Diabetes

1. Key messages

In 2018, 6.3% of the Belgian population had a known diabetes diagnosis. However, more than one in three people with diabetes do not know they have the disease, which brings the estimated true prevalence of diabetes to 10%.
Diabetes prevalence is increasing over time as a result of both the ageing of the population and a true increase in the risk of developing diabetes.
The diabetes prevalence is higher in Wallonia and Brussels than in Flanders, and is higher for individuals with a lower socio-economic status. Socioeconomic differences in the prevalence of diabetes are especially found for the prevalence of unknown or insufficiently controlled diabetes.

2. Background

Diabetes is a condition that is characterized by recurrent high blood sugar levels. If left untreated, diabetes may cause long-term complications such as foot ulcers, damage to the eyes, chronic kidney disease, and cardiovascular disease. A diabetic diet and exercise are important parts of diabetes management, but in a large number of cases, drug therapy will also be required.

A distinction is made between three main types of diabetes:

  • Type 1 diabetes, resulting from an autoimmune destruction of the insulin-producing beta cells in the pancreas;
  • Type 2 diabetes, due to the body's inefficient use of insulin, mainly caused by a combination of excessive body weight and insufficient exercise; and
  • Gestational diabetes, occurring in pregnant women without a previous history of diabetes.

In the absence of an exhaustive diabetes register, several sources of information can be used in Belgium:

  • The InterMutualistic Agency (IMA-AIM), a platform where data gathered from the seven Belgian health insurance funds are collected and analyzed. IMA-AIM data are, amongst others, made available through the IMA-AIM Atlas [1].
  • Surveys in the general population, namely the Health Interview Surveys (HIS) [3] and mainly the Belgian Health Examination Survey (BELHES) [2], which occurred for the first time in 2018; the BELHES aimed to collect objective indicators on the health of the population in a representative sample of people aged 18+.

In the IMA-AIM database, information is found on the use of antidiabetic treatment or on diabetes referring nomenclature. This is considered a good proxy of the prevalence of diagnosed diabetes. Socio-economic characteristics are scarce in the IMA-AIM Atlas. The status of “insured people having right to an increased compensation” is the only available proxy indicator, and it has only two values, yes or no. Persons with a low income or specific medical characteristics such as invalidity are entitled to an increased compensation status.

Since diabetes is a disease with insidious onset, many cases remain undiagnosed. Information on undiagnosed diabetes prevalence is available in the BELHES. The BELHES used self-reported data on diabetes medication use from the Health Interview Survey and objective measurements on blood samples (blood glucose and glycated haemoglobin) to estimate the total diabetes prevalence.

In this report, we will mainly describe :

For information concerning mortality, please consult the following pages: Overall mortality by cause and Premature mortality by cause.

3. Diabetes prevalence

Belgium

In 2018, 6.3% of the Belgian population was diagnosed with diabetes according to the IMA-AIM Atlas. The prevalence of diabetes increases with age, and is higher among men, especially in the older age groups.

According to the BELHES, the estimated total diabetes prevalence reaches 10%, which includes the more than one in three people with diabetes (37%) that is unaware of it.

In the BELHES, 7.7% of people used diabetes medication, however among those 19% have a diabetes which is not well controlled. In other words, 5% of the population is suffering from diabetes either without being aware of it, or without proper diabetes control.

Prevalence of diagnosed diabetes by age and sex, Belgium, 2018
Source: IMA-AIM Atlas [1]

Trends and regional differences

The prevalence of diagnosed diabetes is highest in Wallonia and lowest in Flanders, despite the relatively higher age of the Flemish population. The relatively low diagnosed diabetes prevalence in Brussels is the result of the young age structure: when corrected for age, the diagnosed diabetes prevalence in Brussels becomes higher than the Belgian average. The BELHES has also shown that in Wallonia more people are unaware that they have the disease than in Brussels and Flanders.

From 2007 to 2018, the prevalence of diagnosed diabetes has increased in all three regions, as a result of both the ageing of the populations and a true increase in the risk of developing diabetes that could be related to an increase of overweight/obesity.

  • Crude
  • Age-standardized

Crude prevalence of diagnosed diabetes in Belgium and its regions, 2007-2018
Source: IMA-AIM Atlas [1]

Age-standardized prevalence of diagnosed diabetes in Belgium and its regions, 2007-2018
Source: Own calculations based on IMA-AIM Atlas [1]

Socio-economic differences

The prevalence of diagnosed diabetes (IMA) is nearly twice as high among individuals with an increased compensation status than among individuals with a normal compensation status. The prevalence of diagnosed diabetes has been increasing evenly in both groups over time.

The BELHES has shown that people with a lower education are significantly more likely to suffer from ignored or poorly controlled diabetes compared to people with a higher education (RR=3.6, adjusted for age and gender). This could indicate that there are socioeconomics inequalities in the screening and follow up of diabetes.

Age-standardized prevalence of diagnosed diabetes by compensation status, Belgium, 2007-2018
Source: Own calculations based on IMA-AIM Atlas [1]

4. Read more

View the metadata for this indicator

Definitions

Age-standardized prevalence
The age-standardized prevalence is a weighted average of the individual age-specific prevalences using an external standard population. It is the prevalence that would be observed if the population had the age structure of the standard population. Since age has an important influence on the risk of diabetes, this standardization is necessary when comparing several populations that differ with respect to their age structure. Here, the Belgian 2018 mid-year population is used as standard population.
Increased compensation status
Persons with a low income are entitled to an increased compensation status. They pay less for healthcare and have other financial benefits. Currently, this is the only variable available in the IMA-AIM Atlas that allows assessing socio-economic differences.
Diagnosed diabetes prevalence
The diagnosed diabetes prevalence is estimated based on the number of insured people with delivery of antidiabetics (ATC code A10) or with another diabetes referring nomenclature (diabetes convention, diabetes pass, diabetes care trajectory). Women who gave birth during the year under review are excluded in order to exclude gestational diabetes.
Estimated total diabetes prevalence
The estimated total diabetes prevalence is defined as a fasting blood glucose ≥ 126 mg/dl or glycosylated haemoglobin (HbA1C) ≥ 6.5% or the use of anti-diabetic drugs (self-reported).

References

  1. Intermutualistic Agency Atlas. http://atlas.aim-ima.be/base-de-donnees
  2. Belgian Health Examination Survey (BELHES), Sciensano, 2018. https://his.wiv-isp.be
  3. Belgian Health Interview Survey (BHIS), Sciensano, 1997-2018. https://his.wiv-isp.be