Current Diabetes Reviews - Volume 17, Issue 9, 2021

Background: South Asians are at a significantly increased risk of type 2 diabetes (T2D) and cardiovascular disease (CVD), are diagnosed at relatively younger ages, and exhibit more severe disease phenotypes as compared with other ethnic groups. The pathophysiological mechanisms underlying T2D and CVD risk in South Asians are multifactorial and intricately related. Methods: A narrative review of the pathophysiology of excess risk of T2D and CVD in South Asians. Results: T2D and CVD have shared risk factors that encompass biological factors (early life influences, impaired glucose metabolism, and adverse body composition) as well as behavioral and environmental risk factors (diet, sedentary behavior, tobacco use, and social determinants of health). Genetics and epigenetics also play a role in explaining the increased risk of T2D and CVD among South Asians. Additionally, South Asians harbor several lipid abnormalities including high concentration of small-dense low-density lipoprotein (LDL) particles, elevated triglycerides, low high-density lipoprotein (HDL)- cholesterol levels, dysfunctional HDL particles, and elevated lipoprotein(a) that predispose them to CVD. Conclusion: In this comprehensive review, we have discussed risk factors that provide insights into the pathophysiology of excess risk of T2D and CVD in South Asians.

Background & Objectives: Ischemic heart disease (IHD) is one of the most important causes of death and disability in the world and diabetes is an important risk factor. This review was performed to describe the mortality and morbidity burden from this twin epidemic in South Asian countries. Methods: Country-level data on the epidemiology of IHD and diabetes were obtained from the Global Burden of Disease (GBD) study. Sub-national data were available only for India. We also retrieved epidemiological studies from published reviews on IHD and diabetes in India. These were supplemented with MEDLINE search. Results: GBD study and regional epidemiological studies have reported that there are significant regional variations in IHD mortality and disease burden within South Asian countries. IHD burden has increased significantly from 2000 to 2017. Prospective Urban Rural Epidemiology study has reported that diabetes is an important IHD risk factor in the South Asian region. GBD Study and International Diabetes Federation have reported increasing diabetes-related mortality and disease burden in South Asian countries, especially India. There are regional variations in diabetes-related mortality, disease burden, and prevalence in South Asia. At the macrolevel, rapid food and nutrition transition along with increasing physical inactivity is responsible for this twin epidemic. Conclusion: Increasing trends in IHD and diabetes-related mortality and disease burden with regional variations are observed in South Asian countries.

Background: Estimation of absolute cardiovascular disease (CVD) risk and tailoring therapies according to the estimated risk is a fundamental concept in the primary prevention of CVD is assessed in this study. Numerous CVD risk scores are currently available for use in various populations but unfortunately, none exist for South Asians who have much higher CVD risk as compared to their western counterparts. Methods: A literature search was done using PubMed and Google search engines to prepare a narrative review on this topic. Results: Various currently available CVD risk scores and their pros and cons are summarized. The studies performed in native as well as migrant South Asians evaluating the accuracy of these risk scores for estimation of CVD risk are also summarized. The findings of these studies have generally been inconsistent, but it appears that the British risk scores (e.g. QRISK versions) may be more accurate because of inclusion of migrant South Asians in the derivation of these risk scores. However, the lack of any prospective study precludes our ability to draw any firm conclusions. Finally, the potential solution to these challenges, including the role of recalibration and subclinical atherosclerosis imaging, is also discussed. Conclusion: This review highlights the need to develop large, representative, prospectively followed databases of South Asians providing information on various CVD risk factors and their contribution to incident CVD. Such databases will not only allow the development of validated CVD risk scores for South Asians but will also enable application of machine-learning approaches to provide personalized solutions to CVD risk assessment and management in these populations.

Introduction: South Asians experience more type 2 diabetes, which is earlier in onset and with more rapid glycaemic deterioration, although average body mass indices are lower than in whites. Cardiovascular outcomes from diabetes drug trials are now reported as standard, with data from newer therapies influencing patient management. However, less is known of the effect of such therapies in South Asians. The aim of this narrative review was to extract, wherever possible, the glucose-lowering efficacy and cardiovascular and renal outcome data for these therapies in South Asians. Discussion: Despite the higher prevalence and global burden of type 2 diabetes and adverse outcomes in South Asians, they remain underrepresented in global trials. Even when recruited, the current method of classifying ethnicity does not commonly allow South Asian data to be extracted and reported separately from all Asians. Interrogation of available trial data suggests broadly comparable effects on glycaemia and weight in Asians to other ethnicities with use of glucagon-like peptide 1 receptor agonists (GLP-1 RAs), but a potentially early, albeit marginally, greater glycaemia benefit with Dipeptidyl peptidase-4 inhibitors (DPP4is) which may not be sustained. Furthermore, there appears a potentially greater glycaemia benefit with use of sodium-glucose transport protein 2 inhibitors (SGLT2is) in Asians compared to whites. Whether such findings are true in all Asians subgroups requires further direct study. For cardiovascular outcomes, available data suggest at least comparable and potentially greater outcome benefits in Asians; point estimates were more favourable for Asians in the vast majority of GLP-1 RAs and SGLT2is outcome trials. It was, however, impossible to determine whether the effects were similar across all Asian subgroups. Conclusion: We conclude that trialists should be encouraged to record ethnicity with better granularity to allow differing ethnic groups data to be better interrogated. In the meantime, doctors should, where possible, confidently follow newer guidelines for the use of newer glucose lowering agents for treating glycaemia and for the prevention of cardiovascular and cardiorenal complications in South Asian people with type 2 diabetes.

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

Background: South Asians are at a significantly increased risk of atherosclerotic cardiovascular disease (ASCVD). For a major portion of the South Asian population, the cardiovascular disease events occur at a relatively younger age, are associated with worse outcomes, and have potentially more severe socioeconomic implications compared to their western counterparts. Methods: The term “South Asian” typically constitutes individuals from India, Pakistan, Nepal, Bhutan, Bangladesh, Sri Lanka, and Maldives, including expatriates as well as their families from these countries. Based on this, South Asians form approximately 25% of the world’s population, with a high ASCVD burden in this group. In this review, we discuss the pathophysiological factors underlying ASCVD in South Asians, the dyslipidemia types and management, and discuss approaches to improve the overall ASCVD prevention efforts in this large subset population of the world. Although the pathophysiological mechanisms underlying the excess risk of cardiovascular disease in South Asians are multifactorial, dyslipidemia is a primary risk factor for the incidence and prevalence of this disease. The traditional “South Asian” dyslipidemia pattern includes levels of low-density lipoprotein cholesterol (LDL-C) in the normal range with a high concentration of LDL particles, elevated triglycerides, low levels of high-density lipoprotein cholesterol (HDL-C) with dysfunctional HDL particles, and high levels of lipoprotein(a). Conclusion: While combined efforts to study the expatriate South Asians in western countries have been able to identify South Asian specific dyslipidemias, causal associations and optimal management remain relatively less explored. Larger scale studies are needed to better quantify the relationship of each lipid parameter with ASCVD risk among South Asians as well as optimal lipid targets and management strategies to reduce morbidity and mortality in this high-risk group.

Alpha-lipoic acid (ALA) is a substantial antioxidant in the prevention of diabetes and diabetes complications. It can regenerate other antioxidants like vitamin E, vitamin C, Coenzyme Q10 and glutathione and is often known as a universal antioxidant. Antioxidants play a role in diabetes treatment due to hyperglycemia-induced stimulation of the polyol pathway and formation of advanced glycation end products (AGE) and reactive oxygen species (ROS). Clinical trials examining alpha-lipoic acid supplementation on diabetic neuropathy, nephropathy, cardiomyopathy and erectile dysfunction display positive results, particularly in pain amelioration in neuropathy, asymmetric dimethylarginine reductions in nephropathy and improved oscillatory potential and contrast sensitivity in retinopathy. In diabetic cardiomyopathy (DCM), ALA offers protection through inhibition of NF-kB activation, reduction of fas-ligand and decrease in matrix metalloproteinase-2. This comprehensive review summarises and provides an understanding of the importance of alpha- lipoic acid supplementation to prevent diabetes complications.

Diabetes mellitus (DM), which is defined as high blood glucose level, is a major public health issue worldwide. An enormous amount of data has been gathered regarding DM as populations have been living with it for more than a decade; however, continually updating our knowledge of DM remains important. Comorbidities are among the major challenges associated with DM. Poorly controlled DM, especially type 2 DM (T2DM), is considered a risk factor for many diseases, including but not limited to chronic kidney disease (CKD). Complications might appear over time as the aging process changes body functions; moreover, a significant number of antidiabetic medications are eventually cleared by the kidneys, thereby increasing the burden on kidney function and placing diabetic patients at risk. The significantly high number of patients with uncontrolled diabetes resulting from kidney disease shows the impact of this condition on the quality of life of patients. This review presents an overview of the pathophysiology, etiology, and prevalence of CKD and abnormal renal parameters correlated with poorly controlled T2DM, with an emphasis on clinical studies involving the association between vitamin D insufficiency/deficiency and CKD among patients with T2DM.