Use of medications such as insulin or the obsolete sulfonylurea-type and newer, similar oral hypoglycemic agents (OHAs) that provoke increased insulin production exposes you to the ever-present possibility that your blood sugars may drop far below your target value.* Because your brain requires glucose in order to function properly, a deficit of glucose—or hypoglycemia—can lead to some occasionally bizarre mental symptoms. In extreme cases, it can result in death. Although severe hypoglycemia can be dangerous, it is preventable and treatable. I encourage you to have your family, close friends, or workmates read this chapter so they will be able to assist you in the event you have a hypoglycemic episode and cannot correct it alone. I mention OHAs repeatedly in this chapter because of the hazard of hypoglycemia they pose. Please remember that for oral medications I recommend insulin-sensitizing agents (ISAs) and insulin mimetics, while I oppose the use of OHAs.
For our purposes in this chapter, we will use the term “hypoglycemia” to designate any blood sugar that’s more than 10 mg/dl below target. “Mild” hypoglycemia is any blood sugar that’s 10–20 mg/dl below target. As it drops lower, it’s progressively more “severe,” and can, if left uncorrected, become the condition known as neuroglycopenia, which means “too little glucose in the brain.”
Glucose diffuses in and out of your brain slowly, whereas blood sugar in the rest of your body can rapidly drop to zero in an hour from an intramuscular overdose of rapid-acting insulin. Many diabetics develop physical symptoms or signals that enable them to recognize a hypoglycemic episode and think clearly enough to measure blood sugar and correct it.
When blood sugar drops slowly, neuroglycopenia can occur at about the same time that physical symptoms appear. You may not be aware of them, however, because your brain, severely deprived of glucose, is less capable of comprehending these things. “Hypoglycemia unawareness” (reduced or absent ability to experience early signs of hypoglycemia) is also common in individuals who have recently had frequent hypoglycemic episodes, because of a phenomenon called down-regulation of adrenergic receptors (see here). It can also in theory be caused by a class of cardiac drugs (beta blockers) that slow the heart and lower blood pressure. In reality, however, this may not be true. If you do not notice physical symptoms, you may not be able to think clearly enough to realize that your blood sugar is too low, and your cognitive state may deteriorate.
Following is a partial list of the signs and symptoms of hypoglycemia as they progress, ranging from mild (early) to severe (late), which together make up neuroglycopenia.
Delayed reaction time—e.g., failure to slow down fast enough when driving a car.
Irritable, stubborn behavior and lack of awareness of the physical symptoms of hypoglycemia (see the box here).
Confusion, clumsiness, difficulty speaking, weakness.*
Somnolence (sleepiness) or unresponsiveness.
Loss of consciousness (very rare if you do not take insulin).
Convulsions (extremely rare if you do not take insulin).
Death (extremely rare if you do not take insulin).
In various chapters, particularly those covering insulin, we’ve discussed a number of different potential causes of low blood sugar. Following is a list of some common causes.
Not waiting at least 5 hours after a prior dose of rapid-acting insulin before correcting an elevated blood sugar. This is especially dangerous at bedtime.
Too much delay before eating a meal after taking a rapid-acting insulin or classic OHAs, such as the old sulfonylureas and similar newer agents.
Delayed stomach-emptying after a meal (see Chapter 22).
Reduced activity of counterregulatory hormones during certain phases of the menstrual cycle.
Sudden termination of insulin resistance after abatement of illness or stress that required higher than usual doses of classic OHAs or insulin.
Injecting from a fresh vial of insulin after having used progressively higher doses of insulin that has slowly lost its activity over a period of months.
Switching from an insulin pump to manually injected insulin without lowering the dose.
Incorrectly assuming that the most-rapid insulins are equivalent in potency to regular insulin (see here).
Eating less than the planned amount of carbohydrate or protein for a meal or snack.
Taking too much insulin or OHA.
Engaging in unplanned physical activity or failing to cover physical activity with appropriate carbohydrates.
Drinking too much alcohol, especially prior to or during a meal.
Failure to shake vials of NPH insulin vigorously before using.
Inadvertently injecting long-acting or premeal bolus insulin into a muscle.
Injecting near a muscle that will be strenuously exercised.
Long-term treatment with intravenous gamma globulin, causing random intermittent recovery of beta cells in type 1 diabetics.
Using insulin that contains protamine (NPH; see here).
Taking aspirin in large doses, or anticoagulants, barbiturates, antihistamines, or certain other pharmaceuticals that may lower blood sugar or inhibit glucose production by the liver (see Appendix C).
A sudden change from cool weather to warm weather.
Hunger. This is the most common early symptom. A truly well-controlled, well-nourished diabetic should not be unduly hungry—unless he’s hypoglycemic. This symptom, although frequently ignored, should not be. On the other hand, hunger is also very often a sign of tension or anxiety. One cannot assume that it automatically signals hypoglycemia. Perhaps half of so-called insulin reactions may merely reflect hunger pangs provoked by mealtime, emotional factors, or even high blood sugars. When blood sugars are high, the cells of the body are actually being deprived of glucose, and you may feel hungry. Thus, hunger is very common in poorly controlled diabetics. If you feel hungry, measure your blood sugar!
Impaired visual acuity. Even mild hypoglycemia can make for difficulty in reading street signs or fine print. More severe hypoglycemia can cause double vision.
Elevated pulse rate. Always carry a watch with a sweep second hand. Know your maximum resting pulse rate. When possible symptoms of hypoglycemia appear and you have no handy means of testing your blood sugar (a sign of gross negligence), measure your resting pulse. Many people find it more convenient to measure the temporal pulse (at the temple, on the side of the head between the eyebrow and hairline) or the carotid pulse (on the side of the neck just below the lower edge of the jaw and about 1–3 inches forward of the ear) than the radial, or wrist, pulse. If your resting pulse exceeds your maximum resting value by more than one-third, assume hypoglycemia. This measurement may be normally elevated if you’ve been walking about during the prior 10 minutes. Your health care professional can help you learn how to measure your pulse. This exercise should never be necessary since, of course, you have your blood sugar meter with you at all times.
Nystagmus. This symptom may be demonstrated by slowly moving your eyes from side to side while keeping your head immobile. If another person is asked to watch your eyes, she will notice—when your blood sugar is low—that they may jerk briefly in the reverse direction, or “ratchet,” instead of moving smoothly. You can observe the effect of this by looking at the sweep second hand of your watch. If it seems occasionally to jump ahead, you are experiencing nystagmus (actually, as your eyes jumped to the side for brief instants, you missed seeing bits of motion of the second hand).
Absence of erections. For a man, a fairly reliable sign of early-morning hypoglycemia is awakening without an erection, assuming that he ordinarily experiences morning erections. Failure to experience an erection when sexually stimulated likewise suggests hypoglycemia if this is not a usual problem.
Denial. As hypoglycemia becomes more severe, or if blood sugar has been dropping slowly, many patients will be certain that their blood sugars are fine. An observer suspecting hypoglycemia should insist on a blood sugar measurement before accepting the diabetic’s denial.
Historically, the advice for correction of low blood sugar has been to consume moderately sweet foods or fluids, such as candy bars, fruits, cookies, hard candies, peanut butter crackers, orange juice, milk, and soda pop. Such treatment has never worked properly, for reasons you can probably guess, knowing what you now know about various foods and how they affect your blood sugar.
These moderately sweet foods contain mixtures of slow- and rapid-acting carbohydrates. If, for example, you eat or drink enough that the rapid-acting carbohydrate in these foods raises your blood sugar from 40 mg/dl up to your target of 83 mg/dl over the course of half an hour, you may have simultaneously consumed so much slow-acting carbohydrate that your blood sugar will go up by 300 mg/dl several hours later.
In the old days, before I learned to maintain my blood sugar in normal ranges, my physicians insisted that very high blood sugars after hypoglycemic episodes were due to an “inevitable” hypothetical effect they called rebound, or the Somogyi phenomenon.* Once I learned to avoid the usual foods for treating low blood sugar, I never experienced blood sugar rebound. Nevertheless, the scientific literature does describe occasional mild insulin resistance that lasts up to 8 hours following an episode of very low blood sugar. This is not the dramatic rebound caused by eating the wrong thing to bring up blood sugar.
Hypoglycemia can be hazardous, as the list of its progression here demonstrates. We therefore want to correct it as rapidly as possible. Complex carbohydrate, fructose, lactose (in milk), and even sucrose, which is used in most candies—all must be digested or processed by the liver before they will fully affect blood sugar. This delay makes these types of carbohydrate poor choices for treating hypoglycemia. Furthermore, you need to know exactly how much your blood sugar will rise after eating or drinking something to raise it. With most of the traditional treatments you must continually check your blood sugar many hours later to gauge the unpredictable effect.
What, then, can we use to raise blood sugars rapidly with a predictable outcome? The answer, of course, is glucose.
Glucose, the sugar of blood sugar, does not have to be digested or converted by the liver into anything else. Unlike other sweets, it’s absorbed into the blood directly through the mucous membranes of the stomach and gut. Furthermore, as we discussed in Chapter 14, “Using Exercise to Enhance Insulin Sensitivity and Slow Aging,” we can compute precisely how much a fixed amount of glucose will raise blood sugar. If you have type 2 diabetes and weigh about 140 pounds, 1 gram of pure glucose will likely raise your blood sugar about 5 mg/dl—provided that your blood sugar is below the point at which your pancreas starts to make insulin to bring it down. If you weigh 140 pounds and have type 1 diabetes, 1 gram of glucose will raise your blood sugar about 5 mg/dl no matter what your blood sugar may be, because you cannot produce any insulin to offset the glucose. If you weigh twice that, or 280 pounds, 1 gram will raise your blood sugar only half as much. A 70-pound diabetic child, on the other hand, will experience double the blood sugar increase, or 10 mg/dl per gram of glucose consumed. Thus, the effect of ingested glucose on blood sugar is inversely related to your weight. Table 20-1 gives you the approximate effect of 1 gram glucose upon low blood sugar for various body weights.
If you have handled glucose tablets, be sure to wash your hands before rechecking your blood sugar. If a source of water is not available, lick the finger you intend to prick to remove any residual glucose. You can dry the finger by wiping it on your clothing or a handkerchief.
Do not keep glucose tablets near your blood sugar meter or test strips!
Many countries have available as candies or confections products that contain virtually all of their nutritive ingredients as glucose. These glucose tablets are usually sold in pharmacies. Some countries even have glucose tablets marketed specifically for the treatment of hypoglycemia in diabetics. Table 20-2 lists a few of the products with which we are familiar.
TABLE 20-1
EFFECT OF 1 GRAM GLUCOSE UPON LOW BLOOD SUGAR
| Body weight | 1 gram glucose will raise low blood sugar | ||
| 35 pounds | 16 kilograms | 20 mg/dl | 1.11 mmol/l |
| 70 | 32 | 10 | 0.56 |
| 105 | 48 | 7 | 0.39 |
| 140 | 64 | 5 | 0.28 |
| 175 | 80 | 4 | 0.22 |
| 210 | 95 | 3.3 | 0.18 |
| 245 | 111 | 3 | 0.17 |
| 280 | 128 | 2.5 | 0.14 |
| 315 | 143 | 2.2 | 0.12 |
Of the glucose tablets listed, I personally prefer Dex4 bits because they’re very easy to chew, raise blood sugar quite rapidly, taste good, are conveniently packaged, and are inexpensive. They are also small enough that they usually need not be broken in halves or quarters to make small blood sugar adjustments (except for small children). Dex4 products are available at most pharmacies in the United States, Canada, and possibly the U.K. The bits come in jars of 60. Larger Dex4 tablets contain 4 grams of glucose and are packaged in vials of 10 and jars of 50. These are appropriate for people who weigh more than 220 pounds (100 kg). For smaller children I prefer Smarties or Winkies* because of their tiny size. Most glucose tablets begin to raise blood sugar in about 3 minutes and finish after about 45 minutes, if you don’t have gastroparesis. (If you do, see Chapter 22.)
With this background in mind, how should you proceed when you encounter a low blood sugar?
TABLE 20-2
GLUCOSE TABLETS USED FOR TREATMENT OF HYPOGLYCEMIA BY DIABETICS
| Country of manufacture | Name of product | Grams of glucose per tablet | 1 tablet will raise blood sugar of 140-pound person with low blood sugar approximately | |
|---|---|---|---|---|
| USA, Canada | Dex4 bits | 1 | 5 mg/dl | 0.28 mmol/l |
| USA | SweeTARTS or Wacky Wafers | 2* | 10 | 0.56 |
| USA, Canada | Smarties or Winkies† | 0.4 | 2 | 0.11 |
| USA, Canada | Dex4 | 4 | 20 | 1.10 |
| U.K., Canada | Dextro Energy | 3 | 15 | 0.83 |
| USA, Germany | Dextro Energen | 4 | 20 | 1.10 |
* Tablet size may vary.
† Ideally suited for children because of their small size.
If you experience any of the symptoms of hypoglycemia detailed earlier—especially hunger—measure blood sugar. If blood sugar is 5 mg/dl or more below target, chew enough glucose tablets to bring blood sugar back to your target. If you have no symptoms but discover a low blood sugar upon routine testing, again take enough glucose tablets to bring blood sugar back to your target. Having no symptoms is not a valid reason for not taking tablets. A low blood sugar without symptoms carries more risk than one with symptoms. If you weigh about 140 pounds and your blood sugar is 60 mg/dl but your target is 83 mg/dl, then you might eat 5 Dex4 bits. This would raise your blood sugar, according to Table 20-2, by 25 mg/dl, bringing you to 85 mg/dl. If you are using Dextro Energen, you’d take 1 tablet. Simple.
If your low blood sugar resulted from taking too much insulin or OHA, it may continue to drop after taking glucose if the insulin or OHA hasn’t finished working. You should therefore recheck your blood sugar about 45 minutes after taking the tablets, to rule out this possibility and to see if you’re back where you belong. If blood sugar is still low, take additional tablets and keep testing every 45 minutes—sooner if it is dropping rapidly. If you have delayed stomach-emptying, you may have to wait as much as 2 or more hours for the full effect.*
What if you’re out of your home or workplace and don’t have your blood sugar meter? (A major crime, as noted earlier.) If you think you’re hypoglycemic, play it safe and take enough tablets to raise your blood sugar about 40 mg/dl (2 Dex4 tablets, for example). You may worry that this will bring you too high. If you take insulin, this poses no problem. Simply check your blood sugar when you get back to your meter. If it’s above your target, take enough corrective insulin to bring you back to target, but be sure to wait 5 hours after your last dose of rapid-acting insulin. If you don’t take insulin, your blood sugar should eventually come back on its own, because your pancreas is still making some insulin. It may take several hours, or even a day, depending upon how rapidly you can produce insulin. In any event, you may have saved yourself from an embarrassing or even disastrous situation.
Take your glucose tablets anyway. If you don’t, you may become very hungry, overeat, and be too high hours later. The medication you take for a meal is intended to keep your blood sugar level. So if it was too low before a meal, it will be too low after if you don’t take your glucose but eat properly.
Many of the symptoms of hypoglycemia are actually effects of the hormone epinephrine (which you may know as adrenaline). If you do not have the problems listed in the section “Hypoglycemia Unawareness” later in this chapter, your adrenal glands will respond to hypoglycemia by producing epinephrine. Epinephrine, like glucagon, signals the liver to convert stored glycogen to glucose. It is epinephrine that brings about such symptoms as rapid heart rate, tremors, pallor, and so on. (Beta blocker medications may interfere with the ability of epinephrine to cause these symptoms.) Epinephrine has a half-life in the blood of about 1 hour. This means that an hour after your blood sugar comes back to target, about half the epinephrine you made may still be in your bloodstream. This can cause a persistence of symptoms, even if your blood sugar is normal. Thus, if you took some glucose tablets an hour ago and still feel symptomatic, check your blood sugar again. If it’s on target, try to control the temptation to eat more. If your blood sugar is still low, more tablets are warranted.
Mild to moderate hypoglycemia can cause severe hunger and an associated panic. The drive to eat or drink large amounts of sweet foods can be almost uncontrollable. New patients, before starting our regimen, have told me stories of eating an entire pie, a jar of peanut butter, or a quart of ice cream, or drinking a quart of orange juice in response to hypoglycemia. Before I stumbled onto blood sugar self-monitoring and learned how to use glucose tablets, I did much the same. The eventual outcome, of course, was extremely high blood sugar several hours later.
Since the effects of glucose tablets are so predictable, the panic element has vanished for me and for most of my patients.
Unfortunately, rapid correction of blood sugar does not always correct the hunger. This may be somehow related to the long half-life of epinephrine and the persistence of symptoms even after restoration of normal blood sugars. My patients and I have successfully coped with this problem in a very simple fashion. You can try the same trick we use.
First, consume the appropriate number of glucose tablets.
If overwhelming hunger persists, consider what might satisfy it. Typical options include a full meal (such as another lunch or supper), half a meal, or a quarter of a meal. A full meal means exactly the amounts of carbohydrate and protein that you would ordinarily eat at that meal. Half a meal means exactly half the protein and half the carbohydrate.
Even if your blood sugar has not yet come back to target, since you know you have consumed the proper amount of glucose to eventually bring it back, you can confidently inject the amount of insulin or swallow the dose of the OHA that you normally use to cover that meal. For half a meal, take half the dose; for a quarter of a meal, take one-quarter the dose.
Don’t frustrate yourself by waiting the usual 40–45 minutes or so after injecting regular insulin, or the 20 minutes after injecting a most-rapid insulin, or the 60–120 minutes after taking an OHA. Just inject and eat. An extra meal now and then won’t make you fatter or cause harm. Since you’re eating within the controlled boundaries of your meal plan and not gorging on sugars or unlimited amounts of food, you’re still abiding by the Laws of Small Numbers.
If you know how much insulin or OHA you usually take to cover a certain snack, you might have the snack instead of the meal.
Two of the most common effects of hypoglycemia can make the job of helping you difficult and unpleasant. These effects are irritability, nasty behavior and failure to recognize your own symptoms. At my first interview with many new patients and their families, instances of violence during hypoglycemic episodes are commonly reported. The most common scenario I hear goes like this: “Whenever I see that he’s low, I hand him a glass of orange juice and tell him to drink it, but he throws the juice at me. Sometimes he throws the glass too.” Such stories come as no surprise to me because as a teenager I used to throw the orange juice at my mother, and when I was first married, I did the same to my wife. Why does this happen, and how can we prevent such situations?
First, it’s important to try to understand what’s going on in the minds of you and the family member or partner during a bout with hypoglycemia. The cognitive difficulties that accompany severe hypoglycemia can make the slightest frustration or irritation overwhelming. Your low blood sugar may cause you to act bizarrely, as if intoxicated—and in a sense, you are intoxicated. Because your thinking is impaired, you may be totally unaware that your blood sugar is low. The similarity to drunkenness is not a coincidence, since the higher cognitive centers of the brain, which control rational behavior, are impaired in both cases.
You probably have learned that high blood sugars are to be avoided, and at some level, you remember this, perhaps even cling to it, despite your hypoglycemia. If someone tries to cajole you into eating something sweet, you may decide that it’s the other person who’s irrational. This is especially true if the other person has done the same thing in the past, when blood sugars were actually normal or even high. In “self-protection” against the supposed irrational attempt to get you to eat something sweet, you instinctively may become violent. Most commonly, this occurs if an attempt is made to put food or drink in your mouth. You might view this as an “attack.” In less rational moments, you may even decide, since you know that high blood sugars are harmful, that your spouse or relative is trying to kill you.
The helping relative, usually a spouse or parent, may be terrified to see such strange behavior. If your loved one has been through many such encounters, he or she may, for self-protection, keep candies or other sweets around the house in the hope that you will eat them and thus avoid such situations. The fear can be exacerbated if your loved one has seen you unconscious from hypoglycemia, or is merely aware that hypoglycemia can cause dire consequences. On other occasions, when your blood sugar wasn’t really low, your loved one may have erroneously asked you to eat something sweet. Such erroneous diagnoses are especially common during family squabbles. The spouse or parent may feel that “his blood sugar is low, and that’s why he’s yelling at me.” Your loved one would rather play it safe and give you something sweet, even if your blood sugar isn’t low.
There is a solution to this apparent dilemma. First of all, both parties must recognize that, as a rule, about half of the time that the relative suspects hypoglycemia, you do not have low blood sugar; the other half of the time, blood sugar is indeed low.
No one has ever contradicted me when I’ve made this point.
Encouraging a diabetic to eat sweets when hypoglycemia is suspected, despite conventional teaching, does as much harm as it does good. A better approach would be for the loved one to say, “I’m worried that your blood sugar may be low. Please check it and let me know the result so that I’ll feel less anxious.” As a patient, you should realize that living with a diabetic can often be as much or more of a strain than having diabetes. You, the diabetic, owe some consideration to the needs of your loved ones. Try to look upon the request to check your blood sugar not as an intrusion but as your obligation to relieve someone else’s fear. With this obligation in mind, you should automatically check your blood sugar if asked, just to make the other person feel better. It doesn’t matter whether your blood sugar is low or normal. If your blood sugar is low, you can correct it and find out why. If it’s normal, then you probably will have defused the situation, and now you’ll be able to get back to whatever you were doing, unworried that blood sugar is off target. When you look at blood sugar as something like a clock that you can set—and reset—you take some of the mystery out of it, and can diminish the emotion involved.
If you’re without your meter, take enough glucose tablets to raise your blood sugar about 40 mg/dl—again to make the other person feel better. This is the least you can do for someone who may worry about you every day.
Believe it or not, this simple approach has worked for me and for many of my patients. As I’ve said previously, I went through this with my parents and have gone through it with my wife. Spouses report that it relieves them of a great burden. Some wives have even cried when expressing their gratitude.
This more serious hypoglycemic state is often characterized by extreme tiredness and inability to communicate. You may be sitting and banging your hand on a table, walking around in a daze, or merely failing to respond to questions. It’s important that those who live or work with you learn that this is a fairly severe stage of hypoglycemia. The likelihood that it’s hypoglycemia is so great that valuable time may be wasted if treatment is delayed while someone fumbles about trying to measure your blood sugar. It’s quite possible that if you’re given glucose tablets you will not chew them, and may even spit them out.
The treatment at this stage is glucose gel by mouth.
Glucose prepared as a syrupy gel is sold in the United States under several brand names. At least one of these products is not pure glucose (dextrose) but contains a mixture of long- and short-acting sugars, and therefore will not exert its full effect as rapidly as we’d like. At present, I ask my patients to purchase Dex4 gel. It is packaged in a plastic tube (like toothpaste) with a replaceable screw cap. Each tube contains 15 grams of glucose. From Table 20-1 (here), we see that this amount will raise the blood sugar of a 140-pound person by 75 mg/dl (15 × 5). An appropriate dose for most adults in this condition would be about 1 full tube.
Some of the tubes of decorative icing used to write on birthday cakes contain almost pure glucose (dextrose), so you might save money by purchasing those. Look in the baking section of most supermarkets, but make sure of the contents and weight. To convert ounces to grams, multiply by 30. Make sure that the major ingredient is glucose, as some brands are mostly sucrose, which works too slowly.
We recommend that 2 tubes of a glucose gel, secured together with a rubber band, be placed at strategic locations about your house and place of work, as well as in luggage when you travel with a companion. It should not be refrigerated, as it may harden when cold. To administer, someone should insert the tip of an open tube into the corner of your mouth, in between your lower gum and your cheek, and slowly squeeze out a small amount. You will probably swallow this small amount. After you swallow, a bit more of the gel should be gently squeezed from the tube. Within 5 minutes of ingesting an entire tube, you should be able to answer questions.
When you have fully recovered, check and correct your blood sugar to your target. Since you may have wiped the sticky gel off your mouth with your hands, you should wash them before sticking your finger.
Although glucose gels may not be available in many countries, they are available on the Internet. Most industrialized nations have pharmacies and surgical dealers that sell flavored glucose drinks to physicians for performing oral glucose tolerance tests. These are usually bottled in 10-ounce (296 ml) screw-top bottles that contain 100 grams of glucose. A dose of 2 fluid ounces (60 ml) will provide about 20 grams of glucose, enough to raise the blood sugar of a 140-pound person by 100 mg/dl. Tiny amounts can be administered with the help of a plastic squeeze bottle. Whoever feeds you the liquid or gel must exercise caution, as the possibility exists that you could inhale some of it, causing you to choke. Using a liquid is potentially much more hazardous than using a gel in this respect, so administer only a tiny amount (about 1/4 tsp.) for each swallow.
Hypoglycemia is not the only cause of loss of consciousness. Stroke, heart attack, a sudden drop in blood pressure, and even a bump on the head can render you unconscious. In fact, very high blood sugar (above 400 mg/dl) over several days, especially in a dehydrated individual, can also cause loss of consciousness. We will assume, however, that if you are carefully observing the treatment guidelines of this book, you will not allow such prolonged blood sugar elevation to occur.
If you’re found unconscious by someone who knows how to rapidly check your blood sugar, a measurement may be made. Treatment should not be delayed, however, while people are scampering about trying to find your testing supplies.
The treatment under these conditions is injection of glucagon, a hormone that rapidly raises blood sugar by causing the liver and muscles to convert stored glycogen to glucose. It is imperative, therefore, that those who live with you know how to give an injection. If you use insulin, you can give them some practice by teaching them how to give you insulin injections. Glucagon is sold in pharmacies in many countries as the Glucagon Emergency Kit. This consists of a small plastic box containing a syringe filled with an inert waterlike solution and a little vial of white powder (glucagon). The kit also contains an illustrated instruction sheet that your family should read before an emergency develops. The user injects the water into the vial, withdraws the needle, shakes the vial to dissolve the powder in the water, and draws the solution back into the syringe. The tip of the long needle must be submerged in the liquid. For adults, the entire contents of the syringe should be injected, either intramuscularly or subcutaneously; lesser amounts should be used for small children. Any of the sites shown in Figure 16-1 (here) can be used, as can the deltoid muscle (see Figure 19-2, here), the outer thigh, or even the calf muscle. Your potential benefactors should be warned that if they choose the buttocks, injection should go into the upper outer quadrant, so as not to injure the sciatic nerve. An injection may be given through clothing, provided it is not too thick (for example, through a shirtsleeve or trouser leg, but not through a coat, a jacket, or a trouser pocket).
Under no circumstances should anything be administered by mouth while you are unconscious. Since you will not be able to swallow, oral glucose could asphyxiate you. If your glucagon cannot be found, your companions should dial 911 (in the United States) for the emergency medical service, or take you to the emergency room of a hospital.
When an individual has lost consciousness from hypoglycemia, he may experience convulsions. Signs of this include salivation, tooth-grinding, and tongue-biting. Although the last can cause permanent damage in the mouth, no attempt to intervene should be made. Your heroic savior will not be able to help you if you bite off her fingers. If possible, you should be turned to lie on your side with your head positioned so that your mouth is downward. This is to help drain excess saliva from your mouth so you won’t breathe it in and choke.
You should begin to show signs of recovery within 5 minutes of a glucagon injection. You should fully regain consciousness and be able to talk sensibly within 20 minutes at most. If steady improvement is not apparent during the first 10 minutes, the only recourse is the emergency squad or hospital. The emergency squad should be asked to inject 40 cc of a 50 percent dextrose (glucose) solution into a vein. Individuals weighing under 100 pounds (45 kg) should receive proportionately smaller amounts (e.g., a 70-pound child would receive 20 cc of the dextrose solution).
Glucagon can cause retching or vomiting in some people. Your head should therefore be turned to the side so that if you do vomit, you won’t inhale the vomitus. Keep a 4-ounce (120 ml) bottle of metoclopramide syrup on hand, attached with a rubber band to the Glucagon Emergency Kit. One gulp of metoclopramide, taken after you are sitting up and speaking, should almost immediately stop the feeling of nausea. Do not consume more than one gulp, as large doses can cause unpleasant side effects (see here). In the United States, metoclopramide is available only upon prescription by a physician.
One dose of glucagon can raise your blood sugar by as much as 300 mg/dl, depending upon how much glycogen was stored in your liver at the time of the injection and subsequently converted to glucose. After you’ve fully recovered your senses, you should check your blood sugar. If at least 5 hours have elapsed since your last dose of a rapid-acting insulin, take enough intramuscular (or subcutaneous) rapid-acting insulin to bring your blood sugar back down to your target. This is important, because if your blood sugar is kept normal for about 24 hours, your liver will rebuild its supply of glycogen. This glycogen reserve is of great value for protection from possible subsequent hypoglycemic events.
By the way, if we tried to give glucagon to someone twice in the same day, the second shot might not raise blood sugar. This is possible because liver glycogen reserves may have been totally depleted in response to the first injection. Thus, monitoring and correction of blood sugar every 5 hours for 1 full day is mandatory after the use of glucagon. Additional blood sugar measurements should be taken every 2½ hours to make sure that you’re not again hypoglycemic, but do not correct for high blood sugars every 2½ hours; wait the full 5 hours since the last shot of rapid-acting insulin (see here).
Although reading about possible loss of consciousness may be frightening, remember that this is an extremely rare event, and usually results when a type 1 diabetic makes a major mistake, such as those included in the list here. I know of no case where a type 2 diabetic experienced severe hypoglycemia when using any oral medication that we recommend.
The signs of hypoglycemia during sleep include cold, clammy skin, especially on the neck, erratic breathing, and restlessness. It certainly helps to have a light sleeper sharing your bed. Parents should check diabetic children at night and should feel their necks.
Review your GLUCOGRAF data sheet after all hypoglycemic episodes, even mild ones. It’s important that you reconstruct the events leading up to any episode of low blood sugar, even if it caused no notable symptoms. This is one of the reasons why we recommend (see here) that most insulin-taking diabetics keep faithful records of data pertinent to their blood sugar levels and why we go into so much detail in Chapter 5 teaching you how to record the information. Since severe hypoglycemia can lead to amnesia for events of the prior hour or so, habitual recording of relevant data can be most valuable for this scenario. It is certainly helpful to record times of insulin shots, glucose tablets, meals, and exercise, as well as to note if you overate or underate, and so on. Recording blood sugar data alone may not help you to figure out what caused a problem. If you experience a severe hypoglycemic episode or several mild episodes and cannot figure out how to prevent recurrences, read or show your GLUCOGRAF data sheet to your physician. Your doctor may be able to think of reasons that did not occur to you.
Glucose tablets, glucose gel, and glucagon can each potentially save your life. They won’t help if they’re not around or are allowed to deteriorate. Here are some basic rules:
Place supplies in convenient locations around your house and workplace.
Show others where your supplies are kept.
Keep glucose tablets in your car, pocket, or purse.
When traveling, keep a full set of supplies in your hand luggage and also in your checked luggage—just in case a piece of luggage is lost or stolen.
It may be wise to replace glucagon on or before the expiration date on the vial. In an emergency, however, it isn’t necessary for your savior to worry about the expiration date. In the United States, glucagon is usually sold with very short dating. Many people are sold costly emergency kits marked with expiration dates only a few months later. Don’t worry. Glucagon is sold as a freeze-dried powder that will probably remain effective for five years after the “expiration” date, unless of course it has been exposed to moisture or extreme heat (as in a closed car in the summertime). It retains its longevity especially if it is refrigerated. Once diluted, however, it is good for only 24 hours.
Always replace supplies when some have been used. Never allow your stock to become depleted. Keep plenty of extra glucose tablets and blood sugar test strips on hand.
Bacteria love to eat glucose. Once you have opened your bottle or package of glucose tablets, expect that within six months you will see black spots on each tablet corresponding to bacterial colonies. Even unopened packages will present spotted tablets about one year after manufacture. These tablets will not kill you, but they may be unpleasant-tasting and too hard for easy chewing. Periodically take a look at your supply of glucose tablets.
If you use insulin or OHAs, you should wear an identification tag that displays a recognizable medical emblem, such as a red serpent encircling a red staff. The tag, which may be worn as a bracelet or necklace, should be engraved with a message that will advise emergency medical personnel of your diabetic status. If you take insulin, it might say “Diabetic—takes insulin.” Since bracelets are more likely to be spotted by emergency personnel, I prefer them to the necklaces.
Most pharmacies and jewelers sell medical ID tags. Prices begin at $5 for stainless steel and go into hundreds of dollars for solid gold. The MedicAlert Foundation (2323 Colorado Avenue, Turlock, CA 95382) will keep a record of your medical history and will send you a stainless steel ID bracelet or necklace, with its emblem, for $40. Sterling silver or gold-plated IDs cost slightly more. MedicAlert will also engrave the tag for the same cost. All tags are stamped with your special ID number and with the foundation’s “call collect” 24-hour telephone number. By phoning this number, a hospital or paramedic can secure your name and address, contact information for your next of kin and physician, a list of all your medical conditions, and the doses of medications that you take. You can obtain an application form by writing to the above address, by phoning (888) 633-4298, or by going to www.medicalert.org.
Diabetics who do not take medications that can cause hypoglycemia would also be wise to wear a MedicAlert bracelet, if only to discourage the automatic use of intravenous glucose infusions—a common practice of emergency personnel on victims of motor vehicle accidents, heart attacks, and so on.
If you live alone, you may want to consider using an emergency alarm system. These can automatically phone a friend, relative, or emergency squad when you push a button on a necklace. The system can also be activated if you do not “check in” at predetermined time intervals. The least expensive system that I have encountered is supplied by the MedicAlert Foundation. Their “failure to check in” alert unfortunately can only be activated at 24-hour intervals, so you could be unconscious for 24 hours before someone is notified.
Most of us have jobs that bring us into contact with other people during the day and family with whom we have contact after work. These contacts offer considerable protection from severe hypoglycemia, as colleagues and relatives will intervene if you start walking into walls or talking silly. A sleeping partner can frequently pick up on the labored breathing and cold, clammy skin or damp nightclothes that accompany hypoglycemia and then awaken you and ask you to check your blood sugar.
If you live or sleep alone, or if your sleeping partner is an extremely deep sleeper, however, you don’t have this protection at night.* A backup is available.
Several companies are now marketing continuous glucose monitors.† A CGM works via a tiny sensor implanted beneath the skin, using a technique similar to that used for insulin pump tubing. The sensor constantly measures glucose concentration in the tissue fluid present at its subcutaneous location. A combined power supply and radio transmitter attaches to your skin or clothing. The transmitter sends up to several hundred glucose readings daily to a small portable receiver that you can keep in a pocket. The number displayed is approximately equal to the blood sugar about 20 minutes prior to the reading. So if you had taken a reading with your conventional method 20 minutes ago, this would be roughly the same as the reading from the sensor right now.
Also displayed is an up or down arrow to indicate whether blood sugar is increasing or decreasing. What’s most valuable is an audible alarm that can be set to sound at any selected blood sugar value and also to signal rapid drops in blood sugar.
There are some potential problems associated with these devices, so they’re not for everyone.
One of the CGM manufacturers has disclosed reports of sensors breaking off in the skin, requiring surgical removal.
The sensor remains under the skin for 3 days. During this time, there is always the possibility for inflammation or infection (probably a low risk).
Fibrosis, or scar tissue, can potentially build up at the sensor site over time (although how long this would take is as yet unclear) and eventually make measurements less accurate.
Measurements are inherently less accurate than ordinary blood sugar monitoring, so the devices need to be calibrated against finger-stick blood sugars about twice daily. For now, at least, I would recommend that any blood sugar correction be made based on finger-stick measurements.
Both the equipment and the disposable sensors with associated supplies are quite costly and may not be covered by insurance.
Advertising for these products may falsely imply (but not state outright) that a sensor–insulin pump combination will automatically monitor and inject insulin to keep blood sugars on target around the clock.
The sensor is typically implanted in the abdomen but may have a bulky exterior.
The sensor will typically work for only 3 days, because the enzyme used is then depleted.
The setup requires training to use, usually provided by a salesperson.
While CGMs have at best limited usefulness at the moment, it is entirely feasible—just from an engineering perspective—that they will vastly improve over time and even be able to act as an artificial pancreas. That said, I’m not holding my breath—this technology has been around for decades, and manufacturers have made plenty of money by employing it shoddily. One can still hope, however, that some brilliant entrepreneur will develop a highly accurate and timely monitor that can provide constant, accurate blood sugar readings. One manufacturer has already applied to the FDA for approval in the United States. I suspect, however, that it will pose the same problems as are found with insulin pumps and will not give the same accuracy and precision that we get with injection and an accurate blood sugar meter.
If I were living alone, I’d use a CGM to protect from nighttime hypoglycemic episodes and forget about using an insulin pump.
Some diabetics have absent or diminished ability to experience the warning signs of hypoglycemia. This occurs under six circumstances that have been documented in the scientific literature:
Impaired delivery of glucose to the brain.
Severe autonomic neuropathy (injury, by chronically high blood sugars, to the nerves that control involuntary bodily functions).
Adrenal medullary fibrosis (destruction, by chronically high blood sugars, of the cells in the adrenal glands that produce epinephrine). This is especially common in long-standing poorly controlled diabetes.
Blood sugars that are chronically too low.
The use of beta-blocking medication for treatment of hypertension or cardiac chest pain. A recent study disproves this, but I’m not certain of its universal validity.
The use of large (nonphysiologic) doses of insulin, as is common for individuals on high-carbohydrate diets.
All of these situations result in lowered production of, or sensitivity to, epinephrine, the hormone that produces tremor, pallor, rapid pulse, and other signs that we identify with hypoglycemia. It is ironic that epinephrine production or sensitivity is most commonly diminished in those whose blood sugars have been chronically either very high or very low.
Injury to the autonomic nervous system by elevated blood sugar is discussed here. Individuals whose heart rate variation on the R-R interval study is severely diminished may be especially susceptible to this problem.
People who have frequent episodes of hypoglycemia or chronically low blood sugar tend to adapt to this condition. They appear to be less sensitive to the effects of epinephrine, which, when repeatedly released in large amounts, down-regulates its own receptors. This condition cannot be predicted by R-R studies. It is, however, readily detectable if you measure your own blood sugar frequently. If caused by chronically low blood sugar, this condition can be reversed by taking measures to ensure that blood sugar is maintained at normal levels.
Hypoglycemia unawareness can deprive one of potentially lifesaving warning signals. To compensate for this disability, blood sugar should be checked more frequently. For some rare insulin users, it may be necessary, for example, to measure blood sugar every hour for 5 hours after meals, instead of only once or twice after each meal. Fortunately, we have the tools to circumvent this problem; we need only to use them diligently.
I frequently encounter patients who do not take glucose tablets for low blood sugar measurements because they “feel fine” or are “about to eat anyway.” These are just the people who are most likely to lose consciousness or find themselves in an automobile accident.
Whether or not you have hypoglycemia, it is essential that you check your blood sugar before driving a car and—after finding a place where you can safely stop your vehicle—every hour while driving.
Syncope, or fainting, is fairly common as people get older. It is especially common among diabetics. Even more common is near-syncope. This is merely the feeling that you will pass out unless you lie down right away. Simultaneously, your surroundings may look gray or your vision may fade. There are many causes of syncope and near-syncope. These include cardiac and neurological problems, certain medications, and dehydration. These causes are not nearly as common in diabetics as are sudden drops in blood pressure caused by autonomic neuropathy or by inappropriate use of antihypertensive medications—especially diuretics (“water pills”) and alpha-1 adrenergic antagonists, such as prazosin and terazosin.
When most of us stand from a seated, supine, or squatting position, the brain sends a message to the blood vessels in our legs to constrict reflexively and instantly. This prevents blood from pooling in the legs, which would deprive the brain of blood and oxygen. If you’ve had high blood sugars for many years, the nerves that signal the vessels in the legs may conduct the message poorly (a sign of autonomic neuropathy). A drop in blood pressure upon standing, called postural, or orthostatic, hypotension, occurs when this pooling in the legs occurs. For some, the heart may bring blood pressure back up by increasing its rate and amount of contraction. Unfortunately, this does not occur for many diabetics with autonomic neuropathy.
Alternatively, if you eat a big meal, blood may concentrate in your digestive system, also depriving the brain. The normal mechanisms that protect the brain from this shunting of blood may be deficient if you have autonomic neuropathy. It is in part to gauge the potential for these reactions that I measure supine and standing blood pressures, and perform R-R interval studies on all my diabetic patients. A study of medical (mostly nondiabetic) outpatients in the United States suggests that 20 percent of individuals over age 65 and 30 percent of those over age 70 have documentable postural hypotension. For diabetics the incidence is probably much greater.
A common scenario for syncope or near-syncope involves the diabetic who gets up in the middle of the night to urinate and keels over on the way to the bathroom. A simple way to avoid this is to sit on the edge of the bed with your feet dangling for a few minutes before standing.
Another syncope scenario involves the person who goes to the toilet and passes out while trying to produce a bowel movement or urinate. Again, the reflexes that prevent the shunting of blood away from the brain are blunted by autonomic neuropathy.
If syncope is caused by transient low cerebral blood pressure as a result of autonomic neuropathy, one should lay the victim out flat and elevate his feet high above his head. He should return to consciousness almost immediately.
The symptoms of syncope are similar to those of moderate to severe hypoglycemia. In both cases, the brain is being deprived of a basic nutrient—oxygen in the case of syncope, glucose in the case of hypoglycemia. Furthermore, postural hypotension can also occur as a result of hypoglycemia. Some symptoms of near-syncope include faintness, visual changes, and disorientation.
Whatever the cause of fainting or near-syncope, blood sugar must be checked to rule out hypoglycemia. If blood sugar is normal, no amount of glucose will cure the problem. People with recurrent postural hypotension will usually find relief by wearing surgical stockings of 30–40 mm compression. If these are inadequate, waist-high surgical panty hose should be used.
In 2011 we published in the Journal of Allergy and Immunology my discovery that at least 20 percent of diabetics (types 1 and 2) have an inherited disorder called common variable immunodeficiency (CVID). This involves inadequate blood levels of immunoglobulins (antibodies). About one-tenth of these individuals are so severely affected that they develop nonhealing infections or malignancies. The treatment for CVID is intravenous gamma globulin—usually several times per month. All of my insulin-using patients who get gamma globulin experience frequent, unexpected dangerously low blood sugars or reductions in insulin requirements. This has been attributed to a partial but transient recovery of the beta cells that make insulin. These CVID patients must check their blood sugars every 1–2 hours, especially during the first week after an infusion. They must even set an alarm to awaken them once or twice during the night. Although this situation is rare, it can theoretically affect at least 2 percent of people with diabetes.
If you’ve heard horror stories about the frequency and severity of severe hypoglycemia in type 1 diabetes, the people you’ve been hearing about are probably taking industrial doses of insulin to cover large amounts of dietary carbohydrate. On our regimen, this hazard is virtually nil. Someone would have to make a major mistake, such as taking an insulin dose twice or not waiting the full 5 hours (or 6 hours before bedtime) before correcting an elevated blood sugar, for life-threatening episodes to occur. Many type 1 diabetics seek me out because of their frequent hypoglycemic episodes and not necessarily because of their high blood sugars. Our regimen takes care of both.
Please don’t neglect to ask others to read this chapter. When you are most in need of help for treating hypoglycemia, you may be incapable of rendering it yourself. So show this chapter to your close relatives, friends, and coworkers and ask them to read it. It should increase their own confidence in coping with such situations, and the potential payoff to you may be considerable.
I will personally answer questions from readers for one hour every month. This free service is available by visiting www.askdrbernstein.net.