Updated: Jun 9
Many people think insulin resistance is caused by obesity, or diabetes or other diseases. This is not correct. Insulin resistance start to develop on young healthy individuals at every early age, if their lifestyle is not very healthy. To find out whether you have insulin resistance, the best lab work to take is a KRAFT test.
Dr. Agatston is very well known for inventing the Coronary Artery Calcium (CAC) score, or Agatston score for cardiac event risk assessment. In the following Youtube interview - Early Signs of Insulin Resistance & Heart Disease - Founder of the CAC score - Dr. Arthur Agatston, he showed several KRAFT test results of normal people, type 2 diabetic and people who have insulin resistance but are considered normal by regular lab work standard. The difference between them is obvious. How is KRAFT test done? At the beginning of the test, fasting insulin and fasting glucose level are measured. Then a sugary drink is given to the patient. After that, the patient's insulin and glucose levels are measured every 30min, till 120min after the drink.
For a normal person, the fasting insulin level is between 2 - 5uU/mL. The insulin level peaks at around 30min, then it gradually goes back to its original value at 120min. For a diabetic patient, the fasting insulin level is higher than normal, and it sinks first when glucose is taken, which indicates the pancreatic (beta cell) function failure. Then it goes up gradually and keeps on rising even at 120min.
What about people in between these two cases? A young healthy looking 23 year old kid has also taken a KRAFT test. His insulin peak is delayed and it does not go back to the baseline at 120min, which means he already has pancreatic function decrement and insulin resistance problem, although his BMI is only 21 and his A1C is only 4.9. This tells us that A1C is not a very good biomarker to catch insulin resistance at early stage, but KRAFT test is.
Then, how can we reverse insulin resistance? Dr. Agatston gave another example. This is a 50-year old physician. His CAC score was 58, which is high for his age, and A1C was 5.6, which is considered normal by current standard, back in 2020. By practicing low carb diet and intermittent fasting, he lost 13 lbs in a year. Among them, 10.8 lbs was fat and only 2.3lbs was lean muscle mass.
The interesting thing was that he was getting up in the middle of the night, anxious and hungry. He would go to the refrigerator, eat and then go back to sleep. He did not mention about it at the beginning of the treatment. After several months, this physician came back and said his anxiety and depression were actually cured. Below is his own explanation. He thought his waking up in the middle of the night and feeling anxious was when he was hypoglycemic. What's causing the low glucose level at night? In the figure below, the plot on the right shows his first KRAFT test result. His insulin was peaking very high at 250 and stayed high for a long time. In the middle of the night, when blood sugar drops, normally there is no problem, people just get some extra glucose out of the liver, and keep the blood sugar staying normal, and they can sleep through the night. But since he had this persistent high insulin level, it blocked his access to the sugar storage. So when his glucose came down in the middle of the night, he woke up hypoglycemic, really really hungry, anxious and depressed. These problems were cured after a few months of low carb diet and intermittent fasting. His A1C went from 5.6 down to 5.1. He was still insulin resistance, because insulin was still peaking high, but not nearly as high as before (as shown in the plot on the left in the figure below). It also comes down almost to normal at 120min. If went on an extra hour at night, his insulin is low enough that he then can access to his own sugar when his blood sugar fell. So he stopped waking up in the middle of the night. And he was on the way to have his insulin resistance and beta cell dysfunction cured.
Dr. Agatston further mentioned about his concerns on ALT normal range being increasing over the years. That is because the normal range is defined by taking the average with 95 percent confidence limits. In fact, most of the population has some fatty liver. So average ALT goes up. The normal range is not normal anymore. We should pay more attention to triglyceride to HDL ratio, which is an indicator for fatty liver. When you have a belly, even if you are thin and your A1C is below 5.7, you should watch out and have a KRAFT test done.