Fasting Insulin: Why it’s the Most Important Metabolic Marker You Can Track
You have probably had your fasting blood sugar tracked at the doctor. Your doctor has perhaps even told you that it looks good. You may be one of the people who had “good results” until one annual check-up when your doctor suggested that you go on medication to manage your lipids or blood sugar and wondered how this came out of left field?! Last checkup you were fine and BOOM now you need medication?! How did that happen?
What does insulin have to do with glucose?
When your body is healthy, you eat food, especially carbohydrates and they are turned into glucose which is like money in the body. That glucose is sent into your bloodstream where insulin acts like a money manager: it decides where the glucose ($) you eat will go. So it takes the glucose to cells - they need glucose for energy, then it takes the glucose to the liver where it is stored as glycogen, and it takes it to muscle to store as glycogen (our biggest glucose sink or storage area).
After the money manager delivers glucose to your cells, liver, and muscle, if it has any leftovers that get turned into fat for storage or as I like to call it your mobile savings account. This is a very useful adaptation especially if you are going to be traveling for long distances, dealing with winter, or trying to survive a famine. Now we don’t need to worry about many of these so this very important adaptation which used to keep you alive but now is not as helpful.
When our bodies are not healthy, our insulin (money manager) gets overwhelmed with too much glucose which then gets back up in the bloodstream. This means the insulin has a hard time getting the cells, muscles, and liver to accept more glucose. Your body will make more insulin to manage the glucose money but if your muscles and liver are full of fat from your body storing excess glucose as fat (your mobile savings account) then there is nowhere to put that extra glucose money because the fat (in the liver and muscles) won’t let any new glucose in. Then your blood sugar levels remain high and this is what leads to insulin resistance and later type 2 diabetes.
This process can happen over years and often goes undetected because your body is good at compensating. Your fasting glucose levels may stay healthy for years before they start to creep up and by then you may be well on your way to insulin resistance. However, your fasting insulin levels will start increasing up years before your fasting glucose starts inching up. So, checking your fasting insulin can fix the problem early.
Insulin Resistance Risks
Weight gain
Aging/wrinkles and skin tags
Fatty Liver
High Blood Sugar
Heart Disease (Cardiovascular Disease) - the #1 Killer of women in the US
Elevated Cholesterol and Triglycerides
Increased risk of Dementia and Alzheimers
Increased risk of Cancer
Fasting Insulin
A blood test you can ask your doctor for at your physical. It is relatively cheap and should be covered by insurance (check with your health insurance to be sure). Your fasting insulin should be less than 10, ideally less than 6.
TG: HDL Ratio
If your doctor won’t test your fasting insulin you can make a proxy calculation with your Triglyceride to HDL ratio TG:HDL which, optimally, you want close to 1.