The content in this article should not be taken as medical advice. Please consult with your healthcare provider regarding your individual health needs.
When diagnosed with Type 1, Type 2, or gestational diabetes, tracking and managing glucose levels becomes a crucial part of your daily routine. That can mean injecting doctor-prescribed insulin using a syringe, pen, or pump to stay in a specific glucose range as much as possible based on your needs.
Insulin is a hormone that helps our bodies use sugar for energy. People with diabetes often need to take insulin because their bodies don't make enough of it.
With Type 1 diabetes, the body’s immune system destroys the cells in the pancreas that create insulin. In Type 2 diabetes, the body is unable to use insulin effectively or produce enough. Gestational diabetes can arise during pregnancy when hormonal changes prevent the body from producing enough insulin or using it effectively.
There are two main types of insulin prescribed to people with diabetes: long-acting (basal) and rapid-acting (bolus). After diagnosis, if you’re prescribed insulin you may learn about giving yourself injections for meals or for "background" coverage.
What is basal insulin?
Basal insulin is similar to the insulin our bodies make naturally all day and night. It helps keep our glucose levels steady when we're not eating, like between meals and while we sleep. Think of it as the “cruise control” for glucose. Basal insulin is usually taken once or twice a day and works slowly over a long time. Commonly prescribed basal insulins include Levemir, Lantus, and Tresiba.
What is bolus insulin?
Bolus insulin is the insulin we take to cover the sugar from the food we eat and lower glucose when it gets above target range. It's like the "booster" that helps manage the rise in blood sugar after meals. Bolus insulin works quickly and is usually taken right before meals. It helps prevent our glucose from getting too high after we eat.
Why both basal and bolus insulin are important
Basal insulin keeps blood sugar levels steady throughout the day and night, while bolus insulin helps manage the spikes in blood sugar that happen when we eat. Together, they help people with diabetes keep their glucose levels in a target range. Both basal and bolus insulin are vital for people with Type 1 diabetes, while a person living with Type 2 or gestational diabetes may need only basal or both basal and bolus.
Does everyone with diabetes need both basal and bolus insulin?
It depends on the type of diabetes a person has and what their body needs.
A person living with Type 1 diabetes will always require insulin (injections or insulin pump)—both basal and bolus—because Type 1 diabetes is an autoimmune disease that destroys the cells in the pancreas that make insulin.
Someone living with Type 2 diabetes may or may not require insulin when first diagnosed, or they may need only basal, or may eventually need both basal and bolus insulin. Management of Type 2 diabetes can include healthy food choices, activity, oral medications, GLPI-RA, and/or insulin.
Gestational diabetes management can include healthy food choices and increased activity and may require insulin. Once the baby is born, the mom's glucose may return to non-diabetes levels, but it is important to follow up regularly with your doctor to have glucose levels checked and be screened for diabetes.
Whether its lifestyle changes, other types of medications, basal insulin, bolus insulin, or a combination of these things depending on what is recommended by your health care provider, the goal is to keep your glucose in your targeted range as much as possible. This helps you not only feel healthy day to day, but also avoid potential long-term complications of diabetes such as cardiovascular disease, eye problems, or nerve and kidney damage.
So, how do you know if you might need more or less insulin? How do you know when to bolus? What if your patterns of highs and lows begin to change over time, even when you take bolus or basal insulin as directed by your doctor?
The key is monitoring your glucose accurately and in real time to gain a much clearer picture of what your body is doing. And that's where continuous glucose monitoring systems like Dexcom G7 really help.
Six ways Dexcom CGM helps clear bolus and basal confusion
With Dexcom G7, you can see your glucose levels in real time and set alerts to see highs and lows to better stay on top of your bolus and basal insulin needs. Armed with that real-time knowledge, you can feel more in control and confident dosing insulin as recommended by your doctor.
Here are six ways Dexcom G7 can help you make better and easier decisions about bolus and basal insulin dosing:
- Pre-bolus: Sometimes, your doctor might suggest you "pre-bolus," which means giving yourself a certain amount of insulin with enough time before you eat to allow it to start working as the food is being digested to avoid a glucose spike. If you were to take the insulin right as you start to eat, it would still need 10 to 15 minutes to begin doing its job. A Dexcom G7 reading shows where your glucose level is and how it's trending before dining, so you can better align the timing of your bolus.
- Insulin Pumps and Automated Insulin Dosing: Pumps can deliver insulin at different rates, acting as both basal and bolus insulin and dosing throughout the day. Working with their doctor, pump users can tweak those amounts to be more personalized based on their pattern of glucose highs and lows, or if they need a little more insulin, particularly in morning hours. When paired with Dexcom G7, some insulin pumps can manipulate bolus and basal insulin rates automatically based on your CGM readings, a feature known as Automated Insulin Dosing (AID).
- Physical activity: Glucose levels can also drop or spike based on your physical activity, such as jogging, lifting weights, doing yoga, or going for a walk. When that happens, some might decide to take more or less bolus insulin if they plan to exercise before or after eating. Real-time CGM data can help you make that call with confidence. For example, you might notice patterns of hypoglycemia with physical activity and decrease your bolus amounts with meals prior to exercise.
- Urgent low soon alerts: Dexcom G7 features low alerts, including an Urgent Low Soon alert, which is particularly helpful for people who use bolus or basal insulin. An Urgent Low Soon alert will tell you if your glucose will be less than 55 mg/dL within the next 20 minutes, allowing you to take action, like eating, to avoid crashing glucose levels.
- Insulin stacking: Dexcom G7 also features a Delay 1st High alert that you can activate, if you choose, in the settings. That feature is helpful to avoid insulin stacking (injecting too much insulin too quickly), which compounds the impact of multiple insulin doses by not accounting for the insulin already active in your body, or your "insulin on board." This could happen when you want to give yourself extra insulin because you see your glucose is high after eating a meal, even though you've already bolused, For example, you can set a high alert for 180 mg/dL to let you know if you go above 180 mg/dL for more than two hours. But if you go above 180 mg/dL and come back down to your target range before that two hours elapses, you won't get a high alert. This feature helps if you have alert fatigue and is designed to prevent you from stacking insulin.
- Over-basalization: Dexcom G7 can also help you avoid over-basalization (a condition where a person with diabetes takes too much basal insulin), which causes hypoglycemia and usually occurs overnight. With fingersticking, even if you were to wake up once or twice a night to fingerstick and get a glucose reading, you're still not seeing the complete picture of what's happening within your body as you rest. You might go to bed with glucose at 200 mg/dL and wake up in the middle of the night at 80 mg/dL and be tempted to change your basal insulin dosing. But a CGM can show you the complete picture of what your body is really doing overnight and over time, so you can tell your doctor and get dosing advice and adjustments to better avoid those overnight drops and potential over-basalization.
Get started on Dexcom G7
If you are living with diabetes and not using a CGM, we can help get you started. Click the button below to send us some basic information. Work with a provider and your G7 data if you are considering adjusting insulin. The G7 can help you be prepared to make the most out of your visits and find solutions that work for you.
BRIEF SAFETY STATEMENT: Failure to use the Dexcom Continuous Glucose Monitoring System and its components according to the instructions for use provided with your device and available at https://www.dexcom.com/safety-information and to properly consider all indications, contraindications, warnings, precautions, and cautions in those instructions for use may result in you missing a severe hypoglycemia (low blood glucose) or hyperglycemia (high blood glucose) occurrence and or making a treatment decision that may result in injury. If your glucose alerts and readings from the Dexcom CGM do not match symptoms, use a blood glucose meter to make diabetes treatment decisions. Seek medical advice and attention when appropriate, including for any medical emergency.
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