Diabetes is a condition that interferes with blood sugar levels in people whose bodies don't produce the right amount of insulin — a hormone made in the pancreas. Blood sugar that’s too high (hyperglycemia) or low (hypoglycemia) can be dangerous — and can cause life-threatening complications, like a diabetic coma, diabetic ketoacidosis, dehydration and high blood pressure. That’s why many people with diabetes are given insulin as therapy to manage their diabetes and stabilize their blood sugar levels. Basal insulin is one of those therapies.
What is basal insulin?
Dr. Marie McDonnell, the director of the Brigham Diabetes Program at Brigham and Women’s Hospital in Boston, told TODAY that basal insulin is a long-acting insulin therapy that helps the body process blood sugar. “It’s very simple in that it just replaces a deficient hormone,” she said. Basal insulin is a common treatment for diabetes (most commonly Type 2 diabetes) when insulin deficiency reaches a degree that requires replacement.
According to the American Diabetes Association, insulin doesn’t come in a pill because it would just break down in your stomach during digestion. To get into your bloodstream, it must be injected into the fat under your skin with a tiny needle.
In some cases, a basal bolus insulin regimen may be prescribed. Also known as flexible insulin therapy, this regimen combines timed injections of basal insulin and short-acting bolus insulin throughout the day. With the advent of new delivery devices, however, this therapy is becoming less common.
The benefits of basal insulin
McDonnell said that for those with severe insulin deficiency, including Type 1 diabetes and advanced Type 2 diabetes, insulin keeps them alive. “It’s a hormone that helps us use fuel and store fuel. Without it, basically you starve to death,” she said.
It helps maintain glucose control
People with Type 2 diabetes who can’t make quite enough insulin to maintain control of their glucose use basal insulin.
It can last for at least 12 hours
Basal insulin is usually categorized by how long it lasts in your system, said McDonnell, adding that doctors choose which to prescribe according to the patient’s personal habits. “We might prescribe that ultra-long lasting insulin for a younger person with diabetes, like an adolescent, to start to take control of their diabetes, but they also are kids and might forget.”
Dr. Deena Adimoolam, an endocrinologist at Mount Sinai Morningside in New York City, told TODAY that because basal insulin is long acting, “it keeps your blood sugars stable for a longer period of time. Short acting insulin like aspart (Novolog) or lispro (Humalog) last up to 3 hours only so once it wears off, blood sugars rise again,” she said. “There is NPH, which is also known as intermediate-acting insulin, that may last for 12 hours. Longer-acting insulin, which lasts more than 24 hours, include detemir (Levemir), glargine (Toujeo, Lantus and Basaglar) and degludec (Tresiba).”
How much basal insulin do you need?
Insulin dosages vary dramatically from patient to patient, depending on their situation. “No matter how you start it, you know that the dose you start with is not the dose you're going to end with, after, say, a month of what we call titration,” said McDonnell. “We want to make sure we start the insulin at the right time and not wait too long. If you do take too much insulin, your blood sugar is too low, and that could be very dangerous, so we start low and go slow so that we don't overdose something that somebody could be sensitive to. We can't really rely on lifestyle change or other medicine if insulin is truly what’s needed at the time.”
But McDonnell also indicated that basal insulin is usually prescribed according to weight, like medicine is for children.
What are the side effects?
The main side effect of misdosed basal insulin is hypoglycemia, which is typically defined by a fingerstick test result of less than 70 (blood sugar level), said Adimoolam.
“Hypoglycemia can be uncomfortable at its best, meaning you feel shaking or sweating or hunger. But at its worst it can cause loss of consciousness,” McDonnell said. “Some motor vehicle accidents when people suddenly pass out, for example, can be attributed to hypoglycemia.”
What should or shouldn’t you eat on basal insulin?
The most important thing to do is go over your diet plan with your doctor and eat regularly, McDonnell said. “You don't have to change your diet per se because your dose will be adjusted according to your blood sugars, which generally reflect your diet,” she said. “But you don't want to miss meals because that can actually put you at risk of a low-sugar episode. There are some cases where we might suggest a bedtime snack. We try to dose basal insulin that’s safe enough so that if a patient doesn't eat at that time, their sugars won't go low.”
Adimoolam also said it’s important for those taking basal insulin to avoid skipping meals. To prevent hypoglycemia, she said, “I advise my patients to always have healthy snacks on hand in case they skip a meal. I also advise them to carry glucose tablets or juice with them always in the event their blood sugar drops very low.” She also recommended that those taking basal insulin be especially mindful of their sugary carbohydrate intake, especially sweets (cakes, candies and cookies), because these types of foods can raise one's blood sugar very high, which requires more insulin to control.
If you’ve recently been diagnosed with Type 2 diabetes, it may still be years before insulin is required — if lifestyle modifications are made, said McDonnell. “People can watch the way they eat, reduce refined sugars and carbohydrates and increase their activity by exercising regularly. We start basal insulin if other therapies aren’t working, or if blood sugar becomes very out of control.” It does sometimes happen, she said, that people get diagnosed when they go to the doctor because they feel sick.
“At that point," said McDonnell, "their blood sugar can be very high and insulin is started, but it can be temporary. That's the interesting thing about diabetes. It can be really dramatic and scary in the beginning, and then come under control for many, many, many years.”