It is now recognized that it is the low- and middle-income countries that face the greatest burden of diabetes. However, many governments and public health planners still remain largely unaware of the current magnitude, or, more importantly, the future potential for increases in diabetes and its serious complications in their own countries.
This section of the IDF Diabetes Atlas looks at the global burden of diabetes. It points out the consequences of inaction by revealing the mortality caused by diabetes as well as the mounting health expenditures in countries around the world.
The first part presents estimates of the prevalence of diabetes mellitus and impaired glucose tolerance (IGT) for 216 countries and territories for the years 2010 and 2030; it also looks at the global trends in diabetes in the young and provides estimates for type 1 diabetes in children and adolescents.
Diabetes can lead to complications, the consequences of which can include blindness, kidney damage, and foot ulcers that can result in amputation. There is no single definition for each type of complication (e.g. retinopathy, neuropathy or nephropathy) so studies of the occurrence of diabetes complications are often hard to compare. There have been relatively few studies and a review of most of these studies is available in the Diabetes Atlas, third edition 1 . However, this edition addresses depression, an important condition that is common in people with diabetes. A survey on national diabetes programmes, reported in National Diabetes Programmes, found that psychological and behavioural issues received less attention than other aspects of diabetes care. This section summarizes a review of studies of diabetes and depression, and shows the significance of depression in affecting both the quality of life of people with diabetes and how well diabetes is controlled.
Estimates of the mortality burden related to diabetes for 2010 are also presented in this section, deaths that are largely preventable through public health action directed at primary prevention of diabetes in the population and improvement of care for all people with diabetes.
In addition, this section examines the economic impact of diabetes and provides estimates of national health expenditures to treat and prevent diabetes and its complications for the years 2010 and 2030. The results show that more than 80% of expenditures for medical care for diabetes are made in the world’s economically richest countries, not in the low and middle-income countries where over 70% of people with diabetes live. In the world’s poorest countries, not enough is spent to provide even the least expensive life-saving diabetes drugs.
1: International Diabetes Federation. The Diabetes Atlas. Third Edition. Brussels: International Diabetes Federation; 2006.
|Total world population (billions)||7.0||8.4|
|Adult population (20-79 years, billions)||4.3||5.6|
|Diabetes and IGT (20-79 years)|
|Global prevalence (%)||6.6||7.8|
|Comparative prevalence (%)||6.4||7.7|
|Number of people with diabetes (millions)||285||438|
|Global prevalence (%)||7.9||8.4|
|Comparative prevalence (%)||7.8||8.4|
|Number of people with IGT (millions)||344||472|
Diabetes mellitus (DM) is now one of the most common non-communicable diseases globally. It is the fourth or fifth leading cause of death in most high-income countries and there is substantial evidence that it is epidemic in many economically developing and newly industrialized nations. Complications from diabetes, such as coronary artery and peripheral vascular disease, stroke, diabetic neuropathy, amputations, renal failure and blindness are resulting in increasing disability, reduced life expectancy and enormous health costs for virtually every society. Diabetes is undoubtedly one of the most challenging health problems in the 21st century.
The number of studies describing the epidemiology of diabetes over the last 20 years has been extraordinary. It is now recognized that it is the low- and middle income countries (LMCs) that face the greatest burden of diabetes. However, many governments and public health planners still remain largely unaware of the current magnitude, or, more importantly, the future potential for increases in diabetes and its serious complications in their own countries.
It has been a consistent finding of population-based diabetes studies that a substantial proportion of all people found to have diabetes had not been previously diagnosed. The uncovering of new cases when mass blood testing is undertaken is primarily because of the lack of symptoms associated with the early years of type 2 diabetes, meaning that those with diabetes may be unaware of their condition and therefore not seek medical attention for it.
In addition to diabetes, the condition of impaired glucose tolerance also constitutes a major public health problem, both because of its association with diabetes incidence and its own association with an increased risk of cardiovascular disease.
In this edition of the IDF Diabetes Atlas, the prevalence of diabetes mellitus and IGT has been estimated for each country for the years 2010 and 2030. Data are provided for 216 countries and territories, which have been allocated into one of the seven IDF regions: Africa (AFR), Europe (EUR), Middle East and North Africa (MENA), North America and Caribbean (NAC), South and Central America (SACA), South-East Asia (SEA), and the Western Pacific (WP).
The data presented for adults are for types 1 and 2 diabetes combined, and IGT. Only adults aged from 20 to 79 years are considered because the majority of all people who have diabetes and IGT are adults. Estimates for type 1 diabetes in children and adolescents are presented in the section on Diabetes in the Young.
Two sets of prevalence estimates have been provided in this report: the national, regional or global prevalence (the crude prevalence) and the comparative prevalence. The national, regional or global prevalence indicates the percentage of a particular population that has diabetes. It is appropriate for assessing the burden of diabetes for each country or region. The comparative prevalence is used for making comparisons between countries or regions. It has been calculated by assuming that every country or region has the same age profile (the age profile of the world population has been used). This reduces the effect of the differences of age between countries or regions, and makes this figure approriate for making comparisons.
The data presented here should be interpreted cautiously as general indicators of diabetes frequency, and the estimates will need to be revised as new and better epidemiological information becomes available. Comparison of country, regional, and even global prevalence from one report to the next should be performed with extreme caution. Large changes in the prevalence or numbers of people with diabetes from one edition of the IDF Diabetes Atlas to another are usually due to the use of a more recent study rather than a change in the profile of diabetes within that country. Data sources for this edition include 34 new studies. Thus, the inclusion of recent, and more reliable research brings us closer to the actual rates of diabetes, but these limitations need to be always considered. The key purpose of reports such as these is to stimulate action in the form of preventive and management programmes, as well as further research.
The background paper, Diabetes and Impaired Glucose Tolerance, and country by country estimates on which this summary is based are available in the Downloads section.
Diabetes mellitus can be found in almost every population in the world and epidemiological evidence suggests that, without effective prevention and control programmes, diabetes will likely continue to increase globally 1 .
Type 1 diabetes usually accounts for only a minority of the total burden of diabetes in a population but is increasing in incidence in both poor and rich countries. It is the predominant form of the disease in younger age groups in most high-income countries (see Diabetes in the Young).
Type 2 diabetes constitutes about 85 to 95% of all diabetes in high-income countries 1 and may account for an even higher percentage in low- and middle-income countries. Type 2 diabetes is now a common and serious global health problem, which, for most countries, has evolved in association with rapid cultural and social changes, ageing populations, increasing urbanization, dietary changes, reduced physical activity and other unhealthy lifestyle and behavioural patterns 1 .
Gestational diabetes mellitus is common and, like obesity and type 2 diabetes that are related conditions, is increasing in frequency throughout the world. The risk of developing diabetes after GDM is very high. As the prevalence of type 2 diabetes increases within a population so will the prevalence of GDM 2 . The reported prevalence of GDM has varied widely among different populations around the world. Much of the variability is due to differences in diagnostic criteria and detection methods used in different centres. However, it has not been possible to estimate the prevalence of GDM separately as there are very limited population-based studies on GDM. It is recognized that the challenges of GDM have to be addressed and further research is required in this area.
The methods used here to estimate the prevalence of diabetes are conservative and are mostly based on changes in population size and age sturcture. It has not been possible in these projections to take any account of trends in obesity although the projections for LMCs do take into account trends in urbanization. If levels of obesity continue to increase it is possible that the prevalence of diabetes will be even greater than reported here.
It is estimated that approximately 285 million people worldwide, or 6.6%, in the age group 20-79, will have diabetes in 2010, some 70% of whom live in low- and middle-income countries. This number is expected to increase by more than 50% in the next 20 years if preventive programmes are not put in place. By 2030, some 438 million people, or 7.8% of the adult population, are projected to have diabetes. The largest increases will take place in the regions dominated by developing economies (see Figure 2.1)
2: Hunt KJ, Schuller KL. The increasing prevalence of diabetes in pregnancy. Obstet Gynecol Clin North Am 2007; 34 (2): 173-99, vii.
Impaired glucose tolerance, along with impaired fasting glucose (IFG), is recognized as being a stage in the transition from normality to diabetes. Thus, individuals with IGT are at high risk of progressing to type 2 diabetes, although such progression is not inevitable, and probably over 30% of individuals with IGT will return to normal glucose tolerance over a period of several years.
The decision to include data on IGT was based on two major factors associated with its presence: it greatly increases the risk of developing diabetes 1 , and it is associated with the development of cardiovascular disease 2 3 . In addition, some of the best evidence we have on the prevention of type 2 diabetes comes from studies in people with IGT.
It is estimated that some 344 million people worldwide, or 7.9% in the age group 20-79, will have IGT in 2010, the vast majority of whom live in low- and middle-income countries. By 2030 the number of people with IGT is projected to increase to 472 million, or 8.4% of the adult population.
As with diabetes, the 40-59 age group is expected to have the greatest number of people with IGT with 138 million for 2010, and this will remain true in 2030 with 186 million as shown in Figure 2.3. It is also of note that nearly one-third of all those who will have IGT for 2010 are in the 20-39 age group (see Figure 2.3).
The prevalence of IGT is generally similar to that of diabetes, but somewhat higher for the African and Western Pacific Regions, and slightly lower in the North America and Caribbean Region.
Map 2.3 Prevalence* (%) estimates of impaired glucose tolerance (20-79 years), 2010
1: Shaw JE, Zimmet PZ, de Courten M, et al. Impaired fasting glucose or impaired glucose tolerance. What best predicts future diabetes in Mauritius? Diabetes Care 1999; 22 (3): 399-402.
2: Perry RC, Baron AD. Impaired glucose tolerance. Why is it not a disease? Diabetes Care 1999; 22 (6): 883-885.
3: Tominaga M, Eguchi H, Manaka H, et al. Impaired glucose tolerance is a risk factor for cardiovascular disease, but not impaired fasting glucose. The Funagata Diabetes Study. Diabetes Care 1999; 22 (6): 920-924.
At a Glance
|Total child population (0-14 years, billions)||1.9|
|Type 1 diabetes in children (0-14 years)|
|Number of children with type 1 diabetes (thousands)||479.6|
|Number of newly-diagnosed cases per year (thousands)||75.8|
|Annual increase incidence (%)||3.0|
Type 1 diabetes is rapidly increasing in children and adolescents in many countries, and evidence suggests that in a growing number of countries type 2 diabetes is now also being diagnosed in childhood.
Type 1 diabetes is one of the most common endocrine and metabolic conditions in childhood, and incidence is rapidly increasing especially among the youngest children. Insulin treatment is life-saving and lifelong. Self-discipline and adherence to a balanced diet are necessary if the disease is to be well managed. In many countries, especially in less privileged families, access to self-care tools and also to insulin is limited and this may lead to severe handicap and early death in children with diabetes.
Many children and adolescents find it difficult to cope emotionally with their condition. Diabetes causes them embarrassment, results in discrimination and limits social relationships. It may impact on school performance and family functioning. The financial burden may be aggravated by the costs of treatment and monitoring equipment.
Two international collaborative projects, the Diabetes Mondiale study (DiaMond) 1 and the Europe and Diabetes study (EURODIAB) 2 have been instrumental in monitoring trends in incidence through the establishment of population-based regional or national registries using standardized definitions, data collection forms and methods for validation.
The incidence of childhood onset type 1 diabetes is increasing in many countries in the world, at least in the under 15-year age group. There are strong indications of geographic differences in trends but the overall annual increase is estimated to be around 3%. There is evidence that incidence is increasing more steeply in some of the low prevalence countries such as those in central and eastern Europe. Moreover, several European studies have suggested that, in relative terms, increases are greatest in young children. There are clear indications that similar trends exist in many other parts of the world, but in sub-Saharan Africa incidence data are sparse or non–existent. Special efforts must be made to collect data, especially in those countries where diagnosis may be missed or neglected and, as a result, children die because they do not receive insulin.
It is estimated that annually some 76,000 children aged under 15 years develop type 1 diabetes worldwide. Of the estimated 480,000 children with type 1 diabetes, 24% come from the South-East Asian Region, but the European Region, where the most reliable and up-to-date estimates of incidence are available, comes a close second (23%) (see Figure 2.4).
The continued mapping of global trends in incidence and prevalence of type 1 diabetes in all age groups, through use of data from existing and new registries, is thus important, and in conjunction with other scientific research may provide a logical basis for intervention studies and future primary prevention strategies which must be the ultimate goal.
Type 2 diabetes in children and adolescents is on the increase in all countries, whether poor or rich. As with type 1 diabetes, many children with type 2 diabetes risk developing complications at an early age, which would place a significant burden on the family and society. There is growing recognition that type 2 diabetes in the young is becoming a global public health issue with a potentially serious health outcome 3 , in spite of the paucity of information in this area. A review of studies on type 2 diabetes in the young is available in the Diabetes Atlas, third edition 4 .
Map 2.4 New cases of type 1 diabetes in children, 0-14 years (cases per 100,000 aged 0-14 years per year), 2010
1: D.I.A.M.O.N.D. Project Group. Incidence and trends of childhood Type 1 diabetes worldwide 1990-1999. Diabet Med 2006; 23 (8): 857-866.
2: Patterson CC, Dahlquist GG, Gyürüs E, et al. Incidence trends for childhood type 1 diabetes in Europe during 1989-2003 and predicted new cases 2005-20: a multicentre prospective registration study. Lancet 2009; 373 (9680): 2027-2033.
3: Fagot-Campagna A, Narayan KM, Imperatore G. Type 2 diabetes in children. BMJ 2001; 322 (7283): 377-378.
4: International Diabetes Federation. The Diabetes Atlas. Third Edition. Brussels: International Diabetes Federation; 2006.
Diabetes and depression are chronic debilitating conditions that are associated with high rates of complications and death, and increased healthcare costs. People with diabetes who have depression often find it more difficult to follow diabetes treatment recommendations, and have poor metabolic control, higher complication rates, increased healthcare use and costs, increased disability and lost productivity, lower quality of life as well as increased risk of death. Coordinated strategies for clinical care are necessary to improve the health of people with diabetes and depression, and to reduce the burden of illness.
Worldwide estimates of depression prevalence among people with diabetes appear to vary by diabetes type and among rich and poor nations. Studies have shown that people with diabetes are more likely to have depression than individuals who do not have diabetes. However the mechanisms linking these conditions are not entirely clear. A review of studies found that depression was associated with a 60% increase of type 2 diabetes while type 2 diabetes was only associated with a moderate (15%) increase in risk of depression 1 .
People with diabetes need to successfully manage their disease to avoid complications. Studies have shown a significant relationship between depression and poor adherence to self-management guidelines, which is confirmed by the higher rate of diabetes complications among those who have depression.
People with diabetes and depression are at greater risk of disability, reduced work productivity and lower quality of life. They are also at greater risk of death, as shown in a study that found the coexistence of diabetes and depression is associated with significantly higher risk of death, beyond that due to having either diabetes or depression alone 2 (See Figure 2.5).
Source: Egede et al, 2005 2
As would be expected healthcare costs are higher for people with diabetes and coexisting depression. In the USA, people with diabetes and depression had higher diabetes-related medical costs (USD3,264) than those with diabetes alone (USD1,297) 3 . However, evidence suggests that treatment of depression in people with diabetes is both efficacious and cost effective and can result in improved overall diabetes outcomes.
Many people with diabetes and depression are treated in primary care settings, but studies indicate that consistent recognition and treatment of depression is less than optimal in primary care settings 4 . One barrier to early recognition and treatment of depression is the difficulty in separating the symptoms of depression from the symptoms of poor control of diabetes.
The challenges of treating people with diabetes and depression are influenced by both the individual and the healthcare system. Factors such as stigma and poor provider knowledge have limited the chances of people with diabetes and depression receiving optimal quality care.
Effective management of people with diabetes and depression requires a multidisciplinary approach. In many clinical settings, care for the person with diabetes is fragmented and requires referral to practitioners in the different disciplines, who in many cases are located at a distance from each other. Coordinated clinical care requires the implementation of effective strategies to increase the recognition of depression, the adoption of evidence-based interventions, and the integration of quality measures for the management of depression into diabetes clinical guidelines.
The background paper, Diabetes and Depression, on which this summary is based is available in the Downloads section.
1: Mezuk B, Eaton WW, Albrecht S, et al. Depression and type 2 diabetes over the lifespan: a meta-analysis. Diabetes Care 2008; 31 (12): 2383-2390.
2: Egede LE, Nietert PJ, Zheng D. Depression and all-cause and coronary heart disease mortality among adults with and without diabetes. Diabetes Care 2005; 28 (6): 1339-1345.
3: Le TK, Able SL, Lage MJ. Resource use among patients with diabetes, diabetic neuropathy, or diabetes with depression. Cost Eff Resour Alloc 2006; 4: 18.
4: Egede LE. Failure to recognize depression in primary care: issues and challenges. J Gen Intern Med 2007; 22 (5): 701-703.
Diabetes is one of the major causes of premature illness and death in most countries. Cardiovascular disease, resulting from damage to large blood vessels, causes the death of 50% or more of people with diabetes depending on the population. Damage to small blood vessels (microvascular disease) can affect many parts of the body (see What is Diabetes?). Due to different methods of assessing the presence of these complications it is difficult to make comparisons between different populations. However, it is clear that they are very common, with at least one complication present in a large proportion of people (50% or more in some studies) at the time of diagnosis. Figure 2.6 shows the range of percentages of people with diabetes who have complications, based on the studies that were summarized in the Diabetes Atlas, third edition 1 .
Diabetes complications are frequently the cause of death in people with diabetes. Estimating the mortality burden has been challenging because more than a third of countries of the world do not have any data on diabetes-related mortality and also because existing routine health statistics have been shown to underestimate mortality from diabetes 2 . To provide a more realistic estimate of mortality, a modelling approach has been used to estimate the number of deaths attributable to diabetes in the year 2010.
Close to four million deaths in the 20-79 age group may be attributable to diabetes in 2010, accounting for 6.8% of global all-cause mortality in this age group. This estimated number of premature deaths is similar in magnitude to deaths in this age group from several infectious diseases. The highest number of deaths due to diabetes is expected to occur in countries with large populations as they have the largest numbers of people with diabetes—India, China, United States of America and the Russian Federation. More women than men are expected to die from diabetes-related deaths, and diabetes makes for a higher proportion of deaths in women than in men, reaching up to a quarter of all deaths in middle-aged women in some regions (see Regional Overview). In most age groups women with diabetes, compared to those without, have a higher relative risk of death than men with diabetes. It is this that accounts for diabetes making a proportionately greater contribution to female mortality.
The number of deaths attributable to diabetes in 2010 shows a 5.5% increase over the estimates for the year 2007 1 . This increase is largely due to a 29% increase in the number of deaths due to diabetes in the NAC Region, a 12% increase in the SEA Region and an 11% increase in the WP Region. These increases can be explained by a rise in diabetes prevalence in some highly populated countries in each region, particularly in women.
While there has been a documented decline in the morbidity and mortality of a few chronic non-communicable diseases in some countries 3 , no such decline has been reported for diabetes. Although some high-income countries have documented an improved survival of persons with diabetes, the increased prevalence is most likely due to a rise in incidence rather than improved survival 4 .
Accurate estimates of mortality attributable to diabetes are difficult to obtain with currently available data, and any attempt will be based on a set of assumptions. The mortality estimates in this report should be interpreted with caution. However, they are probably more realistic than estimates derived from routine sources of health statistics which systematically underestimate the burden of mortality due to diabetes, largely because diabetes is often omitted on death certificates as contributing to death. A substantial proportion of these premature deaths are potentially preventable through public health action directed at primary prevention of diabetes in the population and improvement of care for all people with diabetes 5 .
The background paper, Mortality Attributable to Diabetes, and country by country estimates on which this summary is based are available in the Downloads section.
Map 2.5 Number of deaths attributable to diabetes (20-79 years), 2010
1: International Diabetes Federation. The Diabetes Atlas. Third Edition. Brussels: International Diabetes Federation; 2006.
3: Tunstall-Pedoe H, Kuulasmaa K, Mähönen M, et al. Contribution of trends in survival and coronary-event rates to changes in coronary heart disease mortality: 10-year results from 37 WHO MONICA project populations. Monitoring trends and determinants in cardiovascular disease. Lancet 1999; 353 (9164): 1547-1557.
4: Colagiuri S, Borch-Johnsen K, Glümer C, et al. There really is an epidemic of type 2 diabetes. Diabetologia 2005; 48 (8): 1459-1463.
5: World Health Organization. Preventing chronic diseases: a vital investment. Geneva: World Health Organization; 2005. http://www.who.int/chp/chronic_disease_report/contents/en/index.html
Diabetes imposes a large economic burden on the individual, national healthcare system and economy. Healthcare expenditures on diabetes are expected to account for 11.6% of the total healthcare expenditure in the world in 2010. About 80% of the countries covered in this report are predicted to spend between 5% and 13% of their total healthcare dollars on diabetes.
Estimated global healthcare expenditures to treat and prevent diabetes and its complications are expected to total at least US Dollar (USD) 376 billion in 2010. By 2030, this number is projected to exceed some USD490 billion. Expressed in International Dollars (ID), which correct for differences in purchasing power, estimated global expenditures on diabetes will be at least ID418 billion in 2010, and at least ID561 billion in 2030. An estimated average of USD703 (ID878) per person will be spent on diabetes in 2010 globally.
Expenditures spent on diabetes care are not evenly distributed across age and gender groups. The estimates show that more than three-quarters of the global expenditure in 2010 will be used for persons who are between 50 and 80 years of age. Also, more money is expected to be spent on diabetes care for women than for men.
There is a large disparity in healthcare spending on diabetes between regions and countries. More than 80% of the estimated global expenditures on diabetes are made in the world’s economically richest countries, not in the low- and middle-income countries where over 70% of people with diabetes live.
One country, the United States of America, is projected to spend USD198 billion or 52.7% of global expenditure in 2010, while India, the country with the largest population of people living with diabetes, is expected to spend an estimated USD2.8 billion, or less than 1% of the global total. An estimated average of USD7,383 per person with diabetes is expected to be spent on diabetes-related care in the USA but less than USD10 per person will be spent in Burundi, Côte d’Ivoire and Myanmar in 2010.
The financial burden borne by people with diabetes and their families as a result of their disease depends on their economic status and the social insurance policies of their countries. Those living in low-income countries pay a larger share of the expenditure because of poorer organized systems of medical care insurance and/or lack of public medical services. In Latin America, for instance, families pay 40-60% of medical care expenditures from their own pockets. In the poorest countries, people with diabetes and their families bear almost the whole cost of the medical care they can afford.
Besides excess healthcare expenditure, diabetes also imposes large economic burdens in the form of lost productivity and foregone economic growth. The American Diabetes Association estimated that the US economy lost USD58 billion, equivalent to about half of the direct healthcare expenditure on diabetes in 2007, as a result of lost earnings due to lost work days, restricted activity days, lower productivity at work, mortality and permanent disability caused by diabetes. Such losses are perhaps relatively larger in poorer countries because premature death due to diabetes occurs at much younger ages. The World Health Organization (WHO) predicted net losses in national income from diabetes and cardiovascular disease of ID557.7 billion in China, ID303.2 billion in the Russian Federation, ID236.6 billion in India, ID49.2 billion in Brazil and ID2.5 billion in Tanzania (2005 ID), between 2005 and 2015.
The largest economic burden, therefore, is the monetary value associated with disability and loss of life as a result of the disease itself and its related complications. This economic burden, however, can be reduced by implementing many inexpensive, easy-to-use interventions, most of which are cost-effetive or cost-saving, even in the poorest countries. Nonetheless, these interventions are not widely used in low- and middle-income countries.
A relatively simple formula to derive the country estimates in this report was used. The accuracy of these estimates is subject to how well assumptions used in the formula fit the situation of each individual country. The estimated per capita expenditure on diabetes was compared with independent estimates obtained from industrialized countries where direct studies of diabetes costs have been conducted, and found to be reasonably accurate. In general, these estimates are less accurate for LMCs because of poor quality data, underlining the need for well-designed health economic studies to understand the true impact of diabetes.
The background paper, Economic Impact of Diabetes, and country by country estimates on which this summary is based are available in the Downloads section.
Map 2.6 Mean health expenditure per person with diabetes (USD), R = 2, 2010