For people with Type 1 diabetes, is there really anything more personal and significant in your life than your insulin program? In a way, your insulin program defines your lifestyle. It can either dictate your meal, sleep, and activity schedules, or it can set you up for successful control of your diabetes. Unfortunately, most people are given little choice or education on how to select the insulin program that best meets their needs. As a matter of fact, many people probably put more thought and effort into choosing a car — perhaps because they have a better idea of what they’re looking for.
So what should you look for in an insulin program, and how do you know if the one you’re following is really the best one for you? Read on for some tips on this important decision.
What’s in an insulin program?
Every insulin program for people with Type 1 diabetes should include a basal, or “background,” insulin. Basal insulin is necessary to cover the liver’s secretion of glucose throughout the day and night, which provides the cells with a continuous supply of glucose to burn for energy. Insufficient basal insulin at any time will result in a sharp rise in blood glucose level and can also lead to the buildup of ketones, acidic by-products of fat-burning that can accumulate in large amounts if no glucose is being burned simultaneously. If high blood glucose and ketones are not treated promptly, a life-threatening condition called diabetic ketoacidosis can develop.
Each person’s basal insulin requirements are unique, but typically they are higher during the early morning and lower in the middle of the day. This is due to the nighttime production of blood-sugar-raising hormones and to the enhanced insulin sensitivity that comes with daytime physical activity.
Basal insulin coverage can be supplied by a variety of insulins. Intermediate-acting insulin (NPH) is typically taken once or twice daily. NPH begins working within 1–3 hours, provides peak coverage about 4–8 hours after injection, and tapers off about 12–24 hours after the injection. The long-acting basal insulin analogs glargine (brand name Lantus) and detemir (Levemir) offer relatively peakless background insulin for approximately 24 hours; They are usually injected once a day. Insulin pumps deliver rapid-acting insulin in small pulses every few minutes for basal coverage; this output can be adjusted and fine-tuned to match the body’s fluctuating basal insulin needs.
In addition to basal insulin, mealtime insulin “boluses” are needed to cover the rapid blood sugar rise that occurs after eating. Carbohydrate (sugars and starches) usually takes about 10–15 minutes to begin raising your blood sugar level, with a high point occurring about 30–90 minutes after eating, depending on the size and composition of the meal. Ideally, mealtime insulin doses should be timed so that the insulin’s peak activity occurs simultaneously with the peak blood sugar rise after the meal.
The rapid-acting insulin analogs aspart (NovoLog), glulisine (Apidra), and lispro (Humalog) begin acting within 5–15 minutes of injection and peak about 30–90 minutes after injection, making these convenient and effective mealtime insulins: They can be taken just prior to eating, and they clear rapidly from the bloodstream, reducing the risk of low blood glucose later on. Regular insulin, which is considered a short-acting insulin, peaks about 1–3 hours after injection and must be taken 30–60 minutes prior to the meal. Due to its relatively slow and inconsistent peak and long duration of action (it can last up to six hours), Regular can sometimes cause hypoglycemia several hours after a meal. However, Regular can sometimes be the preferred mealtime insulin — for instance, when an extra-large or high-fat meal is likely to raise blood glucose gradually over several hours.