Definition of diabetes

Diabetes mellitus, commonly known as diabetes (IDF 2019), is a group of metabolic disorders characterised by hyperglycaemia (raised blood sugar) (WHO 2019 (pdf)) as a result of insufficient insulin production or utilisation. Insulin is a hormone synthetized in the pancreas that maintains the correct levels of glucose in blood facilitating its use by the tissues (IDF 2019).

Diabetes may remain asymptomatic for many years, making it difficult to diagnose (WHO 2016 (pdf)). Undiagnosed, and therefore unmanaged diabetes may lead to serious health consequences affecting greatly the heart and arteries and the kidneys (WHO 2016 (pdf)). Diabetes-related complications include eye disease (retinopathy), kidney disease (nephropathy), diabetic foot, oral health issues (e.g. inflammation of the gums, dental decay) and pregnancy-related complications (IDF 2019).

Diabetes is also associated with increased risk of other conditions such as erectile dysfunction and cataracts, as well as non-alcoholic fatty liver disease, obesity, cardiovascular diseases, and some infectious diseases (e.g. tuberculosis) (WHO 2019 (pdf)).

There are three main types of diabetes:

Type 1 diabetes mellitus (T1DM), sometimes called insulin-dependent diabetes, is an autoimmune disease ( WHO 2004 (pdf) ) that occurs with early onset most frequently in children and adolescents ( IDF 2019 ). It is characterised by an absolute insulin deficiency as a result of the destruction of the β-cells (mostly immune-mediated) in the pancreas responsible for the production of insulin ( WHO 2019 (pdf) ). The precise cause of type 1 diabetes remains unknown ( IDF 2019 ).

Type 2 diabetes mellitus (T2DM) is the most common diabetes type in adults, accounting for 90% of all cases ( IDF 2019 ). It is characterised by ‘various degrees of β-cell dysfunction and insulin resistance’ (WHO 2019 (pdf)) and it is commonly associated with overweight and obesity (WHO 2019 (pdf)). Contrary to type 1 diabetes, type 2 diabetes onset is of chronic nature and largely preventable ( IDF 2019 ), (WHO 2016 (pdf)), therefore the main focus of this chapter is on type 2 diabetes.

Gestational diabetes mellitus is defined as hyperglycaemia below diagnostic thresholds for diabetes in pregnancy’2. Women with gestational diabetes mellitus are at an increased risk of complications during pregnancy and at delivery. They and their children are also at increased risk of type 2 diabetes in the future ( IDF 2019 ).

Prevalence of diabetes in the EU

According to European Core Health Indicators data, the proportion of people in the EU in 2014 that self-reported having diabetes in the last 12 months averaged 6.9%, ranging from 4.4 to 10% (table 1).

Estimates for 2019 for the International Diabetes Federation (IDF) European region* indicate that there are 59.3 million adults aged 20-79 years with diabetes (around 35 million adults in the EU in 2019) and around 24.2 million people with undiagnosed diabetes, suggesting that the actual number of people with recognised diabetes is underestimated ( IDF 2019 ).

Another 36.6 million people in the Europe IDF region are estimated to have impaired glucose tolerance and thus a risk of developing type 2 diabetes later in life ( IDF 2019 ).

The age-adjusted prevalence of hyperglycaemia in pregnancy was 6.3% in 2019, potentially affecting 2 million live births in the IDF European region ( IDF 2019 ). These estimates suggest a larger burden of diabetes than might be anticipated based on diabetes prevalence data. Additionally, the prevalence of diabetes is increasing among all ages globally ( IDF 2019 ), (WHO 2016 (pdf), (OECD/EU 2018 (pdf)) .

Table 1: Prevalence (%) of self-reported diabetes in the EU in 2014 

Risk factors related to diabetes

There are several factors associated with the development of type 2 diabetes, some confirmed risk factors and others not, some modifiable and others not (such as sex, age, ethnicity or family history)(WHO 2016 (pdf)).

Lifestyle-related factors such as smoking, physical inactivity, unhealthy diet are examples of modifiable risk factors of type 2 diabetes as underlying causes of excess weight (obesity), the most important metabolic risk factor for diabetes ( IDF 2019 ), (WHO 2019 (pdf)), (WHO 2016 (pdf)).

A number of national and international health organizations have examined the role of these risk factors in the development of type 2 diabetes. Their verbatim statements and opinions are listed in table 2.

Table 2: Risk factors related to type 2 diabetes as described by health-related organisations 

More information from international and national institutions about the associations between dietary factors, some not mentioned in this chapter due to insufficient evidence for an association with diabetes, and health can be found in the chapters dedicated to each factor.

Disease and economic burden related to diabetes

The Global Burden of Disease 2019 study estimates that more than 109 000 deaths and 5.3 million Disability Adjusted Life Years (DALYs) in the EU were attributable to type 2 diabetes. In the EU, dietary risks (including diet low in fruits, whole grains, nuts and seeds, diet high in sugar-sweetened beverages, red meat and processed meat) were responsible for 36% of the deaths and 37% of the DALYs attributable to type 2 diabetes.

Moreover, 41% of deaths and 57% of DALYs caused by diabetes were attributable to high body mass index (BMI higher than 21.0-23.0 kg/m²), 8.1% of deaths and 12.3% of DALYs to smoking, and 13% of deaths and 10% of DALYs to low physical activity (Global Burden of Disease Study results tool Health Data )

View visualisation: Disability Adjusted Life Years attributed to type 2 diabetes map 

View visualisation: Mortality attributed to type 2 diabetes map 

The cost of diabetes in the EU in 2014 was estimated at EUR 300 billion annually (including both direct, such as costs of medicines, treatment, time of medical professionals, and indirect costs, such as lost productivity resulting from absenteeism and premature retirement, the costs of rehabilitation and retraining), exceeding 10% of health care budgets in some EU countries (HEA 2014 (pdf)).

It is projected that due to aging population by 2045 the health expenditure on diabetes will grow, especially for people above 70 years, even with the assumption that the mean expenditure per person and diabetes prevalence remains constant (IDF 2019).

Medical costs per patient with diabetes are around 18% higher than for the general population and the majority of medical expenses are due to diabetes complications and comorbidities (OECD 2015).

Moreover, it is estimated that in the OECD countries** nearly 60% of all new diabetes cases in the next 30 years and 70% of all health expenditure on diabetes will be due to overweight (OECD 2019). This indicates that both diabetes and overweight prevention and management are key to reducing the financial burden of diabetes.

Policies related to the prevention of diabetes

In the EU, policies or campaigns aiming for the primary prevention of diabetes are adopted at national or regional levels and are often part of a plan for the overall prevention of non-communicable diseases that share similar risk factors (Richardson et al. 2016), (ECD 2014 (pdf)), (WHO 2017). Such prevention programmes usually cover five key risk factors: promotion of healthy eating and physical activity, reduction of overweight and obesity, smoking, and harmful use of alcohol (ECD 2014 (pdf)).

Furthermore, some programmes are formulated to also address early detection of diabetes among groups at risk. Others include environmental approaches focusing on healthy public policy facilitating access to healthy food, healthy urbanisation and healthy businesses (IDF 2010).

Summaries of policy recommendations addressing modifiable risk factors of diabetes are listed in this Health Promotion and Disease Prevention Knowledge Gateway.

There are also several examples of best practices in diabetes prevention and associated health promotion interventions in the Public Health Best Practice portal of the European Commission.

*Includes 57 countries and territories, comprising of diverse populations, from Norway in the north, the Russian Federation in the east, Turkmenistan in the south and Greenland in the west

**Includes OECD, European Union (EU28) and Group of 20 (G20) countries.