The guidelines below will help you adjust your diabetes medicine and diet as you get ready for your test.
If you see a diabetes educator or diabetes specialist, contact them at least 1 week before your test to ask about adjusting your diabetes medicine or insulin.
Diet
- Follow the instructions the GI Clinic gives you about what you can eat or drink before the test.
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If your test is in the morning, don’t eat or drink anything after midnight.
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If your test is in the afternoon, you can only have clear fluids in List 1 or 2 (below) until 4 hours before the test.
- If your blood sugar drops below 4.0 mmol/L or if you have symptoms of low blood sugar, take 15 grams of a carbohydrate-containing fluid from List 1.
Test your blood sugar again in 15 minutes. If your blood sugar is still low, take another 15 grams of carbohydrate-containing fluid from List 1.
| List 1 - Fluids that have sugar (Each has about 15 grams of carbohydrates) | List 2 - Fluids that are
sugar-free (Choose as desired) |
- Black tea, coffee, or water with 1 rounded tablespoon (15 mL) sugar or honey
- ½ cup (125 mL) regular Jell-O®
- ½ cup (125 mL) regular (sugar sweetened) Kool-Aid®
- ¾ cup (175 mL) fruit drink or fruit juice without pulp (e.g., apple, white grape)
- ¾ cup (175 mL) regular pop
- 1 cup (250 mL) sports drinks (e.g., Gatorade®)
| - Water
- Clear bouillon, broth, or consommé
- Diet pop
- Diet Kool-Aid® or Crystal-Lite®
- Black coffee or tea
- Diet popsicle
- Diet Jell-O®
|
Testing Your Blood Sugar
Test your blood sugar anytime you feel your blood sugar is low or high.
- Test your blood sugar at least every 4 hours. Blood sugars in the range of 8 to 12 mmol/L are fine for these 2 days, even if it’s higher than your usual target.
- If you have type 1 diabetes and your sugars are over
14 mmol/L, test your urine or blood for ketones.
- If positive for ketones, you may need extra insulin. Moderate to large ketones may mean that you’re in DKA (diabetic ketoacidosis) and need to go to the Emergency Department right away.
- If you’re worried about your blood sugar level, speak with your healthcare provider or diabetes educator.
Adjusting Your Diabetes Medicine
If You Take Insulin
The Day Before Your Test
Supper
-
Premix Insulin: Reduce your dose of premix insulin (Humulin 30/70®, Novolin 30/70®, or
Humalog 25/75®) by 25% (or the amount your healthcare provider tells you). Your dose will be
units.
-
All other insulin: All doses stay the same.
Evening/Bedtime
-
Basal Insulin: Reduce your dose of basal insulin (Humulin N®, Novolin® NPH, Lantus®, Toujeo®, or Levemir®) by 25% (or the amount your healthcare provider tells you). Your dose will be
units.
-
Insulin Pump: You may need to reduce your basal rate by 10% to 20% overnight if there are concerns about low blood sugar. If there are no concerns, keep the same basal rate.
Test Day
Morning
-
Bolus (meal) Insulin: Don’t take your morning bolus (meal) insulin (Apidra®, Humalog®, NovoRapid®, Humulin R®, or Novolin® Toronto).
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Premix Insulin: Don’t take your morning premix insulin (Humulin 30/70®, Novolin 30/70®, or Humalog 25/75®).
-
Basal Insulin: Reduce your dose of basal insulin (Humulin N®, Novolin NPH®, Lantus®, Toujeo®, or Levemir®) by 25% (or the amount your healthcare provider tells you). Your dose will be
units.
-
Insulin Pump: You may need to reduce your basal rate by 10% to 20% if there are concerns about low blood sugar. If there are no concerns, keep the same basal rate.
*Be sure to bring a source of fast-acting sugar and your blood glucose meter with you.
After the test
-
Premix Insulin: Reduce your morning dose of premix insulin (Humulin 30/70®, Novolin 30/70®, or
Humalog 25/75®) by 25% (or the amount your healthcare provider tells you) for your first meal after the test. Your dose will be
units.
-
All other insulin: Take as prescribed.
If You Take Diabetes Medicine Other Than Insulin
The Day Before Your Test
- Take your medicine as normal or as your healthcare provider tells you.
Test Day
- Don’t take any diabetes medicine until after your test is done and you’re eating. Then take it as per your scheduled dose.
*Be sure to bring a source of fast-acting sugar and your blood glucose meter with you.
For 24/7 nurse advice and general health information call Health Link at 811.
