**2. An overview of the prevalence of diabetes in South Asians**

South Asia comprises the Indian subcontinent and is home to a diverse population of ethnic, linguistic and religious groups. The total population of South Asia is about 1.5 billion, representing more than 20% of the global population. The countries that fall under this regional demarcation include India, Pakistan, Sri Lanka, Nepal, Bhutan, Maldives, Afghanistan and Bangladesh. With deviating definitions based on often substantially different reasons (usually political), the British Indian Ocean Territory, Mauritius, Iran and the Tibet Autonomous Region are sometimes included as part of the South Asian subcontinent as well. Nevertheless, for the purpose of this review, we defined South Asia as India, Pakistan, Sri Lanka, Nepal, Bhutan, Maldives, Afghanistan and Bangladesh and focused on the diabetes status of the people living in these countries.

A recent study using a Diabetes Population Risk Tool in Canada showed that South Asians have the highest risk of developing diabetes [6], and another study estimated that the prevalence rate of diabetes in South Asians was around four times higher than in other ethnic groups [7]. The total number of people with diabetes in the world is estimated to increase from 171 million in 2000 to 366 million by 2030 [8]; this number among South Asians is predicted to reach 46 million in India, 14 million in Pakistan and 11.1 million in Bangladesh by 2030 [9].

A huge number of people (3.8 million) annually lose their lives due to diabetic complications, a value almost equivalent to the loss of life associated with AIDS [7]. **Table 1** shows the diabetic populations and its prevalence rates in South Asian countries based on the data of the International Diabetes Federation, which was estimated by a statistical investigation of the relevant populations primarily 20–79 years of age [10]. The results suggest that the diabetic populations and the prevalence rates of diabetes in most South Asian countries are thus expected to dramatically increase at a high rate until 2035. In India in particular, which has a large population and is rapidly advancing economically, 109 million people are predicted to develop diabetes by 2035 (**Table 1**). This will place India at the epicenter of this global epidemic [11]. In addition to this upward trend in the prevalence rate, the number of deaths and the economic burden due to diabetes in South Asians have been rapidly increasing. As shown in **Table 1**, around 43–870 USD per person is paid to cure diabetes and its complications. With the rising rate of incidence, people in South Asia will have to compensate for much higher diabetes-related expenditures in the near future, which will constitute a heavy burden upon the respective countries [12, 13].


A, total adult population (20–79 years) in 2014; B, diabetes prevalence per total adult population in 2014; C, deaths number by the disease related to diabetes in 2014; D, mean diabetes-related expenditure per person in 2014; E, estimation of total adult population in 2035; F, diabetes prevalence per total adult population in 2035.

**Table 1.** Prevalence of diabetes in South Asia in 2014 and its estimated prevalence in 2035.
