Early Detection of Insulin Resistance for Improved Patient Outcomes
Fasting blood glucose measurement is considered as adequate screen for blood sugar issues. As long as it was below 100, it was considered normal and therefore of no consequence. For early detection of Diabetes we do test known as oral glucose tolerance test (OGTT). The focus was entirely on blood glucose. Insulin was rarely measured.The limitation of relying entirely on these measurements is that, in the insulin-resistant individual, rising insulin levels may well keep blood sugar at normal, even optimal, levels for years, while elevated circulating insulin damages blood vessels and contributes to central weight gain. By the time the overworked pancreatic cells begin to decrease production of insulin and blood glucose levels skyrocket, the damage has been done. The road back to optimal blood sugar control is much more difficult at this point. When we check Glucose only we will only diagnosed Diabetes and for Detection of early Prediabetes and Insulin Resistance we need to check Insulin on Glucose challenge. That is called Glucose tolerance Insulin Response (GTIR).
This test looks at patterns of insulin response rather than a strict cut-off point for glucose. These patterns delineate the severity of insulin resistance, as a patient progresses from normal insulin sensitivity to postprandial hyperinsulinemia to the insulinopenic state found in beta-cell exhaustion. This spectrum of insulin response allows the clinician to identify insulin resistance early in its development.The resulting evaluation of insulin resistance severity can be used to monitor efficacy of treatment.
Today, of course, the phenomenon of insulin resistance is widely recognized, but the tests commonly used for screening may be missing a great number of patients that could benefit earlier detection and intervention.
Who should be tested for Insulin Resistance?
The American Diabetes Association (ADA) recommends that testing to detect prediabetes be considered in adults who are overweight or obese and have one or more additional risk factors for diabetes.
- Age more than 45
- Overweight or Obese
- Waist more than 94cm for man and 80 cm for female.
- being physically inactive
- having a parent or sibling with diabetes
- having a family background that is African American, Alaska Native, American Indian, Asian American, Hispanic/Latino, or Pacific Islander American
- giving birth to a baby weighing more than 9 pounds
- being diagnosed with gestational diabetes—diabetes that develops only during pregnancy
- having the high blood pressure—140/90 mmHg or above—or being treated for high blood pressure
- HDL cholesterol level below 35 mg/dL or a triglyceride level above 250 mg/dL
- having polycystic ovary syndrome (PCOS)
- having prediabetes, impaired fasting glucose (IFG), or impaired glucose tolerance (IGT) on an earlier testing
- having other conditions associated with insulin resistance, such as obesity or acanthosis nigricans
- having Cardiovascular Disease
Glucose tolerance insulin response test
This was originally researched by Dr, Kraft and also known as kraft pattern Prediabetes Profile. The Kraft Prediabetes Profile measures patterns of insulin activity after drinking a glucose challenge. Dr. Kraft identified five patterns of insulin response that begins with normal sensitivity and progresses to severe insulin resistance and then finally to an insulinopenic state. The five patterns of insulin response correspond with the timing of the insulin peak after the glucose challenge. Normally, insulin peaks quickly after a meal (or glucose challenge in this case) and then drops precipitously back to baseline (Pattern I). As insulin resistance becomes more severe, the insulin response to glucose peaks later and later (Patterns II-IIIB). In Pattern IV, insulin is high in the fasting state and rises even further in an attempt to keep blood sugar under control. Islet cell exhaustion is illustrated by Pattern V, or insulinopenia, in which the patient’s pancreas is no longer able to produce an adequate amount of insulin.
GTIR Pattern Progression
Putting the insulin curves for the different patterns into a single graph illustrates a distinct progression of insulin resistance from normal to insulinopenic. With this test, nascent insulin resistance can be detected long before blood glucose values might start to sound alarm bells. The import of this is magnified when one considers that diabetes has both an individual and societal costs, and that it can largely be prevented or reversed with earlier detection, lifestyle changes, and treatment.
How is the test performed?
A patient needs 12 hours of fasting. When the patient reaches the lab after overnight fast first fasting blood sample is collected. After that, he had given 100 grams of glucose to drink orally after dissolving in water. Glucose consumption time is noted and 30 minutes after that second blood sample is collected. Again after 30 minutes of the second sample, a 3rd blood sample is collected. A 4th blood sample is collected 1 Hour after 3rd sample. Total 4 sample is collected.
Example time: Collect fasting at 8:45 AM and give oral glucose at 9:00 AM following are the timing of samples: Sample-2: at 9:30 AM, Sample-3: at 10:00 AM. Sample-4 : at 11:00AM
The value of the GTIR for early detection and treatment cannot be overstated. The case of Mr.John is a compelling example of this. He is a 38 year old man who came into our clinic in February with a chief complaint of easy weight gain and fatigue. He is 175 cm tall and weighed 100 kg at the initial visit. BMI was 32.6. His pulse and respiration were normal and he is hypertensive but not diabetic. he had a family history of Type II diabetes. Fasting blood sugar was elevated at 100, but HbA1c was 6. Because of the family and personal history a 2-hour Glucose Tolerance/Insulin Resistance test was run. On the GTIR test, fasting and 2 hour glucose were 84.9 and 133.3, respectively, both well within the limits of normal based on American Diabetes Association criteria. So if we look only Blood Glucose and ignore Insulin(Pancreatic Function) then we miised out early insulin resistance. His Fasting insulin was above 11.62 and peaked in the 1st hour at 202.39 and stayed high at 2 hours with value of 123.33. He is having High Insulin that shows moderate insulin resistance. This is a Pattern IV insulin response. His report is linked below.
We had started protocol to reverse insulin resistance and within 3 month he had lost 12 kg weight and and also started reversing his insulin pattern.