Clip_4Twelve years ago, my husband and I packed up all of our belongings and moved to Trivandrum — a steamy, tropical town at the southern tip of India in Kerala. At the time, I was a medical student interested in studying stroke. For the next six months I dressed in a sari and walked to work on jungle roads. At the hospital, I immediately began seeing a steady stream of young patients affected by strokes, many of whom were so severely disabled that they were unable to work. I initially suspected the cause was tuberculosis or dengue fever — after all, this was the developing world, where infections have long been primary culprits for disease. But I soon learned that my hunch was wrong.

One of my first patients was a woman in her mid-30s who came in with a headache, vomiting and an unsteady gait. Her scan showed a brainstem stroke. Her blood sugars were very high. The underlying cause of her stroke was most likely untreated Type 2 diabetes. Here I was, halfway around the globe, in a vastly foreign culture, but I was looking at a disease — and the lifestyle that fostered it — that was startlingly familiar.

Today, I am an endocrinologist, and diabetes has become a full-blown epidemic in India, China, and throughout many emerging economies.

In the United States, diabetes tends to be a disease that, while certainly not benign, is eminently manageable. Just this month, federal researchers reported that health risks for the approximately 25 million Americans with diabetes had fallen sharply over the last two decades. Elsewhere on the globe, however, diabetes plays out in a dramatically different fashion. Patients often lack access to care and can’t get insulin, blood pressure pills and other medicines that diminish the risk of complications. As more and more people develop the disease, hospitals may soon be overrun with patients experiencing all of its worst outcomes: blindness, limb amputation, kidney failure (necessitating dialysis), coma and death.

Within the last few decades, South Asia has experienced a rapid economic transition paralleled by an epidemiological shift in disease patterns. Recently, when I returned to India for a yearlong fellowship, I saw this for myself. Indians are now living more sedentary lives, working in banks, labs and call centers; all the while, their diet is changing, as they eat out more and consume foods higher in calories and saturated fats.

What’s more, evidence suggests that Indians may be especially predisposed to diabetes, so even those who are slightly overweight are more likely to be at risk. India also has a high malnutrition rate among children, and poor nutrition in early life appears to trigger metabolic changes that lead to diabetes in adulthood. The result is a perfect storm of commerce, lifestyle and genetics.

According to the International Diabetes Federation, there are now an estimated 65 million adults with diabetes in India. That number is projected to increase to 109 million by 2035. China also has a diabetes epidemic — with an estimated 98 million people affected. Indonesia has nearly 9 million, and Pakistan nearly 7 million. All told, 382 million people worldwide are living with diabetes, a vast majority in low- and middle-income countries — places where many cases go undiagnosed and untreated.

The costs associated with diabetes are enormous; they include expenses related to acute and chronic complications, the costs of therapies to prevent them, and the fact that those affected may be unable to work and support their families. Many patients are pushed into bankruptcy. In India, only 10 percent of people have medical insurance, and patients cover most expenses out of pocket. In some low- and middle-income countries, diabetes patients living on $1 or $2 per day would need to spend as much as 50 percent of their monthly income to buy just one vial of insulin. Additional materials such as syringes, needles and glucose monitoring tests push costs even higher.

There is much to be done to prepare for this global epidemic. The sheer size of it means that strategies focused solely on treatment will be far too costly. If nothing changes in the next two decades, India will need to provide chronic care for more than 100 million people with diabetes — close to the entire adult population of Russia.

The solution in India and other developing countries has to include prevention, which means promoting healthy eating and physical activity. It’s not easy: We have by no means succeeded in the United States. In India, it will require better policies that favor fruits and vegetables over refined-food products. One opportunity involves India’s Mid Day Meal Scheme, a program that provides lunches to 120 million children. The program has been tainted by corruption and deadly contamination problems, but as the Indian government addresses these issues, it also has a chance to reshape the dietary habits of many young people. Exercise is the other crucial element. Taking a jog or even walking to work in Indian cities often means choking on exhaust fumes and dodging speeding cars. Creating more sidewalks and bike paths could go a long way.

The second step is providing diabetes patients with medicines that are effective, safe and affordable. On the bright side, for at least a decade, India has manufactured affordable generic insulin. But in recent years, pharmaceutical companies, sensing the potential for profits, have begun to market their products aggressively.

In one major government hospital, I saw lines of pharmaceutical representatives with glossy pamphlets and drug samples waiting to speak with clinicians. Some classes of drugs they’re pushing, such as incretin mimetics — which are injected to lower blood sugars — are very costly, and though they are approved for use in both the United States and India, we don’t know enough about their safety in the long run. They don’t appear to lower blood sugar levels any better than cheaper alternatives like metformin, which comes as a pill and is considered the best first choice for many people with diabetes. In America, expenditures on diabetes medications have soared as newer drugs have been rapidly adopted. India desperately needs to create evidence-based guidelines that take into account cost-effectiveness so that marketing doesn’t drive treatment.

But even the best medicines will not work without a well-functioning health care system. Diabetes care is not a quick fix. You can’t take a pill for 10 days and be cured. It means working with a clinical team to control the disease month after month, year after year. This requires a system that is geared toward chronic care, which in many countries simply doesn’t exist. In India, there is now a call for universal health care. This is encouraging but is a long way from being realized. In the meantime, India could leverage the lessons learned from many successful H.I.V. programs throughout the developing world that have empowered communities to deliver complex clinical services to millions of people at low cost.

In order for policy makers and health officials to bring about these changes, we must change how we think about the disease. Most of us in the West assume we know what the risks and burdens of diabetes are. And if we’re talking about a patient in Kansas City or Tokyo, we’re probably right. But when it comes to diabetes, location is everything, and much of the world is now vulnerable to the most devastating consequences of this disease. If we’re going to be any help at all, we need to make a conceptual shift. We think we know diabetes — and that’s the problem.

Kasia Lipska is an endocrinologist at the Yale School of Medicine.