Which countries top the global diabetes numbers table?

Around 537 million adults around the world now live with diabetes – an increase of 73.6 million between 2019 and 2021 – according to the International Diabetes Federation (IDF) Diabetes Atlas 2022. More detail on its findings were presented and discussed at the recent IDF meeting in Lisbon. Dr Susan Aldridge reports.

Introducing the latest edition of the IDF Atlas, Professor Dianna Magliano, Head of Diabetes and Population Health at the Baker Heart and Diabetes Institute said: “Diabetes is a threat to global health, which affects all age groups, regardless of geography, language, income.” And, as co-chair of the team that put the report together, she went on to present its main points.

Since 2000, the annual IDF Atlas has been a detailed and authoritative resource for all those concerned with diabetes care. It presents a picture of the global impact of diabetes, including detailed national and regional data. There are also projections for future years and chapters on special topics.  This IDF Atlas 2022, which presents data for 2021, includes chapters on type 2 diabetes in adults and children, and on COVID-19. 

Global diabetes data

Professor Magliano explained that the Atlas is compiled by collecting all reports of diabetes prevalence, both published and unpublished, and including whole population registries. All data meeting the IDF quality threshold is extracted. The IDF uses the United Nations list of countries and territories, currently standing at 215 in number. If a country does not have its own data, an estimate is done using a country similar in demographics, economics and language. 

For the latest Atlas, there were 219 data sources from 144 countries. Of these, 109 were peer-reviewed, 51 were national health surveys, 41 World Health Organisation STEPS studies [surveillance of non-communicable disease risk factors], 16 diabetes registries and two non-peer reviewed government surveys. There were 71 countries lacking their own in-country data.

Key figures from the 2021 IDF Atlas

One in 10 adults aged between 20 and 79 (537 million people) now lives with diabetes, and three in four of them live in low- to middle-income countries. Almost one in two people who have diabetes are undiagnosed, most of whom live in low- to middle-income countries where access to healthcare and resources may be limited.

However, even in high-income countries, nearly a third of those with diabetes do not know they have the condition. Late or no diagnosis is a serious matter, leading to complications, impaired quality of life and increased healthcare expenditure. When it comes to ‘prediabetes’, a total of 319 million and 541 million adults have impaired fasting glucose and impaired glucose tolerance, respectively, which puts them at risk of developing type 2 diabetes.

One in six live births (21 million) is affected by hyperglycaemia in pregnancy, of which 80% is gestational diabetes. Meanwhile, 1.2 million children and adolescents below the age of 20 have type 1 diabetes.

Diabetes also accounts for 11.5% of global health expenditure ($966 billion) and 12% (6.7 million) of all deaths in the 20 to 79 age group. 

In comparison with 2019 data, 73.6 million more adults have diabetes, nearly 150,000 more children have type 1 diabetes and there were 2.5 million more deaths, while there was an increase of $206 billion spent on treating the condition.

“So our data and our projections tell a sobering story,” said Professor Magliano. “We expect to see rises in every region of the world, with the biggest of these increases being in Africa [excluding North Africa, which is grouped with the Middle East], North Africa and the Middle East, and Southeast Asia.”

The projections say that the number of adults living with diabetes is expected to rise by 46% by 2045, from 537 million to 783 million. Diabetes prevalence will increase in Africa by 134%, North Africa and the Middle East by 87% and Southeast Asia by 68%.

Europe is predicted to have an increase of 13%, which would be the smallest in the world. “The drivers for these increases include a rapid increase in urbanisation, obesity and maybe something as yet unknown in the environment,” said Professor Magliano. 

She showed some of the projections that have been made in Atlases in previous years. “The number of people with diabetes has more than tripled since 2000,” she noted. “What’s really interesting is that, in 2003, our projection for 2025 was that there would be 333 million people with diabetes. We had already passed that figure in 2011 when we reached 366 million, so we are actually underestimating.”

Diabetes by country

The Atlas contains a colour-coded map of the world, which displays countries by the number of adults living there with diabetes. Those with over 20 million are China, Pakistan and the USA but, of course, these are the most densely populated. Most of the countries on the map have between one and 10 million adults living with diabetes.

Then Professor Magliano revealed the top 10 countries in the world by numbers of adults living with diabetes. China leads the pack, with 140.9 million people, followed by India, Pakistan, USA, Indonesia, Brazil, Mexico, Bangladesh, Japan and Egypt. “The 2045 projections tell a similar story, with some differences in the ordering of the ranks,’ said Professor Magliano. “Japan drops out and Turkey replaces it but the top six are the same.”

Turning now to percentage prevalence, as opposed to numbers (thereby taking account of the size of a country’s population), the Atlas shows that Egypt, Mexico, Sudan, South Africa, Pakistan, Turkey, Kuwait, Bangladesh, Malaysia and some of the Pacific islands all have a diabetes prevalence of more than 12%. Pakistan leads the top 10 for prevalence with 30.8% prevalence, followed by several of the Pacific islands and Kuwait, with Egypt bringing up the rear with 20.9%.

Diabetes by age

Diabetes has an impact on people of all ages, not just adults. Hyperglycaemia in pregnancy can affect the baby in the womb, both at birth and later in life. In 2021, the majority (87%) of all live births involving hyperglycaemia in pregnancy occurred in low- and middle-income countries where access to antenatal care may be limited.

There were also some regional differences – in Southeast Asia, hyperglycaemia in pregnancy was involved in 28% of live births, while the Middle East/North Africa region had the lowest proportion at 8.6%. Women under 30 accounted for around half of these pregnancies, but the likelihood of a pregnancy affected by hyperglycaemia rises rapidly with age, with the highest prevalence (42%) occurring among women aged 45 to 49. This reflects the increased risk of type 2 diabetes with age.  

Turning to type 1 diabetes in the under-20s, rates are highest in Sweden, Finland and Norway, and there have been significant increases in the Middle East over the past 20 years. However, Professor Magliano noted, there are still many parts of the world where there are no data on type 1 diabetes prevalence. 

Finally, prevalence of diabetes increases with age in every country in the world but differs by income. By the time people reach their eighth decade, one person in five has diabetes in high and middle-income countries and one in 10 in low-income countries.

As the IDF meeting was being held in Lisbon, Professor Magliano took a quick look at what the Atlas says about diabetes in Portugal. Here, the number of people with diabetes is actually falling because the Portuguese population is decreasing, with fewer babies being born. This is fairly typical across the whole of Europe, with age-adjusted prevalence being 10.3% in 2021 and projected to increase to 11% by 2045.

In conclusion

The IDF Diabetes Atlas is a highly valuable resource but we need to be aware of various limitations in the data and knowledge gaps. The sources of the data are heterogeneous in terms of the year, level of representation of the population and study design, which might have introduced some bias.

Error might also have been introduced by the use of ‘similar country’ data for those countries that have no data of their own. In particular, there is a dearth of data from Africa. And, for the future projections, only age, sex and urbanisation are considered as influences on the data, while there may be many other factors, such as change in lifestyle and obesity, that influence the figures.

Professor Magliano concluded with the following call to action: “There is a strong need for effective intervention strategies and policies to stall the increase in the number of people with diabetes.”

• This presentation and the IDF Diabetes Atlas 2022 are available at www.diabetesatlas.org

Any opinions expressed in this article are the responsibility of the EASD e-Learning Programme Director, Dr Eleanor D Kennedy.