Impact of migration and acculturation on prevalence of type 2 diabetes and related eye complications in Indians living in a newly urbanised society

Extending the diabetic retinopathy screening intervals in Singapore: methodology and preliminary findings of a cohort study

BACKGROUND

The Diabetic Retinopathy Extended Screening Study (DRESS) aims to develop and validate a new DR/diabetic macular edema (DME) risk stratification model in patients with Type 2 diabetes (DM) to identify low-risk groups who can be safely assigned to biennial or triennial screening intervals. We describe the study methodology, participants' baseline characteristics, and preliminary DR progression rates at the first annual follow-up.

METHODS

DRESS is a 3-year ongoing longitudinal study of patients with T2DM and no or mild non-proliferative DR (NPDR, non-referable) who underwent teleophthalmic screening under the Singapore integrated Diabetic Retinopathy Programme (SiDRP) at four SingHealth Polyclinics. Patients with referable DR/DME (> mild NPDR) or ungradable fundus images were excluded. Sociodemographic, lifestyle, medical and clinical information was obtained from medical records and interviewer-administered questionnaires at baseline. These data are extracted from medical records at 12, 24 and 36 months post-enrollment. Baseline descriptive characteristics stratified by DR severity at baseline and rates of progression to referable DR at 12-month follow-up were calculated.

RESULTS

Of 5,840 eligible patients, 78.3% (n = 4,570, median [interquartile range [IQR] age 61.0 [55-67] years; 54.7% male; 68.0% Chinese) completed the baseline assessment. At baseline, 97.4% and 2.6% had none and mild NPDR (worse eye), respectively. Most participants had hypertension (79.2%) and dyslipidemia (92.8%); and almost half were obese (43.4%, BMI ≥ 27.5 kg/m2). Participants without DR (vs mild DR) reported shorter DM duration, and had lower haemoglobin A1c, triglycerides and urine albumin/creatinine ratio (all p < 0.05). To date, we have extracted 41.8% (n = 1909) of the 12-month follow-up data. Of these, 99.7% (n = 1,904) did not progress to referable DR. Those who progressed to referable DR status (0.3%) had no DR at baseline.

CONCLUSIONS

In our prospective study of patients with T2DM and non-referable DR attending polyclinics, we found extremely low annual DR progression rates. These preliminary results suggest that extending screening intervals beyond 12 months may be viable and safe for most participants, although our 3-year follow up data are needed to substantiate this claim and develop the risk stratification model to identify low-risk patients with T2DM who can be assigned biennial or triennial screening intervals.

Prevalence and factors associated with diagnosed diabetes mellitus among Asian Indian adults in the United States

Higher prevalence of diabetes mellitus (DM) has been documented among South Asians living in the United States. However, combining the south Asian subgroups into one category masks the heterogeneity in the diagnosed DM, after controlling for known protective and risk factors. We assessed the association of Asian Indian ethnicity to diagnosed DM using a nationally representative sample of 1,986 Asian Indian adults in the US compared to 109,072 Non-Hispanic Whites (NHWs) using disaggregated data from the National Health Interview Survey (2012-2016) (NHIS). 2010 US census figures were used for age-sex standardization. Age-sex adjusted prevalence of DM was 8.3% in Asian Indians as compared to 5.8% in NHW. In adjusted multivariable logistic regression models, Asian Indians had higher odds ratios of reporting diagnosed DM compared to NHWs (AOR = 1.39, 95% CI: 1.12, 1.71). This association remained strong and significant even after controlling for other risk factors in the model (AOR = 1.47, 95% CI: 1.16, 1.85). Results suggest a favorable socio-economic profile of Asian Indians was not protective on diagnosed DM. In addition, they were more likely to have diagnosed DM due to higher prevalence of obesity despite healthier behaviors of smoking and exercise.

Prevalence and risk factors of diabetic retinopathy among Chinese adults with type 2 diabetes in a suburb of Shanghai, China

Background

To investigate the prevalence and risk factors of diabetic retinopathy (DR) in a Chinese population with type 2 diabetes mellitus (T2DM) in a suburb (Qingpu) of Shanghai, China.

Methods

A population-based cross-sectional study. A total of 7462 residents with T2DM in Qingpu were enrolled according to the resident health archives from January 2020 to December 2020. Blood and urine samples of the subjects were collected. Disc- and macula-centred retinal images were taken to assess DR. SPSS was used to analyse and investigate the prevalence and risk factors of DR.

Results

The fundus images of 6380 (85.5%) subjects were of sufficiently good quality for grading. The average (range) age of 6380 subjects was 63.46±7.77 (28–92) years. Six hundred forty-four subjects were diagnosed with DR. The prevalence of DR was 10.1% (95% CI 9.4%-10.8%), with mild, moderate, and severe non-proliferative retinopathy and proliferative retinopathy being 2.1%, 6.3%, 1.3% and 0.4%, respectively. The prevalence of bilateral DR was 6.5%. Higher T2DM duration (OR, 1.057), fasting plasma glucose (OR, 1.063), glycated hemoglobinA1c (OR, 1.269), urea nitrogen (OR, 1.059), and urinary albumin (OR, 1.001) were associated with the higher DR prevalence.

Conclusion

The prevalence of DR among Chinese adults with T2DM in Qingpu was 10.1%, in which non-proliferative DR was more common. Higher fasting plasma glucose and glycated hemoglobinA1c are well-known risk factors of DR, consistent with the findings in our study. Our study didn’t find the risk between lipid indicators and DR. However, several renal function indicators, like higher urea nitrogen and urinary albumin, were risk factors for DR in this study. Appropriate diagnosis and intervention should be taken in time to prevent and control DR development.

Transcultural Lifestyle Medicine in Type 2 Diabetes Care: Narrative Review of the Literature

Disparities in type 2 diabetes (T2D) care is a global problem across diverse cultures. The Dysglycemia-Based Chronic Disease (DBCD) model promotes early and sustainable interventions along the insulin resistance (stage 1), prediabetes (stage 2), T2D (stage 3), and complications (stage 4) spectrum. In this model, lifestyle medicine is the cornerstone of preventive care to reduce DBCD progression and the socioeconomic/biological burden of disease. A comprehensive literature review, spanning 2000 to 2021, was performed and 55 studies were included examining the effects of lifestyle medicine and their cultural adaptions with different prevention modalities. In stage 1, primordial prevention targets modifiable primary drivers (behavior and environment), unhealthy lifestyles, abnormal adiposity, and insulin resistance with educational and motivational health promotion activities at individual, group, community, and population-based scales. Primary, secondary, and tertiary prevention targets individuals with mild hyperglycemia, severe hyperglycemia, and complications, respectively, using programs that incorporate structured lifestyle interventions. Culturally adapted lifestyle change in primary and secondary prevention improved quality of life and biomarkers, but with a limited impact of tertiary prevention on cardiovascular events. In conclusion, lifestyle medicine with cultural adaptations is an integral part of preventive care in patients with T2D. However, considerable research gaps exist, especially for tertiary prevention.

Changing the landscape of South Asian migrant health research by advancing second-generation immigrant health needs

South Asian immigrants confront a growing non-communicable disease burden, a significant issue in countries such as the USA. While efforts have slowly begun to address South Asian migrant health, second-generation communities remain underserved and understudied despite facing many of the same non-communicable disease concerns. The aim of this commentary is to highlight unique health disparities contributing to the current South Asian migrant health status and identify pathways for further formative research needed to inform subsequent development, implementation, and evaluation of health interventions targeting this community. Extant peer-reviewed literature addressing second-generation South Asian health issues was used to identify key research pathways needed to address existing gaps. Specifically, we call for (a) enhancing targeted surveillance and recruitment in research and (b) collecting data to help characterize behavioral and cultural patterns that may contribute to disease onset and progression. Expanding research on second-generation South Asian migrant health may help to develop tailored and targeted interventions.

Acculturation and Perceived Ethnic Discrimination Predict Elevated Blood Glucose Level in Sub-Saharan African Immigrants in Australia

Sub-Saharan African migrants experience significant sociocultural challenges, including those related to acculturation and perceived ethnic discrimination (PED), in addition to increased risk of non-communicable diseases, such as type 2 diabetes mellitus (T2DM). Although acculturation and PED are each established risk factors for elevated blood glucose level (EGBL) and T2DM, they have not been studied in relation to EBGL risk in a single model. This study aimed to investigate associations between acculturation, PED and EBGL in a sub-Saharan African migrant population in Australia. Face to face survey using a purposive sampling method was used to collect data from 170 adults, aged 18-72 years. A large proportion (41.8%) of the study group was in the integration mode of acculturation, which strongly correlated positively with EBGL/T2DM, although traditional mode correlated inversely with EBGL/T2DM. PED correlated positively with EBG/LT2DM. Immigrants manifesting the integration mode were 4.2 times more likely to have EBGL/T2DM than other acculturation modes. Multiple linear regression showed that the association between integration mode and EBGL/T2DM was mediated by PED. The apparent interaction between PED and acculturation in relation to EBGL/T2DM risk suggests that interventions to lower T2DM risk in this population may benefit from incorporating strategies to address these two important health determinants.

The relationship between air pollution and diabetes: A study on the municipalities of the Metropolitan City of Milan

AIMS

Urbanisation has been linked with an increased risk of developing diabetes mellitus, dramatically worsening the healthcare system's financial burden. Environmental influences are emerging among the causing factors of the urban diabetes epidemic. We evaluated the relationship between air pollution and the prevalence of diabetes in the Municipalities of the Metropolitan City of Milan, comprising more than 3,4 million citizens.

METHODS

The prevalence of diabetes in the resident population and the mean annual air concentrations of PM10 and NO2 were retrieved from the municipal Agency for Health Protection and the regional Agency for Ambient Protection datasets. Two linear regression models were estimated to inspect the relationships between the (logit-based transformed) diabetes prevalence and air pollution concentrations, namely: (i) PM10, and (ii) NO2. Both models were adjusted for five control variables, including the qualitative variable year (2011-2018).

RESULTS

Both models highlight a statistically significant positive relationship between air pollutants and diabetes prevalence. An increase of one PM10 or NO2 concentrations' unit translates into a rise of 0.81% or 0.41% in diabetes prevalence, respectively.

CONCLUSION

Our results contribute to the ongoing research regarding health outcomes of urbanisation dynamics and should be considered in city planning policies.

Association between duration of residence and prevalence of type 2 diabetes among male South Asian expatriate workers in the United Arab Emirates: a cross-sectional study

Expatriates account for about 80% of the total population in the United Arab Emirates (UAE). This study aimed to evaluate the hypothesis that prevalence of type 2 diabetes in male South Asian expatriates increases with increased length of residence in the UAE.

DESIGN, SETTINGS AND PARTICIPANTS

This cross-sectional study recruited a representative sample (n=1375) of male South Asian expatriates aged ≥18 years in Al Ain, UAE. Sociodemographic, anthropometric and lifestyle data were obtained using a pilot-tested adapted version of the WHO STEPS instrument.

MAIN OUTCOME MEASURES

Duration of residence was used as a marker for acculturation. Type 2 diabetes was defined as a self-reported physician diagnosis of diabetes or a glycosylated haemoglobin blood level ≥6.5%.

RESULTS

Mean (±SD) age of participants was 34.0±9.9 years. Overall, the prevalence of type 2 diabetes was 8.3% (95% CI 6.8% to 9.8%). Diabetes prevalence was positively associated with longer duration of residence in the UAE, 2.7%, <5 years; 8.2%, 5-10 years; and 18.8%, >10 years. After adjusting for age, nationality, and income and age, expatriates were more likely to develop diabetes if residing in the UAE for 5-10 years (OR=2.18; 95% CI 1.02 to 4.67) or >10 years (OR=3.23; 95% CI 1.52 to 6.85) compared with those residing for <5 years.

CONCLUSIONS

After controlling for potential confounding factors, longer duration of residence was significantly associated with a higher prevalence of type 2 diabetes in male South Asian expatriate workers in the UAE.

Racial/ethnic differences in the burden of type 2 diabetes over the life course: a focus on the USA and India

Type 2 diabetes is a common disease worldwide, but its prevalence varies widely by geographical region and by race/ethnicity. This review summarises differences in the frequencies of type 2 diabetes according to race, ethnicity, socioeconomic position, area of residence and environmental toxins. Type 2 diabetes susceptibility often begins early in life, starting with genetic susceptibility at conception and continuing in later life, via in utero, childhood and adult exposures. Early-life factors may lead to overt type 2 diabetes in childhood or in later life, supporting the concept of developmental origins of health and disease. The causes of the racial/ethnic differences in incidence of type 2 diabetes are not well understood. Specifically, the relative contributions of genetic and environmental factors to such differences are largely unknown. With a few exceptions in isolated populations, there is little evidence that differences in frequencies of known type 2 diabetes susceptibility genetic alleles account for racial/ethnic differences, although the search for genetic susceptibility has not been uniform among the world's racial/ethnic groups. In the USA, race/ethnicity is associated with many other risk factors for type 2 diabetes, including being overweight/obese, diet and socioeconomic status. Some studies suggest that some of these factors may account for the race/ethnic differences in prevalence of type 2 diabetes, although there is inadequate research in this area. A better understanding of the impact of these factors on type 2 diabetes risk should lead to more effective prevention and treatment of this disease. This has not yet been achieved but should be a goal for future research.

Skinfold thickness and the incidence of type 2 diabetes mellitus and hypertension: an analysis of the PERU MIGRANT study

OBJECTIVE

To determine the association between excess body fat, assessed by skinfold thickness, and the incidence of type 2 diabetes mellitus (T2DM) and hypertension (HT).

DESIGN

Data from the ongoing PERU MIGRANT Study were analysed. The outcomes were T2DM and HT, and the exposure was skinfold thickness measured in bicipital, tricipital, subscapular and suprailiac areas. The Durnin-Womersley formula and SIRI equation were used for body fat percentage estimation. Risk ratios and population attributable fractions (PAF) were calculated using Poisson regression.

SETTING

Rural (Ayacucho) and urban shantytown district (San Juan de Miraflores, Lima) in Peru.

PARTICIPANTS

Adults (n 988) aged ≥30 years (rural, rural-to-urban migrants, urban) completed the baseline study. A total of 785 and 690 were included in T2DM and HT incidence analysis, respectively.

RESULTS

At baseline, age mean was 48·0 (sd 12·0) years and 47 % were males. For T2DM, in 7·6 (sd 1·3) years, sixty-one new cases were identified, overall incidence of 1·0 (95 % CI 0·8, 1·3) per 100 person-years. Bicipital and subscapular skinfolds were associated with 2·8-fold and 6·4-fold risk of developing T2DM. On the other hand, in 6·5 (sd 2·5) years, overall incidence of HT was 2·6 (95 % CI 2·2, 3·1) per 100 person-years. Subscapular and overall fat obesity were associated with 2·4- and 2·9-fold risk for developing HT. The PAF for subscapular skinfold was 73·6 and 39·2 % for T2DM and HT, respectively.

CONCLUSIONS

We found a strong association between subscapular skinfold thickness and developing T2DM and HT. Skinfold assessment can be a laboratory-free strategy to identify high-risk HT and T2DM cases.

Prevalence of diabetic retinopathy, proliferative diabetic retinopathy and non-proliferative diabetic retinopathy in Asian T2DM patients: a systematic review and Meta-analysis

AIM

To investigate the pooled prevalence of diabetic retinopathy (DR), proliferative DR (PDR) and nonproliferative DR (NPDR) in Asian type 2 diabetes mellitus (T2DM) patients.

METHODS

We performed a systematic search online search using PubMed, EMBASE, Web of Science, the Cochrane Library, and China WeiPu Library to identify eligible studies that reported the prevalence of DR, PDR and NPDR in Asian T2DM patients. Effect size (ES) with 95% confidence interval (CI) was used to evaluate the prevalence of DR, PDR and NPDR in Asian T2DM patients, respectively.

RESULTS

There were 41 references and 48 995 T2DM patients involved in this study. The prevalence of DR, PDR, and NPDR was 28%, 6%, and 27% in T2DM patients, respectively; while the prevalence of PDR and NPDR in DR patients was 17% and 83%, respectively. Subgroup analysis showed that prevalence of DR in T2DM patients from Singaporean, Indian, South Korean, Malaysian, Asian, and Chinese was 33%, 42%, 16%, 35%, 21% and 25%, respectively. In T2DM patients with NPDR from Indian, South Korean, Malaysian, Asian, Chinese, higher prevalence was found than that in PDR patients (45% vs 17%, 13% vs 3%, 30% vs 5%, 23% vs 2% and 22% vs 3%), as well as in DR patients (74% vs 26%, 81% vs 19%, 86% vs 14%, 92% vs 8% and 85% vs 15%). The prevalence of PDR in T2DM from India was higher than patients from other locations of Asia, and the same results were also observed in NPDR patients.

CONCLUSION

In either T2DM Asian patients or DR patients, NPDR is more common than PDR. Based on our results, we should pay more attention to NPDR screening and management in T2DM patients, and we also recommend suitable interventions to prevent its progression.

Epidemiology and determinants of type 2 diabetes in south Asia

Type 2 diabetes has rapidly developed into a major public health problem in south Asia (defined here as Bangladesh, Bhutan, India, Nepal, Pakistan, and Sri Lanka) in recent decades. During this period, major lifestyle changes associated with economic transition, industrialisation, urbanisation, and globalisation have been key determinants in the increasing burden of non-communicable diseases. A decline in nutrition quality, reduced physical activity, and increased sedentary behaviours are reflected in the increasing prevalence of type 2 diabetes and related risk factors in the region. The International Diabetes Federation 2017 estimates of the prevalence of diabetes in adults in the region range from 4·0% in Nepal to 8·8% in India. The prevalence of overweight ranges from 16·7% in Nepal to 26·1% in Sri Lanka, and the prevalence of obesity ranges from 2·9% in Nepal to 6·8% in Sri Lanka. An increasing proportion of children, adolescents, and women are overweight or obese, leading to a heightened risk of type 2 diabetes. Ethnic south Asians present with greater metabolic risk at lower levels of BMI compared with other ethnic groups (referred to as the south Asian phenotype), with type 2 diabetes often developing at a younger age, and with rapid progression of diabetic complications. Because of the presence of multiple risk factors and a body composition conducive to the development of type 2 diabetes, south Asians should be aggressively targeted for prevention. In this Series paper, we detail trends in the prevalence of diabetes in the region and address major determinants of the disease in the context of nutrition and physical activity transitions and the south Asian phenotype.

Risk of Incident Cardiovascular Disease and Cardiovascular Risk Factors in First and Second-Generation Indians: The Singapore Indian Eye Study

Population-based data investigating generational differences in the risk of incident cardiovascular disease (CVD) and its risk determinants are rare. We examined the 6-year incidence of CVD and its risk factors in first- and second-generation ethnic Indians living in Singapore. 1749 participants (mean age [SD]: 55.5 [8.8] years; 47.5% male) from a population-based, longitudinal study of Indian adults were included for incident CVD outcome. Incident CVD was defined as self-reported myocardial infarction, angina pectoris or stroke which developed between baseline and follow-up. CVD-related risk factors included incident diabetes, hypertension, hyperlipidemia, obesity and chronic kidney disease (CKD). For incident CVD outcome, of the 1749 participants, 406 (23.2%) and 1343 (76.8%) were first and second-generation Indians, respectively. Of these, 73 (4.1%) reported incident CVD. In multivariable models, second-generation individuals had increased risk of developing CVD (RR = 2.04; 95% CI 1.04, 3.99; p = 0.038), hyperlipidemia (RR = 1.27; 95% CI 1.06, 1.53; p = 0.011), and CKD (RR = 1.92; 95% CI 1.22, 3.04; p = 0.005), compared to first-generation Indians. Second-generation Indians have increased risk of developing CVD and its associated risk factors such as hyperlipidemia and CKD compared to first-generation immigrants, independent of traditional CVD risk factors. More stratified and tailored CVD prevention strategies on second and subsequent generations of Indian immigrants in Singapore are warranted.

On ‘Asian’ Distinctiveness and Race as a Variable: The Case of Ophthalmic Epidemiology in Singapore

The notion that Singapore’s multi-ethnic population provides a unique and quintessentially ‘Asian’ asset for its biomedical sciences initiative has been part of the discourse in local and international media coverage of that sector. It has also been highlighted by scholars as a feature of Singapore’s political economy. This article discusses how ‘racial/ethnic difference’ was initially central but then became peripheral to one high-profile research programme: the Singapore Epidemiology of Eye Disease (SEED) Study Programme. The case study is offered as an example of the flexible deployment and situational enactment of racial/ethnic difference in biomedical science, by demonstrating how it gets entangled with and disentangled from the creation of scientific capital and legitimacy, as well as complicates the notion of ‘Asian’ science.

Six-Year Incidence and Risk Factors of Age-Related Macular Degeneration in Singaporean Indians: The Singapore Indian Eye Study

We aimed to determine the 6-year incidence and risk factors of age-related macular degeneration (AMD) in first and second generations of Singaporean Indians. Baseline examination was conducted in 2007-9 and 6-year propsective follow-up examination of this Indian population in 2013-5. All participants underwent interviews with questionnaires and comprehensive medical and eye examinations. Incidence was age-standardized to Singaporean 2010 census. Risk factors associated with AMD incidence were assessed and compared between first and second generations of immigrants. Among 2200 persons who participated in the follow-up examination (75.5% response rate), gradable fundus photographs were available in 2105. The 6-year age-standardized incidences of early and late AMD were 5.26% and 0.51% respectively. Incident early AMD was associated with cardiovascular disease history (HR 1.59, 95% CI 1.04-2.45), underweight body mass index (BMI) (HR 3.12, 95% CI 1.37-7.14) (BMI of <18.5 vs 18.51-25 kg/m2), heavy alcohol drinking (HR 3.14 95% CI 1.25-7.89) and ARMS2 rs3750847 homozygous genetic loci carrier (HR 2.52, 95% CI 1.59-3.99). We found a relatively low incidence of early AMD in this Singaporean Indian population compared to Caucasian populations. Both first and second-generation Indian immigrants have similar incidence and risk factor patterns for early AMD.

Addressing the impact of urban exposure on the incidence of type 2 diabetes mellitus: The PERU MIGRANT Study

The aim of this study was to estimate the incidence of T2DM in three population groups: rural, rural-to-urban migrants and urban dwellers. Data from the PERU MIGRANT Study was analysed. The baseline assessment was conducted in 2007-2008 using a single-stage random sample and further follow-up was undertaken in 2015-16. T2DM was defined based on fasting glucose and self-reported diagnosis. Poisson regression models and robust variance to account for cluster effects were used for reporting risk ratios (RR) and 95%CI. At baseline, T2DM prevalence was 8% in urban, 3.6% in rural-to-urban migrants and 1.5% in rural dwellers. After 7.7 (SD: 1.1) years, 6,076 person-years of follow-up, 61 new cases were identified. The incidence rates in the urban, migrant and rural groups were 1.6, 0.9 and 0.5 per 100 person-years, respectively. Relative to rural dwellers, a 4.3-fold higher risk (95%CI: 1.6-11.9) for developing T2DM was found in urban dwellers and 2.7-fold higher (95%CI: 1.1-6.8) in migrants with ≥30 years of urban exposure. Migration and urban exposure were found as significant risk factors for developing T2DM. Within-country migration is a sociodemographic phenomenon occurring worldwide; thus, it is necessary to disentangle the effect of urban exposure on non-healthy habits and T2DM development.

Diabetic Retinopathy in the Asia-Pacific

Diabetic retinopathy (DR), the most common complication of diabetes mellitus, is the leading cause of new cases of blindness in middle-aged and elderly in the Asia-Pacific. It has been estimated that 51% of all those with blindness due to DR globally (n = 424,400) and 56% of those with visual impairment due to DR (2.1 million) come from the Asia-Pacific. Prevalence of DR among those with diabetes ranged from 10% in India to 43% in Indonesia within the Asia-Pacific. Awareness of DR among persons with diabetes ranged from 28% to 84%. Most common modifiable risk factors for DR in the Asia-Pacific were hyperglycemia, blood pressure, dyslipidemia, and obesity. Implementation of systematic screening programs for DR and advancement in telemedicine screening methods have increased patient coverage and cost-effectiveness, though there are still numerous factors impeding screening uptake in the low-middle income regions of the Asia-Pacific. Management and treatment of DR in the Asia-Pacific is mainly limited to traditional laser retinopexy, but it is suboptimal despite new clinical approaches such as use of intravitreal anti.vascular endothelial growth factor and steroids due to limited resources. Further research and data are required to structure a more cost-effective public healthcare program and more awareness-building initiatives to increase the effectiveness of DR screening programs.

Significant differences in struvite and cystine stone frequency seen among Chinese nephrolithiasis patients living in North America compared to those living in China

Background

Interracial disparities in nephrolithiasis prevalence have been reported, but the interplay between genetics and the environment for urinary stone disease risk factors is poorly understood. To examine how environment may alter genetic predisposition for stone formation, we established the International Chinese Consortium on Nephrolithiasis (ICCON) as a multi-institutional collaboration to examine patterns of nephrolithiasis presentation between Chinese patients living in different countries.

Methods

Chinese patients undergoing percutaneous nephrolithotomy (PCNL) at six participating institutions in China and North America over 4 years were reviewed retrospectively. Patient demographics and clinical data were compared between Chinese patients living in China and North America.

Results

A total of 806 patients were included, encompassing 721 Chinese patients living in China and 85 living in North America. Nephrolithiasis patients living in China were more likely to be male (67% vs. 56%, P=0.02), present at a younger age (48.6±15.0 vs. 55.0±13.0 years, P<0.01), and have a lower BMI (24.6±4.0 vs. 25.9±5.7, P=0.04) but were less likely to form struvite stones (5.5% vs. 14.1%, P<0.01). No cystine stone patients were seen in North American Chinese patients, whereas 1.8% of nephrolithiasis patients living in China presented with cystine stones. Similar rates of calcium-based and uric acid calculi as well as urinary pH were seen among both groups.

Conclusions

Significant differences exist between Chinese nephrolithiasis patients living in China compared to those living in North America, highlighting the importance of environmental factors in addition to genetics in modulating risk for urinary stone disease.

Plasma Metabonomic Profiling of Diabetic Retinopathy

Diabetic retinopathy (DR) is the most common microvascular complication of diabetes and the leading cause of visual impairment in working-age adults. Patients with diabetes often develop DR despite appropriate control of systemic risk factors, suggesting the involvement of other pathogenic factors. We hypothesize that the plasma metabolic signature of DR is distinct and resolvable from that of diabetes alone. A nested population-based case-control metabonomic study was first performed on 40 DR cases and 40 control subjects with diabetes using gas chromatography-mass spectrometry. Eleven metabolites were found to be correlated with DR, and the majority were robust when adjusted for metabolic risk factors and confounding kidney disease. The metabolite markers 2-deoxyribonic acid; 3,4-dihydroxybutyric acid; erythritol; gluconic acid; and ribose were validated in an independent sample set with 40 DR cases, 40 control subjects with diabetes, and 40 individuals without diabetes. DR cases and control subjects with diabetes were matched by HbA1c in the validation set. Activation of the pentose phosphate pathway was identified from the list of DR metabolite markers. The identification of novel metabolite markers for DR provides insights into potential new pathogenic pathways for this microvascular complication and holds translational value in DR risk stratification and the development of new therapeutic measures.

Is (the study of) mobile phones old wine in a new bottle? A polemic on communication-based acculturation research

Purpose

– The purpose of this paper is to critically analyze the discourses on migrant acculturation and migrants’ mobile phone communication, in order to examine the inclusiveness of communication-acculturation research in the recent years.

Design/methodology/approach

– The paper draws on from 102 qualitative interviews (48 Malayali, 26 Bangla, 17 Tamil and 11 Telugu) for a larger research project that investigated the role of mobile phones in migrant acculturation in Singapore. Respondents were selected using a combination of purposive and snowball sampling methods. The respondents had been in Singapore for varying amount of time: from one month to 19 years.

Findings

– The analysis of the discourses on migrant acculturation and mobile phone communication revealed that labor migrants were excluded on the basis of their temporary status and apprehensions on work productivity. The mobile usage prohibitions that existed in work sites were hinged on similar discourses that stereotyped the labor migrants. The emancipatory metaphor that has been at the center of research on migrants’ mobile phone usage and acculturation needs to be replaced with a critical discourse perspective.

Research limitations/implications

– The data were originally collected for a research project that approached the phenomena of acculturation and mobile phone appropriation from a positivist perspective, whereas this paper analyzed the data to critically examine the discourses that supported the premise of the project itself. Due to this, the findings presented in this paper have limited scope for generalization.

Originality/value

– The paper critiques the research trends in migrant acculturation and mobile phone communication and suggests a possible alternative that goes beyond the “transcendental teleology” that underpins discourse and practice.

The burden of asthma among the South Asian and Chinese population residing in Ontario

BACKGROUND

The South Asian and Chinese populations represent a significant portion of the population of Ontario; however, little is known about the burden of respiratory OBJECTIVE: To investigate the prevalence of asthma and the associated health care burden among South Asian and Chinese populations living in Ontario.

METHODS

Using administrative health data for Ontario, the authors identified individuals of South Asian and Chinese descent using a validated surname algorithm and compared the prevalence of asthma in these groups with the general population using an established asthma case definition for the period 2002 to 2010. Also compared were the rates of asthma-specific emergency department visits and hospitalizations among the ethnic groups.

RESULTS

In 2010, the prevalence of asthma in South Asians residing in Ontario was similar to that of the general population (12.1% versus 12.4%), and was increasing at a faster rate than in the general population (0.51%⁄year versus 0.34%⁄year). Compared with the general population, the South Asian population had fewer emergency department visits for asthma, whereas the asthma-related hospitalization rate was greatest among the South Asian population (0.45 per 100 person-years). The Chinese population had the lowest asthma prevalence and associated health care use.

CONCLUSION

The burden of asthma among South Asians in Ontario is increasing and warrants further investigation to determine the reasons for this rise.

Joint effects of known type 2 diabetes susceptibility loci in genome-wide association study of Singapore Chinese: the Singapore Chinese health study

BACKGROUND

Genome-wide association studies (GWAS) have identified genetic factors in type 2 diabetes (T2D), mostly among individuals of European ancestry. We tested whether previously identified T2D-associated single nucleotide polymorphisms (SNPs) replicate and whether SNPs in regions near known T2D SNPs were associated with T2D within the Singapore Chinese Health Study.

METHODS

2338 cases and 2339 T2D controls from the Singapore Chinese Health Study were genotyped for 507,509 SNPs. Imputation extended the genotyped SNPs to 7,514,461 with high estimated certainty (r(2)>0.8). Replication of known index SNP associations in T2D was attempted. Risk scores were computed as the sum of index risk alleles. SNPs in regions ± 100 kb around each index were tested for associations with T2D in conditional fine-mapping analysis.

RESULTS

Of 69 index SNPs, 20 were genotyped directly and genotypes at 35 others were well imputed. Among the 55 SNPs with data, disease associations were replicated (at p<0.05) for 15 SNPs, while 32 more were directionally consistent with previous reports. Risk score was a significant predictor with a 2.03 fold higher risk CI (1.69-2.44) of T2D comparing the highest to lowest quintile of risk allele burden (p = 5.72 × 10(-14)). Two improved SNPs around index rs10923931 and 5 new candidate SNPs around indices rs10965250 and rs1111875 passed simple Bonferroni corrections for significance in conditional analysis. Nonetheless, only a small fraction (2.3% on the disease liability scale) of T2D burden in Singapore is explained by these SNPs.

CONCLUSIONS

While diabetes risk in Singapore Chinese involves genetic variants, most disease risk remains unexplained. Further genetic work is ongoing in the Singapore Chinese population to identify unique common variants not already seen in earlier studies. However rapid increases in T2D risk have occurred in recent decades in this population, indicating that dynamic environmental influences and possibly gene by environment interactions complicate the genetic architecture of this disease.

Type 2 diabetes prevalence varies by socio-economic status within and between migrant groups: analysis and implications for Australia

BACKGROUND

Ethnic diversity is increasing through migration in many developed countries. Evidence indicates that type 2 diabetes mellitus (T2DM) prevalence varies by ethnicity and socio-economic status (SES), and that in many settings, migrants experience a disproportionate burden of disease compared with locally-born groups. Given Australia's multicultural demography, we sought to identify groups at high risk of T2DM in Victoria, Australia.

METHODS

Using population data from the Australian National Census and diabetes data from the National Diabetes Services Scheme, prevalence of T2DM among immigrant groups in Victoria in January 2010 was investigated, and prevalence odds versus Australian-born residents estimated. Distribution of T2DM by SES was also examined.

RESULTS

Prevalence of diagnosed T2DM in Victoria was 4.1% (n = 98671) in men and 3.5% (n = 87608) in women. Of those with T2DM, over 1 in 5 born in Oceania and in Southern and Central Asia were aged under 50 years. For both men and women, odds of T2DM were higher for all migrant groups than the Australian-born reference population, including, after adjusting for age and SES, 6.3 and 7.2 times higher for men and women born in the Pacific Islands, respectively, and 5.2 and 5.0 times higher for men and women born in Southern and Central Asia, respectively. Effects of SES varied by region of birth.

CONCLUSIONS

Large socio-cultural differences exist in the distribution of T2DM. Across all socio-economic strata, all migrant groups have higher prevalence of T2DM than the Australian-born population. With increasing migration, this health gap potentially has implications for health service planning and delivery, policy and preventive efforts in Australia.