When Diabetes Leads to a Lazy Stomach: The Goods on Gastroparesis
This article was originally published in Diabetes Health in October, 2007.
Gastroparesis doesn't sound good, and it isn't. Literally "stomach paralysis," it is a form of diabetic neuropathy, or nerve damage, that is a common complication of diabetes. The damaged nerve in question is the vagus nerve, named for its vagabond-like wandering nature.
The vagus nerve meanders all the way from the brainstem to the colon, controlling heart rate, sweating, gastrointestinal contractions, and various other involuntary, automatic functions on its way. In the case of gastroparesis, it's the vagus nerve's control of stomach contractions that's damaged.
The stomach is basically a hollow ball made of muscle that serves as a storage container and mixing bowl for food. It's about the size of a small melon, but it can stretch to hold nearly a gallon if you really press the issue. In healthy people, wave-like contractions of the stomach, prompted by the vagus nerve, crush and churn your food into small particles and mix it up with enzymes and acids produced by the stomach's inner lining.
Then the stomach contractions, coming along in waves at about three per minute, slowly and evenly propel the pulverized food out through the pyloric valve, which opens just enough to release an eighth of an ounce of food at a time. From there it's down the small intestine, where the real nutrient absorption occurs. It can take four hours to empty your stomach into your small intestine, especially if you've eaten fat, which slows the process down.
If the vagus nerve has been damaged by years of high blood sugars, the process hits a snag. The walls of the stomach, paralyzed by the lack of vagus nerve stimulation, don't make their muscular wave-like contractions. As a result, food just sticks around in the stomach, unpulverized and going nowhere. It may sit and ferment, creating an environment that fosters the growth of harmful bacteria.
Alternatively, the food can harden into solid masses called bezoars (pronounced "bee's oars") that are similar to a cat's hairball. In olden days, bezoars were thought to be magical poison antidotes and were worth several times their weight in gold. These days, however, all they do is cause nausea and vomiting. Worst case scenario, they can even block the pyloric valve, creating a serious emergency.
The common symptoms of gastroparesis are bloating, abdominal pain, nausea, feeling full after just a few bites of a meal, weight loss, and heartburn. Nausea and vomiting generally occur many hours after the last meal, usually when your stomach is fullest from both food and the secretions stimulated by the food. Because the food hasn't been ground up during the interim, it often comes up in the same shape it went down in, so it is, unpleasantly enough, easily recognized.
Diabetes is the leading risk factor for gastroparesis. About one in five people with type 1 develop it, as well as many people with type 2. Once it develops, it makes blood sugar management even harder because erratic stomach emptying make blood sugar levels difficult to predict and control. Conversely, poor control of blood sugar levels makes gastroparesis worse by tending to slow gastric emptying.
There are any number of new methods to look for gastroparesis, many of which involve eating or drinking something rather unappetizing. In a gastric emptying study, considered one of the most accurate methods to diagnose gastroparesis, you must eat eggs or oatmeal containing a harmless radioactive substance that makes the food visible on a Geiger-counter-like scan. Less commonly, you might undergo a barium x-ray, in which you fast for twelve hours and then drink a sludgy liquid that coats the inside of your stomach and makes its contents visible on x-ray.
Other diagnostic tests involve threading a little tube down into your stomach to assess the strength, frequency, and coordination of your stomach contractions or the electrical signals that travel through your stomach and stimulate its contractions.
The simplest way to address gastroparesis is through dietary changes. Smaller, more frequent meals ameliorate that feeling of fullness and are faster and easier to digest than three big meals. If your appetite diminishes later in the day, eat more in the morning and stick to liquids in the afternoon. By lying on your right side after eating, you can put gravity to work to help empty your stomach.
A big problem is fiber, which helps things move along in the intestines but has the opposite effect in the stomach. The stomach has a hard time breaking down roughage, which is also more likely to sit around and form those unwanted bezoars. So people with gastroparesis are often advised to avoid raw vegetables and eat soft, low-fiber foods like well-cooked fruits and vegetables, fish, chicken, yogurt, refined breads and grains, or pureed or liquid foods.
Sometimes it's advisable to avoid fats, which slow down stomach emptying even in healthy people. If you're vomiting a lot, it's also important to drink water to avoid dehydration and to take supplements in liquid form. If you can't tolerate any food or liquid at all, your doctor might place a feeding tube in your small intestine to bypass your stomach altogether. It's usually a temporary fix, used only in severe cases or when blood sugar levels can't be controlled.
Sometimes gastroparesis can be worsened, or even caused, by medications that slow stomach emptying, including narcotic pain medications, tricyclic anti-depressants, and calcium channel blockers, as well as some blood pressure medications, lithium, and antacids that contain aluminum hydroxide.
Clonidine, dopamine agonists, and progesterone are also implicated. So if you have gastroparesis, your symptoms could improve if you move off those medications under the care of your doctor. Nicotine is also associated with impaired gastric emptying, so you might want to quit smoking.
Especially in people with diabetes, it's critical to regain control of blood sugar levels that are out of whack, especially because better control of blood sugar levels can actually improve stomach emptying. Sometimes it can help to take insulin after meals instead of before. Testing more frequently will allow you to take insulin in response to blood glucose levels as they rise, rather than in response to a meal that might just take awhile to hit the bloodstream. Your doctor can advise you about methods to bring your blood sugars down and, hopefully, relieve your gastroparesis.
There are a number of drugs available to treat gastroparesis: Some of them relieve nausea and vomiting; others ease abdominal pain. Others still, called pro-motility drugs, stimulate contractions of the stomach muscles. There's also the rather new possibility of getting a pacemaker for your stomach, which generates electrical pulses that stimulate the wave-like muscle contractions you need to get things moving again.
The latest (and still experimental) treatment is injection of botulinum toxin (Botox) into the pylorus; just like it does to your forehead wrinkles, the Botox temporarily relaxes the powerful pyloric muscle, thereby enlarging the outlet from the stomach to the intestine and allowing the release of more food.
Gastroparesis is not usually life-threatening, but it can really put a dent in your quality of life and make your diabetes much harder to control. There's been a lot of progress made recently in treatments for the condition, so think about taking a trip to your doctor or gastroenterologist. It just might get things moving along in the right direction.Click Here To View Or Post Comments