In our experience, insulin pumps do not providebetter blood sugar control than multiple injections. Contrary to a common misconcep tion, they do not measurewhat your blood sugaris and correctit auto matically. Furthermore, most pumps areprogrammed to produce meal
Intensive Insulin Regimens 315
boluses that are computed to cover varying amounts of carbohydrate, totally ignoring both dietary protein and the Laws of Small Numbers.
Recendy an insulin pump (OmniPod) has become available that usesboth a slimmer needle (28gauge) and a short length of veryfine tubing.
The pain is virtuallyeliminated, and the long-term problems causedby a largeforeign body (i.e., the tubing) under the skin are con siderably reduced.
The basal infusion rate, however, is still too great (0.5 units per hour) for most people taking physiologic doses of basal insulin.
This may be improved in the future.
INHALED INSULIN
In 2006 the FDA approved a powdered human insulin inhalable through the mouth and absorbed in the lungs.
It is manufactured by Pfizer and carries the brand name Exubera.
Similar products are un der development by other manufacturers.
So at long last, insulin can be administered without puncturing the skin with a needle.
Many physicians and members of the press are praising this accomplishment.
Is it reallya benefit to diabetics, or is it too good to be true?
Exubera is dispensed in 1 mg and 3 mg packets and aerosolized for inhaling by a plastic "puffer" measuring about 2 inches in diameter, 6Vi inches long when closed, and 11 inches long when open for use.
The product has been approved for use before meals by both type 1 and type 2 diabetics.
If you've tried our painlessmethod for injecting insulin, you proba bly will see no advantage to puffing your insulin.
But what about the majority of insulin users, who are taking the usual large doses and in jecting using the conventional "no pain, no gain" method?
For those folks, this product may be viewedas a blessing.
Likewise for those who have heard horror stories about painful injections (from no less emi nent an organization than the Juvenile DiabetesResearchFoundation).
Manyof these people willrefuseto injectinsulin and would rather have high blood sugars or use the potent OHAs that eventually burn out beta cells.
Clearlysuch people willmake up a major market for inhaled insulin, so the profit potential for this product will be considerable.
Are there any likely disadvantages to inhaling insulin?
Indeed there are.
They are listed below in random order of importance
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• There is a possibility of long-term adverse effects upon lung function. • The cost per dose will be much greater than that of injected in sulins.
It is unknown whether this cost will be coveredby many insurers. • It will be necessary to carry around a bulky object for premeal boluses. • Each milligramof powderis equivalent to 1-3 units ofinsulin af ter absorption.
Thus people who require doses smaller than 1 unit cannot be servedby this product. • The actual dose of absorbed insulin can vary from one puff to another, by 1-2 units for the 1 mg packet and by as much as 3-9 units for the 3 mg packet.
This makes precise dosing impossible.
This may be of uncertain importance for those eating large amounts of carbohydrateand taking large premeal boluses, since many diabetics are not following the methods we prescribe and their blood sugars are on a roller coaster anyway.
If you are read ing this book, the chances are that you are seeking to avoidor get off the roller coaster and therefore will want to avoid the hazards of wide blood sugar swings. • The FDA advises against using this product if you have a cold, smoke, or have any lung disorder such as asthma, seasonal aller gic cough, et cetera.
Are there any diabetics who might benefit from inhaled insulin?
I speculate that there may be many obese type 2s making considerable insulin of their own who can't control their carbohydrate craving, don't want to use oral agents that push beta cells to make more in sulin, and refuse to take injections but want to bring their very high postprandialblood sugars down to levels that arelesshigh.
Inhaled in sulin may help them accomplish this.
These people will likely never have normal blood sugars, but they may not care.
20 How to Prevent and Correct Low Blood Sugars
U s e of medications suchasinsulin or the obsolete sulfonylurea- type and newer, similaroralhypoglycemic agents(OHAs) that provoke increased insulin production exposes you to the ever-present possibilitythat your blood sugars may drop below your target value.* Because your brain requiresglucose in order to function properly, a deficit of glucose, or hypoglycemia , can lead to some occasionallybizarre mental symptoms.
In extreme cases, it can result in death.
Although severe hypoglycemia can be dangerous, it is pre ventable, 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 that they pose.
Please remember that I rec ommend insulin-sensitizing agents and insulin mimetics,while I op pose the use of OHAs.
HYPOGLYCEMIA: THE BASICS
For our purposes in this chapter, we will use the term "hypoglycemia" to designate any blood sugarthat's more than 10 mg/dl belowtarget. "Mild"hypoglycemia is anyblood sugarthat's 10-20mg/dl belowtar-
It has been claimedthat the insulin-sensitizing agents(ISAs) cannot causeab normally low blood sugars. This is not so. As we discussed in Chapter 15, I've seen it happen , in a very mild diabetic who was using it to facilitate weight loss. Nevertheless, this is a rare occurrence.
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get.
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 ofyour body can rapidly dropto zero in an hour from an intramuscular overdose of lispro insulin.
Many diabetics develop physical symptoms or signals that enable them to recognize a hypo glycemic 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 awareof them, however, because your brain, severely deprived of glu cose, 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 recendy had frequent hypoglycemic episodes, because of a phenomenon called down-regulation of adrenergicreceptors(seepage 341).
It can also be caused by a class of cardiac drugs (beta blockers) that slow the heart and lower blood pressure.
If you do not notice physical symptoms, you maythen not be able to think clearly enoughto realize that your blood sugar is too low,and your cognitive state will deteriorate.
Progression of Symptoms of Neuroglycopenia Below is a partial fist of the signs and symptoms of hypoglycemia as they progress, ranging from mild (early) to severe (late), which to gether make up neuroglycopenia: • Delayed reaction time , e.g., failure to slowdown fast enough when driving a car. • Irritable, stubborn behavior and lack of awareness of the physi cal symptoms of hypoglycemia (see box, page 322). • Confusion, clumsiness, difficulty speaking,weakness.* • Somnolence (sleepiness) or unresponsiveness. • Lossof consciousness (veryrare if you do not take insulin). • Convulsions (extremely rare if you do not take insulin). • Death (extremelyrare if you do not take insulin).
One study has shown these symptoms to occur when blood sugar drops to 45-65 mg/dl.Furthermore, symptoms were foundto continuefor45 minutesaf ter blood sugarswerenormalized.
HowtoPrevent andCorrect Low Blood Sugars 319
Some Common Causes of Hypoglycemia In various chapters, particularly those covering insulin, we've dis cussed a number of different potential causes of lowblood sugar. Be low is a list of some common causes.
• Not waiting at least 5 hours after mealtime insulin before cor recting an elevated blood sugar.
This is especially dangerous at bedtime. • Too much delay before eating a meal aftertakingregular or lispro insulinor classic OHAs, suchasthe oldsulfonylureas and similar newer agents. • Delayed stomach-emptying aftera meal (see Chapter22). • Reduced activity of counterregulatory hormones during certain phasesof the menstrual cycle. • Sudden termination of insulin resistance after abatement of ill ness or stress that required higher than usual doses of classic OHAs or insulin. • Injecting from a fresh vial of insulin after having used progres sively 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. • Incorrecdyassumingthat lisproisequivalent in potency to regu lar insulin or that biosynthetic human insulinshavethe samepo tency as animal insulins.* • Eating less than the planned amount of carbohydrate or protein for a meal or snack. • Taking too much insulin or OHA. • Engagingin unplanned physical activityor failing to cover phys icalactivity with appropriatecarbohydrates. • Drinkingtoo much alcohol, especially prior to or during a meal. • Failure to shakevialsof NPH insulinvigorously before using. • Inadvertentiy injectinglong-actingor premealbolus insulin into a muscle. • Injecting near a muscle that will be strenuously exercised.
*These new ultra-rapid-acting insulins have about 50 percent more blood sugar-lowering effect than regular insulin, despite statements to the contraryby their manufacturers.
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• Using insulin that contains protamine (NPH; see page 264). • Taking aspirin in largedoses, or anticoagulants, barbiturates, an tihistamines, or certain other pharmaceuticals that may lower blood sugar or inhibit glucose production by the liver (see Ap pendix C). • A sudden change from cool weather to warm weather.
Common Signs and Symptoms of Hypoglycemia
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 frequendy ig nored, 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 merelyreflecthunger pangs provokedby mealtime,emotional factors, or evenhigh blood sugars.
Whenblood sugars are high,the cells of the body are actuallybeingdeprived of glucose, and you mayfeel hungry.
Thus, hunger is very common in poorly controlled diabetics.
Ifyou feel hungry, measure your bloodsugar!
Impaired visual acuity. Even mild hypoglycemia can make for dif ficultyin reading street signsor fine print. More severe hypoglycemia can cause double vision.