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Diabetes: Adjusting your medicine and diet for a hydrogen breath test for small intestine bacterial overgrowth

Diabetes

Adjusting your diabetes medicine and diet for a hydrogen breath test for small intestine bacterial overgrowth

This test is used to find out if you have too much bacteria (overgrowth) in your small intestine. You’ll have to drink liquid that has 75g of glucose for the test. The guidelines below will help you adjust your diabetes medicine as you get ready for your test.

Follow the instructions your gastroenterology (GI) clinic gives you about when and what to eat and drink before the 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.

Monitoring your glucose (sugar) values at home

Test 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 this test, even if it’s higher than your usual target.
  • If you have type 1 diabetes or you are on an SGLT2 inhibitor canagliflozin (Invokana), dapagliflozin (Forxiga), or empagliflozin (Jardiance) and your glucose values are over 14.0 mmol/L, test your urine or blood for ketones.
    • If you have Type 1 diabetes and are 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 for breakfast, lunch, and supper.

Evening/bedtime

  • Basal insulin: Reduce your dose of basal insulin (Basaglar, Humulin N, Lantus, Levemir, Novulin NPH, Semglee, Toujeo, or Tresiba) by 20% or the amount your healthcare provider tells you. You may need to reduce Tresiba for 2 to 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 glucose. 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, Kristy, Novolin Toronto, NovoRapid, or Trurapi).
  • Premix insulin: Do not take your morning pre-mix insulin (Humulin 30/70, Novolin 30/70, or Humalog 25/75).
  • Basal insulin: Reduce your dose of basal insulin (Basaglar, Humulin N, Lantus, Levemir, Novulin NPH, Semglee, Toujeo, or Tresiba) by 20% or the amount your healthcare provider tells you. You may need to reduce Tresiba for 2 to 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 .

During the test

*You’ll be given a 75 g glucose/water solution to drink.*

  • Bolus: Reduce your dose of meal (bolus) insulin (Admelog, Apidra, Fiasp, Humalog, Humulin R, Kristy, Novolin Toronto, NovoRapid, or Trurapi) by 20% or the amount your healthcare provider tells you, and take it before you drink the solution. Write out your dose so that it is easier to remember: Your dose will be __________ units.
  • Premix insulin: Reduce your dose of morning premix insulin (Humulin 30/70, Novolin 30/70, or Humalog 25/75) by 20% (or the amount your healthcare provider tells you) and take it before you drink the solution. Write out your dose so that it is easier to remember: Your dose will be __________ units.

After the test

  • Take your diabetes medicine as per your next scheduled dose.

If you take diabetes medicine other than insulin

The day before your test

  • Take your diabetes medicine as usual or as your healthcare provider tells you.

The day of the test

  • Do not 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_hydrogenbreathtest_sibo_inst.

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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.