While there has been a general decline in the incidence of type 2 diabetes since 2010, the incidence is still increasing in certain ethnic and socio-economic groups.
Type 2 diabetes is a major global health concern, and almost 1.2 million Australians are living with the disease.
New research published in the Medical Journal of Australia has examined the incidence of type 2 diabetes between 2005 and 2019, with an emphasis on the role that socio-demographics plays in incidence rates.
“Incidence is a critical but underused measure of the problem; in contrast to prevalence, it does not rise as mortality falls, and is therefore a more direct measure of population risk,” Professor Dianna Magliano, laboratory head of the Baker Heart and Diabetes institute, and colleagues wrote.
Although previous studies have shown the incidences of diabetes declining or remaining static after 2010, there is limited data on trends in diabetes incidence by ethnic background or socio-economic position, which are key risk factors for type 2 diabetes.
“We therefore analysed National Diabetes Services Scheme (NDSS) data to estimate changes in the incidence of type 2 diabetes in Australia, overall and by age, sex, socio-economic disadvantage, geographic remoteness, and country of birth,” Professor Magliano and colleagues wrote.
A rollercoaster of rises and declines
In examining the NDSS data, the authors found that 741 535 people over the age of 20 years registered with the NDSS between 2005 and 2019, and 421 190 of those registrations were men (56.8%).
They found that the incidence of type 2 diabetes increased with age (until about 70 years) and increased in all age groups between 2005 and 2010, before declining between 2010 and 2019.
Despite the decline, the incidence of type 2 diabetes among men aged 40 years or younger was still higher in 2019 than it was in 2005.
The incidence of type 2 diabetes also increased with socio-economic disadvantage for both sexes and in all calendar years.
Between 2005 and 2015, the highest incidence for type 2 diabetes was among people in inner regional areas, but after 2015, the incidence was highest among people in major cities.
While the age-standardised incidence of type 2 diabetes declined during 2010–2019 across all age, sex, socio-economic disadvantage, and remoteness groups, it increased among people from Asia, North Africa and the Middle East, and the Pacific Islands.
“A decline in the incidence of type 2 diabetes since 2010–2011 in Australia is consistent with recent reports that it is steady or declining in many high income countries, but increasing in low and middle income countries,” the authors wrote.
“Our findings suggest that type 2 diabetes incidence has increased in Australia among those born in Asia, North Africa and the Middle East, and the Pacific Islands in recent years, consistent with the substantial increases in diabetes prevalence in the Pacific Islands, the Middle East, and South Asia.”
The fight is not over yet
An overall decline in the incidence of type 2 diabetes suggests diabetes prevention strategies are leading to effective behavioural and environmental changes, such as the decline in consumption of sugar-sweetened beverages.
The decline may also be attributable to changes in how people are tested for diabetes, with a shift from oral glucose tolerance testing to HbA1c assessment, which identifies fewer people with diabetes.
Despite the overall decline, Professor Magliano and colleagues call for vigilance of at-risk groups still seeing a rise in type 2 diabetes incidence.
“As in 2023 more than 30% of the Australian population were born overseas, we need multifaceted approaches for preventing type 2 diabetes that take into account differences in the risk of developing diabetes, particularly among people with culturally and linguistically diverse backgrounds,” the authors concluded.
Read the research in the Medical Journal of Australia.
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