What is the Connection Between Basal Insulin and Fasting Plasma Glucose?
Effectively managing diabetes involves a comprehensive approach that includes utilizing basal insulin for optimal blood-sugar control and monitoring fasting-plasma-glucose levels.
In this article, we will cover:
- What is fasting plasma glucose?
- What is basal insulin?
- How does basal insulin work?
- What are the benefits of basal insulin?
- How does basal insulin impact fasting plasma glucose?
- Practical considerations for people with diabetes
What is Fasting Plasma Glucose?
Fasting plasma glucose (FPG) is a blood test that measures your blood-sugar levels after not eating for at least eight hours.
FPG is also used to check for diabetes and monitor how well your body manages sugar when you haven’t eaten.
FPG is a critical parameter in diabetes management for several reasons:
Diagnosis
- FPG helps diagnose diabetes and prediabetes.
- An FPG level ≥126 mg/dL (7.0 mmol/L) indicates diabetes, while levels between 100–125 mg/dL (5.6–6.9 mmol/L) suggest prediabetes.
Monitoring
- Maintaining FPG within target ranges is essential for overall blood-sugar management.
Treatment Decisions
- FPG influences treatment choices.
- For instance, metformin therapy is recommended for adults at high risk of type 2 diabetes based on FPG levels.
- Additionally, basal insulin therapy primarily targets FPG control.
Risk Assessment
- Elevated FPG increases the risk of complications.
- Proper management helps prevent long-term health issues.
When there is no food on board while fasting, FPG provides an accurate image of:
- Whether your basal insulin is functioning as it should
- Whether you need to adjust your insulin dosage in response to food or elevated blood sugar levels, or
- Whether modifications are required to other diabetes drugs.
The normal FPG for people without diabetes is 99 mg/dL or below. However, in general, the range for people with diabetes is 70 mg/dL to 130 mg/dL.
Janice Baker, RD, CDCES, explains that the range for people who have diabetes can differ based on age, medication, and other coexisting health conditions.
What is Basal Insulin?
- Basal insulin is like the background music of blood-sugar control.
- Basal insulin works steadily throughout the day, keeping blood-sugar levels stable between meals and during sleep.
- Basal insulin replaces the insulin your body would naturally produce throughout the day in response to signals from your gut, muscles, and brain.
- According to Baker, the goal of basal insulin is to keep blood-sugar levels stable between meals and during sleep.
There are three types of basal insulin: intermediate-acting, long-acting and ultra-long acting.
Intermediate-acting Insulin
- Brand names for intermediate-acting insulin include Humulin and Novolin.
- Intermediate-acting insulin is injected once or twice a day, and is usually mixed with mealtime insulin in the morning, before your evening meal, or both.
- Intermediate-acting insulin is most effective in the four to eight hours after being injected
- It starts decreasing activity after 16 hours.
Long-acting Insulin
- Brand names for long-acting include Lantus, Toujeo, Basaglar.
- This form of insulin starts working between 1.5 and four hours after being injected.
- It stays in your bloodstream for up to 24 hours, but can become less effective a few hours before or after that depending on the person.
- It works at the same rate throughout the day.
Ultra-long-acting Insulin
- This kind of insulin has been around since 2016, and is known as Tresiba.
- It starts working within 30 to 90 minutes of being injected and stays in your blood for up to 42 hours.
- It works at the same rate throughout the day and comes in two strengths, 100 U/mL and 200 U/mL.
How Does Basal Insulin Work?
Basal insulin works like a quiet helper in your body.
Think of basal insulin as a slow, continuous stream of medication that lowers blood-sugar levels without becoming dangerously low.
According to Baker, basal insulin takes the place of insulin that can no longer be produced by the pancreas of people with type 1 diabetes.
Basal insulin also replenishes the insulin that the pancreas is still able to produce in people with type 2 diabetes.
Basal insulin is there all day and night—even when you’re not eating—to make sure your body stays balanced and healthy.
“Basal insulin mimics the body’s ability to use glucose as fuel,” says Baker. “It helps to unlock the cells so glucose can be used as energy or stored instead of having it build up in the bloodstream and cause high blood sugar levels.”
What Are the Benefits of Basal Insulin?
Basal insulin offers several benefits for managing blood-sugar levels in people with diabetes:
Prevents Hyperglycemia
- Basal insulin primarily targets fasting hyperglycemia and the liver’s production of glucose.
Fewer Injections
- Basal insulin requires only one or two shots a day, compared to bolus (“fast-acting”) insulin.
- This convenience enhances adherence and simplifies daily routines.
Steady Glucose Control
- Unlike bolus insulin, basal insulin has no peak time.
- It maintains even blood-sugar levels day and night, providing stability and flexibility in meal timing.
Flexible Lifestyle
- With basal insulin, you can eat more freely without strict timing requirements.
- It allows for variations in meal and injection times.
How Does Basal Insulin Impact Fasting Plasma Glucose?
Basal insulin plays a crucial role in managing diabetes—particularly in regulating FPG levels.
By providing a constant low level of insulin, basal insulin prevents the liver from producing excessive glucose during periods of fasting, such as overnight or between meals.
This steady insulin supply helps keep fasting plasma glucose levels within target ranges, reducing the risk of hyperglycemia.
Overnight, our bodies produce certain hormones to prepare us for the day ahead.
Part of that process plays into what’s called the “Dawn Phenomenon,” which is when blood-sugar levels rise in response to hormones signaling the liver to make more glucose so you have enough energy upon waking.
However, Baker explains that since basal insulin works steadily in the bloodstream, it doesn’t always match the glucose released by the liver in the morning, which can cause higher blood-sugar levels at that time of day.
“Looking at the overall patterns and seeing what’s going on, when was their last meal, their activity level, what was their sleep like, what’s their hydration status—we have to sift out a lot of different things to try to make sense of blood-sugar levels,” she says.
Practical Considerations for People with Diabetes
Just like other types of insulin, basal insulin must be administered using a syringe.
It is injected into the fat under your skin in order to enter your bloodstream.
When taking insulin, checking your blood-sugar levels is crucial to understanding its effect. That information helps your healthcare team make dosing adjustments and allows you to understand how different factors—besides insulin—impact your blood-sugar levels.
As with all medications, there are side effects of basal insulin.
“Any insulin is a powerful medication,” says Baker. “The biggest risk is hypoglycemia.”
Baker adds that variables like kidney function—which impacts how well insulin gets cleared out of your body—and GI issues—such as gastroparesis—also play into the risk of hypoglycemia.
It’s vital that both you and your healthcare provider are aware of these factors.
Conclusion
- Basal insulin is a powerful tool that can benefit fasting plasma glucose and can be easily added to your routine since it is only taken once a day.
- FPG and basal insulin are closely related because FPG gives insight into how well your basal insulin is working.
- There are different types of this insulin available, from intermediate-acting to long-acting to ultra-long acting.
- Basal insulin supplements the insulin still being made with type 2 diabetes
- Basal insulin replaces the insulin no longer being made by the body when type 2 progresses.
- Basal insulin replaces the insulin that a person with type 1 diabetes can no longer make.
- As with any medication, there are considerations to be made, such as side effects and the need to regularly check your blood-sugar levels.
If you have concerns about your diabetes regimen or would like to know if basal insulin is right for you, speak with your healthcare provider. They will be able to give you personalized advice so you can work together to determine which diabetes treatment regimen is right for you.
This content was made possible by Lilly, a Founding Partner of Beyond Type 2.
Beyond Type 2 maintains editorial control over its content.
