The Adjustment: Be prepared to cut back on basal insulin levels after age sixty. Hypoglycemia is particularly dangerous in the elderly because of impaired counter-regulation, the body’s hormones do little to help raise the blood sugar back toward normal in the event of a low, as well as the risk of falls and heart attacks when hypoglycemia strikes.
Brain Work
My dad used to tease me by saying that my brain was the hardest working muscle in my body.
In fact, the central nervous system is one of the body’s major consumers of glucose.
Brain cells rely almost exclusively on glucose for energy.
Whenever the brain is working hard, blood sugar levels may drop.
This can occur during periods of intense concentration (studying, multitasking), adjustment to new surroundings (new job, new home), and complex social situations (hosting a party, business networking, “working the floor”).
Simply being in an environment that features lots of mental stimulation, such as a shopping center, supermarket, arcade, or casino, can make blood sugars drop.
The Adjustment: Predicting when extra brain activity is going to induce a blood sugar drop can be difficult. However, if you detect a pattern of blood sugar drops in certain situations, either reducing your insulin or increasing your food intake in anticipation of such events makes sense.
For example, I have a tendency to “drop while I shop” at the grocery store. In response, I try to go grocery shopping after lunch and reduce my lunch bolus by about a third to prevent hypoglycemia. If I forget to make the adjustment, I’ll just graze on pretzel sticks while I shop.
Alcohol
Alcoholic beverages that contain carbohydrates, such as beer, table and dessert wine, wine coolers, hard lemonade, and frozen and mixed drinks, will raise blood sugar in the short term.
Beer, regular beer and craft beer, is like liquid bread: it raises blood sugar pretty quickly.
However, alcohol has a tendency to lower blood sugar levels several hours later by keeping the liver from secreting its normal amount of glucose into the bloodstream.
As a result, hypoglycemia can occur a while after drinking.
The fact that intoxication often masks the symptoms of hypoglycemia and keeps glucagon from working properly makes the risk of severe hypoglycemia even worse.
Neither the person with diabetes nor people around them are aware of the low blood sugar because the hypoglycemic symptoms take on the look, sound, and feel of being drunk.
Consequently, preventing hypoglycemia is of paramount importance when drinking.
The Adjustment: When drinking, it is usually advisable to bolus to cover the carbohydrates in your beverages. However, it is also necessary to make adjustments to prevent a delayed blood sugar drop from the alcohol. If you use an insulin pump, a temporary basal reduction of 30 to 50 percent for two hours
per drink can work quite well, since each alcoholic beverage takes about two hours (on average) to be processed by the liver (the bigger you are, the less time it takes; the smaller you are, the longer it takes). In other words, if you have three drinks, lower the basal for six hours. Five drinks? Ten hours.
If you take NPH at bedtime, consider lowering the dose by 10 percent for each drink you had that evening, up to an 80 percent reduction. If you take glargine or detemir, take the usual dose, but have a modest-sized slowly digesting snack (without bolusing) before going to bed. Examples include nuts, yogurt, chocolate, and carrots.
Climate
Warm temperatures and humidity have a tendency to cause blood sugar levels to drop. This is due to dilation of blood vessels near the skin surface, resulting in accelerated absorption of insulin from below the skin. Exposure to very cold temperatures can also cause blood sugar levels to decline as the body’s energy expenditure increases in order to produce heat.
The Adjustment: Seasonal changes may require modest (10 to 20 percent) changes in basal as well as bolus insulin doses. You may need short-term dosage adjustments when traveling to a climate that is much colder, warmer, or more humid than what you are used to. When you move exercise from indoors to outdoors, you may require a more significant preworkout bolus reduction than usual, particularly when the weather outside is very hot or humid.
High Altitude
Traveling to altitudes that are much higher than you are accustomed to can cause blood sugar levels to drop.
At high altitudes the metabolism (heart rate, respiration) increases in order to deliver enough oxygen to the body’s cells.
Luckily, the body usually adjusts to high altitudes within a few days, and metabolism returns to normal.
Also, be careful when using your blood glucose meter at very high altitudes.
Some meters do not give accurate readings above ten thousand feet (check your owner’s manual, or call the meter manufacturer to see if your meter may be affected).
Most CGM systems perform normally even at high altitude.
The Adjustment: Be prepared to reduce your basal insulin by 20 to 40 percent for the first couple of days when traveling to high altitudes. This will keep your blood sugar from dropping between meals and while you sleep. Exercising at high altitudes may require a greater dosage reduction than you are used to, as the body has to work extra hard to supply enough oxygen to your muscles.
Nausea
Any time your stomach is upset, there is a good chance that food you have eaten recently will either digest much more slowly than usual or not absorb completely. If vomiting occurs, food you may have bolused for fails to ever reach the bloodstream. This, of course, puts you at risk for hypoglycemia.
The Adjustment: If nausea is common or predictable (such as during chemotherapy or early stages of pregnancy), consider taking your bolus insulin an hour or two
after eating, once you are certain that your food will stay down. Likewise, if your stomach is upset at the time of a meal or snack, consider delaying the bolus until after you have eaten just to make sure you have only covered carbs that you actually consumed.
If your blood sugar is dropping and you are unable to tolerate ordinary food or beverages, there are a few ways to keep your blood sugar from bottoming out.
First, try placing glucose tablets or dextrose-containing candy under your tongue or in your cheek.
Even without swallowing, some of the sugar can be absorbed through the lining of the mouth.
An upset stomach can sometimes tolerate low-sugar (but not sugar-free) beverages, such as sports drinks or diluted juice.
Another option, if you use an insulin pump, is to turn the basal rate on your pump down by 80 to 90 percent for a few hours (something that might occur automatically if you use an automated hybrid closed-loop system).
You may also give yourself a small injection of glucagon, using an insulin syringe to inject the glucagon just below the skin.
Ten to twenty units of glucagon are usually sufficient to reverse a downward trend in the blood sugar fairly quickly.
This type of micro-dosing is possible with the older glucagon kits and the new prefilled glucagon syringes, but not with the nasal version.
Other Medications
Starting or adding any diabetes medication to your management program can reduce your need for insulin. Other medications, including antidepressants (including MAO inhibitors), nicotine patches, and some antibacterial agents, may result in a temporary reduction in blood sugar levels.
The Adjustment: Speak to the physician who prescribed the medication to determine whether the dosage warrants any up-front changes in your insulin doses.
Otherwise, take a wait-and-see approach.
If you notice lower than usual blood sugar levels around-the-clock after starting (or increasing) the medication, cut back on your basal insulin in 10 percent increments until the problem is resolved.
If the lower readings take place at a consistent time of day, reduce your bolus insulin prior to that time.
For example, if you have been going low in the afternoon since starting on a nicotine patch, reduce your lunchtime bolus.
Stuff That Can Make Your Blood Sugar Rise or Fall
Just when you think you have it all figured out, along comes something that can cause blood sugars to rise or fall, depending on the situation. But don’t freak out, we can handle these.
Impaired Digestion
Gastroparesis is a form of diabetic neuropathy in which the stomach is slow to empty its contents into the intestines. Food digests much slower than usual, so the blood sugar has a tendency to rise several hours after eating rather than right after the meal. Those who take rapid-acting insulin at mealtimes sometimes see a drop in their blood sugar soon after eating, as the insulin begins working but the food doesn’t, followed by a rise as the food kicks in around the time the insulin is wearing off.
The Adjustment: Gastroparesis can be treated in a variety of ways.
Facilitating the movement of food into the intestines is possible with oral medications, electrical stimulation, or modifications to the diet.
If these prove to be ineffective, you will need to make adjustments to the timing or type of mealtime insulin.
Switching from rapid-acting insulin to regular insulin works well for many people with gastroparesis.
Regular insulin’s delayed peak (two to three hours after injection) and prolonged duration of action (five to six hours) often matches the absorption of sugars into the bloodstream for those with slow digestion.
Another option is to delay the mealtime bolus until thirty to sixty minutes after the meal.
Those who use insulin pumps can extend their bolus over a couple of hours to delay or blunt the peak and prolong the action curve of the insulin.
Menstruation
During various phases of the menstrual cycle, the body produces hormones that can raise or lower blood sugar levels. Many find that their blood sugar levels are significantly higher for several days before the onset of their period and then lower for a day or two after menses begins.
To determine whether you have a pattern of glucose ups and downs related to your menstrual cycles, note the onset of your period for a few months, and then take a look at the daily or long-term trend report from your meter or CGM. In Figure 8.3 , a period that started on January 28 was preceded by three days of elevated glucose levels.
Figure 8.3: Average glucose levels went up starting three days before the start of menses. Note that the average values are in mmol/l (multiply by 18 for equivalent mg/dl averages).
The Adjustment: If you find a consistent pattern of elevated readings before your period or lower than normal glucose levels after your period starts, it makes sense to adjust your basal insulin dose proactively.
As soon as premenstrual symptoms and elevated glucose levels appear, raise your dose of injected basal insulin (or the basal delivered by your pump) by 20 percent to 40 percent.
Pump users also have the option of setting up a secondary basal program just to use during the premenstrual phase of the month.
Don’t forget to return to your usual settings once your period begins!
To prevent lows after your period, reduce your basal insulin by a similar amount for a day or two.
Travel
Travel can present special challenges for people with diabetes. With changes in meals, activity, and sleep schedules, blood sugars may vary quite a bit when you travel. Time zone changes can wreak havoc on control because your normal basal insulin patterns may not match your sleep/wake schedule at your destination.