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Diabetes and Sleep Apnea: The Two-Way Connection Explained
Last updated: September 21, 2026. Medically reviewed by Dr. Avinesh Bhar, Board-Certified Sleep Physician, SLIIIP.com.
Diabetes and sleep apnea are connected in both directions: untreated sleep apnea makes blood sugar harder to control, and diabetes itself raises the risk of developing sleep apnea in the first place. This is not a coincidence of two common conditions overlapping in the same patients; each one actively worsens the other through distinct physiological pathways. Dr. Avinesh Bhar, Board-Certified Sleep Physician at SLIIIP.com, notes that diabetes management often focuses entirely on diet, medication, and exercise while an undiagnosed breathing disorder quietly works against all three. Recognizing this two-way relationship changes how both conditions should be approached.
SLIIIP’s board-certified sleep physicians can do sleep evaluations for sleep apnea. Virtual consultations in all 50 states. Home sleep tests shipped to your door.
How Sleep Apnea Makes Blood Sugar Harder to Control
Each time breathing stops during an apnea event, the body releases stress hormones including cortisol and adrenaline as part of the arousal response. These hormones directly promote insulin resistance, meaning cells respond less effectively to insulin and blood sugar rises even without any change in diet.
A population-based study from the Wisconsin Sleep Cohort, published in the American Journal of Respiratory and Critical Care Medicine, found that diabetes was more prevalent among people with sleep-disordered breathing, independent of other known risk factors. Repeated nightly oxygen drops also appear to disrupt normal glucose metabolism over time, contributing to higher A1C levels that make day-to-day diabetes management more difficult.
Can Diabetes Itself Increase Sleep Apnea Risk?
Yes, and the relationship works in both directions. Diabetic neuropathy, nerve damage caused by prolonged high blood sugar, can affect the nerves controlling upper airway muscles and the brain’s central respiratory drive, making the airway more prone to collapse during sleep.
Obesity is also a shared risk factor driving both conditions simultaneously: excess fat around the neck narrows the airway, while abdominal fat makes breathing more effortful while lying down. A CDC-supported analysis of national health survey data found that sleep apnea, along with several other sleep problems, was significantly more common among adults with diabetes, independent of body mass index, according to research published on PubMed Central.
Why This Overlap Often Goes Unrecognized
Diabetes appointments typically focus on blood sugar readings, medication adjustments, and diet, with sleep rarely part of the standard conversation unless a patient specifically raises it. Fatigue and difficulty concentrating, both common symptoms of untreated sleep apnea, are also common experiences for people managing diabetes, which makes it easy to attribute everything to blood sugar swings alone.
A patient whose A1C will not improve despite consistent medication adherence and diet changes has a reasonable basis to ask specifically about sleep, snoring, and daytime sleepiness, since an unaddressed breathing disorder can undermine even well-managed diabetes care.
What Happens When Sleep Apnea Is Treated
Treating sleep apnea, most commonly with CPAP therapy, has been shown in multiple studies to improve insulin sensitivity and help lower blood sugar levels in people with type 2 diabetes. Some patients are able to reduce their insulin requirements once consistent, effective sleep apnea treatment is in place.
This does not mean sleep apnea treatment replaces diabetes management, but it means an unaddressed breathing disorder can act as a persistent obstacle that no amount of diet or medication adjustment alone can fully overcome. For patients who have plateaued despite doing everything their diabetes care team has recommended, sleep is a reasonable next place to look rather than assuming the current plan simply needs more discipline.
When to See a Doctor
If you have diabetes and your blood sugar remains difficult to control despite consistent management, or if you snore, feel excessively tired during the day, or have been told you stop breathing at night, a sleep evaluation is worth pursuing alongside your diabetes care. Dr. Bhar recommends screening for sleep apnea in any diabetes patient with these symptoms, since treating the sleep disorder can make every other part of diabetes management more effective.
A home sleep test can determine within one night whether a breathing disorder is contributing to your blood sugar control, information that is valuable to share with whichever physician manages your diabetes care.
Insurance and Cost
SLIIIP works with most major insurance plans, including Medicare and TRICARE, and offers transparent cash pricing for patients without applicable coverage.
SLIIIP’s board-certified sleep physicians can do sleep evaluations for sleep apnea. Virtual consultations in all 50 states. Home sleep tests shipped to your door.
Frequently Asked Questions
Are diabetes and sleep apnea connected?
Yes, the relationship is bidirectional: sleep apnea worsens blood sugar control, and diabetes independently raises the risk of developing sleep apnea.
How does sleep apnea affect blood sugar?
Repeated oxygen drops trigger stress hormones like cortisol, which promote insulin resistance and raise blood sugar levels.
Can diabetes cause sleep apnea?
Diabetic neuropathy can affect the nerves controlling airway muscles and breathing, increasing the risk of airway collapse during sleep.
Should people with diabetes get screened for sleep apnea?
It’s a reasonable step, especially if blood sugar remains hard to control despite consistent management, or if snoring and daytime fatigue are present.
Can treating sleep apnea improve blood sugar control?
Studies show that treating sleep apnea, often with CPAP, can improve insulin sensitivity and lower blood sugar in many patients with type 2 diabetes.
Does obesity explain the whole connection between diabetes and sleep apnea?
Obesity is a shared risk factor, but research shows sleep apnea affects blood sugar independent of body weight.
What percentage of people with diabetes have sleep apnea?
Studies have found a significantly higher prevalence of sleep apnea and other sleep problems among adults with diabetes compared with the general population.
Can sleep apnea cause type 2 diabetes?
Research shows an independent association between sleep-disordered breathing and diabetes, though the exact causal relationship is still being studied.
Does CPAP therapy reduce insulin needs for diabetics?
Some patients with type 2 diabetes reduce their insulin requirements after consistent, effective CPAP treatment.
Can a home sleep test help if I have diabetes?
Yes, it can determine whether a breathing disorder is contributing to blood sugar control difficulties.
Why do diabetes appointments rarely address sleep?
Diabetes care typically focuses on diet, medication, and blood sugar readings, leaving sleep out of the standard conversation.
Can nerve damage from diabetes affect breathing during sleep?
Yes, diabetic neuropathy can impair the nerves controlling upper airway muscles and central respiratory drive.
Is fatigue from diabetes the same as fatigue from sleep apnea?
The two can feel similar, which is why unexplained persistent fatigue in diabetes patients is worth evaluating for sleep apnea.
Does weight loss help both diabetes and sleep apnea?
Yes, weight loss can improve blood sugar control and reduce sleep apnea severity, since both conditions share this risk factor.
Can type 1 diabetes also be linked to sleep apnea?
Yes, research has found a high prevalence of sleep apnea in adults with type 1 diabetes as well as type 2.
What symptoms suggest sleep apnea in a diabetic patient?
Loud snoring, witnessed breathing pauses, morning headaches, and excessive daytime sleepiness are common indicators.
Can poor sleep alone raise blood sugar, even without diagnosed sleep apnea?
Yes, fragmented or insufficient sleep of any cause can affect glucose metabolism and insulin sensitivity.
Should my endocrinologist and sleep physician communicate?
Sharing information between both can help ensure neither condition is managed in isolation when both may be contributing to your symptoms.
Can gestational diabetes be linked to sleep apnea?
Pregnancy-related hormonal changes can increase sleep apnea risk, and this is being studied alongside gestational diabetes risk.
What is the first step if I have diabetes and suspect sleep apnea?
Book a sleep evaluation to determine whether a breathing disorder may be part of why your blood sugar is difficult to manage.
Take the Next Step
SLIIIP’s board-certified sleep physicians can do sleep evaluations for sleep apnea. Virtual consultations in all 50 states. Home sleep tests shipped to your door.
