Insulin Fasting Test

Medically Reviewed By DR. VIJAY KUMAR 12 years of experience in Diabetology April 8, 2024

Welcome to our in-depth exploration of the insulin fasting test – a crucial diagnostic test in understanding metabolic health and assessing insulin resistance. In today’s world, where lifestyle factors and dietary habits play significant roles in health outcomes, comprehending insulin’s role in the body is paramount. In this blog, we delve into the complications of insulin fasting, covering everything from its significance and procedure to its associated symptoms, risk factors, and normal range. Whether you’re seeking to optimize your health or understand a recent diagnosis, join us as we navigate through the nuances of this vital test.

About Insulin Fasting Test

The pancreas produces the insulin hormone, which plays the principal role in stabilising the blood sugar levels. With the help of insulin, glucose present in the blood is moved into organs and cells. In the cells, the glucose is used for energy for cellular functioning and stored for later use. The fasting insulin test measures the amount of sugar present in the blood during the fasting state. If there is an excess amount of glucose present, there is a high chance that you need to be screened for ailments like prediabetes, diabetes and gestational diabetes. When abnormalities are observed in blood sugar, it’s high time to step up and get a proper diagnosis. The insulin fasting test will significantly help in this diagnosis and course of treatment.

Insulin Fasting Test Uses

Fasting insulin test is used along with blood sugar tests for the following:

  • For detecting the level of insulin resistance: Insulin resistance increases the instances of blood sugar fluctuations and the chances of diabetes. Prolonged periods of high insulin resistance in the body may give rise to diabetes-related complications.
  • Helps in figuring out the effectiveness of ongoing treatment: Apart from the two reasons stated above, this test helps monitor your insulin levels during treatment and medications. The doctor, based on the test results, may modify the treatment course and medicines.
  • For monitoring pancreas functioning: The insulin fasting test also helps in analysing proper pancreas functioning, especially after surgeries like islet cell transplantation.

Read More: Urine Sugar Test and Normal Blood Sugar in Urine Chart

Brief Details of Fasting Serum Insulin Test

Also Referred As: Fasting Insulin Test
Purpose: Measuring blood insulin levels and revealing levels of insulin resistance and treatment.
Preparations you need to make: Fasting for at least 8-10 before the test. If on any medication, discuss it with the doctor first.
Fasting Duration before the test: 8 to 10 hours
Report Arrival Time: Generally, within 24 hours
Fasting Insulin Test Cost: Cost ranges between Rs 700 to Rs 800

Read More: Know What A1c Test Measures

Symptoms for Insulin Fasting Test

Symptoms for Insulin Fasting Test

There are certain symptoms that may prompt your doctor to make you go for the insulin fasting test. Here are the leading symptoms that may imply the need for the test:

Excessive thirst and urination

Frequent urination, especially during your night’s sleep, and excessive urge of thirst can be signs of insulin resistance or diabetes, which an insulin fasting test can help diagnose.

Fatigue and lethargy

Another common symptom is just feeling constantly fatigued, like you’re dragging yourself through the day no matter how much sleep you get. Imbalanced insulin and blood sugar levels can definitely cause that zapped energy.

Unexplained weight changes

Sudden, unexplained weight loss or weight gain can be a sign of insulin dysregulation.

Skin tags or Acanthosis nigricans

Developing skin tags or that velvety, darkened skin on the neck or other areas – that’s called acanthosis nigricans, and it’s often linked to insulin resistance. And if you have polycystic ovarian syndrome (PCOS), an insulin test can provide really useful insights since insulin issues are a big part of that condition.

Polycystic ovarian syndrome (PCOS)

Women with PCOS often have underlying insulin resistance, which an insulin fasting test can help evaluate.

Family history of diabetes or metabolic disorders

If you have a close relative with type 2 diabetes or other metabolic conditions, you may be at higher risk and a candidate for an insulin fasting test.

Difficulty losing weight or managing your weight

Persistent challenges with weight management can signal insulin resistance.

The insulin fasting test measures your insulin levels before and after a period of fasting. It helps assess your body’s ability to produce and respond to insulin. Thus providing insights into potential insulin resistance or impaired glucose metabolism. Discussing your persistent symptoms with your trusted doctor/diabetologist can help you judge if the fasting insulin test is a proper fit for your situation.

Read More: Random Glucose Testing, Normal Range & Importance

Risk factors that are considered before Going for a Fasting Insulin Levels Test

Risk factors that are considered before Going for a Fasting Insulin Levels Test

Let’s dive into the key risk factors that are linked to insulin resistance. This is important as insulin resistance can be a precursor to more serious conditions like type 2 diabetes. So your doctor/diabetologist may suggest a fasting insulin test by looking at the following factors:

Overweight and obesity

One of the top risks is being overweight/obese. Carrying excess body fat, especially around the abdomen, is strongly associated with developing insulin resistance. The more body fat you have, the harder your cells work to respond to insulin, leading to that resistance.

Sedentary lifestyle

This is another significant risk factor. Not getting regular physical activity makes it harder for your body to use insulin effectively and can contribute to weight gain, which feeds into insulin resistance. The diet also plays a significant role. Eat a diet high in refined carbs, added sugars, and unhealthy fats. This can overwhelm your body’s ability to regulate sugar and insulin levels properly over time.

Hormonal Imbalance

Hormonal conditions like thyroid and other hormonal imbalance conditions heighten the risk of this test.

Blood Pressure Levels

Hypertension or BP is another prominent risk factor for this.

Cholesterol levels

If your cholesterol is in the higher range, there is a high chance you may develop insulin resistance. Therefore, this calls for immediate treatment.

Medical Conditions

Certain medical conditions can also heighten your risk, like polycystic ovarian syndrome (PCOS) and non-alcoholic fatty liver disease. The underlying hormonal and metabolic imbalances in those disorders tend to promote insulin resistance.

Family history of Diabetes

This is another important consideration. If you have close relatives with type 2 diabetes or other insulin-related conditions, you may be genetically predisposed to developing insulin resistance yourself.

Certain Medicines

Certain medications, including glucocorticoid medications, which are used to treat inflammation, can potentially negatively affect insulin resistance as a side effect.

The good news is that many of these risk factors are modifiable through lifestyle changes. The changes include improving your diet, getting more physical strength workouts, and maintaining a healthy weight.

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What is the Purpose of the Insulin Fasting Test?

  • Diagnosis of Level of Insulin Resistance: Through the insulin fasting test, you get the correct measurement of insulin levels that helps in identifying levels of insulin resistance. The doctor, on the basis of the test, prescribes medications and treatment.
  • Evaluation of Metabolic Health: The lab test for insulin fasting helps in evaluating your metabolic health. The test further helps in analysing diabetes and heart ailments risk.

Overall, scheduling a fasting blood insulin test in a timely manner helps ensure an accurate and prompt diagnosis and the correct treatment course.

Read More: What is a Dangerous Level of A1c?

Fasting Insulin Normal Range

Although fasting serum insulin test readings vary according to individuals, age, gender, present health condition, etc. In general, the fasting insulin normal range should be less than 25 μU/mL, according to the Yashoda Hospital website. Anything above the normal fasting range can be prediabetes, type 2 diabetes, infantile hypoglycemia, Cushing syndrome, etc. On the other hand, having insulin much below this range indicates other health ailments like type 1 diabetes. Now let’s look at the chart showing different insulin levels:

Time Level
Fasting Insulin 25 μU/mL
Insulin after 30 min of sugar intake 30-230 μU/mL
Insulin level after 1 hour of sugar intake 18-276 μU/mL
Insulin level after 2 hours of sugar intake 16-166 μU/mL
Insulin level after more than 3 hours of sugar intake Less than 25 μU/mL

Therefore, it’s essential to stay in touch with your doctor and maintain a testing schedule to prevent further complications.

Read More: What Is The Best Time For HbA1c Test?

Suggestions for Maintaining Fasting Insulin in the Normal Range

Suggestions for Maintaining Fasting Insulin in the Normal Range

Maintaining healthy insulin levels is crucial for overall health, especially for individuals at risk of or managing conditions like diabetes. Here are some suggestions:

Balanced Diet

Focus on a balanced diet full of whole grains, low GI fruits, veggies, lean plant proteins, and healthy fats. Avoid excessive consumption of refined sugars and ultra-processed foods.

Portion Control

Be mindful of portion sizes to avoid overeating, which can lead to spikes in blood sugar levels and strain on insulin production.

Increasing Fiber Intake

When managing insulin levels and diabetes, fiber is your most trusted friend. Fiber helps stabilize blood sugar levels and insulin production.

Complex Carbohydrates

Go for complex carbs like whole grains, legumes, and veggies over simple carbs like white bread and sugary snacks. This is because they are digested more slowly and are less likely to impact on blood sugar levels.

Regular Exercise

Engage in regular strength/muscle-building training to improve insulin range. Aim for a good mix of cardio and compound workouts.

Manage Stress

Chronic stress can contribute to insulin resistance. Practice stress-reducing activities such as meditation, deep breathing exercises, yoga, or nature walks.

Adequate Sleep

Aim for 8 to 9 hours of quality sleep at a strech, as inadequate sleep can affect your insulin range.

Stay Hydrated

Drink plenty of water throughout the day to help maintain optimal hydration levels, supporting overall metabolic function.

Limit Alcohol Consumption

Excessive alcohol intake can disrupt insulin production, so it’s best to consume alcohol in moderation.

Regular Check-ups

Lastly, keep up with your regular fasting insulin test schedules. Individuals having a family history of diabetes or other risk factors are at increased risk.

Read More: HbA1c Test Chart (Hemoglobin A1c): Check HbA1c Normal Range and Levels

Preparations Needed for Insulin Fasting Test

Following are the preparations you need to make for the test:

  • You should undertake a fast for 8-10 hours before the test.
  • If you have some ongoing health ailment, it is advised that you consult with your doctor.
  • Please do not drink alcohol or smoke during fasting hours, which may affect the test results.
  • Do not take stress before the test, which may negatively affect the results.
  • If you have any allergies, do inform your doctor.

Read More: Prediabetes Range HbA1c

Insulin Fasting Test Procedure

Whether fasting insulin home test or lab test for insulin, the procedure is utterly simple. The following are the steps:

  • The pathology assistant will clean the area with disinfectant and tie the tightening band around your arm.
  • After this, they will insert a sterilised syringe into the visible blood vessel and collect the blood.
  • After this, put a cotton dipped in antiseptic and hold it for 30-40 seconds to minimise infection risk.
  • The collected blood sample will be moved to a vial to the lab for the test.

The process is fast and safe. Some may experience slight pain in the punctured area. To eliminate the chances of infection, go to a reputed lab.

Fasting Insulin Test Price 

The price of a fasting insulin test varies from lab to lab. When choosing a lab, consider the quality, accuracy, time, and cost. A reputed lab may cost more, but there is no risk of inaccuracy or infection. The price ranges between Rs 700 and Rs 1000, depending on where you live. The price is higher in metros compared to other cities.

Read More: estimated Glomerular Filtration Rate (eGFR) Test

FAQs (Frequently Asked Questions)

Why don t doctors test for fasting insulin?

Fasting insulin tests is generally not part of the blood test schedules of diabetic patients. This is because many doctors don’t see insulin as a precursor to many health ailments. They also regard insulin testing as partly inconsistent.

Can I drink water before fasting insulin test?

Yes, you can consume water in the fasting hours before the insulin fasting test. Remember that you should only drink water and not anything else.

When is the best time to test fasting insulin?

The best time for the insulin fasting test is early in the morning. In the early morning, after you wake up, you are already in the 8-hour fasting state, so no additional effort is required to fast.

Last Updated on by Dr. Damanjit Duggal 


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