Sleep Apnea as a Risk Factor for Coronary Heart Disease

Sleep, and more importantly quality sleep, plays a vital role in health. While sleeping well by itself will not guarantee good health, it is almost a certainty that poor sleep will lead to a deterioration in well-being. 

Feeling tired, lethargic and worn out are just minor irritants compared to what can happen to the body when the immune system is adversely affected by a lack of sleep.

Researchers in Sydney, Australia have discovered a heightened risk of coronary heart disease, and possibly premature death, can be attributed to a range of sleep-related conditions.

Poor quality of sleep can be attributed to a number of causes including:

  • Insomnia
  • Asthma 
  • Bronchitis
  • Sleep apnea

Any of these can lead to a disrupted sleeping pattern -- but the biggest cause of sleeping problems is sleep apnea.

Sleep apnea causes breathing to stop intermittently during sleep, so the person awakens possibly dozens of times during the night. This can be even more worrying for people with obstructive sleep apnea (OSA) who may get very little quality sleep for numerous nights in a row. 

Left untreated, obstructive sleep apnea has the potential to lead to many health issues including coronary heart disease.

Three Levels of Sleep

One study carried out in Sydney set out to discover how a person's overall health at age forty changed in later years depending on the quality of sleep the subjects enjoyed. 

Detailed records were taken of each subject's average duration of sleep, complaints of snoring or insomnia, and whether the subject was regarded as an early riser or night owl.

Rated healthy at age 40, the subjects were then categorized as poor, intermediate or healthy sleepers and estimates made as to how long each subject should expect to remain free of cardiovascular issues.

  • Poor sleepers were considered likely to lose two or more years of protection from coronary issues.
  • Intermediate sleepers could expect to lose around a year of cardiovascular health.
  • Healthy sleepers fared best with little or no reduction in coronary health expected.

It should be noted that the subjects tested were deemed to be in good or excellent health. Researchers extrapolated that cardiovascular health degenerated more quickly for patients in poor health or with pre-existing medical conditions. 

Researchers concluded that OSA sufferers may be at risk of coronary heart disease up to seven years earlier than would normally be expected.

Sleep Apnea and Heart Disease

Heart disease is recognized globally as the number one cause of death. Although it is impossible to fully eradicate coronary disease, there are ways to minimize the risk.

These include:

  • Healthy, balanced diet
  • Regular physical exercise
  • Not smoking
  • Limiting alcohol intake
  • Regular check-ups

An unhealthy lifestyle can lead to increased blood pressure and cholesterol levels as well as obesity and diabetes. All of these increase the risk of heart problems as does sleep apnea. 

Noted sleep researchers estimate that untreated sleep apnea increases the risk of abnormal heart rhythms by a factor of between two and four times, coronary heart disease by almost 30% and heart attack by as much as 140%

How Sleep Apnea Affects the Cardiovascular System

Research into how sleep apnea can affect the cardiovascular system is still in its infancy, but some important connections have already come to light:

Blood Pressure

Because the body is temporarily deprived of oxygen when breathing is interrupted, the nervous system responds by constricting blood vessels. This forces the heart to beat harder in order to increase blood pressure.

This process occurs repetitively and the resulting fluctuations in blood pressure can lead to hypertension or exacerbate an existing condition. Untreated hypertension greatly increases the risk of stroke or heart attack and is considered a life-threatening condition.


Obstructive sleep apnea causes the airways to temporarily narrow or close, which requires the person to struggle to inhale properly. Over a period of time, this causes pressure changes in the chest cavity which can place additional stress on the heart. 

In severe cases, these pressure changes can cause atrial fibrillation (erratic, rapid heartbeat), blood flow issues and even heart failure.

Oxidative Stress

In order to function properly, the body requires the correct amount of oxygen in the bloodstream. Because people with OSA experience frequent changes to the amount of oxygen they inhale, the oxygen levels become unbalanced, placing stress on the body to redress the balance.

This is called oxidative stress -- and the condition is quite common among OSA patients. Oxidative stress occurs because of an imbalance between antioxidants and free radicals which reduces the body's ability to fight pathogens and infections. 

Inflammatory conditions, high blood pressure and diabetes are often linked to oxidative stress -- but there is also evidence to suggest the condition also plays a role in hardened blood vessels, neurodegenerative diseases, coronary issues and some forms of cancer.

The Bottom Line

It is clear that any breathing difficulties will place additional and unwanted stress on the body -- and prevent it from functioning to the maximum. This is clearly the case with OSA -- as it causes intermittent breathing pauses and also causes disruption to sleep, which is the body's way of recovering and regenerating.

The stresses that OSA place on the body have already been shown to lead to inflammation and infections, but it has also been linked to:

  • Lethargy and drowsiness
  • Depression
  • Increased blood pressure
  • Diabetes

In the majority of cases, obstructive sleep apnea can be treated and controlled in a variety of ways and sufferers can lead a normal life.

Left untreated, however, OSA can worsen over time and result in serious medical conditions including strokes, heart disease and coronary failure. 

Regular snoring, frequent awakenings, morning headaches or sore throats, and daytime drowsiness are possible indicators of OSA and the presence of any or all of these symptoms should be brought to the attention of a doctor sooner rather than later.