Cardiovascular complications and mortality after diabetes diagnosis for South Asian and Chinese patients: a population-based cohort study

Ethnic disparities in quality of diabetes care in Scotland: A national cohort study

AIMS

The aim of this study is to compare quality of diabetes care in people with type 2 diabetes by ethnicity, in Scotland.

METHODS

Using a linked national diabetes registry, we included 162,122 people newly diagnosed with type 2 diabetes between 2009 and 2018. We compared receipt of nine guideline indicated processes of care in the first-year post-diabetes diagnosis using logistic regression, comparing eight ethnicity groups to the White group. We compared annual receipt of HbA1c and eye screening during the entire follow-up using generalised linear mixed effects. All analyses adjusted for confounders.

RESULTS

Receipt of diabetes care was lower in other ethnic groups compared to White people in the first-year post-diagnosis. Differences were most pronounced for people in the: African, Caribbean or Black; Indian; and other ethnicity groups for almost all processes of care. For example, compared to White people, odds of HbA1c monitoring were: 44% lower in African, Caribbean or Black people (OR 0.56 [95% CI 0.48, 0.66]); 47% lower in Indian people (OR 0.53 [95% CI 0.47, 0.61]); and 50% lower in people in the other ethnicity group (OR 0.50 [95% CI 0.46, 0.58]). Odds of receipt of eye screening were 30%-40% lower in most ethnic groups compared to the White group. During median 5 year follow-up, differences in HbA1c monitoring and eye screening largely persisted, but attenuated slightly for the former.

CONCLUSIONS

There are marked ethnic disparities in routine diabetes care in Scotland in the short- and medium-term following diabetes diagnosis. Further investigation is needed to establish and effectively address the underlying reasons.

Epidemiology of adverse drug reactions to antihypertensive, antithrombotic and antidiabetic medications among adult inpatients at a National Referral Hospital, Uganda

INTRODUCTION

Treatment for hypertension, thrombosis and type 2 diabetes mellitus is long term and usually requires a combination of drugs which increases the risk of adverse drug reactions (ADRs). This study aimed to establish the prevalence at admission, incidence during hospitalization and characteristics of ADRs linked to antihypertensive, antithrombotic and antidiabetic drugs among adult inpatients in Uganda.

METHODS

We conducted a secondary analysis of data from a previously assembled prospective cohort study in Uganda's Mulago National Referral Hospital. We reviewed the files of inpatients who received antihypertensive, antithrombotic and/or antidiabetic medications prior to and/or during hospitalization. The modified Schumock and Thornton Preventability Scale, the Division of AIDS Table for Grading the Severity of Adult and Paediatric Adverse Events and the World Health Organization - Uppsala Monitoring Centre seriousness criteria were used to characterize the ADRs.

RESULTS

More than a quarter (27%, 42/155) of the inpatients experienced an ADR at admission or during hospitalization. The point prevalence of ADRs at admission was 8% (13/155) and the incidence of ADRs during hospitalization was 23% (36/155). Forty-one percent (35/86) of the ADRs were serious and the majority (59%, 51/86) were preventable.

CONCLUSION

One in 13 inpatients experienced an ADR on admission and one in four experienced an ADR that developed during hospitalization. Clinicians ought to prescribe medicines with lower ADR risk profile for cardiovascular and/or diabetic patients whenever possible.

Ethnic differences in the association between age at diagnosis of diabetes and the risk of cardiovascular complications: a population-based cohort study

BACKGROUND

We examined ethnic differences in the association between age at diagnosis of diabetes and the risk of cardiovascular complications.

METHODS

We conducted a population-based cohort study in Ontario, Canada among individuals with diabetes and matched individuals without diabetes (2002-18). We fit Cox proportional hazards models to determine the associations of age at diagnosis and ethnicity (Chinese, South Asian, general population) with cardiovascular complications. We tested for an interaction between age at diagnosis and ethnicity.

RESULTS

There were 453,433 individuals with diabetes (49.7% women) and 453,433 matches. There was a significant interaction between age at diagnosis and ethnicity (P < 0.0001). Young-onset diabetes (age at diagnosis < 40) was associated with higher cardiovascular risk [hazard ratios: Chinese 4.25 (3.05-5.91), South Asian: 3.82 (3.19-4.57), General: 3.46 (3.26-3.66)] than usual-onset diabetes [age at diagnosis ≥ 40 years; Chinese: 2.22 (2.04-2.66), South Asian: 2.43 (2.22-2.66), General: 1.83 (1.81-1.86)] versus ethnicity-matched individuals. Among those with young-onset diabetes, Chinese ethnicity was associated with lower overall cardiovascular [0.44 (0.32-0.61)] but similar stroke risks versus the general population; while South Asian ethnicity was associated with lower overall cardiovascular [0.75 (0.64-0.89)] but similar coronary artery disease risks versus the general population. In usual-onset diabetes, Chinese ethnicity was associated with lower cardiovascular risk [0.44 (0.42-0.46)], while South Asian ethnicity was associated with lower cardiovascular [0.90 (0.86-0.95)] and higher coronary artery disease [1.08 (1.01-1.15)] risks versus the general population.

CONCLUSIONS

There are important ethnic differences in the association between age at diagnosis and risk of cardiovascular complications.

Prevalent diabetes and long-term cardiovascular outcomes in adult sepsis survivors: a population-based cohort study

BACKGROUND

Sepsis survivors are at elevated risk for cardiovascular disease during long-term follow-up. Whether diabetes influences cardiovascular risk after sepsis survival remains unknown. We sought to describe the association of diabetes with long-term cardiovascular outcomes in adult sepsis survivors.

METHODS

Population-based cohort study in the province of Ontario, Canada (2008-2017). Adult survivors of a first sepsis-associated hospitalization, without pre-existing cardiovascular disease, were included. Main exposure was pre-existing diabetes (any type). The primary outcome was the composite of myocardial infarction, stroke, and cardiovascular death. Patients were followed up to 5 years from discharge date until outcome occurrence or end of study period (March 2018). We used propensity score matching (i.e., 1:1 to patients with sepsis but no pre-existing diabetes) to adjust for measured confounding at baseline. Cause-specific Cox proportional hazards models with robust standard errors were used to estimate hazard ratios (HR) alongside 95% confidence intervals (CI). A main secondary analysis evaluated the modification of the association between sepsis and cardiovascular disease by pre-existing diabetes.

RESULTS

78,638 patients with pre-existing diabetes who had a sepsis-associated hospitalization were matched to patients hospitalized for sepsis but without diabetes. Mean age of patients was 71 years, and 55% were female. Median duration from diabetes diagnosis was 9.8 years; mean HbA1c was 7.1%. Adult sepsis survivors with pre-existing diabetes experienced a higher hazard of major cardiovascular disease (HR 1.25; 95% CI 1.22-1.29)-including myocardial infarction (HR 1.40; 95% CI 1.34-1.47) and stroke (HR 1.24; 95% CI 1.18-1.29)-during long-term follow-up compared to sepsis survivors without diabetes. Pre-existing diabetes modified the association between sepsis and cardiovascular disease (risk difference: 2.3%; 95% CI 2.0-2.6 and risk difference: 1.8%; 95% CI 1.6-2.0 for the effect of sepsis-compared to no sepsis-among patients with and without diabetes, respectively).

CONCLUSIONS

Sepsis survivors with pre-existing diabetes experience a higher long-term hazard of major cardiovascular events when compared to sepsis survivors without diabetes. Compared to patients without sepsis, the absolute risk increase of cardiovascular events after sepsis is higher in patients with diabetes (i.e., diabetes intensified the higher cardiovascular risk induced by sepsis).

Diabetes with poor-control HbA1c is cardiovascular disease 'risk equivalent' for mortality: UK Biobank and Hong Kong population-based cohort study

INTRODUCTION

Type 2 diabetes mellitus (T2DM) has traditionally been considered a coronary heart disease 'risk equivalent' for future mortality, but significant heterogeneity exists across people with T2DM. This study aims to determine the risk of all-cause mortality of patients with cardiovascular disease (CVD) and T2DM in UK and Hong Kong, with stratifications for hemoglobin A1 (HbA1c) concentrations, compared with those without CVD and diabetes mellitus.

RESEARCH DESIGN AND METHODS

This is a retrospective cohort study of 3 839 391 adults from Hong Kong and a prospective cohort study of 497 779 adults from the UK Biobank. Individuals were divided into seven disease groups: (1) no T2DM and CVD, (2) T2DM only with HbA1c <7%, (3) T2DM only with HbA1c 7%-7.9%, (4) T2DM only with HbA1c 8%-8.9%, (5) T2DM only with HbA1c ≥9%, (6) CVD only, and (7) T2DM and CVD. Differences in all-cause mortality between groups were examined using Cox regression.

RESULTS

After around 10 years of median follow-up, 423 818 and 19 844 deaths were identified in the Hong Kong cohort and UK Biobank, respectively. Compared with individuals without T2DM and CVD, the adjusted HR for all-cause mortality in the other six disease groups for the Hong Kong cohort was 1.25 (95% CI 1.23 to 1.27) for T2DM only with HbA1c <7%, 1.21 (95% CI 1.19 to 1.23) for T2DM only with HbA1c 7%-7.9%, 1.36 (95% CI 1.33 to 1.39) for T2DM only with HbA1c 8%-8.9%, 1.82 (95% CI 1.78 to 1.85) for T2DM only with HbA1c ≥9%, 1.37 (95% CI 1.36 to 1.38) for CVD only, and 1.83 (95% CI 1.81 to 1.85) for T2DM and CVD, and for the UK Biobank the HR was 1.45 (95% CI 1.33 to 1.58), 1.50 (95% CI 1.32 to 1.70), 1.72 (95% CI 1.43 to 2.08), 2.51 (95% CI 2.05 to 3.08), 1.67 (95% CI 1.59 to 1.75) and 2.62 (95% CI 2.42 to 2.83), respectively. This indicates that patients with T2DM had an increased risk of mortality compared with those without T2DM and CVD, and in those with HbA1c ≥9% an even higher risk than people with CVD.

CONCLUSIONS

Patients with T2DM with poor HbA1c control (8%-8.9% and ≥9%) were associated with similar and higher risk of mortality compared with patients with CVD, respectively. Optimal HbA1c, controlled for risk reduction and prevention of mortality and complications in diabetes management, remains important.

Ethnic disparities in mortality among overweight or obese adults with newly diagnosed type 2 diabetes: a population-based cohort study

PURPOSE

Ethnic variation in risk of type 2 diabetes is well established, but its impact on mortality is less well understood. This study investigated the risk of all-cause and cardiovascular mortality associated with newly diagnosed type 2 diabetes in White, Asian and Black adults who were overweight or obese.

METHODS

This population-based cohort study used primary care records from the UK Clinical Practice Research Datalink, linked with secondary care and death registry records. A total of 193,528 obese or overweight adults (BMI of 25 or greater), with ethnicity records and no pre-existing type 2 diabetes were identified between 01 January 1995 and 20 April 2018. Multivariable Cox proportional hazards regression estimated hazards ratios (HR) for incident type 2 diabetes in different ethnic groups. Adjusted hazards ratios for all-cause and cardiovascular mortality were determined in individuals with newly diagnosed type 2 diabetes.

RESULTS

During follow-up (median 9.8 years), the overall incidence rate of type 2 diabetes (per 1,000 person-years) was 20.10 (95% CI 19.90-20.30). Compared to Whites, type 2 diabetes risk was 2.2-fold higher in Asians (HR 2.19 (2.07-2.32)) and 30% higher in Blacks (HR 1.34 (1.23-1.46)). In individuals with newly diagnosed type 2 diabetes, the rates (per 1,000 person-years) of all-cause mortality and cardiovascular mortality were 24.34 (23.73-24.92) and 4.78 (4.51-5.06), respectively. Adjusted hazards ratios for mortality were significantly lower in Asians (HR 0.70 (0.55-0.90)) and Blacks (HR 0.71 (0.51-0.98)) compared to Whites, and these differences in mortality risk were not explained by differences in severity of hyperglycaemia.

CONCLUSIONS/INTERPRETATION

Type 2 diabetes risk in overweight and obese adults is greater in Asian and Black compared to White ethnic populations, but mortality is significantly higher in the latter. Greater attention to optimising screening, disease and risk management appropriate to all communities with type 2 diabetes is needed.

Type 2 diabetes burden among migrants in Europe: unravelling the causal pathways

European populations are ethnically and culturally diverse due to international migration. Evidence indicates large ethnic inequalities in the prevalence of type 2 diabetes. This review discusses the burden of type 2 diabetes and its related complications, and the potential explanatory mechanisms among migrants in Europe. The current available data suggest that the rate of type 2 diabetes is higher in all migrant groups and that they develop this disease at an earlier age than the host European populations. The level of diabetes awareness among migrant populations is high, but glycaemic control remains suboptimal compared with Europeans. The culturally adapted lifestyle modification intervention trials to prevent type 2 diabetes mainly focus on South Asian adults in Europe. Diabetes-related microvascular and macrovascular complications remain a major burden among migrant populations in Europe. Earlier studies found higher mortality rates among migrants, but recent studies seem to suggest a shifting trend in favour of first-generation migrants. However, the extent of the burden of type 2 diabetes varies across migrant groups and European countries. Despite the higher burden of type 2 diabetes among migrants, the key underlying factors are not well understood mainly due to limited investment in basic science research and development of prospective cohort studies. We hypothesise that the underlying risk factors for the high burden of type 2 diabetes and its related complications in migrants are multifaceted and include pre-migration factors, post-migration factors and genetic predispositions. Given the multi-ethnic nature of the current European population, there is a clear need for investment in research among migrant populations to gain insight into factors driving the high burden of type 2 diabetes and related complications to facilitate prevention and treatment efforts in Europe.

Association of Hypertension and Diabetes with Ischemic Heart Disease and Stroke Mortality in India: The Million Death Study

Background

The cardiovascular outcomes of hypertension and diabetes in India have never been studied at the national level.

Objectives

We conducted a nationally-representative proportional mortality study to measure the associations of hypertension and diabetes with premature mortality due to ischemic heart disease (IHD) and stroke among Indian adults.

Methods

We determined causes of death by verbal autopsy from 2001-14 among 2.4 million households. We defined cases as those who died of the study outcomes and controls as those who died of injuries, respiratory causes, or cancer. We used multivariable logistic regression models to compute adjusted odds ratios (OR) measuring the association of hypertension and diabetes with IHD or stroke mortality, population-attributable fractions (PAF), and time trends.

Results

The mean age at death was 55.6 (standard deviation 9.9) years for IHD, 58.2 (9.0) years for stroke, and 46.8 (injury) to 59.8 (respiratory) years for controls. There were more men among both the cases (IHD: 70.1%; stroke: 59.0%) and controls (injury: 76.6%; cancer: 55.4%; respiratory: 59.8%). Hypertension was associated with six- to eight-fold increases in the odds of IHD (OR 5.9, 99% CI 5.6-6.2) and stroke mortality (7.9, 7.4-8.5). Diabetes was associated with double the odds (1.9, 1.7-2.0) of IHD mortality and increased odds of stroke mortality (1.6, 1.4-1.7). Hypertension accounted for an increasing PAF of IHD mortality and decreasing PAF of stroke mortality. Diabetes was associated with relatively lower PAFs and variable time trends.

Conclusions

Hypertension is associated with an unexpectedly high burden of cardiovascular mortality, and contributes to an increasing proportion of IHD deaths and a decreasing proportion of stroke deaths. Better management of hypertension and diabetes is urgently required to reduce premature cardiovascular mortality.

Sex and ethnic differences in the cardiovascular complications of type 2 diabetes

Diabetes mellitus represents a global health concern affecting 463 million adults and is projected to rapidly rise to 700 million people by 2045. Amongst those with type 2 diabetes (T2D), there are recognised differences in the impact of the disease on different sex and ethnic groups. The relative risk of cardiovascular complications between individuals with and without T2D is higher in females than males. People of South Asian heritage are two to four times more likely to develop T2D than white people, but conversely not more likely to experience cardiovascular complications. Differences in the pathophysiological responses in these groups may identify potential areas for intervention beyond glycaemic control. In this review, we highlight key differences of diabetes-associated cardiovascular complications by sex and ethnic background, with a particular emphasis on South Asians. Evidence assessing therapeutic efficacy of new glucose lowering drugs in minority groups is limited and many major cardiovascular outcomes trials do not report ethnic specific data. Conversely, lifestyle intervention and bariatric surgery appear to have similar benefits regardless of sex and ethnic groups. We encourage future studies with better representation of women and ethnic minorities that will provide valuable data to allow better risk stratification and tailored prevention and management strategies to improve cardiovascular outcomes in T2D.

Greater macrovascular and microvascular morbidity from type 2 diabetes in northern compared with southern China: A cross-sectional study

AIMS/INTRODUCTION

There are substantial differences in genes, diet, culture and environment between the northern and southern Chinese populations, which might influence treatment strategy and screening policy. We studied the differences in type 2 diabetes and diabetic complications between northern and southern China.

MATERIALS AND METHODS

We carried out a cross-sectional survey using data from the China Cardiometabolic Registries on blood pressure, blood lipids and blood glucose in 25,398 Chinese type 2 diabetes patients. Macrovascular, microvascular and other complications were collected by self-report or medical records, and then divided into the northern and southern groups by the boundary of the Yangtze River.

RESULTS

Northern patients were younger, and had heavier weight, greater body mass index and waist circumference, higher blood pressure, higher total cholesterol, higher low-density lipoprotein cholesterol, and higher hemoglobin A1C. The prevalence of cardiovascular, cerebrovascular and macrovascular complications were 1.76-fold, 1.24-fold and 1.47-fold more in northern than that in southern Chinese patients. In addition, the prevalence of diabetic nephropathy, retinopathy, neuropathy and microvascular complications in northern Chinese patients also increased. When stratified by age, the difference in both cardiovascular disease and ischemic stroke morbidity became significant, even in the 35-44 years age group.

CONCLUSIONS

More macrovascular and microvascular complications were found in northern compared with southern patients, and the largest difference also appeared in the younger age groups <55 years, which might be meaningful to a screening and treatment strategy according to geographic differences.

Type 2 Diabetes and Atherosclerotic Cardiovascular Disease in South Asians: a Unique Population with a Growing Challenge

PURPOSE OF REVIEW

The purpose of this review is to summarize our current knowledge of factors that influence clinical decision making and management of type 2 diabetes mellitus (T2DM) and atherosclerotic cardiovascular disease (ASCVD) among South Asians (SA).

RECENT FINDINGS

ASCVD and T2DM in SAs have been examined in recent times. Pathophysiologic and genetic factors including the role of adiponectin, visceral adiposity, lower beta cell function, and psycho-social factors like sedentary lifestyle, poor adherence to medications, and carbohydrate dense meals play a role in early development and the high-risk presentation of both ASCVD and T2DM in SA. Recently, large population-based cohort studies have attempted to compare outcomes and interventions that can be translated to timely detection and targeted interventions in this high-risk group. SAs in the USA are more likely to be diagnosed with T2DM and ASCVD when compared to non-Hispanic whites, non-Hispanic Blacks, and Hispanic populations. The development of personalized ethnic risk assessment tools and better representation of SAs in prospective studies are essential to increasing our understanding and management of cardio-metabolic disease in SA living in the USA.

Contribution of type 2 diabetes to all-cause mortality, cardiovascular disease incidence and cancer incidence in white Europeans and South Asians: findings from the UK Biobank population-based cohort study

OBJECTIVE

To investigate whether the health implications of having type 2 diabetes (T2D) were different in South Asian compared with white European participants.

RESEARCH DESIGN AND METHODS

Prospective data from UK Biobank were used, and 457 935 participants of white European and 7102 of South Asian background were included. Cox proportional regression was performed to investigate the association between T2D and health outcome by ethnicity.

RESULTS

Over a mean of 7.0 years (IQR 6.3-7.6) of follow-up, 12 974 participants had died, and 30 347 and 27 159 developed cardiovascular disease (CVD) and cancer, respectively. South Asians had a higher risk for CVD mortality (HR: 1.42, 95% CI 1.07 to 1.89) and incidence (HR: 1.78, 95% CI 1.63 to 1.94), but a decreased risk for cancer mortality (HR: 0.59, 95% CI 0.41 to 0.85) and incidence (HR: 0.80, 95% CI 0.70 to 0.92) compared with white Europeans. Compared with individuals without T2D, both white Europeans and South Asians with T2D had a higher risk for all-cause mortality (1.59 (1.48 to 1.71) vs 2.83 (1.76 to 4.53)), CVD mortality (2.04 (1.82 to 2.28) vs 4.40 (2.37 to 8.16)) and CVD incidence (1.37 (1.31 to 1.44) vs 1.60 (1.31 to 1.95)), respectively. However, the magnitude of the risk was higher for South Asians than white Europeans.

CONCLUSIONS

Although T2D was associated with a higher risk for all-cause mortality and CVD incidence and mortality, in both white Europeans and South Asians, the risk experienced by South Asians with T2D was higher than their white European counterparts.

Penetration of new antidiabetic medications in East Asian countries and the United States: A cross-national comparative study

BACKGROUND

The number of patients with diabetes is increasing particularly in Asia-Pacific region. Many of them are treated with antidiabetics. As the basis of the studies on the benefit and harm of antidiabetic drugs in the region, the information on patterns of market penetration of new classes of antidiabetic medications is important in providing context for subsequent research and analyzing and interpreting results.

METHODS

We compared penetration patterns of dipeptidyl peptidase-4 (DPP-4) inhibitors in Taiwan, Hong Kong, Japan, and the United States. We used the Taiwan National Health Insurance Research Database, a random sample of the Hong Kong Clinical Data Analysis and Reporting System, the Japan Medical Data Center database, and a 5% random sample of the US Medicare database converted to the Observational Medical Outcomes Partnership's Common Data Model to identify new users of oral antidiabetic medications. We standardized prevalence and incidence rates of medication use by age and sex to those in the 2010 Taiwanese population. We compared age, sex, comorbid conditions, and concurrent medications between new users of DPP-4 inhibitors and biguanides.

RESULTS

Use of DPP-4 inhibitors 1 year after market entry was highest in Japan and lowest in Hong Kong. New users had more heart failure, hyperlipidemia, and renal failure than biguanide users in Taiwan, Hong Kong, and the United States while the proportions were similar in Japan. In a country with low penetration of DPP-4 inhibitors (eg, Hong Kong), users had diabetes with multiple comorbid conditions compared with biguanidine users. In a country with high penetration (eg, Japan), the proportion of users with comorbid conditions was similar to that of biguanide users.

CONCLUSIONS

We observed a marked difference of the penetration patterns of newly marketed antidiabetics in different countries in Asia. Those results will provide the basic information useful in the future studies.

Gene expression profiles of rat MMECs with different glucose levels and fgl2 gene silencing

BACKGROUND

Cardiac microvascular endothelial cells (MMECs) is one of the key factors in the process of diabetic cardiomyopathy, a common chronic complication of diabetes. Fibrinogen-like protein 2 (FGL2) is linked to apoptosis, angiogenesis, and inflammatory response, all of which also occur in diabetes. Thus, we investigate the role of FGL 2 and other genes in the pathology of diabetic cardiomyopathy.

METHODS

In the present study, we used high-throughput microarray to profile gene expression in rat myocardial MMECs with or without silencing the fgl2 gene and in different glucose environments. We use volcanic maps to isolate genes with significantly different expression levels between conditions, using the standard statistical criteria of fold changes ≥1.5 and P-values ≤0.05. From this list, we identified genes with the most signicant changes in RNA levels and confirmed their protein-level changes with Western blot. Furthermore, bioinformatic analysis predicts possible pathophysiology and clinical relevance of these proteins in diabetic cardiomyopathy.

RESULTS

We identified 17 upregulated and 15 downregulated genes caused by silencing fgl2 gene. Most of them are involved in metabolism, ion transport, cell membrane surface recognition signal modification, inflammatory response, and immune response. Using Western blot, we were able to confirm protein-level expression changes of three genes. Specifically, in both normal and high glucose conditions, silencing fgl2 significantly decreased the expression levels of CCL3 and PLAGL1 while increasing the expression level of CTSC. Significantly, bioinformatic analyses show that CCL3 is related to type 1 diabetes, PLAGL1 to cardiomyocytes, and CTSC to albuminuria in type 2 diabetes.

CONCLUSIONS

Our study provides clues for further studies on the mechanism of diabetic cardiomyopathy as well as function of FGL2 in this process, potentially offering new therapeutic strategies for treating diabetic cardiomyopathy.

Cardiovascular and Mortality Risks in Migrant South Asians with Type 2 Diabetes: Are We Winning the Battle?

PURPOSE OF REVIEW

We seek to describe the relationship between diabetes mellitus and cardiovascular risk in migrant South Asians compared to native white Europeans, and to determine the temporal change in this relationship over recent years.

RECENT FINDINGS

Recent evidence suggests that the excess mortality risk associated with diabetes is lower in the migrant South Asian population compared with white Europeans. By contrast, South Asians continue to demonstrate elevated cardiovascular morbidity compared to white Europeans, although to a lesser extent than was observed in previous decades. The excess mortality previously observed in South Asian migrants has attenuated with a lower mortality risk compared to white Europeans observed in several recent studies. We speculate that these findings may relate in part to earlier diabetes diagnosis and more prolonged exposure to cardiovascular risk factor management in the South Asian population. Further study is required to confirm these hypotheses.

Inadequate screening for retinopathy among recent immigrants with type 2 diabetes despite universal health care: A population-based study

AIMS

To examine retinopathy screening and treatment rates for recent immigrants compared to non-immigrants in a universal health care system.

METHODS

Linked health care and immigration databases were used to identify all 771,564 adults diagnosed with diabetes between 1996 and 2007, in Ontario, Canada. The cohort was stratified by their immigration status and followed until 2013 for retinopathy screening and treatment visits.

RESULTS

Retinopathy screening rates were low, and recent immigrants were considerably less likely to receive screening than long-term residents (≥1 examination within 1year: 37.5% vs. 50.5%, adjusted OR 0.76 [95% CI, 0.75-0.77]; ≥3 examinations within 6years: 46.6% vs. 61.9%, adjusted OR 0.77 [95% Cl, 0.76-0.79]). Immigrants were also less likely to receive surgical treatment for retinopathy, but adjustment for the frequency of screening attenuated these differences.

CONCLUSIONS

Despite universal access to physician services, only half of all individuals with newly-diagnosed type 2 diabetes received retinopathy screening within the first year, and recent immigrants were markedly less likely to be screened. After adjusting for screening rates, gaps in surgical treatment for retinopathy were attenuated, suggesting that treatable retinopathy may be being missed among recent immigrants because of inadequate screening.

Life Expectancy and Cause-Specific Mortality in Type 2 Diabetes: A Population-Based Cohort Study Quantifying Relationships in Ethnic Subgroups

OBJECTIVES

This study 1) investigated life expectancy and cause-specific mortality rates associated with type 2 diabetes and 2) quantified these relationships in ethnic subgroups.

RESEARCH DESIGN AND METHODS

This was a cohort study using Clinical Practice Research Datalink data from 383 general practices in England with linked hospitalization and mortality records. A total of 187,968 patients with incident type 2 diabetes from 1998 to 2015 were matched to 908,016 control subjects. Abridged life tables estimated years of life lost, and a competing risk survival model quantified cause-specific hazard ratios (HRs).

RESULTS

A total of 40,286 deaths occurred in patients with type 2 diabetes. At age 40, white men with diabetes lost 5 years of life and white women lost 6 years compared with those without diabetes. A loss of between 1 and 2 years was observed for South Asians and blacks with diabetes. At age older than 65 years, South Asians with diabetes had up to 1.1 years' longer life expectancy than South Asians without diabetes. Compared with whites with diabetes, South Asians with diabetes had lower adjusted risks for mortality from cardiovascular (HR 0.82; 95% CI 0.75, 0.89), cancer (HR 0.43; 95% CI 0.36, 0.51), and respiratory diseases (HR 0.60; 95% CI 0.48, 0.76). A similar pattern was observed in blacks with diabetes compared with whites with diabetes.

CONCLUSIONS

Type 2 diabetes was associated with more years of life lost among whites than among South Asians or blacks, with older South Asians experiencing longer life expectancy compared with South Asians without diabetes. The findings support optimized cardiovascular disease risk factor management, especially in whites with type 2 diabetes.

Hypertensive diabetic patients: incidence of cardiovascular and renal outcomes in a historical cohort over 11 years

BACKGROUND

Diabetics have increased risks for cardiovascular disease (CVD) and mortality, reducing their life expectancy by up to 15 years. Type 2 diabetes mellitus specifically increases the risk for cardiovascular mortality nearly fivefold. When hypertension is combined with diabetes, the risk of CVD is even greater.

OBJECTIVE

Identify non-fatal cardiovascular outcomes and renal function impairment in a cohort of hypertensive patients in regular treatment in a reference treatment center, over 11 years of follow-up.

METHODS

Historical cohort of hypertensive patients in regular treatment for at least 11 years in a specialized service for hypertension treatment. The exposed group was hypertensive diabetic patients at the beginning of the cohort, and the non-exposed group had hypertension without diabetes. The cohort began in 2004, with follow-ups in 2009 and 2015. Variables used: gender, race, age, physical activity, alcohol consumption, smoking, blood pressure, body mass index, glycated hemoglobin, diabetes and hypertension diagnosis times, treatment time in specialized service, non-fatal cardiovascular outcomes, and renal impairment assessed by creatinine clearance.

RESULTS

139 patients participated in the study (55 diabetic hypertensive; 84 non-diabetic hypertensive), with an initial (2004) mean hypertension treatment time of 5.8 years. Females were the majority (75.5%) in both groups. Groups were similar regarding socio-demographic variables, but the group of hypertensive diabetic patients had higher frequency of obesity and uncontrolled BP, which persisted in all follow-ups. In 11 years of follow-up (2004-2015), the diabetic group had more cardiovascular events, with increased risk of acute myocardial infarction (RR 95% CI 1.6 12.2-95.0), stroke (RR 95% CI 1.3-6.1 27.7) and complications requiring hospitalization (RR 95% CI 1.6 2.2-3.0). Worsened renal function occurred more often in the non-exposed group, but in the end, the proportion of renal function loss was similar between groups.

CONCLUSIONS

Exposure to type 2 diabetes increased the risk of new cardiovascular outcomes over 11 years of follow-up of hypertensive patients. Diabetes by itself increased the risk of cardiovascular outcomes, justifying more intensive actions in this population.

Clinical diabetes research using data mining: a Canadian perspective

With the advent of the digitization of large amounts of information and the computer power capable of analyzing this volume of information, data mining is increasingly being applied to medical research. Datasets created for administration of the healthcare system provide a wealth of information from different healthcare sectors, and Canadian provinces' single-payer universal healthcare systems mean that data are more comprehensive and complete in this country than in many other jurisdictions. The increasing ability to also link clinical information, such as electronic medical records, laboratory test results and disease registries, has broadened the types of data available for analysis. Data-mining methods have been used in many different areas of diabetes clinical research, including classic epidemiology, effectiveness research, population health and health services research. Although methodologic challenges and privacy concerns remain important barriers to using these techniques, data mining remains a powerful tool for clinical research.

Determinants of mortality in patients with type 2 diabetes: a review

We aimed to review and summarize the evidence from accomplished trials analyzing factors influencing mortality in patients with T2DM and to provide some recommendations for targets and treatment in the European region. The following databases were searched for relevant trials: PubMed and the Cochrane Library. Of 3.806 citations, 134 trials met our inclusion criteria.

RESULTS

The reduction in lifetime for 65 + -years-old patients having less than 10 years T2DM amounts to 1.8 years. Having T2DM for more than 10 years lifetime will be reduced by 2.7 years. However, the lifetime shortening factor of T2DM will even be stronger for 40 + -years-old patients at onset. Males will lose 11.6 years of life and 18.6 QUALYs. T2DM among females will reduce life by 14 QUALYs by 22 years. From a statistical point of view, the highest mortality rate will occur in an over 55-years-old European smoking and non-compliant diabetic woman with alcohol abuse living in a rural area with a low level of education and a low socio-economic status. Furthermore, other co-morbidities such as cardiovascular diseases, gout, and depression affect mortality. Additionally, mortality will increase with a BMI over 35 and also with a BMI under 20-25. This refers to the obesity paradox indicating a higher mortality rate among normal weight patients with T2DM compared to overweight patients with T2DM. HbA1c-levels between 6.5 % and 7 % are associated with the lowest impact on mortality.

Type 2 diabetes in migrant south Asians: mechanisms, mitigation, and management

South Asians, particularly when living in high-income countries, are at a substantially elevated risk of type 2 diabetes compared with white Europeans, and typically develop the disease 5-10 years earlier and at a lower BMI. Migrant south Asians seem to be more insulin resistant than white Europeans across the life course and potentially experience β-cell exhaustion at a younger age. Differences in adiposity (high percentage of body fat and high proportion of deep subcutaneous and visceral fat) and skeletal muscle (low percentage of lean mass and low cardiorespiratory fitness) are likely to contribute these factors. No clear evidence is available suggesting genetic factors make a major contribution to the increased risk of diabetes in south Asians, but epigenetic factors might have a role. Irrespective of future mechanistic discoveries, south Asians need to be encouraged and helped-by various culturally appropriate methods--to maintain a high physical activity level and low bodyweight across the life course to prevent diabetes. In clinical terms, cardiovascular risks have attenuated over time in migrant south Asians with diabetes but retinopathy and renal complication risks remain high because of the high levels of glycaemia and rapid glycaemic deterioration noted in this population. We review these aspects and suggest areas for future research.

A competing risk analysis of sequential complication development in Asian type 2 diabetes mellitus patients

This retrospective cohort study investigated the progression risk of sequential complication in Asian type 2 diabetes (T2D) patients using the Taiwan Pay-for-Performance Diabetes Registry and claim data from November 2003 to February 2009. 226,310 adult T2D patients without complication were followed from diagnosis to complications, including myocardial infarction (MI), other ischemic heart disease (IHD), congestive heart failure (CHF), stroke, chronic kidney disease (CKD), retinopathy, amputation, death or to the end of study. Cumulative incidences (CIs) of first and second complications were analyzed in 30 and 4 years using the cumulative incidence competing risk method. IHD (29.8%), CKD (24.5%) and stroke (16.0%) are the most common first complications. The further development of T2D complications depends on a patient’s existing complication profiles. Patients who initially developed cardiovascular complications had a higher risk (9.2% to 24.4%) of developing IHD or CKD, respectively. All-cause mortality was the most likely consequence for patients with a prior MI (12.0%), so as stroke in patients with a prior MI (10.8%) or IHD (8.9%). Patients with CKD had higher risk of developing IHD (16.3%), stroke (8.9%) and all-cause mortality (8.7%) than end-stage renal disease (4.0%). Following an amputation, patients had a considerable risk of all-cause mortality (42.1%).

Risk of dementia in seniors with newly diagnosed diabetes: a population-based study

OBJECTIVE

To study whether diabetes onset in late life is a risk factor for dementia.

RESEARCH DESIGN AND METHODS

We conducted a population-based matched cohort study using provincial health data from Ontario, Canada. Seniors with (n = 225,045) and without newly diagnosed diabetes (n = 668,070) between April 1995 and March 2007 were followed until March 2012 for a new diagnosis of dementia. Cox proportional hazards modeling was used to compare the risk of dementia between groups after adjusting for baseline cardiovascular disease, chronic kidney disease (CKD), hypertension, and other risk factors.

RESULTS

Over this period, we observed 169,114 new cases of dementia. Individuals with diabetes had a modestly higher incidence of dementia (2.68 vs. 2.62 per 100 person-years) than those without diabetes. In the fully adjusted Cox model, the risk of dementia was 16% higher among our subgroup with diabetes (hazard ratio [HR] 1.16 [95% CI 1.15-1.18]). Adjusted HRs for dementia were 1.20 (95% CI 1.17-1.22) and 1.14 (95% CI 1.12-1.16) among men and women, respectively. Among seniors with diabetes, the risk of dementia was greatest in those with prior cerebrovascular disease (HR 2.03; 95% CI 1.88-2.19), peripheral vascular disease (HR 1.47; 95% CI 1.19-1.82), and CKD (HR 1.44; 95% CI 1.38-1.51), and those with one or more hospital visits for hypoglycemia (HR 1.73; 95% CI 1.62-1.84).

CONCLUSIONS

In this population-based study, newly diagnosed diabetes was associated with a 16% increase in the risk of dementia among seniors. Preexisting vascular disease and severe hypoglycemia were the greatest risk factors for dementia in seniors with diabetes.

Deceased Organ Donation Registration and Familial Consent among Chinese and South Asians in Ontario, Canada

Objective

For various reasons, people of Chinese (China, Hong Kong or Taiwan) and South Asian (Indian subcontinent) ancestry (the two largest ethnic minority groups in Ontario, Canada) may be less likely to register for deceased organ donation than the general public, and their families may be less likely to consent for deceased organ donation at the time of death.

Methods

We conducted two population-based studies: (1) a cross-sectional study of deceased organ donor registration as of May 2013, and (2) a cohort study of the steps in proceeding with deceased organ donation for patients who died in hospital from October 2008 to December 2012.

Results

A total of 49 938 of 559 714 Chinese individuals (8.9%) and 47 774 of 374 291 South Asians (12.8%) were registered for deceased organ donation, proportions lower than the general public (2 676 260 of 10 548 249 (25.4%). Among the 168 703 Ontarians who died in a hospital, the families of 33 of 81 Chinese (40.1%; 95% CI: 30.7%-51.6%) and 39 of 72 South Asian individuals (54.2%; 95% CI: 42.7-65.2%) consented for deceased organ donation, proportions lower than the general public (68.3%; 95% CI: 66.4%-70.0%).

Conclusions

In Ontario, Canada Chinese and South Asian individuals are less likely to register and their families are less likely to consent to deceased organ donation compared to the remaining general public. There is an opportunity to build support for organ and tissue donation in these two large ethnic communities in Canada.

Cardiovascular Disease in South Asian Migrants

Cardiovascular disease (CVD) represents a significant cause of global mortality and morbidity. South Asians (SAs) have a particularly high burden of coronary artery disease (CAD). This review describes current literature regarding the prevalence, incidence, etiology, and prognosis of CVD in SA migrants to high-income nations. We conducted a narrative review of CVD in the SA diaspora through a search of MEDLINE and PubMed. We included observational studies, randomized clinical trials, nonsystematic reviews, systematic reviews, and meta-analyses written in English. Of 15,231 articles identified, 827 articles were screened and 124 formed the basis for review. SA migrants have a 1.5-2 times greater prevalence of CAD than age- and sex-adjusted Europids. Increased abdominal obesity and body fat and increased burden of type 2 diabetes mellitus and dyslipidemia appear to be primary drivers of the excess CAD burden in SAs. Sedentary lifestyle and changes in diet after immigration are important contributors to weight gain and adiposity. Early life factors, physical activity patterns and, in some cases, reduced adherence to medical therapy may contribute to increased CVD risks in SAs. Novel biomarkers like leptin and adipokines may show distinct patterns in SAs and provide insights into cardiometabolic risk determinants. In conclusion, SAs have distinct CVD risk predispositions, with a complex relationship to cultural, innate, and acquired factors. Although CVD risk factor management and treatment among SAs is improving, opportunities exist for further advances.

Ethnic specific differences in survival of patients with type 2 diabetes: analysis of data collected from an Australian multi-ethnic cohort over a 25 year period

AIMS

To examine the survival of patients with type 2 diabetes from 7 ethnic groups, living in the shared environment of an Australian city.

METHODS

Hazard ratio of death (HR) after diagnosis of diabetes was compared between Anglo-Celtic (n=5433), Indigenous Australian (n=439), Pacific Islander (n=354), Mediterranean (n=3138), Arabic (n=768), Indian (n=702) and Chinese (n=1632) patients who live in metropolitan Sydney. Mortality was ascertained by data-linkage with the Australian National Death Index. The modulating effects of glycaemic control, diabetes/vascular complications and risk factors, year of diabetes diagnosis and duration of diabetes on ethnic differences were analysed by Cox regression. Socio-economic status and competence in English were also examined.

RESULTS

There were significant differences in survival between the ethnic groups; the Indigenous Australians had the highest HR for death (2.3, 95% CI 1.7-3.0) and the Chinese the lowest (0.4, 95% CI 0.4-0.5). The survival of the Anglo-Celtics (HR 1) was surprisingly poorer than for Indian (0.6, 95% CI 0.5-0.8), Arab (0.7, 95% CI 0.6-0.8) and Mediterranean groups (0.8, 95% CI 0.7-0.9). Prevalence of smoking and albuminuria were strongly associated with HR. The better survival of Chinese and Arab and the worse survival of Indigenous Australians remained after adjustment of risk factors. Need for an interpreter was a favourable risk factor for survival.

CONCLUSIONS

Ethnicity is a significant determinant of survival in type 2 diabetes and this is substantially but not completely mediated by smoking and vascular risk factors. The favourable impact associated with less competence in English may represent a Healthy-migrant effect.

Gender differences in the impact of poverty on health: disparities in risk of diabetes-related amputation

AIMS

To assess the combined impact of socio-economic status and gender on the risk of diabetes-related lower extremity amputation within a universal healthcare system.

METHODS

We conducted a population-based cohort study using administrative health databases from Ontario, Canada. Adults with pre-existing or newly diagnosed diabetes (N = 606 494) were included and the incidence of lower extremity amputation was assessed for the period 1 April 2002 to 31 March 2009. Socio-economic status was based on neighbourhood-level income groups, assigned to individuals using the Canadian Census and their postal code of residence.

RESULTS

Low socio-economic status was associated with a significantly higher incidence of lower extremity amputation (27.0 vs 19.3 per 10,000 person-years in the lowest (Q1) vs the highest (Q5) socio-economic status quintile. This relationship persisted after adjusting for primary care use, region of residence and comorbidity, and was greater among men (adjusted Q1:Q5 hazard ratio 1.41, 95% CI 1.30-1.54; P < 0.0001 for all male gender-socio-economic status interactions) than women (hazard ratio 1.20, 95% CI 1.06-1.36). Overall, the incidence of lower extremity amputation was higher among men than women (hazard ratio for men vs women: 1.87, 95% CI 1.79-1.96), with the greatest disparity between men in the lowest socio-economic status category and women in the highest (hazard ratio 2.39, 95% CI 2.06-2.77 and hazard ratio 2.30, 95% CI 1.97-2.68, for major and minor amputation, respectively).

CONCLUSIONS

Despite universal access to hospital and physician care, we found marked socio-economic status and gender disparities in the risk of lower extremity amputation among patients with diabetes. Men living in low-income neighbourhoods were at greatest risk.

Cardiovascular risk among South Asians living in Canada: a systematic review and meta-analysis

BACKGROUND

South Asians represent about 3% of the Canadian population and have a higher burden of certain cardiovascular risk factors and cardiovascular disease (CVD) compared with white people. The objective of this study was to review the literature to compare cardiovascular risk factors and disease management practices among adult South Asian and white Canadians.

METHODS

We searched MEDLINE, Embase, Cochrane and Cumulative Index to Nursing and Allied Health Literature databases from their inception through Feb. 17, 2014 and the reference lists of the selected articles. English-language studies of interventions and observational studies of biological mechanisms underlying CVD risk in South Asians conducted in Canada were eligible for inclusion. Where appropriate, we used random-effects meta-analyses to integrate results comparing the CVD risk profiles of South Asian and white Canadians.

RESULTS

We included 50 articles (n = 5 805 313 individuals) in this review. Compared with white Canadians, South Asian Canadians had a higher prevalence and incidence of CVD, an increased prevalence of diabetes (odds ratio [OR] 2.25, 95% confidence interval [CI] 1.81 to 2.80, p < 0.001) and hypertension (OR 1.11, 95% CI 1.02 to 1.22, p = 0.02), lower high-density lipoprotein cholesterol levels (mean difference -0.19 mmol/L, 95% CI -0.25 to -0.13 mmol/L, p < 0.001) and a higher percentage of body fat (men: absolute mean difference 3.23%, 95% CI 0.83% to 5.62%, p = 0.008; women: absolute mean difference 4.09%, 95% CI 3.46% to 4.72%, p < 0.001). South Asian people are also more sedentary, consume higher levels of carbohydrates and are less likely to smoke tobacco (OR 0.38, 95% CI 0.24 to 0.60, p < 0.001]) than white Canadians. No differences in access to diagnostic tests, outcomes following cardiovascular surgery or use of cardiac rehabilitation programs were apparent.

INTERPRETATION

Compared with white people, South Asian people living in Canada have a higher prevalence and incidence of CVD and possess a unique cardiovascular risk profile.