Migration and diabetes incidence among Chinese adults in Canada, China, Hong Kong, and Taiwan: An international population-based comparative study from 2000 to 2017

Determinants, Prevention, and Incidence of Cardiovascular Disease Among Immigrant and Refugee Populations

Immigration policies shape the composition, socioeconomic characteristics, and health of migrant populations. The health of migrants is also influenced by a confluence of social, economic, environmental, and political factors. Immigrants and refugees often face various barriers to accessing health care because of factors such as lack of familiarity with navigating the health care system, language barriers, systemic racism, and gaps in health insurance. Social determinants of health and access to primary care health services likely influence the burden of cardiovascular risk factors among immigrants. The relatively low burden of many cardiovascular risk factors in many immigrant populations likely contributes to the generally lower incidence rates of acute myocardial infarction, heart failure, and stroke in immigrants compared with nonimmigrants, although cardiovascular disease incidence rates vary substantially by country of origin. The "healthy immigrant effect" is the hypothesis that immigrants to high-income countries, such as Canada, are healthier than nonimmigrants in the host population. However, this effect may not apply universally across all immigrants, including recent refugees, immigrants without formal education, and unmarried immigrants. As unfolding sociopolitical events generate new waves of global migration, policymakers and health care providers need to focus on addressing social and structural determinants of health to better manage cardiovascular risk factors and prevent cardiovascular disease, especially among the most marginalized immigrants and refugees.

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.

Prevalence and risk factors contributing to the occurrence of diabetes mellitus in Chinese international migrants: A narrative review

AIMS

This paper reviewed the literature on diabetes prevalence and risk factors associated with diabetes among first-generation Chinese international migrants.

METHODS

MEDLINE, Scopus, Web of Science, CINAHL and Maternity and Infant Care were searched until March 2022, for articles written in English. The quality of the included articles was assessed using the Newcastle-Ottawa Scale.

RESULTS

In total, 17 articles were included (nine for gestational diabetes, six for type 2 diabetes, and none for type 1 diabetes). The average crude prevalence rate for type 2 diabetes and gestational diabetes was 12.1% and 9.3% respectively. Risk factors contributing to the occurrence of type 2 diabetes included older age, sex, family history of type 2 diabetes, higher BMI/waist circumference, longer time since migration, alcohol consumption, smoker, hypertension, and high triglycerides. Risk factors contributing to the occurrence of gestational diabetes included older maternal age, history of gestational diabetes, higher weight/pre-pregnancy BMI, longer time since migration, and Chinese ethnicity.

CONCLUSIONS

We identified a research gap in the diabetes health of Chinese migrants, particularly for type 1 diabetes, highlighting the need for ethnic-specific diabetes research and care, including for subsequent generations of migrants and those living in developing countries.

Pathophysiology, phenotypes and management of type 2 diabetes mellitus in Indian and Chinese populations

Nearly half of all adults with type 2 diabetes mellitus (T2DM) live in India and China. These populations have an underlying predisposition to deficient insulin secretion, which has a key role in the pathogenesis of T2DM. Indian and Chinese people might be more susceptible to hepatic or skeletal muscle insulin resistance, respectively, than other populations, resulting in specific forms of insulin deficiency. Cluster-based phenotypic analyses demonstrate a higher frequency of severe insulin-deficient diabetes mellitus and younger ages at diagnosis, lower β-cell function, lower insulin resistance and lower BMI among Indian and Chinese people compared with European people. Individuals diagnosed earliest in life have the most aggressive course of disease and the highest risk of complications. These characteristics might contribute to distinctive responses to glucose-lowering medications. Incretin-based agents are particularly effective for lowering glucose levels in these populations; they enhance incretin-augmented insulin secretion and suppress glucagon secretion. Sodium-glucose cotransporter 2 inhibitors might also lower blood levels of glucose especially effectively among Asian people, while α-glucosidase inhibitors are better tolerated in east Asian populations versus other populations. Further research is needed to better characterize and address the pathophysiology and phenotypes of T2DM in Indian and Chinese populations, and to further develop individualized treatment strategies.