Many people are reassured that their blood sugar is
normal because their HbA1c falls within the reference
range. However, HbA1c tells only part of the story.
How Blood Sugar Works
After we eat, food is broken down into glucose and
absorbed into the bloodstream. The pancreas then
releases insulin to move that glucose into our cells.
Once inside, it is either burned for immediate energy or
stored for later, much like filling a gas tank. Under
normal conditions, this process is efficient and blood
sugar remains within a normal range.
The problem arises when we regularly consume more
carbohydrates and sugar than the body can efficiently
process. The pancreas responds by producing
increasing amounts of insulin to keep blood sugar in
check. This can continue for years before signs of
strain begin to appear.
Signs & Symptoms of Blood Sugar Imbalance
- Feeling sleepy after meals
- Craving sweets shortly after eating
- Brain fog after lunch
- Constant hunger
- Difficulty losing weight
- Increasing abdominal fat
The Limits of HbA1c
Hemoglobin A1c (HbA1c) is the standard test used to
screen for and monitor diabetes. It reflects average
blood sugar over the previous 6-8 weeks. The key word
is average.
While HbA1c is an excellent test for diagnosing and
monitoring diabetes, it is not a reliable indicator of how
well the body regulates blood sugar from day to day.
A normal HbA1c result may simply mean that higher
insulin levels are successfully keeping blood sugar in
range. But behind the scenes, the body may be working
harder than it should.
Why It Matters
Beyond the risk of diabetes, repeated spikes in blood
sugar may affect the intestinal barrier and contribute to
systemic inflammation. Over time, this is associated
with changes in how the body handles energy and
responds to food.
Advanced glycation processes and chronic exposure to
elevated glucose have also been associated with longterm tissue changes, including stiffness and wear in
various tissues. These processes may begin years
before the classic signs of diabetes appear.
Looking Beyond HbA1c
When symptoms suggest a blood sugar issue but
HbA1c is normal, more sensitive testing can provide
additional insight:
Oral Glucose Tolerance Test (OGTT) with insulin measurements
After drinking a measured glucose solution, blood
sugar and insulin are measured over the next 1-2 hours.
This shows how hard the body has to work to keep
blood sugar under control and can detect insulin
resistance years before HbA1c becomes abnormal.
Fructosamine
Reflects average blood sugar over the previous 2-3
weeks. It provides a shorter-term view than HbA1c, but
still represents an average rather than how the body
responds after meals.
GlycoMark (1,5-anhydroglucitol)
Helps detect frequent blood sugar spikes after meals.
Unlike HbA1c or fructosamine, it is more sensitive to
short-term changes in blood sugar.
Continuous Glucose Monitor (CGM)
Wearing a CGM for a period of time is one of the best
ways to learn how your blood sugar responds to food,
exercise, sleep, and everyday life. It provides real-time
feedback that reveals post-meal spikes, overnight
patterns, and how quickly blood sugar returns to
normal after eating. No other test offers this level of
insight.
Putting it all together
HbA1c remains a valuable test, but it does not capture
the full picture of blood sugar regulation. This is why
evaluation needs to go beyond HbA1c and include
symptoms, the body’s response to food, and more
sensitive testing when appropriate.
References
Martinez-Hervas S, et al. Metabolism. 2011.
Abbasi F, et al. Diabetes Research and Clinical Practice. 2018.
Thaiss CA, et al. Science. 2018.
Liu S, et al. Journal of Clinical Endocrinology & Metabolism. 2015.
Abbasi F, et al. Diabetes Research and Clinical Practice. 2018.
Thaiss CA, et al. Science. 2018.
Liu S, et al. Journal of Clinical Endocrinology & Metabolism. 2015.