By Dr. Niteesh Choudhry
India is home to the world’s second-largest adult diabetes population, and every sixth person with diabetes in the world is an Indian. The past three decades witnessed a 150% increase in the number of people with diabetes in the country. The prevalence of type 2 diabetes, often known as DM2, has also increased significantly in India. As of 2020, 77 million Indians have diabetes, which is 17% of the global burden of people with this condition. About 98 million Indians could have diabetes by 2030 — these projections come from the International Diabetes Federation and the Global Burden of Disease project.
The greater risk and earlier onset of type 2 diabetes among Indians is a result of differences between what this disease looks like in Indians compared to other racial, ethnic, and geographic groupings. This is often referred to as the ‘Asian Indian’ phenotype. Indians are diagnosed with diabetes at a younger age and at a lower body mass index than white and black patients. Indians with diabetes have high levels of inflammation and higher rates of heart disease than other populations. There are several underlying causes of why diabetes is so different in Indians.
Our genes are an essential contributor to why we develop diabetes. The genetic factors that predispose Indians to diabetes are generally similar to those that cause the disease in other populations. New research from the Indian Institute of Technology (IIT) Madras has identified a variation in a gene for a protein called pancreastatin, which inhibits insulin uptake in response to elevated glucose. Mutations in this gene are associated with 1.5 times higher risk of type 2 diabetes in Indians.
In addition, there are several “epigenetic” factors (which are changes in the structure of DNA due to behaviors or the environment) that contribute to the risk of DM2 among Indians. For example, one specific change (methylation at several CpG sites) is significantly more frequent among South Asians and accounts for one-third of the increased risk of type 2 diabetes. Conditions that we experience in utero, such as maternal malnutrition, higher levels of maternal fasting glucose and other metabolic parameters, also predispose Indians to diabetes.
Increased insulin resistance and reduced beta-cell function of the pancreatic beta (β) cells
The ultimate mechanism leading to the high rate of type 2 diabetes among Indians is greater insulin resistance. Data supporting this mechanism has existed for almost 4 decades and has been replicated many times and persists after adjusting for physical activity and other important confounders. Concurrent with higher insulin resistance is evidence suggesting a lower function of the pancreatic beta-cells and premature beta-cell failure. For example, the beta-cell function increases with age among Europeans to compensate for increasing insulin resistance but declines among South Asians.
Diabetic risk is also influenced by dietary habits. Indian diets usually have a higher sugar content (often called glycemic load). The consumption of diets rich in carbohydrates, such as white rice and wheat, is responsible for diabetes development among the young population.
The sedentary lifestyle of most Indians is one of the significant causes of not just diabetes but also obesity and cardiovascular failure. Studies show that 7% of the burden of diabetes is due to physical inactivity. A study shows that a large percentage of people in India are inactive, with fewer than 10% engaging in recreational physical activity. Another key contributor to insulin resistance is cardiorespiratory fitness, defined as “the ability of the cardiovascular and respiratory systems to supply oxygen to working muscles during sustained physical activity.” Cardiorespiratory fitness is highly correlated with levels of physical activity, but even holding activity, enduring Indians have lower levels of cardiorespiratory fitness than white Europeans.
A research conducted to measure the cumulative effects of environmental factors on type 2 diabetes. As determined by the Environmental Quality Index (EQI), which includes data on air, water, and land quality as well as sociodemographic factors. According to this analysis, poorer environmental quality was associated with a higher prevalence of type 2 diabetes. Other factors contributing to this include polluted water, stress, vitamin D deficiency, exposure to enteroviruses, and damage to immune cells.
The Bottom line
The diabetes epidemic is escalating in India and increasingly targeting younger individuals. Before it goes out of control, appropriate interventions and a combined societal effort are required to keep this rapidly growing disorder at bay.
(The author is Prof. Harvard University & Chief Medical Advisor, Decipher Health. The article is for informational purposes only. Please consult medical experts and health professionals before starting any therapy, medication and/or remedy. Views expressed are personal and do not reflect the official position or policy of the FinancialExpress.com.)