According to the new report published in The Lancet journal, the health condition affected around 14% of adults worldwide in 2022, compared with 7% in 1990.
The groundbreaking study is the first global analysis of diabetes rates and treatment across all countries. It reveals a significant rise in diabetes prevalence, particularly in low- and middle-income nations.
Conducted by scientists from NCD Risk Factor Collaboration in collaboration with the World Health Organisation, the research analysed data from over 140 million people aged 18 or older, collected through more than 1,000 studies globally.
Taking into account the growing global population, its authors estimated that more than 800 million people are now diabetic, versus under 200 million in 1990.
These figures include both main types of diabetes. Type-1 affects patients from a young age and is more difficult to treat as it is caused by an insulin deficiency. Type-2 mainly affects middle-aged or older people who lose their sensitivity to insulin.
Behind the global numbers, national figures varied widely. The rate of diabetes stayed the same or even fell in wealthier countries such as Japan and Canada, as well as western European nations such as France and Denmark.
“The burden of diabetes and untreated diabetes is increasingly borne by low- and middle-income countries,” the report highlighted. For example, nearly a third of women in Pakistan are now diabetic, compared to under a tenth in 1990.
The scientists emphasise that obesity is an “important driver” of type-2 diabetes, as is an unhealthy diet.
The gap between how diabetes is treated in richer and poorer countries is also widening: three out of five people aged over 30 with diabetes – or 445 million adults – did not receive treatment in 2022, the researchers estimated.
India alone was home to almost a third of that number, while in sub-Saharan Africa, only 5-10% of adults with diabetes received treatment that year.
Some developing countries such as Mexico are doing well in treating their population – but overall the global gap is widening, the experts noted.
“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,” said senior study author Majid Ezzati of Imperial College London.
Uncontrolled diabetes can lead to serious health complications including hyperglycaemia (high blood sugar), which, over time, damages blood vessels and nerves, affecting vital organs.
Other complications include “amputation, heart disease, kidney damage or vision loss – or in some cases, premature death”, Ezzati added.