As the global diabetes rate soared over the past quarter-century, the affected population transformed: What was once predominantly a rich-country problem has become one that disproportionately affects poorer countries.
That's one of the many conclusions of the World Health Organization's first global report on the chronic disease. Worldwide, diabetes rates nearly doubled, from 4.7 percent in 1980 to 8.5 percent in 2014. Roughly one in 12 people living in the world today have the disease, which has spread dramatically.
“If we are to make any headway in halting the rise in diabetes, we need to rethink our daily lives: To eat healthily, be physically active, and avoid excessive weight gain,” Dr. Margaret Chan, WHO Director-General, said in a statement. “Even in the poorest settings, governments must ensure that people are able to make these healthy choices and that health systems are able to diagnose and treat people with diabetes.”
Most of the 422 million adults living with diabetes are, in fact, in poorer countries, the WHO found.
The disease has spread unequally, too.
Over the past decade, diabetes prevalence rose faster in low- and middle-income countries than high-income ones.
As the chart below shows, diabetes prevalence in high-income countries rose from just over 5 percent to about 7 percent.
Low-income countries saw rates grow from just over 3 percent to more than 7 percent, overtaking high-income countries for the first time within the past decade.
That switch is likely linked to other factors, such as rising global obesity, says Etienne Krug, director of the WHO Department for Management of Noncommunicable Diseases, Disability, Violence and Injury Prevention.
"What's happening in the low- and the middle-income countries quite quickly is very rapid urbanization," Krug said. "People who used to work in the fields doing quite hard physical work, had access to vegetables and fruit very cheaply and did most of their transportation by walking or bicycle, are now living in cities where the type of work they do, the type of transportation modes they use and the type of food they eat is very different."
Poverty is also a factor, he said, as people in poorer countries have a harder time accessing healthy foods.
Certain regions are also disproportionately affected by the disease.
The Eastern Mediterranean widened its lead over the rest of the world, from 0.6 percentage points in 1980 to 5.1 percentage points in 2014. Diabetes prevalence there is up to 13.7 percent, from 5.9 percent.
WHO officials can't quite say why that is.
"We do think that it has to do, again, with eating habits changing and with physical activity rates changing as well, but we don't have a full explanation for it," Krug said.
Whatever is driving it, the growth in the global diabetes rate is taking an economic toll, costing the world an estimated $827 billion a year.
Global health-care spending on the disease more than tripled from 2003 to 2013, according to the International Diabetes Federation.
And the burden of ongoing growth in diabetes health spending will fall disproportionately on low- and middle-income countries, the WHO notes. The major cost drivers are inpatient and outpatient care, but spending on patented, branded drugs contributes, too.
Slowing that growth — and maybe even reversing it — depends on prevention and management, Krug said.
Health experts don't know how to prevent Type 1 diabetes, which is characterized by the insufficient production of insulin, a regulator of blood sugar.
But Type 2 diabetes — in which the body uses insulin ineffectively — can be prevented.
"For Type 2, there's a lot we can do," Krug said. That includes healthier eating, reducing sugars and fats in foods, and exercising more.
Diabetes should also be better managed, he said.
"There are important complications if we don't diagnose diabetes on time," he said. Doing that means improving access to insulin by reducing or subsidizing prices or strengthening the supply chain and improving diagnosis and treatment.
The report was released on Wednesday, ahead of World Health Day. Many countries have set a goal of reducing diabetes by one third by 2030.