BUSAN, SOUTH KOREA — The diabetes epidemic may be abating in higher-income parts of the world, but overall prevalence continues to rise, according to the latest version of the International Diabetes Federation (IDF) Atlas.
On December 4 here at the IDF Congress 2019, speakers summarized findings from the ninth edition of the Diabetes Atlas and discussed the difficulties in determining the incidence of the disease because of limitations in data collection.
"We've started to see a sign that the incidence of diabetes is starting to abate, in high-income countries at least. In other countries, we don't have enough data," session speaker Dianna J. Magliano, PhD, told Medscape Medical News.
The clinical message is that "[type 2] diabetes prevention actually does work, and if we keep at it we might stop the trends from getting worse again," said Magliano, who was not an author of the Atlas but whose recent work, as reported by Medscape Medical News, was used in its development.
"Just because incidence is starting to plateau in some countries doesn't mean we should take our foot off the pedal or eye off the ball. We still have to continue to work hard at prevention because we know we can make a difference," added Magliano, who is professor of epidemiology at the Baker Heart and Diabetes Institute, Melbourne, Australia.
Most Comprehensive Assessment of Diabetes Worldwide
The 2019 Atlas includes figures from 221 countries but only 138 had quality data, whereas data for the other 73 were extrapolated from neighboring countries with similar demographics.
Future predictions were calculated using the United Nations population predictions and degree of urbanization, explained Stephen Colagiuri, MD, deputy chair of the Atlas writing committee and professor of metabolic health and director of the Boden Institute at the University of Sydney, Australia.
Overall, the data in the Atlas account for more than 93% of the global population, he said.
Atlas committee member Edward Boyko, MD, of the University of Washington, Seattle, told Medscape Medical News, "We think it's the most comprehensive and serious assessment of the impact of diabetes worldwide...We try to utilize all the data sources we can find...Diabetes incidence appears to be diminishing in some areas; we'll have to see if the trend continues."
Since the previous edition in 2017, new information has been added in chapters on children and adolescents, and on diabetes complications and comorbidities.
As in previous editions, the last chapter of the 2019 Atlas addresses "action on diabetes," including information about prevention or delay of type 1 and type 2 diabetes, using data to drive action on care delivery, universal health coverage, and access to insulin.
Recommendations for action include prioritizing diabetes care and control; developing and implementing national plans and strategies to reduce the impact of diabetes; extending health promotion programs to reduce the impact of diabetes and its complications; and promoting high-quality research in diabetes.
The IDF Atlas is supported by Pfizer, MSD, Lilly, and Novo Nordisk.
Diabetes by the Numbers
The Atlas is chock-full of statistics, and it's free online for those who are looking for specifics by region. Among the more notable findings:
The number of adults aged 20-79 years with diabetes is about 463 million, or one in every 11. By contrast, the estimate was just 151 million in the first IDF Atlas from 2000.
Among those older than 65 years, the number is 136 million, or one in every five.
Age-adjusted prevalence of diabetes is more than 10% of the populations in the Middle East/North Africa, Western Pacific, South East Asia, and North America/Caribbean.
Projections for the numbers of people with diabetes for 2025, 2030, and 2045 are 438 million, 578 million, and 700 million, respectively. By region, those represent estimated increases ranging from 31% in the Western Pacific to 143% in Africa.
The estimated number of adults aged 20-79 years with undiagnosed diabetes is 232 million, or one in two with diabetes. The estimated number with impaired glucose tolerance is 374 million, or one in 13.
Worldwide, one in six live births, or 20 million, is affected by hyperglycemia in pregnancy, of which 84% is due to gestational diabetes.
The number of deaths in 2019 attributable to diabetes is 4.2 million, and diabetes is associated with 11.3% of deaths worldwide.
In 2019, total diabetes-related health expenditure will reach $760 billion (US dollars), a 4.5% increase since 2017.
Countries with the highest diabetes-related health expenditure in 2019 were the United States ($294.6 billion), China ($109 billion), and Brazil ($52.3 billion).
Incidence Versus Prevalence: Is Diabetes Finally Declining?
During her presentation, Magliano explained that gathering data on diabetes incidence is more difficult than on prevalence for a variety of reasons.
Cohort studies are hard to conduct and the information is often out of date, whereas gathering prevalence data using administrative databases is inexpensive, includes large populations, and is current.
In an attempt to gather better incidence data, Magliano and colleagues first conducted a systematic review of the published literature on the trends in type 2 diabetes incidence. That review, published in BMJ in September 2019, as reported by Medscape Medical News, showed the proportion of populations showing increasing trends were highest in the 1990s and early 2000s, but that two thirds of all populations with decreasing or stable trends were in the 2006-2014 period.
Thus, "In most populations since 2006, incidence is stable or falling," she commented.
But she also pointed out the limitations of the systematic review, including differing definitions of diabetes across studies and limited data in low- and middle-income countries.
In the second part of her research in this area, diabetes incidence and mortality data were gathered from diabetes registries, health insurance databases, and health maintenance organizations by age and sex in 1995-2016. Participating countries included Australia, Denmark, Scotland, Israel, Italy, Taiwan, Ukraine, Latvia, United States, Canada, Singapore, Hong Kong, Lithuania, Korea, Spain, the Netherlands, Norway, Hungary, and France.
The age- and sex-standardized incidence of diabetes appeared to be stable or decreasing everywhere except Ukraine, Lithuania, Singapore, and the United States.
Evidence suggests that the fall in incidence in some places is more likely because of prevention activities than either reductions in screening or the introduction of hemoglobin A1c for diagnosis, Magliano said.
What About Type 1 Diabetes?
Data for type 1 diabetes incidence is almost solely based on studies of children and adolescents. Atlas coauthor Chris Patterson, PhD, of the Centre for Public Health, Queen's University Belfast, UK, reviewed several sources of data used in the Atlas.
Among these were his own recent work, as reported by Medscape Medical News, showing that, despite reductions in the rate of increase in some high-risk European countries, the pooled estimate across centers continues to show a 3.4% annual increase in incidence, predicting a doubling of type 1 diabetes incidence within about 20 years in Europe.
Patterson told Medscape Medical News: "There is evidence that the incidence of type 1 diabetes has leveled off at least temporarily in some of the high-incidence countries, but the overall pattern is still one of increase in the European centers."
"So there are grounds for some optimism, but I do think that more likely this is a temporary blip. It's happened before. The only thing that's unusual about this is a lot of countries are showing this leveling off at the same time, which tends to suggest some environmental factor is involved, although what it is we don't really know," he said.
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Cite this: Diabetes Epidemic May Be Abating in Some Areas: IDF Atlas - Medscape - Dec 04, 2019.