The Silent Majority: Type 2 Diabetes Mellitus and South Asia Phenotype

There are 415 million people live under diabetes in the whole world, and there is an estimation of 193 million people have undiagnosed diabetes. Diabetes Mellitus is a group of diseases which can result in hyperglycemia. There are generally two types of diabetes. Type 1 diabetes mellitus (T1DM) is a genetic chronic condition in which the pancreas produce little or no insulin. Thus, T1DM can be treated by daily injection of insulin. Type 2 Diabetes Mellitus (T2DM) is an acquired chronic condition that affects the way body processes blood glucose, and is closely linked to obesity. T2DM accounts for 90% percent of all diabetes. Individuals with T2DM have higher risks for both macrovascular (such as cardiovascular comorbidities) and microvascular (including retinopathy, nephropathy and neuropathy) complications. T2DM is characterized by insulin deficiency caused by b-cells dysfunction and insulin resistance in targeting organs. Both environmental and genetic factors contribute to the impair of glucose homeostasis. Especially in South Asia area, the estimation of the prevalence of diabetes in adults in the region range from 4.0% in Nepal to 8.8% in India (Hills 2018). The prevalence of overweight ranges from 16.7% in Nepal to 26.1% In Sri Lanka (Hills 2018). An increasing proportion of children, adolescents, and women are overweight or obese, leading to heightened risk of T2DM. Ethnic south Asians present with greater metabolic risk at lower level of BMI compared with other ethnic groups (referred to as the south Asian phenotype), with T2DM often developing at a younger age, and with rapid progression of diabetic complications. This review paper mainly focused on insulin, pathology of diabetes, epidemiology, and South-Asia phenotype.