Entries in Heart Disease (9)

Monday
Apr132015

Atrial Fibrillation Care: Put the Catheter (and Rx Pad) Down

The Dolder Grand
Medical Wellness & Rejuvenation

PD Dr. Rainer Arendt
Internal Medicine & Cardiology FMH
Prevention & Regenerative Medicine

 

 

My approach to patients with atrial fibrillation (AF) has changed. Completely and fundamentally. This is a before-and-after moment in AF care.

Before: We saw atrial fibrillation as a disease rather than seeing it as a result of other diseases. That explains why our treatments (drugs and ablation) have performed so poorly. It is a wrong-target problem. It is akin to stenting an artery and saying atherosclerosis is fixed or prescribing an antipyretic for bacterial infection.

After: Atrial fibrillation in the vast majority of patients (excluding those with brief episodes that are a form of focal atrial tachycardia) is a sign that something is awry in the body—usually exposure to an excess. The atria, with their sensitivity to stretch, neural connections, and plastic cells, are a window onto overall health.

Year after year I have watched the drugs fail and the AF return after ablation. It is a relief to (better) understand AF and to be able to cite evidence that supports the concept that the atria fibrillate for a reason. And that reason is the main therapeutic target.

 

You may know the story. A group of researchers in Adelaide have shown—first in animal models [1,2] and now in humans [3,4]—that promoting basic health dramatically improves AF burden. Their methods and results have taught us how AF happens. Although work remains, it is clear that lifestyle diseases (with inflammation due to diet-induced intestinal dysbiosis, see below), via pressure- and volume-induced atrial stretch, inflammation, or neural imbalances, induce disease in and around the cells of the heart.

 

The coolest part about these data are that treatment of lifestyle diseases—mostly, the removal of excesses—not only reduces AF burden but also improves the structure of the heart. Even fibrosis (aka scar) can regress, which is a novel way to think about cardiac biology.

This "upstream" approach to AF is no longer a radical idea. Nearly all the leaders in cardiology agree. It changes the way doctors should treat people with AF. Namely, the idea that AF is fixable with rhythm drugs or ablation is as wrong as thinking a stent fixes atherosclerosis or that treating fever cures infection.

Before I go on, let me make a note of caution. I am not saying AF drugs or ablation have no role. They do. But their (much smaller) role now is similar to stents or beta-blockers in patients with coronary artery disease: to stabilize an acute situation or to help transiently restore regular rhythm so that patients can feel well enough to exercise and enjoy life—things that make the atria healthier.

I no longer think of an antiarrhythmic drug as long-term therapy. For instance, I cardiovert and medicate so that patients can feel well enough to exercise every day they eat. I buy time. Then patients can lose weight or address other lifestyle issues, such as sleep disorders, alcohol intake, and perhaps overexercise and overwork. This improves glucose handling, lowers blood pressure, and relieves inflammation. People start to feel better. When they come back for follow-up, I discuss stopping the rhythm drugs—because they have served their adjunctive purpose.

On the matter of stroke risk: think about what it means to improve high blood pressure, diabetes, inflammation, and hyperlipidemia. Now think what it means to do so in millions of people.

You can see how this new approach upends the role of AF ablation. It is one thing to prescribe a pill; it is yet another to deliver 60 to 80 burns to the left atrium. Recall that patients who choose AF ablation walk into the hospital the morning of the procedure. They may not be perfect, they have AF after all, but they are alive and functioning. What awaits them in the EP lab is nothing small. They will endure 2 to 3 hours of general anesthesia, vascular access in both legs, two transseptal punctures, a fluid load, and purposeful damage to the heart done in proximity to the esophagus, phrenic nerve, pulmonary veins, and the thin left atrial appendage.

And . . . that $100 000 procedure, with its (real-world) 5% to 7% risk,[5] often fails. Repeat procedures are required in one of four patients. Even when the procedure is done well, recent research [3] shows that long-term success is fivefold lower when patients do not remove excesses from their lives.

This new approach to patients with AF has significant implications for the cardiology and healthcare community.

Consider those affected:

•             Hospitals invest in expensive ablation labs. They have banked on the epidemic of new atrial-fibrillation patients who will "need" procedures. Recently, I did a marketing video for my hospital on AF treatment. We filmed in our EP lab, the ablation machines as the backdrop. I was excited to speak about the new discoveries in AF care. But I stammered when the interviewer asked me about the "procedures we do here." I thought to myself: we do procedures here, we do them well, we do them safely, but we are sure to do a lot fewer in the future.

•             Doctors—like me—have reaped the rewards of AF misthink. We are paid well to do and redo AF ablation. The financial reward for helping people help themselves pales in comparison. Yet I urge you not to blame overtreatment on fee for service. The main reasons doctors overtreat are do-something bias and the disease model of care. First, doing things is what we are taught, and it is what society expects. We might give cursory mention to lifestyle but then we rush to drugs and procedures. Second, the disease model of care tricks us into putting problems—like AF—into silos (cardiac, renal, pulmonary, etc), which we treat in isolation. So ingrained is the silo model that it has been daring to use the word holistic. As if things are not connected in the body.

•             Workforce needs will be disrupted. A few years ago, cardiology groups and hospitals felt like they needed more electrophysiologists to handle the epidemic of atrial fibrillation. Now it is clear that what we need more of is not people with catheter skills, but people with people skills. The painful truth is that American cities and American hospitals do not need more EP labs.

•             Policy makers and payers are bound to notice. Think about the billions of dollars spent to care for the millions of patients with AF. Why would any insurer pay for drugs and procedures that are doomed to fail unless lifestyle measures are addressed? I wonder whether this could be the spark that gets payers to see the value of helping people live healthier lives?

•             Industry will have to adjust. Imagine the boardrooms of pharmaceutical and medical device companies in the past decade: they saw atrial fibrillation as a major opportunity. We will develop drugs, catheters, and mapping systems to treat the millions of afflicted patients. What these companies should see now is that AF drugs and ablation will go the way of renal denervation—useful in very selected cases, but no gold mine.

•             Patients are most affected by this new discovery. Although there will be small numbers of people afflicted by fluky focal AF (a confusing fact), the vast majority of patients with AF will enjoy the best results when they and their caregivers treat the root causes. From now forward, when a patient with AF sees a doctor who recommends rhythm drugs or ablation without first exploring how that person sleeps, eats, drinks, moves, and deals with stress, it will be a signal to get another opinion. Rushing to drugs or ablation will be as wrong as prescribing antibiotics for a viral infection.

This discovery about atrial fibrillation teaches us that focal (easy) solutions for systemic diseases due to lifestyle are destined to fail. Given the rise of lifestyle-related diseases, this is a critical lesson, one we should learn sooner rather than later.

Source: John Mandrola, Atrial Fibrillation Care: Put the Catheter (and Rx Pad) Down. Medscape. Apr 07, 2015.

References

1.            Abed HS, Samuel CS, Lau DH, et al. Obesity results in progressive atrial structural and electrical remodeling: Implications for atrial fibrillation. Heart Rhythm 2013; 10:90-100. Article

2.            Mahajan R, Brooks AG, Shipp N, et al. AF and obesity: Impact of weight reduction on the atrial substrate. Heart Rhythm Society 2013 Annual Scientific Sessions; May 8-11, 2013; Denver, CO. Abstract YIA-01

3.            Pathak RK, Middeldorp ME, Lau DH, et al. Aggressive risk factor reduction study for atrial fibrillation and implications for the outcome of ablation: the ARREST-AF cohort study. J Am Coll Cardiol 2014; 64:2222-2231. Article

4.            Pathak R, et al. Long-term effect of goal directed weight management in an atrial fibrillation cohort: A long-term follow-up study (LEGACY Study). J Am Coll Cardiol 2015; DOI:101016/jacc.2015.03.002. Abstract

5.            Deshmukh A, Patel NJ, Pant S, et al. In-hospital complications associated with catheter ablation of atrial fibrillation in the United States between 2000 and 2010: Analysis of 93 801 procedures. Circulation 2013; 128:2104-2112. Article

Sunday
Apr122015

Gut microbiota serve as new targets for the prevention and treatment of cardiovascular disease

The Dolder Grand
Medical Wellness & Rejuvenation

PD Dr. Rainer Arendt
Internal Medicine & Cardiology FMH
Prevention & Regenerative Medicine

 

We are living in a bacterial world, and it's impacting us more than previously thought.

 

 

 

Recent studies reveal a contribution of intestinal microbes in the expression of metabolic or cardiovascular disease. The mechanisms through which intestinal microbiota and/or their metabolic products alter systemic homoeostasis and cardio-metabolic disease risks are just beginning to be dissected. Intervention studies in humans aiming to either selectively alter the composition of the intestinal microbiota or to pharmacologically manipulate the microbiota to influence production of their metabolites are crucial next steps. The intestinal microbiome represents a new potential therapeutic target for the treatment of cardio-metabolic diseases.

Vinjé S1, Stroes E, Nieuwdorp M, Hazen SL.: The gut microbiome as novel cardio-metabolic target: the time has come! Eur Heart J. 2014 Apr;35(14):883-7. doi: 10.1093/eurheartj/eht467. Epub 2013 Nov 11.


 

The human gastrointestinal tract is home to trillions of bacteria, which vastly outnumber host cells in the body. Although generally overlooked in the field of endocrinology, gut microbial symbionts organize to form a key endocrine organ that converts nutritional cues from the environment into hormone-like signals that impact both normal physiology and chronic disease in the human host. Recent evidence suggests that several gut microbial-derived products are sensed by dedicated host receptor systems to alter cardiovascular disease progression. In fact, gut microbial metabolism of dietary components results in the production of proatherogenic circulating factors that act through a meta-organismal endocrine axis to impact cardiovascular disease risk.

Brown JM1, Hazen SL.: The gut microbial endocrine organ: bacterially derived signals driving cardiometabolic diseases. Annu Rev Med. 2015;66:343-59. doi: 10.1146/annurev-med-060513-093205.


 

It has recently been discovered that certain dietary nutrients possessing a trimethylamine (TMA) moiety, namely choline/phosphatidylcholine and L-carnitine, participate in the development of atherosclerotic heart disease. A meta-organismal pathway was elucidated involving gut microbiota-dependent formation of TMA and host hepatic flavin monooxygenase 3-dependent (FMO3-dependent) formation of TMA-N-oxide (TMAO), a metabolite shown to be both mechanistically linked to atherosclerosis and whose levels are strongly linked to cardiovascular disease (CVD) risks. Collectively, these studies reveal that gut microbiota serve as new targets for the prevention and treatment of cardiovascular disease.

Tang WH, Hazen SL.: The contributory role of gut microbiota in cardiovascular disease. J Clin Invest. 2014 Oct;124(10):4204-11. doi: 10.1172/JCI72331. Epub 2014 Oct 1.



We offer gut microbiome exchange (transplantation) as novel opportunity in prevention and treatment of cardiovascular disease.

Saturday
Mar072015

Detox and chelation therapy in combination with oral high-dose multivitamins and minerals

Medical practitioners have treated atherosclerotic disease (heart attack, stroke, smoker’s leg) with chelation therapy for over 50 years. Lack of strong evidence led conventional practitioners to abandon its use in the 1960s and 1970s. This relegated chelation therapy to complementary and alternative medicine practitioners, who reported good anecdotal results.

Concurrently, the epidemiologic evidence linking xenobiotic metals with cardiovascular disease and mortality gradually accumulated, again suggesting a plausible role for chelation therapy. On the basis of the continued use of chelation, the National Institutes of Health (Bethesda, Maryland, USA) initiated a definitive trial of chelation therapy.

The Trial to Assess Chelation Therapy (TACT) proved chelation therapy to be safe. Chelation therapy reduced cardiovascular events and death from all causes significantly. The 5-year relative risk reduction in all-cause mortality was 43%. The magnitude of benefit is such that it suggests urgency in implementation of chelation therapy.

Recently, additive beneficial effects have been shown for the combination of chelation with high-dose oral vitamins. Compared to double placebo the active combination further reduced heart attack, stroke or death to an extent that was both statistically significant and of high clinical relevance.

Ref.: Clarke, N.E., Clarke, C.N., and Mosher, R.E. Treatment of angina pectoris with disodium ethylene diamine tetraacetic acid. Am J Med Sci. 1956; 232: 654–666, Lamas, G.A., Goertz, C., Boineau, R. et al. Effect of disodium EDTA chelation regimen on cardiovascular events in patients with previous myocardial infarction: the TACT randomized trial. JAMA. 2013; 309: 1241–1250, Lamas GA, Boineau R, Goertz C, Mark DB, Rosenberg Y, Stylianou M, Rozema T, Nahin RL, Terry Chappell L, Lindblad L, Lewis EF, Drisko J, Lee KL. EDTA chelation therapy alone and in combination with oral high-dose multivitamins and minerals for coronary disease: The factorial group results of the Trial to Assess Chelation Therapy. Am Heart J. 2014;168:37-44. Peguero JG, Arenas I, Lamas GA. Chelation therapy and cardiovascular disease: connecting scientific silos to benefit cardiac patients. Trends Cardiovasc Med. 2014;24:232-40.

 

These study results had come as a surprise to the scientific community, where it was held for long that you can’t detox your body. Let’s look at the facts. Is there anything on top of a prudent (Mediterranean) eating style and exercise to get healthy? And which regime if any can really make a difference? Detoxing – the idea that you can flush your system of impurities and leave your organs clean has been a pseudo-medical concept for centuries, and many of the oldest religions practise fasting and purification. And while is has been known for long that e.g. metals play an important role in human biology, e.g. iron is critical for oxygen transport, e.g. zinc is a critical part of enzymes, novel evidence revealed there are many metals that are toxic to humans. These metals have been referred to as heavy metals or toxic metals. The terms are imprecise, we will use the term xenobiotic metal to refer to those toxic metals. The epidemiologic evidence that xenobiotic metals are toxic is robust. For example, arsenic, cadmium, lead, and mercury are ranked among the top 10 on the current Agency for Toxic Substances and Disease Registry Priority List of Hazardous Substances. Arsenic, lead, and mercury are ranked as the top 3 hazardous substances.

 

Within the cardiovascular system, xenobiotic metals have been linked to hypertension, atherosclerosis, dyslipidaemia, coronary artery disease, and peripheral artery disease (smoker’s leg). Especially, lead and cadmium demonstrate hazardous effects on human health. That explains in part the beneficial effects of removing these toxins from your system by chelation and detox therapy. However, additional mechanisms are at play, and all the benefits of the chelation and detox treatment are not yet understood.

The basic lifestyle ‘detox’ is not smoking, exercising and enjoying a healthy balanced eating style. Close your eyes, if you will, and imagine a Mediterranean diet. A table adorned with meat once per week, fish three times per week, and daily olive oil, cheeses, salads, wholegrain cereals, nuts and fruits. All these foods give the protein, amino acids, fats, fibre, starches, vitamins and minerals to keep the body – and your immune system, the biggest protector from ill-health – functioning perfectly.

So there is no need - with such a feast available - to punish ourselves to be healthy. In fact, it may be even more true today than 2400 years ago, “Let food be thy medicine and medicine be thy food,” ― Hippocrates. This eating the right foods and spices—and avoiding the wrong ones—could go a long way toward staving off everything from gut ailments to cancer.

However, in order to counteract the stresses of modern life, and the impact of a heavily polluted environment – unknown to Hippokrates, we have developed a 7-day oral chelation and detox program that is comfortable and based on modern medicine, in fact, regular detoxing together with healthy nutrition is at the core of every form of regenerative and preventative medicine, and basis to treating modern lifestyle illnesses. Our chelation and detox treatment enables the body to regenerate and newly organize its powers of self-healing.

Wednesday
Sep052012

Foods That Can Save Your Heart

The Dolder Grand

Health Care &
Rejuvenation

 

PD Dr. Rainer Arendt
Internal Medicine & Cardiology FMH
Prevention & Regenerative Medicine 

 

 

 

 

 

 

 

 

 

via WebMD

Fresh Herbs

Fresh herbs make many other foods heart-healthy, especially when they replace salt, sugar, fat, and cholesterol. These flavor powerhouses, along with nuts, berries -- even coffee -- form a global approach to heart-wise eating. Read on for more delicious ways to fight heart disease, stroke, high blood pressure, high cholesterol, and diabetes.

Fact: Rosemary, sage, oregano, and thyme contain antioxidants.

 

Black Beans

Mild, tender black beans are packed with heart-healthy nutrients including folate, antioxidants, magnesium for lowering blood pressure, and fiber -- which helps control both cholesterol and blood sugar levels.

Tip: Canned black beans are quick additions to soups and salads. Rinse to remove extra sodium.

 

Red Wine and Resveratrol

If you drink alcohol, a little red wine may be a heart-healthy choice. Resveratrol and catechins, two antioxidants in red wine, may protect artery walls. Alcohol can also boost HDL, the good cholesterol.

Tip: Don't exceed one drink a day for women; one to two drinks for men -- and talk to your doctor first. Alcohol may cause problems for people taking aspirin and other medications. Too much alcohol hurts the heart.

 

Salmon: Super Food

A top food for heart health, it's rich in the omega-3s EPA and DHA. Omega-3s lower risk of rhythm disorders, which can lead to sudden cardiac death. Salmon also lowers blood triglycerides and reduces inflammation. We recommend at least two servings of salmon or other oily fish a week.

Tip: Bake in foil with herbs and veggies. Toss extra cooked salmon in fish tacos and salads.

 

Tuna for Omega-3s

Tuna is a good source of heart-healthy omega-3s. Albacore (white tuna) contains more omega-3s than other tuna varieties. Reel in these other sources of omega-3s, too: mackerel, herring, lake trout, sardines, and anchovies.

Tip: Grill tuna steak with dill and lemon; choose tuna packed in water, not oil. 

Extra Virgin Olive Oil

This oil, made from the first press of olives, is especially rich in heart-healthy antioxidants called polyphenols, as well as healthy monounsaturated fats. Olive oil can help lower cholesterol levels. Polyphenols may protect blood vessels.

Tip: Use for salads, on cooked veggies, with bread. Look for cold-pressed and use within six months.

 

Walnuts

A handful of walnuts a day may lower your cholesterol and reduce inflammation in the arteries of the heart. Walnuts are packed with omega-3s, monounsaturated fats, and fiber. The benefits come when walnuts replace bad fats, like those in chips and cookies -- and you don't increase your calorie count.

Tip: A handful has nearly 300 calories. Walnut oil has omega–3s, too; use in salad dressings.

 

Almonds

Slivered almonds go well with vegetables, fish, chicken, even desserts, and just a handful adds a good measure of heart health to your meals. They're chock full of vitamin E, plant sterols, fiber, and heart-healthy fats. Almonds may help lower LDL cholesterol and reduce the risk of diabetes.

Tip: Toast to enhance almonds' creamy, mild flavor

Edamame

These green soybeans are moving beyond Japanese restaurants, where they're a tasty appetizer. They're packed with soy protein, which can lower blood triglyceride levels. A half cup of edamame also has 9 grams of cholesterol-lowering fiber -- equal to four slices of whole-wheat bread.

Tip: Try frozen edamame, boil, and serve warm in the pod.

 

Sweet Potatoes

Sweet potatoes are a hearty, healthy substitute for white potatoes for people concerned about diabetes. With a low glycemic index, these spuds won't cause a quick spike in blood sugar. Ample fiber, vitamin A, and lycopene add to their heart-healthy profile.

Tip: Enhance their natural sweetness with cinnamon and lime juice, instead of sugary toppings.

 

Oranges

This sweet, juicy fruit contains the cholesterol-fighting fiber pectin -- as well as potassium, which helps control blood pressure. A small study shows that oranges may improve blood vessel function and modestly lower blood pressure through the antioxidant hesperidin.

Tip: A medium orange averages 62 calories, with 3 grams of fiber.

 

Swiss Chard

The dark green, leafy vegetable is rich in potassium and magnesium, minerals that help control blood pressure. Fiber, vitamin A, and the antioxidants, lutein and zeaxanthin, add to the heart-healthy profile.

Tip: Serve with grilled meats or as a bed for fish. Saute with olive oil and garlic until wilted, season with herbs and pepper.

 

Carrots

The latest research on carrots shows these sweet, crunchy veggies may help control blood sugar levels and reduce the risk of developing diabetes. They're also a top cholesterol-fighting food, thanks to ample amounts of soluble fiber -- the kind found in oats.

Tip: Sneak shredded carrots into spaghetti sauce and muffin batter.

 

Barley

Try this nutty, whole grain in place of rice with dinner or simmer barley into soups and stews. The fiber in barley can help lower cholesterol levels and may lower blood glucose levels, too.

Tip: Hulled or "whole grain" barley is the most nutritious. Barley grits are toasted and ground; nice for cereal or as a side dish. Pearl barley is quick, but much of the heart-healthy fiber has been removed.

 

Oatmeal

Oats in all forms can help your heart by lowering LDL, the bad cholesterol. A warm bowl of oatmeal fills you up for hours, fights snack attacks, and helps keep blood sugar levels stable over time -- making it useful for people with diabetes, too.

Tip: Swap oats for one-third of the flour in pancakes, muffins, and baked goods. Use oats instead of bread crumbs in cooking.

 

Flaxseed

This shiny, honey-colored seed has three elements that are good for your heart: fiber, phytochemicals called lignans, and ALA, an omega-3 fatty acid found in plants. The body converts ALA to the more powerful omega-3s, EPA and DHA.

Tip: Grind flaxseed for the best nutrition. Add it to cereal, baked goods, yogurt, even mustard on a sandwich.

 

Yogurt

While dairy is most often touted for bone health, these foods can help control high blood pressure, too. Milk is high in calcium and potassium and yogurt has twice as much of these important minerals.

Tip: Avoid all chemically processed foods, low-fat or non-fat varieties are not foods they are chemicals and may be detrimental to your health.

Coffee

Coffee and tea may help protect your heart by warding off type 2 diabetes. Studies show that people who drink 3-4 cups a day may cut their risk by 25%. Caution is due, however, for those who already have diabetes or hypertension; caffeine can complicate these conditions.

Tip: Prefer black coffee, avoid sugar if possible. Never use any artificial sweeteners, they may be detrimental to your health. Avoid decaffeinated coffee, this is highly processed and not a natural food product anymore but an industrial chemical.

 

Cayenne Chili Pepper

Shaking hot chili powder on food may help prevent a spike in insulin levels after meals. A small study in Australia showed that simply adding chili to a hamburger meal (not a good idea for overweight individuals) produced lower insulin levels in overweight volunteers.

Tip: Chili powder is a blend of five spices, while dried chili pepper comes from a single hot pepper. Both are good substitutes for salt in recipes.

 

Fleur de sel, or Kosher salt

This may be worth a try for people with high blood pressure. Kosher salt may give you more salty flavor with less actual salt -- and less sodium -- than if you sprinkled table salt on your food. The larger crystals impart more flavor than finely ground salt. You’ll still need to measure carefully; a teaspoon of Kosher salt has 1,120-2,000 mg of sodium, while the daily limit for most people is 1,500 mg. And in cooking, the taste advantage is lost.

Tip: Mix with your favorite herbs for a homemade, lower-sodium spice blend.

Cherries

Cherries are packed with anthocyanins, an antioxidant believed to help protect blood vessels. Cherries in any form provide these heart-healthy nutrients: the larger heart-shaped sweet cherries, the sour cherries used for baking, as well as dried cherries and cherry juice.

Tip: Sprinkle dried cherries into cereal, muffin batter, green salads and wild rice.

 

Blueberries

The list of healthy nutrients in blueberries is extensive: anthocyanins give them their deep blue color and support heart health. Blueberries also contain ellagic acid, beta-carotene, lutein, vitamin C, folate, magnesium, potassium, and fiber.

Tip: Add fresh or dried blueberries to cereal, pancakes, or yogurt. Puree a batch for a dessert sauce.

 

 

Wednesday
Oct262011

High Testosterone Levels Protect Against Stroke And Heart Attack

Consultations and sessions are also available via email, skype, phone or video conference (assisted by an interpret if requested). Email rainer.arendt@doublecheck.ch or call +41788250803 or +41442121100 to arrange an appointment time with Dr. Rainer Arendt.

Aesthetic + Health Link
Medical Wellness Practice

The Dolder Grand

 

PD Dr. Rainer Arendt

Internal Medicine & Cardiology FMH
Med. Hypnosis, Exec. Coaching & Corporate Health


Timeea-Laura Burci

Lifestyle Coach & Jin Shin Jyutsu

 

   

By Lisa Nainggolan
Medscape

Testosterone and sex hormone-binding globulin (SHBG) levels have important metabolic effects that might contribute to the risk for cardiovascular disease among  men. The authors of a current study note that low serum testosterone levels are associated with increased adiposity, an adverse metabolic risk profile, and atherosclerosis. Low levels of SHBG are associated with pre-diabetes and obesity.

Cross-sectional studies suggest that adults with coronary heart disease have lower testosterone levels, but the results of prospective research evaluating the possible link between testosterone levels and cardiovascular risk are more mixed. Moreover, limited data exist regarding the role of SHBG in the development of cardiovascular disease. The current study by Ohlsson and colleagues uses data from a large cohort of older men to address these issues.

 

Study Synopsis and Perspective

A new Swedish study has shown that elderly men in the highest quartile of serum testosterone levels have around a 30% lower risk of cardiovascular events over five years compared with men in the lower three quartiles [1].

And the association remains even after adjustment for traditional cardiovascular risk factors and excluding those with cardiovascular disease at baseline, say Dr Claes Ohlsson (University of Gothenburg, Sweden) and colleagues in their paper in the October 11, 2011 issue of the Journal of the American College of Cardiology.

Senior author Dr Asa Tivesten (University of Gothenburg) told heartwire : "This paper is an important start, because previously data have been inconsistent about whether there is an association between serum testosterone and cardiovascular events or not. We now know there is an association, but we don't know what is causing it."

(Unpublished research we had done years ago at the University of Munich, indicated that testosterone blocks the release of  the most potent endogenous vasoconstrictor endothelin from blood vessel wall cells - endothelial cells -  thus counteracting any decrease in blood vessel diameter. ra)

 Endothelin-1 in human cell line

 

Study Looked at Community-Dwelling Elderly Men

Ohlsson and colleagues analyzed baseline levels of testosterone in 2416 men aged 69 to 81 years who were participating in the prospective, population-based Osteoporotic Fractures in Men Study (MrOS). They also measured SHBG and obtained cardiovascular clinical outcomes from central Swedish registries.

This paper is an important start, because previously data have been inconsistent about whether there is an association between serum testosterone and cardiovascular events or not.

Over a median of five years of follow-up, there were 485 fatal and nonfatal cardiovascular events, and both total testosterone and SHBG levels were inversely associated with risk of cardiovascular events (trend over quartiles p=0.009 and p=0.012, respectively).

Tivesten said initially they used quartile 1 (ie, the lowest levels of serum testosterone) as a reference and compared events in this group with those in quartiles 2, 3, and 4. However, they saw no significant difference in the number of cardiovascular events between the first three quartiles.

But men in the highest quartile of testosterone (>550 ng/dL) had a lower risk of cardiovascular events compared with men in the lower three quartiles (hazard ratio 0.70; p=0.002). This association remained when the first 2.6 years of follow-up were excluded--in order to rule out any effect of baseline (subacute) disease--and was only slightly attenuated after adjustment for confounding factors (hazard ratio 0.77; p=0.032).

In models that included testosterone and SHBG, testosterone, but not SHBG, predicted risk.

 

More Research to Assess Risk/Benefit of Testosterone Supplements

Tivesten says that more work is required to investigate whether testosterone supplements should be used to try to prevent cardiovascular disease, because one trial using high doses of exogenous testosterone in older men has actually shown an increase in cardiovascular events.

However, what is established, she says, is that men with testosterone deficiency should receive testosterone supplementation. But there is currently a debate as to what level of testosterone represents a true deficiency, so this is a gray area, she notes.

 

References

1. Ohlsson C, Barrett-Connor E, Bhasin S, et al. High serum testosterone is associated with reduced risk of cardiovascular events in elderly men. The MrOS (osteoporotic fractures in men) Study in Sweden. J Am Coll Cardiol 2011; 58:1674-1681.   

Clinical Implications

 

  • Low serum testosterone levels are associated with increased adiposity, an adverse metabolic risk profile, and atherosclerosis. Low levels of SHBG are associated with higher rates of insulin resistance and obesity.
  • The current study by Ohlsson and colleagues suggests that high serum testosterone levels are significantly protective against the risk for cardiovascular events among older men.