You might not expect your breathing patterns at night to affect your blood sugar. But for many people with Type 2 diabetes or prediabetes, undiagnosed or untreated sleep apnea could be interfering with their ability to reach stable A1C levels.
Let’s break down how these two conditions intersect—and whether treating your sleep-disordered breathing could support better long-term glucose control.
Understanding A1C and Its Importance
Your A1C level (also called HbA1c) reflects the average amount of glucose attached to your red blood cells over the past 2–3 months. It’s a common test used to diagnose and monitor diabetes or prediabetes.
- A1C under 5.7% = normal
- 5.7%–6.4% = prediabetes
- 6.5% or higher = diabetes
Many people with high A1C levels find it difficult to lower them, even with diet and medication. For some, the issue may lie in a less obvious factor: interrupted sleep and oxygen desaturation from sleep apnea.
How Sleep Apnea Disrupts Glucose Regulation
Obstructive Sleep Apnea (OSA) causes repeated breathing pauses during sleep, which in turn leads to intermittent drops in blood oxygen (hypoxia) and frequent arousals from deep sleep. These disruptions activate the sympathetic nervous system, increasing levels of cortisol and other stress hormones—both of which raise blood sugar.
Research shows that even in people without diabetes, these nocturnal events can cause spikes in glucose and insulin resistance the next morning.
In fact, a study in Diabetes Care found that patients with Type 2 diabetes and OSA who used CPAP therapy saw improved insulin sensitivity and a modest drop in A1C over time.
The Link Between Apnea Severity and A1C
The worse the apnea, the higher the risk.
People with moderate to severe OSA often experience:
- Elevated fasting blood glucose
- Increased insulin resistance
- Higher A1C scores
- More frequent glucose variability overnight
In one meta-analysis published in Sleep & Breathing, researchers found a strong correlation between OSA severity and A1C levels, particularly in people with uncontrolled diabetes.
Does Treating Apnea Actually Lower A1C?
Yes—especially when treatment is consistent.
Patients who adhere to CPAP therapy (Continuous Positive Airway Pressure) often experience:
- Better glucose control throughout the night
- Reduced insulin resistance
- Improved blood pressure and cardiovascular markers
- Lower systemic inflammation
That said, results vary based on consistency of use and individual metabolic factors. Some people see dramatic improvement in A1C, while others notice better daily glucose trends and fewer spikes, which still contributes positively to long-term health.
Additionally, newer oral appliances for mild-to-moderate OSA also show promise in supporting better sleep-related glucose control.
What About Non-CPAP Options?
Not everyone tolerates CPAP, and thankfully, it’s not the only path forward.
Here are other interventions that may help lower A1C by improving sleep quality:
- Mandibular advancement devices: These reposition the jaw to keep airways open.
- EPAP valves: Disposable valves that create resistance during exhalation, helping maintain airflow.
- Hypoglossal nerve stimulators: Implanted devices that stimulate tongue muscles to prevent airway collapse.
- Weight loss: Studies show that a 10% weight reduction can significantly improve both OSA and A1C.
- Positional therapy: Simply sleeping on your side can reduce apneic events in some people.
These options may be particularly useful for people with mild OSA or those who want to explore non-invasive treatments.
When to Suspect Sleep Apnea Is Affecting A1C
If you’re doing everything right—eating well, taking your medication, exercising—and your A1C won’t budge, your sleep may be the missing variable.
Watch for these clues:
- Snoring or gasping for air at night
- Waking up tired despite 7–8 hours in bed
- Dry mouth or headaches in the morning
- Frequent nighttime urination
- Daytime grogginess or irritability
Even without obvious signs, undiagnosed OSA can still be present, especially in people with metabolic syndrome or central obesity.
How to Get Tested Quickly and Easily
We offer a 60-second AI facial scan that analyzes key structural features known to correlate with OSA risk. This can be done right from your phone—no appointment needed.
If your scan flags concerns, you’ll receive a home sleep test kit with finger sensors (no chest belts or wires) to record breathing, oxygen levels, and sleep stages over 1–2 nights. Results and prescription follow-up are included.
The Bottom Line
Treating OSA isn’t a guaranteed A1C fix—but for many, it’s the missing piece of the puzzle.
By stabilizing your breathing and oxygen levels during sleep, you give your body the chance to repair, regulate hormones, and keep blood sugar within a safer range overnight.
It’s not just about better rest—it’s about better metabolic health.
