Sleep Apnea and Diabetes: Blood Sugar Connection

Sleep apnea and diabetes are closely connected. Obstructive sleep apnea can repeatedly interrupt breathing and sleep during the night, contributing to changes in insulin sensitivity and glucose metabolism. At the same time, sleep apnea is common among people with type 2 diabetes, particularly those who also have overweight or obesity.

Recognizing and treating sleep apnea may improve sleep quality, daytime energy, blood pressure, and overall diabetes management.

Quick Answer

Sleep apnea can affect diabetes by disrupting sleep and repeatedly lowering oxygen levels during the night. These changes can contribute to insulin resistance and make blood sugar management more difficult.

Obstructive sleep apnea is particularly common in people with type 2 diabetes. The American Diabetes Association (ADA) recommends screening people with diabetes for sleep problems and sleep disorders and referring them for further evaluation when appropriate.¹

Key Points

Sleep apnea and type 2 diabetes commonly occur together.
Obstructive sleep apnea can contribute to insulin resistance and impaired glucose metabolism.
Loud snoring, witnessed pauses in breathing, morning headaches, and excessive daytime sleepiness are important warning signs.
A sleep study can determine whether you have sleep apnea and how severe it is.
Treating sleep apnea can improve sleep quality, daytime functioning, and blood pressure, although its effect on blood sugar varies among individuals.

What Is the Connection Between Sleep Apnea and Diabetes?

The strongest connection involves obstructive sleep apnea (OSA), the most common form of sleep apnea. OSA occurs when the upper airway repeatedly becomes partially or completely blocked during sleep.

Each episode can briefly reduce oxygen levels and cause the brain to wake the body enough to restore normal breathing. This cycle may happen repeatedly throughout the night, even when you do not remember waking up.

These repeated drops in oxygen and disruptions in sleep can activate stress responses and affect how the body processes glucose. Research has linked sleep disturbances with reduced insulin sensitivity and impaired glucose tolerance.²

The relationship also works in both directions through shared risk factors. Obesity, particularly excess weight around the abdomen and upper airway, increases the likelihood of both obstructive sleep apnea and type 2 diabetes.

How Common Is Sleep Apnea in People With Diabetes?

Sleep apnea is especially common among people with type 2 diabetes.

According to the ADA’s 2026 Standards of Care, the prevalence of obstructive sleep apnea among people with type 2 diabetes may be as high as 23%, while some form of sleep-disordered breathing may affect as many as 58%.³

The prevalence can be substantially higher among people who also have obesity.

Sleep problems are not limited to type 2 diabetes. People with type 1 diabetes can also experience obstructive sleep apnea and other sleep disturbances, although the relationship has been studied less extensively.

Can Sleep Apnea Raise Blood Sugar?

Sleep apnea may contribute to higher or more difficult-to-manage blood sugar by affecting insulin sensitivity.

When sleep is repeatedly interrupted, the body experiences physiological stress. Intermittent low oxygen levels and sleep fragmentation may affect hormones, the nervous system, inflammation, and glucose metabolism.

The result can be greater insulin resistance, meaning the body’s cells do not respond to insulin as effectively.

NIDDK notes that obstructive sleep apnea is associated with type 2 diabetes and that greater OSA severity is associated with lower insulin sensitivity.⁴

For someone who already has diabetes, this may be one factor contributing to glucose levels that are harder to manage. If you’re monitoring these changes, compare your readings with our Blood Sugar Charts to see typical fasting, before-meal, and after-meal glucose ranges.

Symptoms of Sleep Apnea to Watch For

Sleep apnea often goes undiagnosed because many symptoms occur while you are asleep.

Common warning signs include:

loud, persistent snoring
pauses in breathing noticed by another person
gasping or choking during sleep
frequent nighttime awakenings
morning headaches
dry mouth after waking
excessive daytime sleepiness
difficulty concentrating
irritability or mood changes
waking up feeling unrefreshed despite spending enough time in bed

The ADA specifically recommends evaluating obstructive sleep apnea when symptoms such as snoring, witnessed apnea, or excessive daytime sleepiness are present.³

If you have diabetes and regularly experience these symptoms, discuss them with your healthcare provider.

How Is Sleep Apnea Diagnosed?

Your healthcare provider may begin by reviewing your symptoms, medical history, sleep patterns, and risk factors.

If sleep apnea is suspected, you may be referred for a sleep study. Depending on your situation, testing may be performed overnight in a sleep center or with an appropriate home sleep apnea test.

The test records breathing and other measurements while you sleep and can help determine whether sleep apnea is present and how severe it is.

How Is Sleep Apnea Treated?

Treatment depends on the type and severity of sleep apnea and your individual health needs.

CPAP Therapy

Continuous positive airway pressure (CPAP) is a common treatment for obstructive sleep apnea. A CPAP machine delivers pressurized air through a mask to help keep the airway open during sleep.

Consistent treatment can reduce breathing interruptions and improve sleep quality and daytime symptoms.

Weight Management

When overweight or obesity contributes to obstructive sleep apnea, weight loss may reduce its severity. Weight management can also improve insulin sensitivity and other metabolic risk factors.

Oral Appliances

Some people with mild or moderate obstructive sleep apnea may benefit from an oral appliance that helps position the jaw or tongue to keep the airway open.

Other Treatments

Depending on the cause and severity of OSA, treatment may also include positional therapy, lifestyle changes, or certain surgical procedures.

Does Treating Sleep Apnea Improve Diabetes?

Treating sleep apnea has clear benefits, but the effect on blood sugar is less predictable.

Sleep apnea treatment can improve quality of life and blood pressure management.³

Studies examining whether CPAP directly lowers blood glucose or A1C have produced mixed results. If you’re tracking longer-term glucose control, our A1C Calculator can help you see how A1C relates to estimated average glucose (eAG). Benefits may depend partly on the severity of sleep apnea, how consistently CPAP is used, and other factors affecting glucose management.

For that reason, CPAP should not be considered a replacement for diabetes medications, nutrition, physical activity, glucose monitoring, or other parts of your diabetes treatment plan.

Instead, treating sleep apnea addresses an important health problem that may otherwise make diabetes management more difficult.

When Should You Talk to Your Doctor?

Consider discussing sleep apnea with your healthcare provider if you have diabetes and:

snore loudly on a regular basis
wake up gasping or choking
have been told you stop breathing while sleeping
experience persistent daytime sleepiness
regularly wake with headaches
sleep enough hours but rarely feel rested
have difficult-to-manage blood pressure
have unexplained changes in your usual glucose patterns

Sleep apnea is treatable, and identifying it may improve more than just your sleep.

The Bottom Line

Sleep apnea and diabetes can influence each other through sleep disruption, insulin resistance, obesity, and other metabolic factors. The association is particularly strong with type 2 diabetes.

If you have diabetes and symptoms such as loud snoring, witnessed breathing pauses, or significant daytime sleepiness, talk with your healthcare provider about sleep apnea screening.

Treating sleep apnea may not automatically lower your A1C, but it can improve sleep, quality of life, and blood pressure while removing one potential obstacle to effective diabetes management.

Frequently Asked Questions

Sleep apnea does not mean you will develop diabetes. However, obstructive sleep apnea is associated with insulin resistance and an increased risk of developing type 2 diabetes.

It can. Repeated sleep disruption and intermittent drops in oxygen may reduce insulin sensitivity and make glucose regulation more difficult.

Potentially. Sleep apnea can affect hormones and insulin sensitivity overnight, which may contribute to higher glucose levels in some people. However, high morning blood sugar can have many causes, including the dawn phenomenon, medication or insulin needs, food intake, and other factors. If your fasting readings are consistently elevated, see our guide to High Morning Blood Sugar for other possible causes.

Not necessarily. Research on CPAP and glycemic control has produced mixed results. CPAP is effective for treating obstructive sleep apnea, but it should complement rather than replace your diabetes treatment plan.

People with diabetes should be assessed for sleep health and symptoms of sleep disorders. Symptoms such as loud snoring, excessive daytime sleepiness, and witnessed pauses in breathing are particularly important reasons to discuss sleep apnea evaluation with your healthcare provider.

Medically reviewed by Dr. Seshadri G. Das, MD

Board Certified in Endocrinology, Diabetes & Metabolism

Last updated: September 2026

References

American Diabetes Association Professional Practice Committee. Facilitating Positive Health Behaviors and Well-being to Improve Health Outcomes: Standards of Care in Diabetes—2026. Diabetes Care. 2026;49(Suppl. 1). ADA Standards of Care 2026 — Section 5 [↩]
Reutrakul S, Van Cauter E. Interactions Between Sleep, Circadian Function, and Glucose Metabolism: Implications for Risk and Severity of Diabetes. Ann N Y Acad Sci. 2014;1311:151–173. doi:10.1111/nyas.12355. PubMed — Reutrakul & Van Cauter [↩]
American Diabetes Association Professional Practice Committee. Comprehensive Medical Evaluation and Assessment of Comorbidities: Standards of Care in Diabetes—2026. Diabetes Care. 2026;49(Suppl. 1). ADA Standards of Care 2026 — Section 4 [↩] [↩] [↩]
National Institute of Diabetes and Digestive and Kidney Diseases. The Impact of Poor Sleep on Type 2 Diabetes. March 17, 2021. NIDDK — The Impact of Poor Sleep on Type 2 Diabetes [↩]