Does A1c Tell The Whole Story?

Does A1c Tell The Whole Story?

An alarming study published by University of North Carolina researchers in 2018 showed that only one in eight or 12% of Americans were metabolically healthy.  This has serious implications for public health but what does it mean to the person who is metabolically unhealthy? You may wonder what defines a metabolic disorder.  In this study,  researchers  analyzed  five factors: blood sugar (also called blood glucose), triglycerides, HDL (good cholesterol),blood pressure levels, and waist circumference.  To be considered metabolically healthy, a person had to be within normal limits on these measures without medications.

Researchers indicated that both health care providers and individuals should pay closer attention to metabolic health and interventions that would prevent metabolic syndrome. When they looked at subgroups, they found that less than 1% of obese adults are metabolically healthy. It’s no surprise that people who get more exercise seem to have better metabolic health.  The researchers pleaded for more studies surrounding risk factors for metabolic disease development in normal weight and overweight adults.

Four years later, what has changed in medicine for reviewing metabolic health? The newest opportunity allows health care providers to move beyond fasting blood glucose and A1C measures alone. The introduction of continuous glucose monitoring devices and the subsequent rise in use allows for a new measure. This measure is called time in range. Time In Range analyzes a person’s level of blood glucose constantly throughout the day over many days.

In a recent survey conducted by diatribe, endocrinologists indicated they were using time in range more than ever. They looked at time in range most often in type 1 diabetics but in recent times were also using the measure for Type 2 patients. But what does this mean for regular people? You know,  the 38% of Americans who are in the “black hole” of metabolic health. If 88% of Americans are metabolically unhealthy, but only 50% are diagnosed as diabetic or prediabetic what happens to the ones in between? Should we wait for them to spiral into diabetes, insulin resistance, or metabolic syndrome? Or should we identify these at-risk people and help them prevent disease?

In the healthy middle, we discuss those patients who appeared to be healthy but when we investigate further, show signs of impending metabolic illness. They haven’t raised any red flags with their health care providers and have clinically normal A1C.

25-30 years ago, most doctors primarily used fasting blood glucose as a measure for glucose health. As healthcare evolved physicians began adding A1C testing to their evaluations. Most endocrinologists would agree that by also evaluating A1C that glucose dysregulation is better identified. So how do we take the newest healthcare technology and the powerful data that comes from continuous glucose monitors (CGM) and do what the University of North Carolina Chapel Hill researchers begged us to do?

Let’s look at three case studies, Carlos, Ashley, and Anthony to better understand how time in range tells us more than A1C.  Dr. Andrea Hayes, Florida Board Certified Concierge Endocrinologist and Type 1 diabetic herself,  will help us understand the glucose profiles.

Carlos is 54 years old. He’s a busy professional with a wife and three kids. Carlos has a sweet tooth, and sometimes with his busy schedule, stops at fast-food restaurants. Office demands and sometimes long hours mean that Carlos doesn’t get much regular exercise. This is Carlos blood glucose graph:


Do you see all these points outside of normal glucose measures?  Even though he has a normal A1C of 5.5 now, what does this mean for Carlos’s health?  Let’s see what Dr. Andrea Hayes interprets.

“Although Carlos does not yet meet criteria for the diagnosis of Type 2 Diabetes, he numbers are dangerously close.  Two random blood sugars over 200, meets the criteria for the diagnosis.  But blood sugars of 180 meet the criteria for “impaired glucose tolerance”.  This means that Anthony is a set up for developing overt diabetes.  These numbers are warning signs of future problems.  Lifestyle/dietary changes are in order for the purpose of preventing diabetes.”

Now let’s look at Ashley. Ashley is naturally at a lower risk of metabolic disease simply because she’s a woman. She’s 38 years old, married, and has decided that her fur babies will be her only children.  Ashley works remotely from her home and can easily access healthy meals. Due to her flexibility of schedule, she regularly exercises on her fancy exercise bike. She even takes Pilates classes each week.  She, like Carlos, has an A1C of 5.5. But let’s look at her chart below:


Looks great, right? all Ashley’s glucose measures are in range and her blood sugar looks very stable.  What does Dr. Hayes think about her data?

 This information is comforting to know at this time.  Ashley should still stay vigilant about her health and strive to keep her BMI in normal range.  A lot of factors play into insulin resistance including genetics, body weight distribution, lifestyle, medications, stress, and more.  Some risk factors can’t be controlled but many can!  Keep up the good work Ashley!

Now let’s look at Anthony. He is 43 years old and a busy surgeon. This means his sleep schedule is often disrupted and he must go long stretches without eating or drinking. He does the best he can with his diet under these circumstances and still manages to hit the gym a few times a week. He hasn’t yet settled down, so he has fun with his friends on the weekends. This means enjoying nice restaurants and the occasional adult beverage. Let’s look at his graph:


Although Anthony also has a 5.5 A 1C you’ll notice he does have some points outside of the normal range.  Dr. Hayes’s take: “The A1C is a measurement of 90 day blood eagar average.  It measures how much sugar is attached to red blood cells which typically live for about 60 to 90 days.  Because this test measures AVERAGE blood sugar it doesn’t reflect glucose excursions that can occur in response to meals.  In other words, the A1C can remain normal for a long time in patients with pre-diabetes, metabolic syndrome, and glucose intolerance.  We need a real-time birds eye view of how the body handles nutrient intake on a daily basis.”

As you can see from these case studies there are three different people with the same A1C whose glucose metabolism looks completely different. Now that Carlos and Anthony have insight into their glucose health, they can make changes to their lifestyle to lower the risk of future metabolic dysregulation.

Can you now imagine if this tool is so powerful in identifying risk in the healthy middle, what would this mean for obese and overweight people, pre-diabetic patients, and all diabetics regardless of type one or type 2? How many people are walking around with glucose dysfunction and don’t realize it until they have a pre-diabetic or diabetes diagnosis?