Frequently asked questions

1. What is HELIUS?

HELIUS (Healthy Life in an Urban Setting) is a unique study on the health of various population groups in Amsterdam. It is a joint initiative of the Academic Medical Center and the Public Health Service of Amsterdam (GGD Amsterdam). The aim of HELIUS is to provide Amsterdam residents with equal opportunities for good health and good health care in future.

HELIUS is studying a number of common diseases like cardiovascular disease (including diabetes). HELIUS is the first large-scale study on ethnic diversity in health and health care in the Netherlands. HELIUS is studying people of Surinamese, Ghanaian, Turkish, Moroccan, and Dutch origin.

2. What is the HELIUS study expected to achieve?

HELIUS is expected to provide the answers to a number of questions, among them:

  • Why are Surinamese people more likely to develop high blood pressure and diabetes? And why do they often die of cardiovascular disease at a relatively young age?
  • Why is overweight and high blood pressure so common among Ghanaian Amsterdam residents?
  • Why do we see asthma more often among Amsterdam residents of Turkish and Moroccan origin?
  • Why are Amsterdam residents of Moroccan origin less likely to suffer from cardiovascular disease than those of Dutch origin?
  • Why are certain medications for lowering blood pressure less effective in some population groups than they are for ethnic Dutch people?
3. What is the study’s main research question?

The main research question of HELIUS is: What are the reasons for the fact that there are such large differences in health and the risk of developing chronic diseases between various ethnic groups?

4. Which groups is HELIUS studying?

HELIUS is studying the following groups: Amsterdam residents of Surinamese, Ghanaian, Turkish, Moroccan, and Dutch origin.

5. Why are only these groups being included in HELIUS and not others?

Because it is not possible to study all of the population groups in Amsterdam, we decided to include four of the largest population groups along with residents of Dutch origin.

An exception to this are the Ghanaians. Although Ghanaians form a smaller group, we included them in this study because this population group is growing rapidly, and earlier research has shown that a subsequent study such as HELIUS might be able to provide better explanations for many of the health problems that occur in this group.

6. What is the study’s social relevance?

We know from earlier research that there are large health differences between people of various ethnic origins.

We don’t know what causes these differences. When we know what causes these differences, we can use this knowledge to deal with these health problems more effectively in future. We can better target our prevention efforts, and we might be able to develop new treatment methods with this knowledge.

An example: Diabetes is very common in people of Hindustani origin. This cannot be explained solely by the known risk factors, such as a greater likelihood of overweight in this population group. The question is, what else might be causing this? Is it hereditary? And are there factors that are not yet understood – for example, diet and nutrition – that play a role in this? If we know more about this, we can take specific measures to keep so many people in these groups from developing diabetes.

7. Are participants informed of the results of HELIUS?

It will be some time before the initial results of HELIUS are known. When they become available, we will publish them on our website.

8. What does participation in the study mean for me?

By taking part in HELIUS, you will be helping pave the way to better health and health care in the future for your own ethnic group in Amsterdam. In addition, after the physical examination you will be given a number of your personal results such as blood pressure, cholesterol, and blood sugar levels.

9. What requirements do I have to meet to take part?

To be able to take part in HELIUS, you must have participated in the first (baseline) measurements of HELIUS between 2011-2015.

10. When will I be invited to take part?

This is different for everyone. We started sending invitations from April 2019. We expect the research to take about 2 years.

11. Can I send a family member or friend instead of going myself?

An invitation to take part in HELIUS is for you personally. Because of this it is not possible to send a family member in your place. If a family member or friend participated in HELIUS before, they will receive a personal invitation.

12. Is there a charge for taking part?

Taking part is free of charge. To cover any travel expenses, we will give you a GVB public transport card you can use to make 2 free trips of 1 hour each in Amsterdam.

13. Are there risks associated with participation?

There are no risks associated with participation. Your privacy is also guaranteed. For more information, please see the next question.

14. Is my privacy guaranteed?

Your data will be processed anonymously, and stored using a unique code. This means that the researchers who work with your research data will not know your name or address. We never pass on your data to third parties (such as health insurance companies).

15. How long will it take before I receive my personal results?

You will receive your personal results about 2 to 4 weeks after the physical examination, together with a short explanation. Your results will be sent to your e-mail address.

16. Who else will receive my personal results?

Your personal results will also be sent to your general practitioner (GP). We do this because we think it is important for your GP to have the most up-to-date information on your health situation. If you don’t want your GP to receive this information, then unfortunately you won’t be able to take part in the study.

17. I don’t have a general practitioner. Can I still take part in HELIUS?

No – if you don’t have a general practitioner (GP), then unfortunately you won’t be able to take part in HELIUS. We think it is important for your GP to know about your personal results from the physical examination in case you should need any follow-up care. If you don’t have a GP and would still like to take part, we recommend you register with a GP in your neighbourhood.

18. What should I do if my results show something is wrong?

If the letter with your personal results contains a level that is too high or too low, this doesn’t always mean that something is seriously wrong. If you have a level that is too high or too low, we recommend that you contact your GP. If you would like to know how high or low your own levels are, you can consult the table below. This table contains the levels we use as ‘reference measurements’:



Reference values




Glucose (fasting)


> 7,0 mmol/L



> 42 mmol/mol



< 7,5 mmol/L (women)

< 8,5 mmol/L (men)



< 150 x109/L



> 400 x109/L



> 2,0 mmol/L



> 3,0 mmol/L



< 1,3 mmol/L (women)



< 1,0 mmol/L (men)

Totaal cholesterol


> 5,0 mmol/L 



> 90 umol/L (women)



> 110 umol/L (men)

Alanine aminotransferase (ALAT)


≥ 60 U/L (women)

≥ 75 U/L (men)

Aspartaat aminotransferase (ASAT)


≥ 75 U/L

Gamma glutamyltransferase (Gamma-GT)


≥ 60 U/L




Micro-alb/ creat ratio


> 3,5 mg/mmol (women)



> 2,5 mg/mmol (men)

Blood pressure:



Systolic blood pressure


> 140 mmHg

Diastolic blood pressure


> 90 mmHg




Body mass index (BMI)


<18,5 kg/ m2



> 25 kg/m2 and ≤ 30 kg/m2



> 30 kg/m2

NB: > = higher then, < = less then

19. What happens to the specimens that have been taken?

A portion of your specimens (such as blood and urine) will be examined in the laboratory immediately. This is how we measure things like your cholesterol and blood sugar levels. The results of these measurements will be contained in the letter we will send to both you and your GP later on.

We will store the rest of the specimens in the freezer, so we can use them in future for more measurements. By storing the specimens now, we can repeat these measurements in future without having to ask participants to come back to the research location. We never pass on your data to third parties.

20. Why don’t I receive results from all of the specimens that were taken?

We cannot always take all of the measurements we would like to right away due to a lack of money or personnel. Because we don’t want to inconvenience participants more than we have to and therefore don’t want them to have to come to the research location unnecessarily, we store specimens in the freezer so we can use them again for research in the future.

21. What is done with the results of measurements carried out in future on my stored specimens? Do I also receive these by post?

If they are important to your health, we will we send your GP the results of any measurements carried out on your stored specimens in the future. If necessary, your GP will contact you about this.

22. I want to take part in HELIUS, but I don’t want my specimens to be stored for future research as part of HELIUS. Can I request this?

Yes. When you have your physical examination, we will ask you to sign an informed consent form. On this form you can indicate whether or not you give your permission to store your specimens. If you don’t give permission for storing your specimens, you can still take part in the study.

When you take part in the HELIUS study about the coronavirus, you can unfornately not request this. If you don't want us to store your blood, you can not take part in the HELIUS study.

23. I would like to take part, but haven’t received an invitation. Can I still participate?

You can only take part in the HELIUS study if you received an invitation from us. To obtain valid research results, we use what is known as the sampling method. This means that we obtain the names and addresses of the people we invite to take part in the study by way of a sample we receive from the population registry.

24. If my results are good but I still have complaints, should I go to my GP anyway?

If you are worried about your health or have complaints, we would always advise you to contact your GP.

For more information on health and well-being, you can also visit the website of the Public Health Service of Amsterdam (GGD Amsterdam) at

In addition, for advice and help you can contact Stichting Korrelatie [‘Correlation Foundation’] via internet (, in Dutch) or by phone (0900-1450, 15 eurocents per minute).

If you want to find out if you have a sexually transmitted infection (STI), you can contact the STI Outpatient Clinic at GGD Amsterdam for a free, anonymous, consultation if you belong to one of the following groups:

  • people with an increased risk of STIs (men who have sex with men, people who earn money with sex, people who come from places where STIs are common);
  • people who have been told they have an STI;
  • people with symptoms that point to an STI;
  • people younger than 25.

For more information, go to

25. I live outside Amsterdam. Can I take part in HELIUS too?

If you received an invitation you can participate in HELIUS.

26. How do I find the research location?

For more information about the research locations, please go to Participants/Research locations, and click on the name of the location for the address and directions.

27. When are the research locations open?

The research locations are open Monday through Friday from 7 a.m. until 2 p.m. Appointments for physical examinations start at 7:30 a.m.

28. Why can’t I take part if I don’t want the results to be sent to my GP?

We think it is very important to keep your GP informed about your health. As soon as we find a health risk, we are ethically obliged to pass this on to your GP.