HbA1c Explained: Your Long-Term Blood Sugar
Understanding hemoglobin A1c and what it reveals about diabetes risk and metabolic health
Medical Disclaimer
This article is for educational purposes only and does not constitute medical advice. Diabetes management requires professional medical supervision. Always consult with your healthcare provider before making changes to your treatment plan.
What is HbA1c?
HbA1c (hemoglobin A1c), also called glycated hemoglobin, is a blood test that measures your average blood glucose levels over the past 2-3 months. Think of it as a "report card" for blood sugar control.
How it works: When glucose circulates in your blood, it binds to hemoglobin (the protein in red blood cells that carries oxygen). The more glucose in your blood, the more hemoglobin becomes "glycated." Since red blood cells live for about 120 days, HbA1c reflects your average glucose exposure over that period.
Why it matters: Unlike fasting glucose (which shows a snapshot of one moment), HbA1c reveals long-term patterns. It's the gold standard for diagnosing diabetes and prediabetes, and for monitoring treatment effectiveness.
Understanding Your HbA1c Results
| HbA1c Value | Classification | What It Means |
|---|---|---|
| < 5.7% | Normal | Low risk for diabetes |
| 5.7% - 6.4% | Prediabetes | Increased risk—intervention needed |
| ≥ 6.5% | Diabetes | Requires medical management |
Optimal vs. Normal
While < 5.7% is considered "normal," many longevity-focused practitioners aim for HbA1c < 5.3% for optimal metabolic health. Research suggests that even within the "normal" range, lower HbA1c is associated with reduced cardiovascular risk and inflammation.
Important caveat: HbA1c can be less accurate in people with certain conditions (anemia, hemoglobinopathies, recent blood transfusions). In these cases, alternative markers like fructosamine or continuous glucose monitoring (CGM) may be more reliable.
Why Prediabetes is a Critical Warning
Prediabetes (HbA1c 5.7-6.4%) isn't just a "pre-disease"—it's already causing damage. Studies show that:
- •Cardiovascular risk increases: Even at HbA1c 5.7%, your risk of heart disease rises significantly.
- •Nerve damage begins: Peripheral neuropathy can start in the prediabetic range.
- •Without intervention: 70% of people with prediabetes will develop type 2 diabetes within 10 years.
The good news: Prediabetes is reversible. Lifestyle changes (diet, exercise, weight loss) can reduce your risk of progressing to diabetes by 58% or more.
How to Lower Your HbA1c
🥗 Dietary Changes (Most Impactful)
- ✓Reduce refined carbs: White bread, pasta, sugary snacks spike blood sugar rapidly.
- ✓Prioritize fiber: Vegetables, whole grains, legumes slow glucose absorption.
- ✓Increase protein & healthy fats: Stabilizes blood sugar and improves satiety.
- ✓Time-restricted eating: Intermittent fasting can improve insulin sensitivity.
- →Expected impact: 0.5-2.0% reduction in HbA1c within 3-6 months.
🏃 Exercise (Insulin Sensitizer)
- →Aerobic exercise: 150+ minutes/week (brisk walking, cycling, swimming).
- →Resistance training: Builds muscle, which acts as a "glucose sink." 2-3x/week minimum.
- →Post-meal walks: Even 15 minutes after meals significantly blunts glucose spikes.
- →Expected impact: 0.5-1.0% reduction in HbA1c.
⚖️ Weight Loss (If Overweight)
Losing just 5-7% of body weight can dramatically improve insulin sensitivity. Visceral fat (belly fat) is particularly insulin-resistant and inflammatory.
Expected impact: 1-2% reduction in HbA1c with 10% weight loss.
💊 Medications (When Needed)
If lifestyle changes aren't enough, your doctor may prescribe:
- •Metformin: First-line drug for type 2 diabetes and prediabetes. Improves insulin sensitivity.
- •GLP-1 agonists: Injectable drugs (e.g., semaglutide) that lower blood sugar and promote weight loss.
- •SGLT2 inhibitors: Help kidneys remove excess glucose through urine.
Tracking Progress: How Often to Test
- •No diabetes, normal HbA1c: Test every 1-3 years as part of routine screening.
- •Prediabetes: Test every 6 months to monitor intervention effectiveness.
- •Diabetes (controlled): Test every 3-6 months.
- •Diabetes (poorly controlled): Test every 3 months or as directed by your doctor.
Pro tip: Upload your HbA1c results to Toowit to visualize trends over time. Seeing your progress is incredibly motivating!
Beyond HbA1c: Complementary Tests
HbA1c is excellent for long-term trends, but combining it with other markers gives a fuller picture:
- •Fasting glucose: Measures blood sugar after an overnight fast. Should be < 100 mg/dL.
- •Fasting insulin: Detects insulin resistance before glucose rises. Optimal < 5 µU/mL.
- •HOMA-IR: Calculated from fasting glucose + insulin. Measures insulin resistance severity.
- •Continuous glucose monitor (CGM): Tracks real-time glucose fluctuations. Great for identifying food triggers.
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