The number of people with diabetes has doubled over the past 30 years to more than 800 million worldwide, according to a groundbreaking international study.
Global analysis published in the Lancet found that rates of diabetes in adults doubled from about 7% to about 14% between 1990 to 2022, with the largest increase in low and middle-income countries.
The study is the first global analysis of diabetes rates and treatment in all countries. Scientists at NCD-RisC in collaboration with the World Health Organization used data from more than 140 million people aged 18 or older from more than 1,000 studies in different countries. They applied statistical tools to enable accurate comparisons of prevalence and treatment between countries and regions.
Diabetes is a chronic disease caused when the pancreas does not produce enough (or any) insulin or the body cannot effectively use the insulin it produces. Uncontrolled diabetes can cause hyperglycaemia, or raised blood sugar, which over time can cause serious damage to many of the body’s systems, especially the nerves and blood vessels.
Type 1 diabetes is an autoimmune disease in which the body destroys the cells in the pancreas that produce insulin. Type 2 diabetes is a metabolic disorder which stops the body using insulin properly. More than 95% of people with diabetes have type 2 diabetes. Unlike type 1, type 2 diabetes can largely be prevented. Being overweight, eating unhealthily and not exercising enough, as well as genetic factors, can increase the risk of developing diabetes. Growing levels of obesity are fuelling an epidemic in type 2 diabetes.
The study highlighted growing health inequalities. More than half of global diabetes cases were concentrated in four countries. Of those with diabetes in 2022, more than a quarter (212 million) lived in India, 148 million were in China, 42 million were in the US and 36 million in Pakistan. Indonesia and Brazil accounted for a further 25 million and 22 million cases, respectively.
In some countries in the Pacific islands, Caribbean, Middle East and north Africa, more than 25% of the female and male population have diabetes, the study found, while the US (12.5%) and the UK (8.8%) had the highest diabetes rates among high-income western countries.
In contrast, diabetes rates in 2022 were as low as 2-4% for women in France, Denmark, Spain, Switzerland and Sweden, and 3-5% for men in Denmark, France, Uganda, Kenya, Malawi, Spain and Rwanda.
Increases in obesity, alongside an ageing global population means growing numbers of people are at greater risk of developing type-2 diabetes.
Dr Ranjit Mohan Anjana, the joint first author and president of the Madras Diabetes Research Foundation in India, said: “Given the disabling and potentially fatal consequences of diabetes, preventing diabetes through healthy diet and exercise is essential for better health throughout the world.
“Our findings highlight the need to see more ambitious policies, especially in lower-income regions of the world, that restrict unhealthy foods, make healthy foods affordable and improve opportunities to exercise, through measures such as subsidies for healthy foods and free healthy school meals as well as promoting safe places for walking and exercising including free entrance to public parks and fitness centres.”
Despite the availability of effective, off-patent glucose-lowering medications, lack of treatment is also fuelling inequalities, the study found. Whereas many, often higher-income countries have seen vast improvements in treatment rates, with more than 55% of adult diabetics receiving treatment in 2022, for many low and middle-income countries the proportion receiving treatment has not improved.
As a result more than half of adults with diabetes – 445 million (59%) – aged 30 and over did not receive treatment in 2022.
A senior author of the study, Prof Majid Ezzati, of Imperial College London, said: “Our study highlights widening global inequalities in diabetes, with treatment rates stagnating in many low and middle-income countries where numbers of adults with diabetes are drastically increasing. This is especially concerning as people with diabetes tend to be younger in low-income countries and, in the absence of effective treatment, are at risk of life-long complications – including amputation, heart disease, kidney damage or vision loss – or in some cases, premature death.”
Responding to the findings, the WHO director general, Dr Tedros Adhanom Ghebreyesus, said: “We have seen an alarming rise in diabetes over the past three decades, which reflects the increase in obesity, compounded by the impacts of the marketing of unhealthy food, a lack of physical activity, and economic hardship.
“To bring the global diabetes epidemic under control, countries must urgently take action. This starts with enacting policies that support healthy diets and physical activity and, most importantly, health systems that provide prevention, early detection, and treatment.”
Chantal Mathieu, the president of the European Association for the Study of Diabetes, said: “[Diabetes] has reached pandemic proportions, posing a profound threat to public health and economies alike.”
Policymakers must “adopt preventive strategies, expand access to screening, and support initiatives for better long-term management”, she added.
• This article was amended on 14 November 2024 to add further information regarding type 1 and type 2 diabetes.
