Richard K. Bernstein, MD, FACE, FACN, FACCWS
Part 2 Chapter 22
How Does Gastroparesis Affect Blood Sugar Control? – Part 2Consider the individual who has very little phase I insulin release and must take fast-acting insulin or one of the older-type (sulfonylurea) or newer pancreas-provoking OHAs before each meal. If he were to take his medication and then skip the meal, his blood sugar would plummet.
When the stomach empties too slowly, it can have almost the same effect as skipping a meal. If we knew when the stomach would empty, we could delay the insulin shot or add some NPH insulin to the regular to slow down its action. The big problem with gastroparesis, however, is its unpredictability. We never know when, or how fast, the stomach will empty. If the pyloric valve is not in spasm, the stomach contents may
empty partially within minutes and totally within 3 hours. On another occasion, when the valve is tightly closed, the stomach may remain loaded for days. Thus, blood sugar may plummet 1–2 hours after eating, and then rise very high, say 12 hours later, after emptying eventually occurs. It is this unpredictability that can make blood sugar control impossible if significant gastroparesis is ignored in people who take insulin (or the type of OHAs I don’t recommend) before meals.
For most type 2 diabetics, fortunately, even symptomatic gastroparesis may not grossly impede blood sugar control, because they may still produce some phase I and phase II insulin. They therefore may not require significant amounts of injected insulin to cover their lowcarbohydrate meals. Much of their insulin is produced in response to blood sugar elevation. Thus, if the stomach does not empty, only the low basal (fasting) levels of insulin are released, and hypoglycemia does not occur. Of course, the sulfonylurea and similar OHAs (which I don’t recommend) can cause hypoglycemia under such circumstances.
If the stomach empties continually but very slowly, the beta cells of most type 2s will produce insulin concurrently. Sometimes the stomach may empty suddenly, as the pyloric valve relaxes. This will produce a rapid blood sugar rise, caused by the sudden absorption of carbohydrate following the entrance of stomach contents into the small intestine. Most beta cells of type 2 patients then cannot counter rapidly enough. Eventually, however, insulin release catches up and blood sugar drops to normal, if a reasonable regimen is followed. If your supper doesn’t fully leave your stomach before you sleep, you may awaken with a high morning blood sugar due to emptying overnight,
even though your bedtime blood sugar was low or normal.
In any event, if you do not require insulin or use a sulfonylurea type OHA before meals, there is no hazard of hypoglycemia due to delayed stomach-emptying. This assumes that any long-acting insulin or sulfonylurea is administered in doses that cover only the fasting state, as discussed in prior chapters. The traditional use of large doses of
these medications, meant to cover both the fasting and fed states, brings with it the hazard of postprandial hypoglycemia when gastroparesis is present.
We would like to thank the publisher Little Brown and Company and Dr. Richard K. Bernstein, for allowing us to provide excerpts from The Diabetes Diet.
Copyright © 2005 by Richard K. Bernstein, M.D. All rights reserved. No part of this book may be reproduced in any form or by any electronic or mechanical means, including information storage and retrieval systems, without permission in writing from the publisher, except by a reviewer who may quote brief passages in a review.
This book is not intended as a substitute for professional medical care. The reader should regularly consult a physician for all health-related problems and routine care.
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