I’ll never forget the night. There I was, sound asleep, when I was awoken by a loud rumbling noise. I could literally feel the wall vibrating. My heart pounding, I moved to the window to see what it could be. I thought it might be a helicopter overhead. Seeing nothing outside, I turned away from the window and realized that my husband, Derrick, was not in the bed. The noise continued. I crept out into the hall and peeked around the corner – only to find Derrick asleep in the bathtub, snoring up a storm.
Let’s just ignore the fact that most grown men don’t usually fall sleep in the bathtub. The point is that Derrick is a LOUD and constant snorer. And while it makes for funny stories (I could go on and on), it really is no laughing matter. In fact, research shows his snoring could be a serious threat to his health.
In the past decade we’ve learned that snoring is often a sign of sleep apnea, a serious condition that affects more than 12 million people in the U.S. And we’ve also learned that people with sleep apnea have a greater chance of dying from a heart attack, stroke, high blood pressure, and coronary heart disease. But what we haven’t really understood until now is “why?”
Recent research is shedding a new light on the connection. A study in the September issue of the medical journal “Chest” reveals that heart disease patients with confirmed sleep apnea have extremely high levels of homocysteine – levels as much as 20 percent higher than their counterparts without the condition.
THE THREE WAYS SLEEP APNEA LEAVES YOU BREATHLESS
What exactly is sleep apnea? The word apnea literally means “without breath,” and that’s a pretty fair representation. During sleep, people with sleep apnea actually stop breathing, sometimes a hundred times per night, with each episode lasting a minute or longer. There are actually three kinds of sleep apnea: obstructive, central, and mixed. Obstructive occurs when the soft tissue in the back of the throat collapses during sleep, closing off the airway. In the case of central sleep apnea, the airway isn’t blocked but the brain doesn’t signal the muscles to breathe. Mixed sleep apnea is a combination of both obstructive and central. But obstructive sleep apnea (OSA) is by far the most common of the three, and the type most often studied in clinical trials.
You may also be wondering, “what is homocysteine?” Long-time members of HSI have known about this important heart-health marker since 1996 – a full year before it was picked up by mainstream medical journals like JAMA and the New England Journal of Medicine. Five years ago, we told you how this amino acid can damage artery walls and open the door for artherosclerosis. And since then, the body of evidence has steadily grown, proving that homocysteine is one of the most important markers for cardiovascular disease – as important (or even more so) than the elevated cholesterol and triglyceride levels doctors always look for.
HIGH HOMOCYSTEINE COMBINED WITH OSA RAISES RISK ALMOST 50%
Knowing that both sleep apnea and elevated homocysteine levels are linked to an increased risk of cardiovascular death, the researchers set out to discover if there was any link between the two. They recruited a total of 345 men, who fell into three groups: 237 men with obstructive sleep apnea (OSA), 35 men with heart disease but no sign of OSA, and a control group of 73 men with neither OSA nor any type of disease. The OSA group was further classified into three sub-groups: men who had heart disease and OSA, men who had OSA and high blood pressure but no sign of heart disease, and men who had OSA but no signs of hypertension or heart disease.
Each participant fasted over night, and then submitted to a blood test. The researchers also recorded body mass index (BMI) and age, and controlled for these factors as well as for incidence of type II diabetes, smoking, history of heart attack, and usage of various medications.
Here’s what they found: even after controlling for all those confounding factors, patients with OSA and ischemic heart disease had significantly higher homocysteine levels than any other analyzed group. Most doctors consider a homocystiene level below 12 micromoles per liter to be “normal.” In this study’s control group, the average homocysteine level was 9.78 mmol/l. Those with “OSA only” came in at 9.85, and those with “heart disease only” had average levels of 11.92 – still within the normal range. But participants with heart disease and OSA had average homocysteine levels of 14.6 mmol/l.
That may not seem like that big of a jump, but consider this: one meta-analysis concluded that a 5 mmol/l increase in homocysteine levels elevates cardiovascular risk by as much as a 20 mg/dL increase in total cholesterol. If your total cholesterol jumped from 180 to 200, it would certainly get your attention – and your doctor’s.
LACK OF NITRIC OXIDE COULD BE HIDDEN CAUSE
But how does this connect to sleep apnea? The study’s authors say that more research is needed to clarify the mechanisms at work. But they present several hypotheses to explain the relationship. First, the interrupted flow of oxygen during sleep apnea may lead to the increased free radical formation, and may inhibit the production of nitric oxide (NO), a compound that binds homocysteine. Under normal conditions, the endothelial cells that line the heart and the blood vessels release NO. But over time, high homocysteine concentrations damage the endothelium, and the production of NO is reduced. This feeds a vicious cycle: too little nitric oxide leads to too much homocystiene, and too much homocysteine leads to too little nitric oxide. The NO connection is supported by other research; studies have shown that OSA is associated with endothelial damage and decreased levels of circulating nitric oxide.
As the study shows, not everyone with sleep apnea has high levels of homocystiene. Conversely, not everyone with high homocysteine levels has sleep apnea. But there’s definitely enough of an association here to make you take notice. Here’s the bottom line: if you consistently snore, consider it a health risk. Consult your doctor for a sleep apnea evaluation. Depending on your doctor and your insurance, you may be referred to a sleep specialist. Usually the diagnosis requires the use of a monitoring device that is attached to you while you sleep; it records the frequency and duration of apnea episodes. Often, sleep apnea can be treated with a therapy called nasal continuous positive airway pressure (CPAP), a device that pushes air through the airway to keep it open through sleep. (The studies that found decreased levels of NO among OSA patients saw NO levels return to normal after CPAP treatment began.)
And while you’re at the doctor’s office, ask to have your homocysteine levels analyzed. Actually, everyone should be concerned about their homocysteine levels, whether they snore or not. Not only is it a critical marker for heart disease, but subsequent research has also reported links between elevated homocysteine levels and cognitive decline, Alzheimer’s disease, fibromyalgia, and chronic fatigue syndrome.
COMMON VITAMINS ARE FIRST STEP TOWARD LOWERING RISK
If you find that your homocysteine level is too high, you can lower it safely and effectively with a simple, natural approach. Years of research have shown that homocysteine can be controlled by taking supplemental vitamin B6, B12, and folic acid. These vitamins are methylating factors, agents that allow homocystiene to convert into another, harmless form. In today’s world, it’s almost impossible to get the necessary amounts of these essential nutrients through our food alone. For several years, we’ve recommended a unique formulation designed specifically to combat high homocysteine levels called CardioSupport (formerly Cardiocysteine). It’s available from Advanced Nutritional Products. For more information, call them directly at 1-888-436-7200.
I’m proud that HSI was one of the first health publications to write about homocysteine, and happy that many doctors are now realizing its importance and doing further research into this amino acid’s role in heart health. I’m going to urge Derrick to have his levels and his snoring checked – and to stop falling asleep in the bathtub.
Copyright 1997-2002 by Institute of Health Sciences, L.L.C.
