Those who use premixed insulin twice daily are, essentially, utilizing this approach for their basal insulin program. Each injection of premixed insulin contains anywhere from 50 to 75 percent NPH insulin, with the remainder being either regular or rapid-acting insulin.
Basal Option C: Detemir Once Daily
For most people, taking detemir once daily fails to provide stable twenty-four-hour basal insulin coverage (see Figure 5.5 ). However, some find that detemir’s modest peak can help offset a middle-of-the-night or early-morning dawn effect, if timed properly.
Figure 5.5: Basal insulin supplied by detemir (Levemir) taken once daily
Basal Option D: Glargine or Degludec Once Daily, or Detemir Twice Daily
Detemir can be taken twice daily in order to provide more stable twenty-four-hour basal insulin.
When injected twice daily, it is best to split the doses evenly and take them approximately twelve hours apart.
Taking more in the evening and less in the morning does not tend to produce a desired ebb/flow to the basal insulin.
The main advantage of using detemir twice daily, or glargine or degludec once daily, is the relatively unwavering state of the basal insulin (see Figure 5.6 ).
However, the blood sugar may rise during the night or early morning hours (when the liver tends to secrete extra glucose) or drop in the afternoon, as the basal insulin level may exceed the liver’s production of glucose.
Some studies suggest that the longer, flatter profile produced by concentrated degludec (brand name Tresiba) results in less risk of hypoglycemia, particularly overnight.
Figure 5.6: Basal insulin supplied by glargine once daily, degludec once daily, or detemir twice daily
To overcome some of the pitfalls of only using long-acting or NPH insulin, it is possible to use both. A modest dose of glargine or degludec can provide around-the-clock background insulin (and not enough to cause the blood sugar to drop between meals during the daytime), and a modest dose of NPH in the evening can provide a basal peak to offset a nighttime or early-morning rise (see Figure 5.7 ). This program offers the unique advantage of allowing day-to-day adjustment of the overnight basal insulin level (by adjusting the NPH dose) without affecting the basal insulin level the following day.
The disadvantages include the need for at least two separate injections (you can’t mix NPH and long-acting insulin in the same syringe or pen) and the filling of multiple prescriptions. There is also potential for mixing up doses or taking the wrong insulin at the wrong time because several different types of insulin are being used simultaneously.
Figure 5.7: Combining long-acting basal insulin with NPH can provide a better match for those who need a basal peak overnight or in the early morning.
Basal Option E: Insulin Pump Therapy
Insulin pump therapy allows for the greatest degree of fine-tuning in terms of basal insulin.
Because the pump uses pulses of rapid-acting insulin to deliver basal insulin, it is pretty easy to program basal peaks and valleys at various times of day (see Figure 5.8 ).
Pumps also permit temporary changes to basal insulin levels in order to accommodate short-term changes in basal insulin needs (for situations such as illness, high/low activity levels, and stress).
Certain patch pumps, such as the V-Go, deliver a constant or flat rate of basal insulin; the delivery rate cannot be altered by time of day, and temporary adjustments to delivery are not possible.
Perhaps the greatest drawback to delivering basal insulin with a pump is the risk of ketoacidosis.
Any mechanical problem resulting in a lack of basal insulin delivery can result in a severe insulin deficiency in just a few hours.
Without any insulin in the body, cells begin burning large amounts of fat (instead of sugar) for energy.
As a result, large amounts of acidic ketone molecules, a natural waste product of fat metabolism, build up.
This rarely occurs when taking injections of long-acting insulin because there is almost always some insulin working (as long as injections are not missed).
Figure 5.8: Basal insulin supplied by an insulin pump can match each person’s basal insulin needs quite closely.
Bolus Insulin
Basal insulin by itself would work just fine, if we never ate.
Needless to say, bolus insulin is also necessary to deal with the blood sugar rise that occurs after eating.
As discussed in the previous chapter, all carbohydrates (with the exception of fiber) eventually turn into glucose.
Most carbohydrates take about ten to twenty minutes to start raising the blood sugar level and two to four hours to finish digesting.
Usually, the blood sugar hits a high point (peak) thirty to ninety minutes after eating.
Thus the need for bolus insulin for offsetting the effects of food and for bringing elevated blood sugars down as quickly as possible.
Bolus Option A: Rapid Insulin
Rapid-acting insulin analogs such as aspart (Novolog/NovoRapid), glulisine (Apidra), and lispro (Humalog, admelog) peak sharply about sixty to ninety minutes after injection.
Rapid insulin can be used to cover meals and minimize postmeal blood sugar spikes when taken at the right times (usually ten to fifteen minutes prior to eating).
Rapid insulin is particularly effective when consuming sugars and easily digesting starches such as bread, cereal, potato, rice, pastries, juices, and candies.
Rapid insulin can also be used to bring elevated blood sugar levels back down to normal in about three to four hours.
Bolus Option B: Ultra Rapid Insulin
Insulin manufacturers continue to look for ways to make rapid-acting insulin work even faster, in order to eliminate the need for premeal dosing and correct high readings even more quickly.
The first ultra-rapid insulin on the market, Fiasp from Novo Nordisk, starts working and peaks an average of eight minutes earlier than traditional aspart insulin.
During the first hour after injection, Fiasp works 50 percent harder than traditional aspart, which results in less of a postmeal blood sugar peak.
Fiasp is well-tolerated by most users, but some report mild site irritation.
Pump users sometimes report inconsistent absorption after using Fiasp for a few months; the problem typically resolves when switching back to traditional aspart.
Other companies are using creative approaches to make lispro insulin work faster, by combining it with ingredients that dilate blood vessels near the skin surface or “liquify” the subcutaneous fat layer to help accelerate the insulin’s absorption. With any ultra-rapid insulin, users must pay careful attention to the timing of their boluses, particularly with slowly digesting meals. Bolus timing will be discussed in greater detail in