Maintaining healthy insulin levels is essential for overall well-being, as insulin plays a pivotal role in regulating blood sugar and ensuring the proper functioning of the body's metabolic processes. Insulin levels can vary based on many factors, including genetics, age, ethnicity, race, and gender. In this article, we'll look into normal insulin levels for women.
What Is Insulin and How Does It Work?
Insulin is a hormone that regulates blood glucose levels. It is produced in the pancreas by pancreatic beta cells. When you eat food, beta cells release insulin, which carries blood sugar into tissues and organs, where it is either used to produce energy or stored.¹
Lack of insulin or insulin inefficiency causes diabetes, which is a chronic disease characterized by abnormal blood glucose levels. Most people don't know that they have prediabetes and even diabetes. That's why early diagnosis of abnormal insulin and blood glucose is crucial to prevent diabetes.
Diabetes and Insulin Resistance
Generally, the body lives with abnormal blood glucose levels and insulin resistance long before the diagnosis of insulin resistance or diabetes. In the U.S., 1 in 5 people don't know they have diabetes because they don't experience symptoms.
Let's learn what insulin resistance is and how it can lead to diabetes if left untreated.
Insulin is produced to carry blood glucose to cells. In insulin resistance, tissues and organs resist insulin, so they don't respond as they should. So, the blood glucose level doesn't decrease as much as it normally does. As a result, the pancreas produces even more insulin to lower blood glucose levels, so blood glucose and insulin levels stay elevated.²
There are many types of diabetes, but the most common are type 1 and type 2 diabetes. In type 1 diabetes, beta cells produce little or no insulin. In type 2 diabetes, beta cells still produce insulin, but tissues and organs resist it, so it's not effective to maintain blood glucose levels in a healthy range.
What Are Normal Insulin Levels for Women?
There is a range of normal levels of insulin. Healthy blood insulin levels can vary based on many factors, including genetics, age, ethnicity, race, and gender. Sex-specific insulin levels are suggested in some research papers for specific populations; however, there is no general reference value for women.³
Normal insulin fasting insulin levels are below 25 mIU/L (174 pmol/L). ⁴ Some resources indicate lower levels, such as 3–15 mIU/L (18–90 pmol/L). ⁵
Diagnosis of insulin resistance is not generally made with the result of only blood insulin levels. Additional tests include fasting glucose, oral glucose tolerance test (OGTT), hemoglobin A1c (HbA1c), and medical assessment. All tests are evaluated in context by a healthcare professional. ²
What is Considered a High Insulin Level?
High insulin levels, often called hyperinsulinemia, occur when the pancreas produces more insulin than usual to regulate blood sugar levels. Common causes of high insulin levels:
Resistance to Insulin
This occurs when cells become less responsive to insulin, leading the body to produce more insulin to lower blood glucose levels. Insulin resistance is often associated with obesity, metabolic syndrome, and type 2 diabetes.
Women go through physiological changes during pregnancy. Insulin increases, especially during late pregnancy. In the third trimester, insulin sensitivity (which represents how responsive your cells are to insulin) drops by 50% of the normal value.⁶
The placenta, an organ that connects mother and child, produces hormones. Increases in certain hormones (including estrogen, cortisol, and human placental lactogen) can decrease insulin response, leading to insulin resistance. ⁷
Gestational diabetes is a type of diabetes resulting from pregnancy, and generally, it heals after giving birth. Between 24 and 28 weeks of pregnancy, pregnant women are tested for gestational diabetes.
Obesity and insulin resistance are like a chicken and egg question. Excess fat tissue can contribute to insulin resistance and high insulin levels. On the other side, insulin resistance can accelerate obesity. Obesity is a major risk factor for insulin resistance and type 2 diabetes.
Steroid medications, HIV treatments, and psychiatric and blood pressure medications can cause insulin resistance.⁸
Type 2 Diabetes
People with type 2 diabetes can have elevated insulin levels due to the body's attempt to compensate for the impaired insulin action. However, the pancreas gets tired at some point and damages pancreatic beta cells, resulting in low insulin production.
Polycystic Ovary Syndrome (PCOS)
Hormonal imbalances and insulin resistance characterize PCOS. High insulin levels are often seen in individuals with PCOS.⁹
Symptoms of High Insulin Levels
High insulin levels are commonly caused by insulin resistance; however, in some cases, it can be caused by a tumor in pancreatic beta cells called insulinoma.
Hyperinsulinemia may not show any symptoms because the pancreas overproduces too much hormone to compensate for the insufficiency of insulin seen in insulin resistance.¹⁰ Some of the symptoms of high insulin levels are:
- Weight gain
- Sugar cravings
- Feeling intense hunger
- Difficulty concentrating
- Lack of focus or motivation
And How About Low Insulin Levels?
Too little insulin is as harmful as too much insulin.
Your healthcare provider will evaluate the results of insulin levels alongside other biological parameters such as blood glucose levels and HbA1c, a marker of insulin resistance.¹¹ There could be many reasons for low insulin levels, including:
Type 1 Diabetes
The most common reason for low insulin levels is type 1 diabetes, characterized by low insulin and high blood glucose levels.
Low insulin levels can be caused by pancreatitis as well. An inflamed pancreas causes pancreatitis. The pancreas also produces some digestive enzymes. When digestive enzymes digest the pancreas, pancreatitis occurs. It can be acute and chronic, a dangerous disease that can cause death if untreated. ¹²
In hypopituitarism, the pituitary gland does not produce sufficient hormones, including growth hormone and adrenocorticotropic hormone (ACTH). These deficiencies can impact insulin production and blood sugar regulation.
Improper Insulin Use
People living with diabetes who take insulin to manage their blood sugar levels may accidentally administer too much insulin, causing blood sugar to drop too low.
Symptoms of Low Insulin Levels
Low insulin levels can lead to a condition known as hyperglycemia, where blood sugar levels drop below the normal range. Hyperglycemia can occur in individuals living with diabetes who take insulin or diabetes medications.¹³ The symptoms can be:
- Increased thirst
- Dry mouth
- Frequently peeing
- Blurred vision
- Unintentional weight loss
- Recurrent infections
Why It's Important To Keep Healthy Insulin Levels
Abnormal insulin levels, whether too high or too low, can lead to serious health problems, including obesity, diabetes, metabolic syndrome, polycystic ovary syndrome (PCOS), and cardiovascular diseases.
Insulin resistance can be treated with medications and lifestyle interventions.
High insulin levels due to improper use of diabetes medication (taking too much insulin) can lead to hypoglycemia (low blood sugar), which can cause shakiness, dizziness, confusion, and even loss of consciousness.
In insulin resistance, tissues and organs resist insulin, decreasing glucose entrance in cells and leading to high blood sugar levels. One way the body deals with excess glucose is by converting it into fat. This process is known as lipogenesis. The fat is then stored in adipose tissue throughout the body.
In the early stages of insulin resistance, insulin levels are high; however, the pancreas cannot produce too much insulin forever. Pancreatic beta cells get exhausted with time, and tissue damage happens, resulting in low insulin production and diabetes. Lack of diabetes treatment and management can cause serious health problems, including kidney disease, nerve damage, organ loss, and vision problems.
Metabolic syndrome is characterized by high blood pressure (hypertension), glucose, abdominal adiposity, and abnormal cholesterol. Insulin resistance contributes to metabolic syndrome by accelerating obesity and cholesterol.
Polycystic ovary syndrome (PCOS)
High insulin is commonly seen in women with PCOS. Interventions (lifestyle changes and medications) to improve insulin resistance can support PCOS treatment.
Insulin resistance can increase heart disease risk.¹⁴ Lipid profile changes from insulin resistance can contribute to coronary artery disease, increasing the risk of heart attack and stroke. ¹⁵
How to Check and Get Your Insulin Levels Tested
Both high blood insulin and low blood insulin threaten health. ¹⁶
If blood insulin levels exceed the healthy range, there is a risk for hypoglycemia and abnormally low blood glucose levels. Severe hypoglycemia can cause brain damage.
On the contrary, If blood insulin is too low, glucose can't enter the cells; thus, blood glucose levels rise too much, which is called hyperglycemia. Chronic rise in blood glucose levels can lead to type 2 diabetes.
An insulin blood test evaluates pancreas function, diagnoses insulin resistance, finds the cause of abnormal blood glucose, and decides the best treatment for type 2 diabetes.
Insulin blood test is commonly called fasting insulin, free insulin, total insulin, and insulin serum. The C-peptide test is generally done alongside the insulin test. C-peptide is a molecule that releases the bloodstream in equal amounts of insulin. Because C-peptide stays longer in the blood, it's considered a better measure of insulin production.
A healthcare professional will take a blood sample from your vein; it's an easy procedure, and only a small needle is used.
You need to stop eating and drinking 8 to 12 hours prior to the tests. If you're using supplements containing biotin, stop taking them at least a day before the tests. You shouldn't stop taking any prescribed medications before consulting your doctor.
Your doctor will evaluate the blood test results alongside your medical history.
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Topics discussed in this article:
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- PCOS (Polycystic Ovary Syndrome) and Diabetes. Centers for Disease Control and Prevention (CDC). Retrieved June 17, 2023 from: https://www.cdc.gov/diabetes/basics/pcos.html
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