Diabetes is one of the most common non-communicable diseases in the world. It is a leading cause of death in advanced nations and is developing into an epidemic in emerging economies. But how prevalent is it and are the statistics on diabetes reliable?
The International Diabetes Federation (IDF) is an umbrella organization of over 200 national diabetes associations in over 160 countries.
Besides promoting diabetes care and prevention, the IDF tracks statistics on diabetes and diabetics on a worldwide basis.
The Federation publishes the Diabetes Atlas, a collection of statistics and comments on diabetes which is issued from time-to-time.
The Atlas is based on data supplied by its members. As these are national associations, the facts and figures published by the IDF are considered quite reliable.
According to the 6th edition of the IDF Diabetes Atlas, which was published in 2013, the total population of the world is 7.2 billion. This is expected to have risen to 8.7 billion by 2035, ie in 22 years time.
This total population includes 4.6 billion adults and these have been projected to reach 5.9 billion by 2035.
The IDF defines an adult as a person aged 20–79 years, the most likely age range for the development of type 2 diabetes.
According to the Diabetes Atlas, 382 million people around the world or 8.3% of all 4.6 million adults (20–79 years) are estimated to be suffering from diabetes.
Almost half of all adults with diabetes are aged 40–59 years, the age range during which people are at their most productive phase in life.
The number of people with type 2 diabetes is increasing in every country. If current trends continue, the IDF expects that there will be more than 592 million diabetics by 2035, a rise of 55%, when one adult in ten will be diabetic.
Type 2 diabetes may be undiagnosed for several reasons.
There are few symptoms in the early years of the disease. In addition, the complications vary so widely that, even when symptoms do exist, diabetes may not be recognised as the cause.
The IDF figure for 382 million diabetics in 2013 includes 175 million who are undiagnosed.
I must admit I was astounded when I first read that 46% of diabetics are undiagnosed. How can you count something if you don’t know it exists?
Estimating the number of undiagnosed diabetics, I discovered, is relatively easy. All the IDF had to do was to arrange tests for a sample of people living in a particular area.
The tests, which are carried out by the IDF’s national associates, identify both known and unknown cases of diabetes, and it is a simple mathematical exercise to extrapolate to the population as a whole with a high degree of accuracy.
Many (but not all) persons who know they have the disease will be making some attempts to beat their diabetes.
The problem with undiagnosed diabetes is that these diabetics will not be managing their blood glucose levels and may be developing complications, such as kidney disease, heart failure, retinopathy and neuropathy, unbeknownst to themselves.
The Diabetes Atlas provides statistics for 219 countries which the IDF have grouped into seven regions: Africa, Europe, the Middle East & North Africa, North America & the Caribbean, South & Central America, South-east Asia, and the Western Pacific.
The IDF estimates that 80% of diabetics live in low- and middle-income countries where the disease is increasing very fast and posing a threat to development.
The prevalence of diabetes, however, varies widely from region to region and country to country. It also varies widely within regions … to an extent that suggests that the grouping of countries into regions by the IDF needs revising.
While about 8% of adults (aged 20–79) in the Western Pacific have diabetes, in certain countries in that region the proportion of adult diabetics is much higher. In Tokelau, for example, 37.5% of adults are diabetic. The figure for the Federated States of Micronesia is 35%.
In the Middle East and North Africa, nearly 11% of adults have diabetes. However this is an average for the entire region and the figures for the Arabian Gulf states are much higher, more than double the average, with 24% of adults in Saudi Arabia, 23.1% in Kuwait and 22.9% in Qatar being diabetic.
Undiagnosed diabetes also varies from region to region. In some countries in sub-Saharan Africa up to 90% of diabetics are undiagnosed, mainly due to a lack of resources and priorities.
By contrast, in high-income countries about one-third of the people with diabetes have not been diagnosed.
In most countries diabetes is increasing in tandem with rapid economic development, which is leading to changes in diets, ageing populations, increasing urbanisation, reduced physical activity and unhealthy behaviour.
Many governments, however, seem to be unaware of the growing crisis and the likelihood of serious consequences that could stifle their countries’ development.
Impaired glucose tolerance (IGT)
The IDF estimates that about 316 million people or 6.9% of adults (20–79) have impaired glucose tolerance (IGT). By 2035 this number is expected to have risen to 471 million (8.0% of the world’s adult population).
This is serious, as people with IGT or pre-diabetes have a greatly increased risk of developing type 2 diabetes. IGT is also linked with the development of cardiovascular disease.
The majority of adults with IGT (about 3.5% of the world’s total adult population) are under the age of 50 and are thus at a high risk of becoming type 2 diabetics later in life.
Even more worry-some is the fact that nearly 1/3 of all those who have IGT are aged 20 to 39 years. Unless they overhaul their life-styles these people are virtually guaranteed to become diabetic later in life.
Adding the number of diabetics worldwide (382 million) to the number of people with IGT (316 million) gives a total of 698 million. In other words, nearly 10% of the total population of the world or over 15% of all adults (20–79) have either diabetes or pre-diabetes.
By comparison, only 33.4 million people on this planet are living with HIV/AIDS … about 1/20th of all diabetics and pre-diabetics. It’s glaringly obvious that diabetes and pre-diabetes represent a massive crisis that is threatening to overwhelm global health systems.
Received opinion is that the medical complications caused by diabetes, such as heart failure and kidney disease, are major causes of death in most countries.
However, it is very difficult to accurately estimate the number of deaths because (a) more than a third of countries do not maintain data on death due to diabetes and (b) routine health statistics under-record these deaths, because the death certificates on which these statistics are based often omit diabetes as a cause of death.
To overcome these problems, the IDF uses a modelling approach to estimate the number of deaths attributable to diabetes, and appears to have come up with some reasonable estimates.
Diabetes is expected to be the cause of about 5.1 million deaths in adults aged between 20 and 79 in 2013 and nearly half (48%) of these will be people under the age of 60. Diabetes ranks as a leading cause of premature death.
These deaths represent about 8.4% of all deaths of adults (20–79). Deaths due to diabetes are increasing.
The estimated overall number of deaths in 2013 represents an 11% increase over the estimates for 2011. Death from diabetes is on a rising trend.
There is no cure for diabetes. For this reason, diabetics have to look after their health assiduously.
Where they are unable to control their diabetes through diet and exercise, they have to resort to regular medication. This can be expensive both for health systems and for diabetics and their families.
The IDF has estimated global health spending on diabetes to be at least USD 548 billion dollars in 2013 … 11% of the total spent on adult health. This is expected to exceed USD 627 billion by 2035.
Where diabetes is undiagnosed, the benefits of early diagnosis and treatment are lost. Thus, the costs relating to undiagnosed diabetes must be considerable.
One study found that undiagnosed diabetes in the USA was responsible for an additional USD 18 billion in healthcare costs in one year.
There are large disparities in spending between regions and countries. Only 20% of global health expenditure on diabetes was made in the low- and middle-income countries where 80% of diabetics live. On average, the estimate spend in 2013 is USD 5,621 per diabetic in high-income countries but only USD 356 in low- and middle-income countries.
However, when individual countries are compared, the disparities are extremely stark. Norway spends an average of USD 10,368 on diabetes healthcare per diabetic, while countries such as Somalia and Eritrea spend less than USD 30.
The costs associated with diabetes, however, are much wider that just the costs of providing the appropriate health services. The overall costs include losses in productivity, social costs such as disability payments, and losses of income.
Without a doubt, diabetes imposes a heavy economic burden on countries, families and individuals.
To find out more, visit IDF Diabetes Atlas where you can download the book free of charge.
You’ll also find plenty more statistics at Diabetes: Facts & Figures.