Original DIY OGTT Instruction Guide

Oral Glucose Tolerance Test – Read the instructions completely before starting with the test The Oral Glucose Tolerance Test (OGTT) consits of measuring blood glucose levels and determining insulin concentrations before and after drinking a glucose solution. Blood glucose levels can be measured point-of-care with a device, while insulin concentrations can be determined in the lab from dried blood spots on filter paper.

Note: - For this measurement it is important that you are fasting for at least 8 hours. I.e. you should not have eaten or drunk anything (except for water) in the 8 hour before taking the test. The OGTT is therefore best done in the morning, before breakfast.

- Make sure that you have two hours resting or relaxing time when you are taking the OGTT. - Preferably ask someone to help you (especially if it is the first time that you are taking the test).

- Pick a day at which mail can be send, since the dried blood spots should be send to the lab the same day.

Preparation □ Put everything in place (a day in advance): - the envelope with the OGTT kit (with the correct week number); - a clean table that can be used for performing the finger pricks and collecting the blood spots; - a place to dry the filter paper for blood spot collection, without direct exposure to sunlight or heat. The blood spots should dry to the air, without folding back the protection; - read the instructions thoroughly. □ Lay out all the necessities for the measurement [A]: 1. Glucose solution 2. Glucosemeter 3. Test-strips (5 pieces) 4. Lancet (for fingerprick) (5 pieces) 5. Score form 6. Tissues 7. Plasters 8. Stopwatch (can be a Smartphone) 9. Numbered filter paper cards for blood spot collection (5 pieces)

A 6 5

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Instructions – Do-it-yourself measurements

March 2016

Starting with the measurement s □ Put a test-strip in de glucosemeter [B], such that the white triangle sticks out at the bottom. Touch the test-strip mostly on the sides, and not on the backside.

When you enter the test-strip in the meter, you will hear a few beeps and icons will appear on the display. □ Push the start-button ([C]) on the right-hand side; you will now see a flashing blood drop on the display. [D] □ Put the right filter paper card for the blood spot collection ready. [E] Note: there is a time-point on all filter paper cards (t=0, t=30, t=60, t=90, t=120).

Make sure you use the right filter paper at the right point in time during the measurement!

First measurement – before drinking the glucose solution □ Ensure proper circulation to the hands (warm hands). This can be achieved for example by holding your hands under warm running water, rubbing your hands together and / or swinging around with your arms. □ Take a lancet and carefully twist of the safety cap. Place the white tip of the lancet on the side of the fingertip and press the lancet firmly against your finger until you hear a click. [F] □ Remove the first drop of blood with a tissue. [G] □ Use the next large drop [H] that develops and start filling the circles of the first blood sampling card (for t = 0) moving from left to right across the card. [I] Make sure your finger is pointing vertically downward to help the bleeding. Let the drop of blood (but not the finger) come into contact with the circle, starting in the middle. Do not smear out the blood drops!

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□ Fill one circle completely (this may require 2 - 3 drops of blood) before you fill the next. Repeat this step until you filled all circles on the first card.

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Instructions – Do-it-yourself measurements

March 2016

TIP: If you are having difficulties with getting large enough blood drops, you can try the following suggestions:  swing around with your arms,  warm your hands by rubbing them against each other  Rub your hand carefully from the palm up to the lower joints of the fingers.

Do not press your fingertip!

K

□ After filling the filter paper card, make sure another blood drop is formed on your finger tip, and keep this blood drop at the front end of the test-strip in the glucose meter. [K] The blood is automatically absorbed. □ It can be that the meter shut down in the meantime; make sure you turn it on again as previously described. □ If enough blood is absorbed, the measurement will start automatically. □ Write down the result and the (exact) time of the measurement down on the score form (or in the portal). [L] □ Throw the test strip and lancet away in the trash bin. □ Lay the open filter paper card away for drying.

L

□ Directly continue with starting the second measurement!

Tweede meting – na het drinken van het suikerdrankje □ Put the filter paper cards for 30, 60, 90 and 120 minutes ready, and write your participant number and the date (dd-mm-yyyy) and time (hours : minutes) on all cards. □ Start the stopwatch. [A] □ Thereafter, directly start drinking the glucose solution and finish drinking it within 5 minutes. [B]

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B

Note: do no teat or drink during the remaining two hours of the test! If necessary, a sip of water is allowed.

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Instructions – Do-it-yourself measurements

March 2016

Attention: the next steps should be repeated at 30, 60, 90 and 120 minutes after starting the stopwatch. □ Place a new test-strip in de glucose meter. □ 30 minutes (or 60, 90 or 120 min) after you started drinking the glucose solution (and you started the stopwatch), do another finger prick with a lancet. [C] □ Wipe away the first drop of blood with a tissue. □ Use the next large drop [H] that develops and start filling the circles on the corresponding blood sampling card moving from left to right across the card. [I]

C

□ Fill one circle completely (this may require 2 - 3 drops of blood) before you fill the next. Repeat this step until you filled all circles on the first card.

Make sure your finger is pointing vertically downward to help the bleeding. Let the drop of blood (but not the finger) come into contact with the circle, starting in the middle. Do not smear out the blood drops! □ After filling the filter paper card, make sure another blood drop is formed on your finger tip, and keep this blood drop at the front end of the test-strip in the glucose meter. The blood is automatically absorbed.

If enough blood is absorbed, the measurement will start automatically. [D]

E

□ Write down the result and (exact) time of the measurement on the score form or directly in the portal. [E] □ Let de stopwatch continue. [F] □ Put the card away for drying at room temperature. This takes approximately two to three hours. This can best be done in a cupboard or drawer to protect the card from dirt and light. Put the card on the foil bag.

Attention!: do not put the card on top of a radiator or in direct sunlight.

F

D

□ Repeat these steps at 60, 90 and 120 minutes (collection of blood spots and glucose measurements).

Wrap-up □ after the cards have dried (approx. 2-3 hour after collecting the blood spots), you put every card in a seperate foil bag. Make sure each foil bag contains a small sachet of drying agent. Try to squeeze out as much air as possible and close the bags with the zip lock. □ Put all foil bags in the enveloppe addressed to TNO and post it the same day.

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Instructions – Do-it-yourself measurements

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