From the Guidelines
Checking fasting insulin levels is crucial for assessing insulin resistance and identifying individuals at risk for developing type 2 diabetes, metabolic syndrome, and cardiovascular disease, as it provides insight into the body's ability to regulate blood sugar levels, even when blood glucose levels appear normal 1.
Importance of Fasting Insulin Levels
Fasting insulin levels are a valuable tool in evaluating insulin resistance, which is often associated with type 2 diabetes, obesity, hypertension, and dyslipidemia. The test is typically performed after an 8-12 hour fast and is often ordered alongside fasting glucose tests.
- Elevated fasting insulin levels (above 15 mU/L) may indicate insulin resistance, even when blood glucose levels remain normal.
- This can help identify individuals at risk for developing type 2 diabetes, metabolic syndrome, polycystic ovary syndrome (PCOS), or cardiovascular disease before more obvious symptoms appear.
- Measuring fasting insulin provides insight into how hard the pancreas is working to maintain normal blood sugar levels, as persistently high insulin production can eventually lead to pancreatic beta cell exhaustion and diabetes.
Clinical Application
The test is particularly valuable for patients with:
- Obesity
- A family history of diabetes
- High blood pressure
- Abnormal cholesterol levels
- Those experiencing unexplained fatigue For accurate results, patients should avoid eating, drinking anything except water, exercising, or taking certain medications before the test as directed by their healthcare provider.
Recent Guidelines
Recent studies, such as those published in 2020 and 2021 1, have emphasized the importance of glucose monitoring in managing diabetes, but the specific focus on fasting insulin levels as a diagnostic tool for insulin resistance remains a critical aspect of preventive care, as highlighted in earlier guidelines 1.
From the Research
Importance of Checking Fasting Insulin Levels
Checking fasting insulin levels is crucial for several reasons:
- It helps in assessing insulin resistance, a common finding in diabetes mellitus 2
- Insulin resistance can serve as a measure of efficacy of therapies for diabetes mellitus, such as exercise, exogenous insulin, sulfonylureas, and PPAR gamma agonists 2
- Fasting insulin levels can be used as a possible marker for risk of developing type II diabetes mellitus 2
- Elevated fasting insulin levels may be more specific for insulin resistance, while other measures like QUICKI might be more sensitive 2
Relationship with Metabolic Risk Factors
Fasting insulin levels are related to various metabolic risk factors, including:
- Waist circumference and BMI, which are significant factors associated with fasting insulin levels 3
- Triglycerides and HDL cholesterol, which are also associated with fasting insulin levels 3
- Mean blood pressure, which is another factor related to fasting insulin levels 3
Association with Mortality Risk
Elevated fasting insulin levels or insulin resistance are associated with an increased risk of: