Federal Assistant Minister for Health Ken Wyatt claims diabetes is a growing and global issue.

The claim: Federal Assistant Health Minister Ken Wyatt says that "if diabetes was a country it would be the fifth largest country in the world".

Federal Assistant Health Minister Ken Wyatt says that "if diabetes was a country it would be the fifth largest country in the world". The verdict: The International Diabetes Federation says there are 208 million people with diagnosed diabetes in the world, which is the size of Brazil, the fifth largest country. However, looking at all people living with diabetes, including those who haven't been diagnosed, would make diabetes the third largest country in the world behind China and India. Mr Wyatt's claim is justified.

"If I could just give you one stat: if diabetes was a country it would be the fifth largest country in the world. That's how many people across the globe are affected and so there is much work we've got to do," he said on ABC TV's Q&A on October 12.

So just how many people around the world have diabetes?

ABC Fact Check takes a look.

Diabetes around the world

Diabetes is a chronic disease that occurs when the pancreas can no longer produce enough insulin or when the body is unable to make good use of insulin.

The resulting high blood glucose levels cause damage in other organs and lead to heart attacks, strokes, blindness, kidney damage and amputations.

In Australia, 1.176 million people are registered with the National Diabetes Services Scheme, which helps people with diabetes manage their condition.

Diabetes Australia, a non-profit organisation that works to reduce the impact of the disease, estimates that another 500,000 Australians have diabetes but have not been diagnosed.

According to the not-for-profit International Diabetes Federation (IDF), there were 387 million people with diabetes in the world in 2013.

Its figure was arrived at by searching for country prevalence studies in the PubMed, Medline and Google Scholar databases, as well as reviewing national health surveys from governments and non-government organisations from January 1980 to April 2013.

When no studies were available for a particular country, studies from similar countries in the region, with similar wealth and ethnicity, were used.

Undiagnosed diabetes

Sufferers of diabetes are often required to test their blood sugar levels several times a day. ( ABC TV )

A spokeswoman for Mr Wyatt told Fact Check the IDF's data was the basis for his claim and that he was referring to diagnosed cases of diabetes.

The 387 million people with diabetes identified by the IDF includes a global estimate of people with undiagnosed diabetes of 179 million, or 46 per cent of the total number.

That means there are an estimated 208 million people with diagnosed diabetes in the world.

The IDF study notes that factors such as under-performing health systems, low awareness and the often slow onset or progression of type 2 diabetes means the condition can remain undiagnosed.

Undiagnosed diabetes numbers were taken from population studies where people were asked whether they had diabetes.

The prevalence was calculated by working out how many people who said they did not have diabetes were subsequently found to have diabetes based on blood glucose tests.

These region-specific undiagnosed proportions were applied to all areas using country, age and sex-specific estimates.

World Health Organization data

The World Health Organization (WHO) also collects data on diabetes cases worldwide.

Sorry, this video has expired Ken Wyatt tells Q&A that if diabetes were a country, it would be "the fifth largest in the world".

It publishes a "fact file" on diabetes that puts the number of cases at 347 million.

Its website sources its estimate to research published in The Lancet medical journal in 2011, which was based on data from health examination surveys and epidemiological studies of 2.7 million participants.

The WHO number is based on 2008 data so Fact Check has used the IDF's more recent estimate to assess Mr Wyatt's claim.

Populations of the world's largest nations

The United Nations 2015 world population prospects shows that China is the world's most populous nation, with 1.376 billion people.

Next is India, whose population is 1.311 billion.

Sorry, this video has expired Watch John Barron present the facts.

The third ranked nation is the United States of America with an estimated population of 322 million.

Indonesia, with 258 million, and Brazil, with 208 million, are the fourth and fifth largest countries, respectively.

That means that if people with diagnosed diabetes made up one nation, at 208 million it would be the size of Brazil, which is the fifth largest country in the world.

However, the IDF refers to people with diabetes as those both diagnosed and undiagnosed, and at 387 million they would represent the third largest country in the world, behind China and India.

The verdict

Mr Wyatt claims that if diabetes were a country, it would be the fifth largest in the world.

The International Diabetes Federation says there are 208 million people with diagnosed diabetes in the world, which is the size of Brazil, the fifth largest country.

However, looking at all people living with diabetes, including those who haven't been diagnosed, would make diabetes the third largest country in the world behind China and India.

Mr Wyatt's claim is justified.

Sources