Obstructive sleep apnea (OSA) is more than just a sleep disorder; it’s a significant health threat linked to heart disease, diabetes, stroke, and even cognitive decline. Left untreated, the repeated interruptions in breathing during sleep create a cascade of physiological stress, damaging your body over time. Understanding these risks is crucial for proactive treatment and long-term well-being.
How OSA Harms Your Body
OSA isn’t just about feeling tired. Every night, the pauses in breathing trigger stress hormones, keeping blood pressure high and interfering with blood sugar control. As Raj Dasgupta, MD, a sleep medicine specialist, explains: “Instead of sleep being restorative, apnea causes repetitive physiological stress that accelerates cardiovascular, metabolic, and neurological disease.”
This happens through several mechanisms:
- Intermittent Low Oxygen (Hypoxia): Each breathing pause drops oxygen levels, leading to oxidative stress. This damages blood vessels and strains the heart.
- Sympathetic Surges: OSA activates your “fight or flight” response during sleep, elevating blood pressure and heart rate instead of allowing them to naturally slow down.
- Intrathoracic Pressure Swings: The effort to breathe against a blocked airway puts physical strain on your chest and heart.
- Sleep Fragmentation: Hundreds of nightly interruptions prevent deep, restorative sleep needed for brain, heart, and immune system recovery.
OSA and Cardiovascular Disease
Untreated OSA severely strains the heart and blood vessels. Over time, this chronic stress can lead to:
- Resistant Hypertension: OSA increases the risk of high blood pressure that doesn’t respond to treatment fivefold.
- Left Ventricular Hypertrophy: High blood pressure and OSA cause the heart muscle to thicken, increasing the risk of blood clots, heart attack, and heart failure.
- Arrhythmias: Fluctuations in oxygen and pressure disrupt the heart’s electrical system, leading to irregular heartbeats and even sudden death.
- Stroke: Low oxygen and high blood pressure from OSA raise stroke risk, with up to 70% of stroke patients also having sleep apnea.
- Heart Failure: OSA is linked to heart failure in up to 60% of cases, increasing hospitalization rates and mortality.
Metabolic Disruption and Diabetes Risk
OSA disrupts how your body handles food and energy. Priya Jaisinghani, MD, explains: “Untreated OSA makes weight management and glycemic control significantly more difficult.” This vicious cycle is driven by:
- Hormonal Changes: OSA lowers leptin (the satiety hormone) and raises ghrelin (the hunger hormone), promoting cravings and weight gain.
- Cortisol Release: Sleep interruptions cause the brain to release cortisol, raising blood sugar and leading to insulin resistance.
As a result, OSA significantly increases the risk of type 2 diabetes. Up to 80% of people with diabetes also have OSA, and untreated apnea worsens both conditions.
OSA is also linked to:
- Liver Disease: About half of people with OSA have metabolic dysfunction–associated steatotic liver disease (MASLD), formerly known as nonalcoholic fatty liver disease.
- Kidney Disease: OSA prevalence increases with the severity of chronic kidney disease, affecting 31% of those in early stages and 45% in severe cases.
The Bottom Line
Obstructive sleep apnea is a serious health condition that extends far beyond disrupted sleep. It strains your heart, disrupts metabolism, and increases the risk of chronic disease. Effective treatment isn’t just about feeling rested; it’s about protecting your long-term health. If you suspect you have OSA, seek medical evaluation and consider treatment options like CPAP or newer medications to reduce these risks.
