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Diabetes: Adjusting your diabetes medicine and diet for a gastroscopy or esophagogastroduodenoscopy (EGD)

Diabetes

Adjusting your diabetes medicine and diet for a gastroscopy or esophagogastroduodenoscopy (EGD)

The guidelines below will help you adjust your diet and diabetes medicine 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 gastroenterology (GI) clinic gives you about what you can eat or drink before the test.
  • If your test is in the morning, don’t eat or drink anything after midnight.
  • If your test is in the afternoon, you can only have clear fluids in List 1 or List 2 (below) until 4 hours before the test.
  • If your glucose (sugar) drops below 4.0 mmol/L or if you have symptoms of low glucose, take 15 grams of a carbohydrate-containing fluid from List 1. Test your glucose again in 15 minutes. If your glucose is still low, take another 15 grams of carbohydrate-containing fluid from List 1.
  • If you're worried your glucose will run too low, take extra 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 (like apple or white grape)
  • ¾ cup (175 mL) regular pop
  • 1 cup (250 mL) sports drinks (like Gatorade)
  • water
  • clear bouillon, broth, or consommé
  • diet pop
  • diet Kool-Aid or Crystal-Lite
  • black coffee or tea
  • diet popsicle
  • diet Jell-O

Monitoring your glucose values at home

Monitor your glucose levels anytime you feel your glucose level is low or high.

  • Test your glucose at least every 4 hours. Glucose values in the range of 8.0 to 12.0 mmol/L are fine for these 2 days before the test, even if it’s higher than your usual target.
  • If you have type 1 diabetes or you are on an SGLT2 inhibitor, like canagliflozin (Invokana), dapagliflozin (Forxiga), or empagliflozin (Jardiance) and your glucose is over 14.0 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). Go to the emergency department right away.
  • If you’re worried about your glucose levels, speak with your healthcare provider or diabetes educator.

Adjusting your diabetes medicine

If you take insulin

The day before your test

  • All doses stay the same at breakfast, lunch and supper.

Evening/bedtime

  • Basal insulin: Reduce your dose of basal insulin (Basaglar, Humulin N, Lantus, Levemir, Novolin NPH, Semglee, Toujeo, or Tresiba) by 20% or the amount your healthcare provider tells you. You may need to reduce Tresiba for 2-3 days before the test. Talk with your healthcare provider. Write out your dose so that it is easier to remember: 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 glucsoe. If there are no concerns, keep the same basal rate.

The day of your test

Morning

  • Bolus (meal) insulin: Do not take your morning bolus (meal) insulin (Admelog, Apidra, Fiasp, Humalog, Humulin R, Kirsty, Novolin Toronto, Novorapid, Trurapi).
  • Premix insulin: Do not take your morning premix insulin (Humulin 30/70, Novolin 30/70, or Humalog 25/75).
  • Basal insulin: Reduce your dose of basal insulin (Basaglar, Humulin N, Lantus, Levemir, Novolin NPH, Semglee, Toujeo, or Tresiba) by 20% or the amount your healthcare provider tells you. You may need to reduce Tresiba for 2-3 days before the test. Talk with your healthcare provider. Write out your dose so that it is easier to remember: 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 glucose. If there are no concerns, keep the same basal rate.

*Be sure to bring a source of fast-acting sugar and your glucose monitor to the test 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 20% (or the amount your healthcare provider tells you) for your first meal after the test. Write out your dose so that it is easier to remember: 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.

The day of your test

  • 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 glucose monitor to the test with you.

To see this information online and learn more, visit MyHealth.Alberta.ca/health/pages/conditions.aspx?Hwid=custom.ab_diabetes_gastroscopy_inst.

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For 24/7 nurse advice and general health information call Health Link at 811.

Current as of: July 19, 2023

Author: Endocrinology and Metabolism Program, Alberta Health Services

This material is not a substitute for the advice of a qualified health professional. This material is intended for general information only and is provided on an "as is", "where is" basis. Although reasonable efforts were made to confirm the accuracy of the information, Alberta Health Services does not make any representation or warranty, express, implied or statutory, as to the accuracy, reliability, completeness, applicability or fitness for a particular purpose of such information. Alberta Health Services expressly disclaims all liability for the use of these materials, and for any claims, actions, demands or suits arising from such use.