When an insulin sensitive (normal) person eats foods that contain carbohydrates, the food is digested and the glucose is absorbed. That glucose enters the bloodstream, signaling the pancreas to release insulin. Insulin helps transport the glucose out of the bloodstream and into the cells where it can be used to make energy or stored as glycogen for later use. Once glucose levels normalize, the pancreas will halt making more insulin.

Insulin resistance is a condition where your body does not respond well to insulin. When there is insulin resistance, glucose uptake by the cells is impaired. This leads to a higher demand for insulin to get the glucose out of the blood, which can overwhelm the pancreas and result in high insulin levels in the blood. High insulin levels can further worsen insulin resistance and create a vicious cycle.

There is not a single test that is used to measure insulin resistance, but several tests can provide insight. A fasting insulin level is not routinely checked by health care providers. However, a fasting insulin level reflects how much insulin your pancreas produces, giving insight on how sensitive your cells are to insulin. A high level can mean your cells do not respond well to insulin. This is a different value than a fasting glucose and an a1c, which are more commonly checked by health care providers. These can provide helpful information, but are utilized more to diagnose pre-diabetes or diabetes and do not always show insulin resistance stages. Insulin resistance can be estimated using HOMA-IR and QUICKI index calculators using your fasting glucose and fasting insulin results from bloodwork.  High triglycerides and a high triglyceride/HDL ratio can also be a sign of metabolic issues.

Insulin resistance is influenced by lifestyle factors, genetics, aging, and excess body fat. While diet is one of the biggest contributors, studies have shown that various toxins, such as BPA exposure and air pollution, are associated with changes in insulin levels [1].  Insulin resistance can cause many health problems, such as high blood sugar, high blood pressure, high cholesterol, inflammation, fatty liver, and increased risk of diabetes and heart disease. According to studies, insulin resistance precedes the development of type 2 diabetes by approximately 10 to 15 years [2]. Learning more about your insulin resistance status can help you make early changes to prevent further health issues from developing.

Insulin resistance may present with varying symptoms. Some with mild insulin resistance may have no symptoms. Others may notice: weight gain or difficulty losing weight, sugar cravings, depression, anxiety, irritability, brain fog, fatigue, increased hunger or thirst, or frequent urination.

Insulin resistance can be prevented or treated by adopting a healthy lifestyle that includes regular exercise, a balanced diet, weight loss, and stress management. These interventions can improve the sensitivity of your cells to insulin and lower your blood sugar and insulin levels. In some cases, supplements or medication may be needed to help control your blood sugar or insulin levels. Several herbs and supplements, such as cinnamon, have been clinically shown to help insulin resistance by improving cellular insulin sensitivity [3].

Being proactive about your health is a goal of functional medicine. Even if you are not symptomatic of insulin resistance, getting a baseline fasting insulin level can provide you valuable information about your current health. Don’t wait until there’s a concern to get screened!

Sources:
[1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6735759/
[2] https://pubmed.ncbi.nlm.nih.gov/29939616/
[3] https://pubmed.ncbi.nlm.nih.gov/20515642/