Metabolic Health: Know Your Numbers
At MTN HLTH we are all about helping people understand the importance of maintaining good metabolic health through lifestyle and hormone optimization. This includes improving insulin sensitivity and metabolic flexibility – the ability to switch between glucose and fats as fuels for the body. Your metabolic health is extremely impactful when it comes to your overall health, your life span, and your health span – the percentage of your life spent in good health. However, what constitutes “good” metabolic health may vary from one clinic to the next. Some practitioners base their ideas of “good” according to what is deemed “normal for your age.”
Normal vs Optimal
“In our current society, it is absolutely ‘normal’ to be overweight or obese.”
At MTN HLTH, we are much more interested in what is “optimal” for human beings, no matter what age. In our current society, it is absolutely “normal” to be overweight or obese. But as we all know, this is not “optimal.” So, let’s break down some of the most common measurements, how and why we use them, and what we believe to be “optimal values.”
Insulin Resistance Biomarkers:
Fasting Blood Glucose AKA Blood Sugar
Glucose is just another term for sugar. Our body uses glucose to fuel metabolic processes throughout the body. This readily-used molecule is transported in the blood to the cells that need it, and measuring it can indicate how well your body responds to energy needs. A fasted blood glucose level is a common way to take a snapshot of your glucose control. While humans can function in the short-term at a wide range of blood glucose levels, a metabolically healthy person will maintain a fasted glucose between 70 – 99 mg/dL. When the body cannot maintain an optimal fasting blood glucose long-term, cellular damage can begin to occur. This is a sign of becoming insulin resistant; meaning the hormone insulin which regulates blood sugar is unable to efficiently perform its duty. A fasted glucose between 100 and 125 mg/dL would be in the “prediabetic” or mildly insulin resistant range. A fasted blood glucose of 126 mg/dL or greater would be considered in the “diabetic” or severely insulin resistant range.
There are several ways to measure blood glucose. The gold standard involves a blood draw and processing in a lab. A less invasive and quicker method involves a simple finger prick and a small drop of blood in a portable measuring device. You may have also heard about continuous glucose monitors (CGM). These small devices are implanted just under the skin and measure glucose in the fluid between your cells (interstitial fluid). These devices take a glucose reading every few minutes to give real-time data without the pain of repeated finger pricks. This can be a very useful tool to understand how different foods can affect your blood sugar and how efficiently you metabolize nutrients. Understanding how your glucose levels respond to various foods and activities can help paint an accurate picture of your metabolic health. Check out Levels for more info on GCMs.
Hemoglobin A1C, HbA1C, or “A1C”
Instead of a “snapshot” of your glucose, The A1C marker is able to predict your blood sugar control over a longer period of time. As glucose circulates through your bloodstream, some of it attaches to your red blood cells on a protein known as hemoglobin. Red blood cells only live for about 3 months, so measuring the percent of cells that have glucose on them is a good indication of how well your blood sugar has been maintained over that timeframe. Maintaining an A1C below 5.7% is considered normal for most practitioners. We believe an A1C of < 5.3% is optimal. 5.7%-6.4% is considered the “prediabetic” range, and anything above 6.5% is an indication of diabetes. Measuring A1C requires a blood draw and processing in a lab. Maintaining healthy glucose ranges consistently over time will help bring this to a healthy level.
Insulin
Measuring insulin levels also requires a blood draw. Insulin is an extremely important hormone in our metabolism and overall health. One of the key functions of insulin is to signal cells throughout the body to take in glucose from the bloodstream. In healthy people, insulin is released when blood glucose is high. In this situation, as in after consumption of a meal high in carbohydrates, the body will immediately prioritize the glucose in the bloodstream to fuel its processes. This stops any lipolysis (breaking down fat to use for fuel) and works to bring blood glucose back to a healthy range. Thus, keeping blood sugar under control is a great strategy to achieve and maintain a healthy weight. A fasting insulin < 6 is considered optimal. Up to 24 is still considered normal.
Insulin resistance (IR) is the desensitization at the cellular level (muscles cells in particular) to the influence of insulin. This loss of insulin sensitivity is at the root of many chronic diseases like diabetes, heart disease, Alzheimer’s disease, hypertension, low testosterone, and infertility. When we see a patient with a fasting insulin > 10, we aggressively treat and monitor to be sure that they are becoming more and more insulin sensitive and not more and more insulin resistant.
Homa-IR
The Homeostasis Model Assessment of Insulin Resistance (HOMA-IR) is a tool that indirectly calculates insulin resistance. This test was created in the 1980s and requires a blood draw to measure both fasting insulin and fasting glucose levels. This calculation estimates how much insulin your pancreas needs to make to control your glucose levels. The higher your HOMA-IR score, the more insulin it takes to control your blood sugar and the more insulin resistant you are. A HOMA-IR score of less < 1 is optimal. Levels above 1.9 are an indication of early insulin resistance, and levels above 2.9 indicate significant insulin resistance. This is how a HOMI-IR is calculated:
fasting insulin (microU/mL) x fasting glucose (mg/dL)/405
Lipid Panel
This is typically performed in a fasted state so that the food you have just consumed does not interfere with what is going on at baseline. It includes:
Total Cholesterol
Triglycerides (TG)
HDL Cholesterol (High Density Lipoprotein)
LDL Cholesterol (Low Density Lipoprotein)
The mainstream medical community for decades has focused on what is termed the “cholesterol-centric model” for predicting cardiovascular disease (CVD) risk. Having a high total cholesterol and LDL cholesterol (“bad cholesterol”) will earn you a prescription for statin medication to lower cholesterol levels. However, more recent studies have shown that the Triglyceride-to-HDL ratio is a better predictor for heart disease risk as a elevated ratio (> 3.5) has been linked repeatedly to insulin resistance and diabetes which leads to increased risk of CVD.
Optimal values:
Total cholesterol (150-250)
Triglycerides (< 100)
HDL Cholesterol ( > 60)
LDL Cholesterol (100-150)
Triglyceride / HDL ( 1:1 )
Hormonal Health
We’ve already mentioned Insulin and its important influence on your metabolic health. Other hormones that impact metabolic health include the so-called “hunger hormones” leptin & ghrelin, thyroid hormone and sex hormones. But these will be discussed, in detail, in another blog post to come.
Conclusion
While there are many markers that give us insights into metabolic health, this should help clarify when, why, and how some of the most common tests are used. Probably the best marker for metabolic health however would be more intuitive – how do you feel on a daily basis? Your metabolic health will impact how you feel on a day-to-day basis and greatly influence your healthspan. This should empower you to engage in healthy habits that are proven to optimize your metabolism, namely regular exercise, occasional fasting, stress reduction, and dietary patterns that prioritize the regulate blood sugar & insulin.
