians.

CONCLUSIONS

From our data, it appears that the mechanism of development of atherosclerotic disease in the Indians may be different because they have smaller vessels, smaller necrotic core, and greater proteoglycan deposition. Other etiologies, especially those related to a high carbohydrate diet (which is typical for South Indians), should be considered.

Lifestyle of Asian Indians with coronary heart disease: the Australian context

This paper aims to report lifestyle factors of Asian Indians in Australia in relation to coronary heart disease. This issue has not been previously explored in the Australian context. This study also seeks to identify factors that could inform health education and rehabilitation programs for migrant Asian Indians in Australia. The qualitative descriptive approach of constructivism was used for this study. Semi-structured, in-depth conversations were conducted with eight patients and five family members. Participants were at risk for coronary heart disease either due to unhealthy diet and/or lack of physical exercise and irregular health checks. Although lifestyle modifications were implemented by participants after the cardiac event; these changes were implemented inconsistently and without continuity. Knowledge of the beneficial effects of a healthy diet did not deter the participants from continuing to follow unhealthy dietary habits. The introduction of any exercise or physical activity by participants in this study lacked consistency. A positive aspect revealed from this study was the influence of culture and religious faith, which helped patients and family members to cope with the illness trajectory. The results of this study suggest that health education and rehabilitation programs need to be designed specifically for this high-risk group would be beneficial when initiated early in life and need to be targeted to the individual.

Detection of impaired glucose tolerance and undiagnosed type 2 diabetes in UK South Asians: an effective screening strategy

AIM

We tested a stepwise, community-based screening strategy for glucose intolerance in South Asians using a health questionnaire in conjunction with body mass index (BMI). Anthropometric measurements (waist and hip circumference, sagittal diameter and percentage body fat) were then conducted in a hospital setting followed by an oral glucose tolerance test (OGTT) to identify subjects at the highest risk and analyse the factors predicting that risk.

METHODS

A health questionnaire was administered to 435 subjects in a community setting and BMI was measured. Subjects were graded by a risk score based on the health questionnaire as high, medium and low. Subjects with high and medium risk scores and a representative sample of those with low scores had anthropometric measurements in hospital followed by an OGTT. In total, 205 (47%) of the subjects had an OGTT performed.

RESULTS

In total, 48.7% of the subjects tested with an OGTT had evidence of glucose dysregulation: 20% had diabetes and 28.7% had impaired glucose tolerance (IGT). Logistic regression model explained 49.1% of the total variability. The significant predictors of diabetes and IGT were Blood Glucose Monitoring Strips (BMI), random blood glucose (BM), sibling with diabetes and presence of diagnosed hypertension or ischaemic disease. Most of these predictors along with other heredity diabetes factors create a composite score, with high predictability, as the receiver operating curve analysis shows.

CONCLUSION

We describe a simple, stepwise strategy in a community setting, based on a health questionnaire and anthropometric measurements, to explain about 50% of cases with IGT and diabetes and diagnose about 50% of cases from the population screened. We have also identified factors that predict the risk.

Urban living and obesity: is it independent of its population and lifestyle characteristics?

OBJECTIVES

Living in an urban area influences obesity. However, little is known about whether this relationship is truly independent of, or merely mediated through, the demographic, socio-economic and lifestyle characteristics of urban populations. We aimed to identify and quantify the magnitude of this relationship in a Sri Lankan population.

METHODS

Cross-sectional study of adults aged 20-64 years representing the urban (n = 770) and rural (n = 630) populations, in the district of Colombo in 2004. Obesity was measured as a continuous variable using body mass index (BMI). Demographic, socio-economic and lifestyle factors were assessed. Gender-specific multivariable regression models were developed to quantify the independent effect of urban/ rural living and other variables on increased BMI.

RESULTS

The BMI (mean; 95% confidence interval) differed significantly between urban (men: 23.3; 22.8-23.8; women: 24.2; 23.7-24.7) and rural (men: 22.3; 21.9-22.7; women: 23.2; 22.7-23.7) sectors (P < 0.01). The observed association remained stable independently of all other variables in the regression models among both men (coefficient = 0.64) and women (coefficient = 0.95). These coefficients equated to 2.2 kg weight for the average man and 1.7 kg for the average woman. Other independent associations of BMI were with income (coefficient = 1.74), marital status (1.48), meal size (1.53) and religion (1.20) among men, and with age (0.87), marital status (2.25) and physical activity (0.96) among women.

CONCLUSIONS

Urban living is associated with obesity independently of most other demographic, socio-economic and lifestyle characteristics of the population. Targeting urban populations may be useful for consideration when developing strategies to reduce the prevalence of obesity.

A comparative study of the prevalence of the metabolic syndrome and its components in type 2 diabetic patients in two Caribbean islands using the new International Diabetes Federation definition

BACKGROUND AND AIM

Tobago and Trinidad are two Caribbean islands with distinct genetic background and lifestyles; while Tobago is serene and a tourist centre, Trinidad is characterized by a hustling and bustling lifestyle. The study was aimed at determining and comparing the prevalence of the metabolic syndrome (MetS) and its critical components in type 2 diabetic patients using the new International Diabetes Federation (IDF) definition.

METHODS

Four hundred and thirteen (166 Tobago, 247 Trinidad) type 2 diabetic patients visiting 10 lifestyle disease clinics were studied. Blood pressure, anthropometric parameters (height, weight, body mass index and waist circumference) and overnight fasting blood samples were taken. Plasma glucose and serum triglycerides, total cholesterol, LDL- and HDL-cholesterol, insulin, and adiponectin were determined. Insulin resistance (IR) was determined using the HOMA method.

RESULTS

The patients in Tobago were significantly older than patients in Trinidad (p < 0.001) but the duration of diabetes (9.4 +/- 0.5 vs. 11.1 +/- 0.7 yr), medications, generalized (31.7 vs. 38.8%) and central (78.5 vs. 83.7%) obesity were similar (p > 0.05). In comparison with patients in Tobago, diabetic patients in Trinidad, irrespective of gender, had significantly higher prevalence of IDF critical components such as raised BP, raised triglycerides and reduced HDL-cholesterol (all, p < 0.001). Thus, while more patients in Trinidad were diagnosed with MetS based on three or four components, more patients in Tobago were diagnosed based on two components (p < 0.001).

CONCLUSIONS

There were high prevalence rates of the components of the MetS in both the islands of Tobago and Trinidad. Quantitatively, the aggregation of the components is higher in patients in Trinidad, which constitute greater risk for adverse cardiovascular outcome. Controlling central obesity should be the target in preventing MetS in the two islands.

Platelet reactivity among Asian Indians and Caucasians

Asian Indians are reported to have higher mortality and morbidity from coronary artery disease (CAD) than other ethnic groups. This variation in events cannot be explained only by differences in conventional risk factors. Platelet activation is an important factor in the pathogenesis of CAD, however, there are limited data concerning platelet reactivity in Asian Indians. Therefore, we aimed to examine platelet reactivity in healthy Asian Indians vs. Caucasians. Thirty-five healthy, nonsmoking Asian Indians (mean age 30.1 +/- 3.6 years, 31.4% women) were matched for age and sex with 35 healthy, nonsmoking Caucasians (mean age 30.8 +/- 5 years, 31.4% women). Platelet reactivity was evaluated by measuring platelet aggregation, platelet leukocyte aggregates (PLA) formation in response to a 6-mer thrombin receptor agonist peptide (TRAP) at a final concentration of 40 microM and flow cytometry determined P-selectin expression induced by ADP, TRAP and arachidonic acid (AA). In addition, P-Selectin glycoprotein ligand-1 (PSGL-1) density on leukocytes was measured. There were no differences in platelet aggregation, basal PLA or PSGL-1 density on leukocytes between the two groups. AA-stimulated P-selectin expression was significantly higher in Asian Indians than in Caucasians (6.1 +/- 0.51 vs. 4.2 +/- 0.41 MFI, P < 0.02). After stimulation with TRAP, platelets from Asian Indians had increased PLA formation compared with Caucasians (41.6 +/- 2.9% vs. 31.4 +/- 2.7%, P < 0.02). AA induced P-selectin expression and TRAP stimulated PLA formation is increased in Asian Indians compared with Caucasians. These differences indicate an increase in measures of platelet reactivity among Asian Indians and may help elucidate the reported disparity in cardiovascular disease rates between the two ethnic groups.

Vascular phenotype and subclinical inflammation in diabetic Asian Indians without overt cardiovascular disease

Although Asian Indian (AI) patients with diabetes mellitus type 2 (DM2) are at high risk for cardiovascular disease (CVD), not all patients develop CVD. The vascular phenotype of AI-DM2 without CVD has not been elucidated and may point to protective features. Using baseline data from a clinical trial we provide an initial description of vascular parameters in AI-DM2 compared to Europid Caucasian controls (ECs) matched for age and gender. Endpoints of the study were endothelial function, low-grade systemic inflammation (CRP) and carotid intima-media thickness (cIMT). AIs had longer duration of diabetes, worse glycemic control and more microangiopathy. Both groups demonstrated marked endothelial dysfunction. CRP levels were similar: 1.7 (4.9) mg/L in AIs and 2.8 (3.6) mg/L in ECs. cIMT values were significantly lower in AI-DM2 than EC-DM2 (0.655mm (0.12) versus 0.711mm (0.15), p=0.03). Multiple regression analysis showed that variability in CRP was mainly determined by waist circumference, not by ethnicity. In contrast, ethnicity was a significantly explanatory variable for cIMT. Vascular phenotype of AI-DM2 without CVD was characterized by endothelial dysfunction and relatively low levels of CRP, comparable to EC-DM2 controls. In contrast, lower cIMT values were observed in AI-DM2 despite longer duration of diabetes and worse metabolic control. We propose that mechanisms slowing its progression may have atheroprotective potential in AI-DM2.

How well controlled are our type 2 diabetic patients in 2002? An observational study in North and Central Trinidad

OBJECTIVES

To determine the proportion of diabetic patients that achieved glycemic control (HbA1c pound7.0%) and to explore some of the barriers to achieve this control.

DESIGN

Cross-sectional, observational study.

SETTING

Health centres in North and Central Trinidad.

PATIENTS

One hundred and thirty-two type 2 diabetics attending the health centres for more than 1 year.

MAIN OUTCOME MEASURES

HbA1c levels and the proportion of patients who achieve glycemic control, HbA1c pound7.0%.

RESULTS

The patients were categorized into two groups: well controlled, HbA1c Y7.0% and poorly controlled, HbA1c>7.0%. The majority of patients were poorly controlled (55.3%), duration of diabetes impacted negatively older patients and patients attending the clinics for longer periods were less likely to be well controlled. There was no correlation between pharmacological treatment, availability of individual counselling by a dietician or regular monitoring of blood glucose and glycemic control (p>0.05).

CONCLUSION

A 44.7% of patients with type 2 diabetes were found to be well controlled. Old age (51-70 years) and lengthy periods of attendance seem to be barriers to achieving glycemic control. This study highlights the fact that there is a need for re-evaluation of the diabetic program since despite changes in the primary care system over the past 5 years a large proportion of diabetics are still uncontrolled.

Gender differentials of abdominal obesity among the adults in the district of Colombo, Sri Lanka

OBJECTIVE

To assess the gender-specific prevalence and determinants of abdominal obesity (AO) within the population and lifestyle diversity of an urban district in Sri Lanka.

METHODS

Prevalence of AO (defined by waist circumference) was estimated in a cross-sectional study of 1400 adults aged 20-64, residing in the district of Colombo in 2004. Demographic, socio-economic and lifestyle factors were assessed in gender-specific logistic regression models to identify determinants of AO.

RESULTS

Prevalence of AO was 44.7% (95% confidence interval (CI): 41.0, 48.5) in females and 25.7% (95% CI: 22.6, 29.0) in males. Significant determinants of AO were age 35-49 (adjusted odds ratio: 1.7; 95% CI: 1.2, 2.5), moderately urban sector (1.9; 1.3, 2.9) and insufficient level of physical activity (1.7; 1.1, 2.4) among females in contrast to household income >Rupees 10,000 (6.1; 2.7, 13.5), increased alcohol (medium: 1.9; 1.2, 2.9; high: 2.1; 1.2, 3.5), low-fiber diet (1.6; 1.1, 2.4) and frequent large meals (1.7; 1.0, 2.8) among males. Determinants common to males (M) and females (F) were age >or=50 years (M: 2.5; 1.5, 4.2 and F: 2.9; 1.9, 4.4), most urban sector (M: 2.0; 1.3, 3.1 and F: 1.8; 1.2, 2.7) and married status (M: 2.2; 1.3, 3.6 and F: 2.4; 1.6, 3.6).

CONCLUSIONS

A distinct gender differential was observed in the prevalence and determinants of AO. It appears vital that preventive strategies of AO be developed to be more 'gender-sensitive' in urban districts.

Coronary artery disease in South Asians: an emerging risk group

Coronary artery disease (CAD) is a leading cause of morbidity and mortality worldwide and was responsible for 7.2 million deaths in 2003. Various studies have pointed out that South Asians have a higher prevalence of CAD as compared with other ethnicities. South Asians may have a genetic predisposition to CAD; however, environmental, nutritional, and lifestyle factors may also be responsible. South Asians have a much higher prevalence of metabolic syndrome, diabetes, insulin resistance (and resultant hyperinsulinemia), central obesity, dyslipidemias (lower high-density lipoprotein, increased lipoprotein[a], higher triglyceride levels), increased thrombotic tendency (increased plasminogen activator inhibitor-1 and decreased tissue plasminogen activator levels), decreased levels of physical activity, and low birth weights ("fetal origins hypothesis"). In addition, the dietary indiscretions and sedentary lifestyle practiced by most South Asians puts them at a higher risk. A multidisciplinary approach involving the population at risk, healthcare personnel, and the government is required to diminish the incidence. Educational programs regarding the genetic predisposition as well as risk factors for CAD, physical activity, and dietary modifications need to be encouraged. There is a need for implementation of newer guidelines as well as a lower threshold for initiating therapeutic interventions in this population. Mass media should be involved to bring about behavioral changes, and these changes should be reinforced at the physician's level.

Accuracy of the ratio of triglycerides to high-density lipoprotein cholesterol for predicting low-density lipoprotein cholesterol particle sizes, phenotype B, and particle concentrations among Asian Indians

Asian Indians have unusually high rates of coronary artery disease. Small low-density lipoprotein (LDL) particle predominance (phenotype B) is associated with a fourfold atherogenic risk. This study examined the accuracy of a triglyceride/high-density lipoprotein cholesterol (HDL) ratio of > or =3.8 (determined from the Adult Treatment Panel III guidelines, normal triglycerides <150 mg/dl and HDL >40 mg/dl) for predicting phenotype B in Asian Indians. Fasting blood samples were collected from 150 healthy Asian Indians. LDL size analysis was performed by nuclear magnetic resonance spectroscopy. The triglyceride/HDL cholesterol ratio correlated inversely with the LDL size and positively with the particle concentration. A triglyceride/HDL cholesterol ratio of > or =3.8 had 76% sensitivity, 93% specificity, and 83% positive and 89% negative predictive values for predicting phenotype B.

Soluble P-selectin and CD40L levels in subjects with prediabetes, diabetes mellitus, and metabolic syndrome--the Chennai Urban Rural Epidemiology Study

The aim of the study was to determine whether the levels of soluble P-selectin (sP-selectin) and soluble CD40L (sCD40L) are elevated in Asian Indian subjects with impaired glucose tolerance (IGT), diabetes, and metabolic syndrome (MS). Study subjects were recruited from the Chennai Urban Rural Epidemiology Study (CURES), an ongoing population-based study on a representative population of Chennai city in southern India, and were grouped as follows: group 1, normal glucose tolerance (NGT) (n = 60); group 2, IGT (n = 60); and group 3, type 2 diabetes mellitus (n = 60). Normal glucose tolerance, IGT, and diabetes were defined using World Health Organization consulting group criteria. The inclusion criteria were nonsmokers; normal resting 12-lead electrocardiogram; absence of angina, myocardial infarction, or history of any known vascular, infectious, or inflammatory diseases; and subjects not on statins or aspirin. Insulin resistance was calculated using the homeostasis assessment model using the formula: fasting insulin (microIU/mL) x fasting glucose (mmol/L)/22.5. Soluble P-selectin and sCD40L were estimated by enzyme-linked immunosorbent assay. Metabolic syndrome was defined using Adult Treatment Panel III guidelines. Subjects with diabetes and IGT were older (diabetes: 53 +/- 9 years, P < .01; IGT: 51 +/- 10 years, P < .05) compared with the NGT group (48 +/- 10 years). Subjects with diabetes and IGT had higher levels of sP-selectin (diabetes: 162 +/- 79 ng/mL, P < .001; IGT: 102 +/- 37 ng/mL, P < .001) compared with the NGT group (55 +/- 48 ng/mL). Soluble CD40L levels were also higher in those with diabetes and IGT (diabetes: 3.2 +/- 2.0 ng/mL, P < .001; IGT: 2.0 +/- 1.3 ng/mL, P < .001) compared with the NGT group (1.1 +/- 0.9 ng/mL). Subjects with MS had significantly higher levels of sP-selectin (with MS, 118 +/- 76 ng/mL; without MS, 95 +/- 66 ng/mL; P = .028) and sCD40L (with MS, 2.4 +/- 1.8 ng/mL; without MS, 1.9 +/- 1.5 ng/mL; P = .036) compared with subjects without MS. Among subjects with NGT and IGT, the mean levels of sP-selectin (tertile I, 65.0 ng/mL; tertile II, 80.0 ng/mL; tertile III, 91.0 ng/mL) and sCD40L levels (tertile I, 1.2 ng/mL; tertile II, 1.7 ng/mL; tertile III, 1.8 ng/mL) increased with increase in tertiles of homeostasis assessment model-insulin resistance, and the difference reached statistical significance in the last tertile compared with the first tertile (P < .05). This study demonstrates that increased levels of sP-selectin and sCD40L are seen in Asian Indian subjects with IGT, type 2 diabetes mellitus, MS, and insulin resistance.

Circadian and circaseptan (about-weekly) aspects of immigrant Indians' blood pressure and heart rate in California, USA

Time structurally (chronomically) interpreted half-hourly monitoring of blood pressure (BP) and heart rate (HR) for at least 7 days and preferably for 17 days is recommended, separately for a diagnosis of BP disorders and when necessary again for the same or longer spans for treatment, whenever a positive diagnosis of a disorder is made. In this study, 30 clinically healthy subjects underwent 7-day monitoring and provided a series of findings, including the detection of Circadian Hyper-Amplitude-Tension (CHAT), that is blood pressure overswinging, which carries a high risk of hard cardiovascular events. The results specifically bear upon south-east Asian-Indian immigrants. They show that cardiovascular disease risk increases with age, with a positive family history of hypertension and/or other cardiovascular diseases and even with the duration of stay in the USA. A relation to body mass index is also shown. Such monitoring for prehabilitation may eventually reduce the need for rehabilitation.

Cardiorespiratory fitness, all-cause mortality, and risk of cardiovascular disease in Trinidadian men--the St James survey

BACKGROUND

This study examined whether cardiorespiratory fitness is a risk factor for cardiovascular disease, myocardial infarction, and all-cause mortality in a low- to middle-income Trinidadian community of African, South Asian Indian, and European origin. Those of Indian descent have a distinctively high rate of myocardial infarction.

METHODS

The St James Study is a prospective total community survey located in Port-of-Spain, Trinidad, West Indies. A random sample of 626 men aged 35-69 years, without angina of effort, previous myocardial infarction, partial or complete atrio-ventricular conduction defect, complete heart block, or exercise-induced asthma, was used for the assessment of cardiorespiratory fitness by cycle ergometry. Surveillance for morbidity and mortality was maintained for an average of 7.3 years.

RESULTS

When the subjects were grouped into those with an age- and fat-free mass-adjusted peak oxygen uptake above and below the mean of 60.4 mmol/min (1.34 l/min), the hazard ratios (below/above) (95% confidence interval) for all-cause mortality, cardiovascular disease incidence, and incidence of myocardial infarction, after allowance for conventional cardiovascular risk factors, were 2.08 (1.23-3.52), 2.13 (1.22-3.69), and 2.36 (0.84-6.67), respectively. For those unable to achieve a level of work requiring an oxygen uptake of 67 mmol/min (1.5 l/min) during progressive exercise, the respective hazard ratios were 3.49 (1.57-7.76), 2.29 (1.21-4.33), and 5.45 (1.22-24.34). Indian ethnicity remained a predictor of myocardial infarction after allowance for cardiorespiratory performance.

CONCLUSION

Low cardiorespiratory fitness is a risk factor for cardiovascular disease morbidity and mortality in the low- to middle-income developing community of Trinidad.

Postprandial hypertriglyceridemia and carotid intima-media thickness in north Indian type 2 diabetic subjects

Hypertriglyceridemia is an important risk factor for coronary heart disease (CHD) and in the development of atherosclerosis, especially in subgroups of the population like those with type 2 diabetes. Although triglycerides are generally increased in the postprandial period, the association between postprandial triglyceride (ppTG) levels and atherosclerosis has not been investigated in north Indian type 2 diabetic subjects known to have a very high prevalence rate of premature CHD and insulin resistance. To investigate the role of ppTG levels in atherosclerosis in type 2 diabetes, we examined the correlation between ppTG levels and carotid intima-media thickness (IMT). Carotid IMT was determined by high resolution B-mode ultrasonography in 86 newly detected type 2 diabetic subjects (1-12 months duration) having good glycemic control (HbA(1C)<7%) and 45 non-diabetic subjects matched according to age and body mass index (BMI). Plasma glucose, insulin, total cholesterol, LDL-cholesterol, HDL-cholesterol and triglycerides were measured after overnight fasting. Plasma insulin and glucose were also measured 2h and plasma triglycerides 4h after breakfast. The mean carotid IMT in diabetic subjects was higher than those in non-diabetic subjects (0.77+/-0.15 mm versus 0.53+/-0.16 mm, P<0.001). Based on the fasting and postprandial triglyceride levels, the diabetic subjects were divided into three groups: normo-normo (NN); normo-hyper (NH); hyper-hyper (HH) [NN: fTG<1.70 mmol/L and ppTG<2.30 mmol/L; NH: fTG<1.70 mmol/L and ppTG>2.30 mmol/L; HH: fTG>1.70 mmol/L and ppTG>2.30 mmol/L]. Carotid IMT was significantly increased in the NH (0.79+/-0.09 mm) and HH (0.82+/-0.06 mm) groups compared with the NN group (0.59+/-0.09 mm, P<0.001). Although ppTG, age, fasting LDL-cholesterol, HOMA-estimated insulin resistance, HbA(1C) were all independently correlated with carotid IMT, age and ppTG levels had the strongest statistical influence (P<0.002).

Effect of leisure time exercise on high-density lipoprotein cholesterol, its subclasses, and size in Asian Indians

Asian Indians have a greater prevalence and incidence of coronary artery disease than other ethnic groups, despite similar routine lipid profiles. High-density lipoprotein (HDL) cholesterol, particularly the large subclass, is predominantly associated with coronary artery disease protection. Exercise reduces coronary artery disease risk by improving HDL cholesterol levels. The effect of exercise on HDL cholesterol concentrations, subclasses, and size, measured by nuclear magnetic resonance spectroscopy, was assessed in 388 healthy Asian Indians. Exercise was associated with significantly greater concentrations of total HDL cholesterol, entirely due to significant increases in the cardioprotective large HDL subclass and larger HDL cholesterol particle sizes.

Comparison of high-density and low-density lipoprotein cholesterol subclasses and sizes in Asian Indian women with Caucasian women from the Framingham Offspring Study

BACKGROUND

Asian Indian women have a higher rate of coronary artery disease (CAD) than do other ethnic groups, despite similar conventional risk factors and lipid profiles. Smaller high-density lipoprotein cholesterol (HDL-C) particle size is associated with reduced cardiac protection or even an increased risk of CAD. Exceptional longevity correlates better with larger HDL-C particle sizes.

HYPOTHESIS

Higher rates of CAD among Asian Indian women may partly be explained by the differenes in the prevalence of atherogenic HDL-C and low-density lipoprotein cholesterol (LDL-C) sizes and their subclass concentrations among Asian Indian women compared with Caucasian women.

METHODS

We measured HDL-C concentrations and sizes by nuclear magnetic resonance spectroscopy in 119 relatively healthy Asian Indian women and compared them with those of 1752 Caucasian women from the Framingham Offspring Study (FOS).

RESULTS

Asian Indian women were significantly younger (47.9 +/- 11.2 vs. 51.0 +/- 10.1 years, p = 0.0001), leaner (body mass index 24.0 +/- 4.7 vs. 26.0 +/- 5.6, p = < 0.0002), less likely to be postmenopausal (32 vs. 54%, p = < 0.0001), or smoke (< 1 vs. 20%, p = < 0.0001); nevertheless, prevalence of CAD was higher in Asian Indian women (4.2 vs. 1%, p = 0.0006). Asian Indian women had similar HDL-C (53 +/- 13 vs. 53 +/- 13 mg/dl, p = 0.99), smaller HDL-C particle size (8.9 +/- 0.35 vs. 9.4 +/- 0.44 nm, p = < 0.0001), higher total cholesterol (209 +/- 40 vs. 199 +/- 42 mg/dl, p = 0.01), and similar triglyceride (120 +/- 77 vs. 108 +/- 110 mg/d, p = 0.24) levels. Low-density lipoprotein cholesterol, particle concentrations and sizes, as well as prevalence of pattern B were similar.

CONCLUSIONS

Compared with the FOS, Asian Indian women have significantly smaller overall HDL particle size and similar levels of HDL-C, which may reflect impaired, reverse cholesterol transport. Total cholesterol was higher, whereas triglyceride and LDL-C levels were similar. This may partly explain the higher CAD rates in Asian Indian women. Further large scale, prospective, long-term studies are warranted.

Prevalence of diabetes mellitus and related conditions in Asian Indians living in the United States

This study is the first attempt to evaluate the prevalence of diabetes mellitus and related conditions in Asian Indians living in the United States. A community-based survey of 1,046 Asian Indian immigrants living in and around the Atlanta metro area of Georgia was conducted and found an overall prevalence of diabetes mellitus of 18.3% (22.5% in men and 13.6% in women). This prevalence of diabetes mellitus in Asian Indians is much higher than in whites, blacks, and Hispanics living in the United States.

Type 2 diabetes in South Asians: a pathophysiologic focus on the Asian-Indian epidemic

There is a high prevalence of type 2 diabetes mellitus and coronary artery disease among urban and migrant Asian Indians, despite the absence of traditional risk factors. Evidence exists that Asian Indians are more insulin resistant than white persons and that insulin resistance may play an important role in the pathogenesis of these diseases. Increased visceral fat in Asian Indians is associated with increased generalized obesity, which is not apparent from their nonobese body mass index. Increased visceral fat is related to dyslipidemia and increased frequency of insulin resistance and may account for the increased prevalence of diabetes mellitus and cardiovascular disease in Asian Indians. In addition, early protein energy deprivation, as indicated by low weight at birth and at 1 year of age, may induce a state of vulnerability to the development of type 2 diabetes in later life, especially if the quantitative and qualitative aspects of nutrition and altered lifestyles during adult years pose an additional challenge.

Risk factors for coronary heart disease in two similar Indian population groups, one residing in India, and the other in Sydney, Australia

OBJECTIVE

To identify the prevalence of coronary risk factors among South Asian Indians in Australia and India.

DESIGN

Cross-sectional intercountry comparison.

SUBJECTS

Healthy volunteers aged 23-75 y recruited from the Indian community in Sydney Australia (n=125), and their nominated relatives in India, (n=125).

RESULTS

The two groups were of similar background with over 90% of the group in India being siblings, parents or relatives of the group in Australia. There was no difference in the populations between India and Australia with regard to mean age (40+/-11.5 vs 39+/-10.3 y), body mass index (BMI) (25+/-3.3 vs 25+/-3.5 kg/m(2)), lipoprotein (a) (178 vs 202 mg/l), total cholesterol (5.3+/-1.3 vs 5.3+/-1.2 mmol/l) or triglyceride (1.7+/-0.8 vs 1.7+/-0.8 mmol/l). The group in India had higher insulin (median values) (139 vs 83 pmol/l, P=0.0001), waist-to-hip ratio (WHR) (0.88+/-0.08 vs 0.85+/-0.09, P=0.01), exercise time (23.7+/-32.7 vs 17.2+/-23.2 h/week, P=0.07), lower waist (83+/-10.0 vs 85+/-11.1 cm, P=0.05) and high-density lipoprotein (0.9+/-0.3 vs 1.1+/-0.6 mmol/l, P=0.02). Women in India had lower BMI (22.7+/-2.9 vs 25.3+/-4.2 kg/m(2), P<0.001), higher insulin (182 vs 90 pmol/l, P<0.001), WHR (0.86+/-0.08 vs 0.77+/-0.06, P<0.001)) and prevalence of abdominal obesity (% WHR >0.8, 73 vs 23%, P<0.001; odds of waist >90 cm=2.3, P<0.05). Men in India had the same BMI, lower waist (85.5+/-8.8 vs 92.9+/-7.2 cm, P<0.001) and WHR (0.89+/-0.09 vs 0.93+/-0.05, P<0.01) but higher insulin (137 vs 76 pmol/l).

CONCLUSION

The group in Australia (especially women) have a more favourable disease risk profile than those in India. The fact that the groups are of such similar background and partly related, make it unlikely that changes due to migration have a strong genetic bias. In contrast to other studies, the absence here of excessive weight gain on migration may be a key factor in disease risk prevention.

Duration of residence in the United States as a new risk factor for coronary artery disease (The Konkani Heart Study)

A survey conducted in a relatively homogeneous group of 527 Konkani subjects revealed a high prevalence of coronary artery disease (CAD) despite a lack of smoking and significant obesity. Traditional risk factors (age, gender, high cholesterol, hypertension, and diabetes) were significant predictors of CAD. In addition, duration of residence in the United States (US) emerged as a new independent risk factor. Independent predictors of CAD included age, gender, ever smoking, and duration of residence in the US. We conclude that acculturation may be a major risk factor for CAD in immigrant populations.

Genetic polymorphism PC-1 K121Q and ethnic susceptibility to insulin resistance

Genetic susceptibility may be responsible for high prevalence of insulin resistance in Asian Indians. This study was carried out in samples of local Asian Indians and Caucasians to determine whether plasma cell membrane glycoprotein (PC)-1 K121Q and insulin receptor substrate-1 (IRS-1) G972A polymorphisms contribute significantly to susceptibility to insulin resistance in Asian Indians. The frequency of carrying at least one copy of the PC-1 121Q variant in Asian Indians was significantly higher than that in Caucasians (P = 0.01), but the frequency was similar for IRS-1 972A (6% and 7%). A significantly higher insulin area under the curve during oral glucose tolerance testing (P < 0.0001) and lower insulin sensitivity during hyperinsulinemic-euglycemic clamps (P = 0.04) were found in Asian Indians with PC-1 121Q variant compared with Asian Indians with wild-type PC-1 and with Caucasians with or without the polymorphism. IRS-1 972A was not associated with any change in insulin sensitivity. We conclude that the PC-1 K121Q polymorphism associates with primary insulin resistance in migrant Asian Indians. A relatively high frequency of this polymorphism thus may be one factor contributing to insulin resistance susceptibility in Asian Indians. This finding indicates the need for expanded studies on the association between PC-1 K121Q and insulin resistance in a representative sample of the Asian Indian population.

Lack of association between central adiposity and lipaemia in UK Sikh men

OBJECTIVE

To determine whether the positive statistical associations between measures of total and regional adiposity and measures of glucose, insulin and triacylglycerol (TAG) metabolism reported in Caucasian men, are also observed in UK Sikhs.

DESIGN

A matched cross-sectional study in which each volunteer provided a blood sample after a 12-h overnight fast and had anthropometric measurements taken.

SUBJECTS

A total of 55 healthy Caucasian and 55 healthy UK Sikh men were recruited. The Caucasian and Sikh men were matched for age (48.7+/-10.9 and 48.3+/-10.0 y, respectively) and body mass index (BMI) (26.1+/-2.8 and 26.3+/-3.2 kg/m(2), respectively).

MEASUREMENTS

Anthropometric measurements were performed to assess total and regional fat depots. The concentrations of plasma total cholesterol, high-density cholesterol (HDL-C), low-density cholesterol (LDL-C) and small dense LDL (LDL3), TAG, glucose, fasting insulin (ins) and nonesterified fatty acids (NEFA) were analysed in fasted plasma. Surrogate measures of insulin resistance (HOMA-IR) and insulin sensitivity (RQUICKI) were calculated from insulin and glucose (HOMA-IR) and insulin, glucose and NEFA (RQUICKI) measurements.

RESULTS

The Sikh men had significantly higher body fat, with the sum of the four skinfold measurements (Ssk) (P=0.0001) and subscapular skinfold value (P=0.009) higher compared with the Caucasian men. The Sikh volunteers also had characteristics of the metabolic syndrome: lower HDL-C (P=0.07), higher TAG (P=0.004), higher % LDL3 (P=0.0001) and insulin resistance (P=0.05). Both ethnic groups demonstrated positive correlations between insulin and waist circumference (Caucasian: r=0.661, P=0.0001; Sikh: r=0.477, P=0.0001). The Caucasian men also demonstrated significant positive correlations between central adiposity (r=0.275, P=0.04), other measures of adiposity (BMI and suprailiac skinfold) and plasma TAG, whereas the Sikh men showed no correlation for central adiposity (r=0.019, ns) and TAG with a trend to a negative relationship between other measures (Ssk and suprailiac) which reached near significance for subscapular skinfold and TAG (r=-0.246, P=0.007). The expected positive association between insulin and TAG was observed in the Caucasian men (r=0.318, P=0.04) but not in the Sikh men (r=0.011, ns).

CONCLUSIONS

In the Caucasian men, the expected positive association between plasma TAG and centralized body fat was observed. However, a lack of association between centralized, or any other measure of adiposity, and plasma TAG was observed in the matched Sikh men, although both ethnic groups showed the positive association between centralized body fat and insulin resistance, which was less strong for Sikhs. These findings in the Sikh men were not consistent with the hypothesis that there is a clear causal relationship between body fat and its distribution, insulin resistance, and lipid abnormalities associated with the metabolic syndrome, in this ethnic group.

Analysis of Fc gamma receptor II (CD32) polymorphism in populations of African and South Asian ancestry reveals east-west geographic gradients of allele frequencies

Analysis of FcgammaRIIA alleles in Pakistanis and in Trinidadians of South Asian, African and mixed ancestry revealed no significant differences between Trinidadian South Asians and Pakistanis. H131 homozygotes were more common among Trinidadian South Asians than among Africans and those of mixed ancestry. Comparison with other populations revealed east-west geographic gradients of allele frequencies.

Lean, nondiabetic Asian Indians have decreased insulin sensitivity and insulin clearance, and raised leptin compared to Caucasians and Chinese subjects

OBJECTIVE

To study and compare the insulin sensitivity of healthy, nondiabetic Asian Indians with that of two other ethnic groups (Caucasian and Chinese) living in Singapore.

DESIGN

Study of insulin sensitivity using euglycaemic hyperinsulinaemic glucose clamp.

SUBJECTS

A total of 10 healthy, lean, young male subjects of each ethnic group, matched for age, body mass index (BMI) and physical activity. They all had normal glucose tolerance and had no family history of diabetes.

MEASUREMENTS

Anthropometric parameters (BMI, waist-hip ratio (WHR) and percentage body fat (PBF)), fasting lipid profile and leptin concentration, insulin sensitivity index, and insulin clearance.

RESULTS

Healthy lean (BMI 22.1+/-1.5 kg/m(2) (mean+/-s.d.)) Indians had significantly higher fasting serum leptin (5.1+/-2.5 vs Chinese 1.0+/-0.9 vs Caucasian 2.3+/-1.2 ng/ml; P<0.001), lower insulin sensitivity index (9.9+/-3.3 vs Chinese 14.1+/-3.5 vs Caucasian 18.8+/-9.2 mg/min kg fat-free mass/microU/ml; P<0.002), and lower insulin clearance (461.4+/-54.8 vs Chinese 621.0+/-99.3 vs Caucasian 646.9+/-49.2 ml/min m(2); P<0.001). Indians also had a higher PBF (26.5+/-5.2 vs Chinese 19.5+/-2.2 vs Caucasians 22.9+/-1.4%; P<0.001), diastolic blood pressure (P=0.036), fasting insulin (P<0.006) and fasting triglyceride (P=0.022). Stepwise regression analysis showed that ethnicity was the only significant independent determinant variable for the differences in insulin sensitivity index (P=0.008).

CONCLUSION

Healthy lean nondiabetic Indians were more insulin resistant compared to other ethnic groups despite the similarity in living environment. These findings may warrant preventive health-care strategies for type II diabetes and coronary artery disease to target Indians at an earlier stage compared to other ethnic groups.

A comparison of HLA-DR and -DQ allele and haplotype frequencies in Trinidadian populations of African, South Asian, and mixed ancestry

Using polymerase chain reaction-sequence-specific primer (PCR-SSP) typing, this study determined the frequency of human leukocyte antigen (HLA) DR- and -DQ alleles and haplotypes in individuals of African (n = 75), South Asian (n = 98), and mixed (n = 102) ancestry from the Caribbean island of Trinidad. We detected 19 different haplotypes containing DRB3, 8 containing DRB4, 6 containing DRB5, and 6 different haplotypes without DRB3/4/5 genes. Twenty-nine haplotypes were identified in Africans, 24 in the South Asians, and 32 in the mixed group. We detected significant differences between the populations, principally at the DQA1 and DQB1 loci, although the allele frequency for DRB1*0901 was highest in the Africans (p(c) < 0.05). Trinidad African and mixed groups were generally more diverse than the South Asians and displayed a wider range of DRB1-DQB1 associations; DQB1*02 and DQB1*0301 each associated with five to six different DRB1 alleles in the Africans and mixed group but only two in South Asians. In the Africans and the mixed group, DQB1*04 was found with DRB1*0302 and DRB1*04, but only with DRB1*08 in the South Asians. Trinidad Africans revealed consistencies with populations in Western, Central, and Northern Africa, but differed considerably from individual populations on the African continent. Trinidad South Asians displayed similar allele frequencies and associations to other populations from Northern India.