In Heart Disease, Women and Men Are Not Created Equal

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It may seem as if heart disease affects mostly men, but in fact it’s the No. 1 cause of death for both genders—more people die from heart disease than all cancers combined. Perhaps even more surprising is that more women than men will develop heart failure or die within a year of a heart attack.

Medical professionals don’t completely understand why women have worse outcomes than men when it comes to heart disease. One factor, however, is that heart attack symptoms are often very different in women and in some cases aren’t as obvious. Like men, women may experience classic chest pain, but they may also have a variety of more general symptoms, including:

  • nausea or vomiting,
  • indigestion,
  • shortness of breath,
  • pain in the upper back or arm,
  • neck and jaw pain, or
  • unusual fatigue.

Sometimes these symptoms may fade and reappear.

Men and women often have different types of artery disease. This may be a key to why symptoms are not the same. Men are more likely to have significant blockage of a major artery whereas many women have no evidence of arterial blockage. Women are more likely to have microvascular disease, which affects the heart’s smaller blood vessels.

Because many people believe that women are less likely to have a heart attack—combined with the differences in symptoms—may be why women don’t always realize they are having one. As a result, they may not seek treatment immediately. In one study, women did not get medical treatment for an average of 50 hours, compared to fewer than 16 hours for men. A delay in treatment contributes to a greater chance of dying from a heart attack.

In the emergency room, the lack of classic heart attack symptoms can lead to misdiagnosis, resulting in a delay in treatment. Studies show that women are less likely to receive appropriate treatment for heart attack compared to men. Even when they are treated appropriately, women often experience a higher risk of complications.

Although there have been tremendous improvements in the treatment of heart disease in women, more still needs to be done. Increased education and improved training will help the general public and medical professionals recognize the differences between men’s and women’s symptoms. In addition, more clinical research is needed to understand the reason for these gender-related differences and to better personalize the management of heart disease in women.

February is American Heart Month. Visit the American Heart Association’s website to learn more about heart disease in women.

 

John ChathamJohn Chatham, DPhil, is a professor of pathology and director of the Division of Molecular and Cellular Pathology at the University of Alabama at Birmingham.

 

Why Marriage Is Good for Your Heart

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Valentine’s Day is a time when many of us reflect on the importance of our closest relationships. Whether they include family, friends or a significant other, science is not silent on the impact these relationships have on our health. A review of 148 studies reveals that strong social relationships are associated with a 50 percent increased likelihood of survival, regardless of medical condition. Other studies link low social support to an increased risk and incidence of heart disease. The newest research, however, explores the effect our most intimate relationships—with a romantic partner—have on heart health.

A study that looked at more than 6,000 people reports that being single is associated with heart disease. Specifically, people who were single had a 45 percent higher rate of death from heart disease than those who were married. A striking finding in this study was that even though the reason for being unmarried varied among the participants—some people had never married, others were divorced, separated or widowed—the risks were consistently lower in married people. From these results, the overall benefit of the spousal relationship on heart health seems clear.

Many factors may account for the positive effect of marriage on heart health, including:

  • improved social support,
  • a less sedentary lifestyle, and
  • increased motivation to make healthy lifestyle changes.

The quality of marital relationships over time also influences heart disease risk factors. Men who described their relationships as “improving” had a lowering of risk factors compared to those in marriages categorized as “consistently good” or “deteriorating.”

In other words, marriage is generally good for your heart health and even better when you work to improve that relationship over time. So as you think about those closest to your heart on Valentine’s Day, do your heart a favor and take your sweetheart on a date.

Shawn Bender, PhD

Shawn Bender, PhD, is an assistant professor at the University of Missouri and a research health scientist at the Harry S. Truman Memorial Veterans’ Hospital.

Why Does Muscle Matter?

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When young people think about their muscles, they often focus on enhancing their muscle size and strength for cosmetic or athletic reasons. Those older than 50, however, need to be more concerned with just keeping the muscle they have. On average, people over the age of 50 lose 1 to 2 percent of their muscle mass each year, and after age 60, this number increases to 3 percent. Bed rest, lack of exercise and sedentary behavior in the elderly can speed up this gradual loss over time. Why is maintaining muscle so important for the elderly?

The simplest reason is that muscle is essential for all kinds of movement. Mobility is a crucial component of maintaining independence as we age. Adequate muscle mass and strength allow seniors to continue performing simple daily activities—things like bathing, getting dressed and preparing food—without assistance. Another less obvious reason is that muscle burns a large percentage of the energy that we get from the foods we eat. Losing muscle mass means that we do not use the energy from food as effectively, which can lead to chronic health conditions. In fact, loss of muscle mass is a major contributor to the increased rates of type 2 diabetes in older adults.

Current research has revealed, however, that muscle size is not the only, or even best measure of muscle health. Scientists have traditionally used the term “sarcopenia” to refer to aged-related loss of muscle mass, but many scientists are now focusing more on “dynapenia,” which indicates the loss of muscle function due to aging. New research is showing that how well muscle works can be just as important as how much muscle mass remains. In fact, a person with a smaller amount of muscle mass whose muscle function is good may be stronger and healthier than someone with more muscle mass but poor muscle function. This realization has led to new strategies for promoting muscle health in aging. Although maintaining muscle mass is still important, new approaches are targeting improvement in muscle function. These strategies go beyond simply lifting weights and look at ways to make the inner machinery of the muscle work better. Although nothing can completely stop the loss of muscle function with age, promising new nutritional and exercise therapies are emerging to substantially slow the decline, helping seniors stay active and independent for as long as possible.

Ben MillerBenjamin Miller, PhD, is an associate professor in the department of Health and Exercise Science at Colorado State University. He co-directs the Translational Research in Aging and Chronic Disease (TRACD) Laboratory.

Relieve Stress and Anxiety with Exercise in the New Year

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If getting more exercise is one of your New Year’s resolutions, here is another reason to stick with it: daily exercise—which is known to lower blood pressure—has also been shown to reduce stress and anxiety. I am not the first to notice that physical activity improves my ability to respond to stressful situations, but as a physiologist, I naturally wonder about the biological basis of this observation.

The hippocampus—one of the brain regions that regulates anxiety levels—becomes activated during both exercise and stress. Research suggests that exercise can calm some of the nerve cells in the hippocampus that become overstimulated during times of stress. While we don’t fully understand the mechanisms, we do know that certain chemical signals in the brain inhibit nerve cell activity, and some of these signals are likely responsible for the observed reduction in stress and anxiety.

Reduced anxiety and stress immediately after physical activity is not the only benefit of exercise. Blood pressure also declines to healthier levels within minutes after exercising. Studies suggest that exercise causes vasodilation, or widening of the blood vessels. When blood vessels open wider, it allows the blood to flow more easily, thereby lowering the pressure of the blood inside the vessels. Activation of histamine receptors is one mechanism that contributes to the reduction in blood pressure following exercise.

While there are many other benefits to regular exercise, the reductions in stress and blood pressure occur immediately and last for many hours. So, consider engaging in a physically active lifestyle that includes daily exercise, and encourage family and friends to join in. The result could be less stress, less anxiety, and lower blood pressure. What better way to start 2018?

william-farquharWilliam B. Farquhar, PhD, is a professor in the department of kinesiology and applied physiology at the University of Delaware. In addition to being a member of the American Physiological Society, he is a Fellow of the American College of Sports Medicine.

 

Keeping the Juices Flowing with Beets

Beetroot Juice

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With the new year upon us, many people are setting new goals for themselves related to improving their health or focusing on career-related goals. If establishing better exercise and nutrition habits are part of your quest to attain optimal health and productivity in 2018, you are not alone. New gym memberships are likely to rise in the coming months, and some may try nutritional products such as fruit and vegetable juice concoctions touted to enhance performance and overall health. The global juicing industry has gained a lot of traction in the last several years due to a wider health awareness among consumers. Emerging evidence suggests that casting beets in the starring role of your juice habit—along with aerobic exercise—may be one potential route to improving your cardiovascular health, and more recently shown, brain health.

Beets are a good source of antioxidants, minerals and nitrates. The nitrate-rich properties of beets have caught the attention of researchers, particularly those in the field of vascular medicine. Nitrates in food are converted to nitric oxide in the body. Nitric oxide relaxes the walls of the arteries, lowering blood pressure and increasing blood flow to muscles. That is one of the reasons why the nitrates in beetroot juice have been shown to enhance exercise performance in high-performing athletes, as well as in less elite exercisers.

In addition to the cardiovascular and performance benefits of consuming beets, recent studies suggest that the root vegetable may also be linked to brain health. One study found that older adults who performed aerobic exercise for six weeks and drank beetroot juice daily had greater improvements in brain activity related to movement than the participants who exercised without drinking beetroot juice. The brain networks of the juicing group more closely resembled the brains of younger adults, suggesting that when combined with exercise, beets can enhance the brain’s ability to make new connections between brain cells. Another study showed that young adults who drank a single dose of beetroot juice had increased blood flow to the area of the brain involved in higher-order thinking. The study participants also fared better in cognitive tasks such as basic math.

So, before you lace up your running shoes or settle back into your office chair, consider topping off with a dose of beetroot to keep the juices flowing.

 

Yasina Somani cropYasina Somani, MS, is a PhD student in the Cardiovascular Aging and Exercise Lab at Penn State. She is interested in studying the effects of novel exercise and nutritional therapies on cardiovascular outcomes in both healthy and clinical populations.

 

Taking Ibuprofen during Exercise May Cause More Harm than Good

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Every January gym memberships spike and the wait to get on the treadmill gets longer. This happens because about 40 percent of Americans make New Year’s resolutions, the most common of which are exercising more and improving fitness. Some people may believe in the concept of “no pain no gain,” but it’s a common misconception that if your muscles don’t feel sore then you are not working out hard enough. Many athletes reach for nonsteroidal anti-inflammatory drugs (NSAIDs) to ease the aches and pains of a hard workout. Naproxen and ibuprofen are two commonly used NSAIDs that are available over the counter. Studies estimate that up to 75 percent of long-distance runners take NSAIDs before, after or during training.

Microscopic tears in the muscles cause soreness following strenuous exercise. In response to injury, the body produces compounds called prostaglandins, which play an important role in healing. NSAIDs reduce pain by slowing the production of prostaglandins, which reduces inflammation. The problem is that inflammation also plays an important role in healing damaged muscle as well as helping the muscle growth that occurs with regular exercise. In other words, taking NSAIDs after a workout may not necessarily be a good thing.

A recent study in mice found that levels of a specific prostaglandin increased after minor muscle injury. This particular prostaglandin stimulated regeneration of new muscle stem cells to repair the damage. But when the mice were given NSAIDs their bodies produced fewer active stem cells, leading to weaker muscles even after the injuries had healed.

Other negative effects, such as kidney injury, have been associated with NSAIDs. In one study, elite athletes took either 400 milligrams of ibuprofen or a placebo every four hours during a 50-mile race. At the end of the race, more than 40 percent of the runners tested high for creatinine, a marker of kidney injury. Runners who took ibuprofen instead of the placebo were more likely to develop kidney injury and their degree of injury tended to be worse. The study did not explain why ibuprofen may cause kidney injury in elite athletes, and it’s not clear whether the risks are similar in people participating in less-intense workouts. More studies are needed to examine the effects of ibuprofen following different types of exercise.

If exercising is one of your New Year’s resolutions, start off slow to avoid muscle pain. If you do overdo it, try easing your aches with a warm heating pad before reaching for the ibuprofen.

John ChathamJohn Chatham, DPhil, is a professor of pathology and director of the Division of Molecular and Cellular Pathology at the University of Alabama at Birmingham.

2017’s 10 Most-read Posts

Using technology to take brainstorming to the next level

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Another physiology-filled year on the I Spy Physiology blog is almost over. This year, we’ve explored dozens of topics, ranging from skin cancer, gut health and spinal cord injury to the mystery of how hibernating animals’ muscles remain strong. We’ve celebrated women in science and smiled at the thought of turkeys running on treadmills. Today, we’re highlighting the 10 most-read posts of 2017.

Scholarly articles highlight the need for more research about women’s responses to illness and disease risk. In that vein, our most popular post this year looked at the relationship between sex-specific hormones and asthma. Posts about the danger of e-cigs—especially in the under-21 set—and how muscle rebuilds during the daunting feat of cycling the 500-mile Colorado Trail rounded out the top three. Take a look at this year’s top 10:

  1. When Hormones Take Your Breath Away
  2. The Trouble with E-Cigs: Why They May Pose More Harm than Good
  3. Muscle Rebuilding on the Colorado Trail
  4. Beer Does a Body Good?
  5. Meet Karyn Hamilton, Health and Exercise Science Professor
  6. Dog Gazing: Bond between Hound and Human
  7. Why Does Air Pollution Affect More Women than Men?
  8. When Vampires Attack: How Your Body Reacts to Extreme Blood Loss
  9. Microvesicles and Blood Vessels and Exercise, Oh My!
  10. The Hispanic Paradox: Why Are Some Ethnic Groups Living Longer than Others?

We’d love to hear what you’d like us to feature next year. Share your thoughts in the comments or send us an email. And don’t forget to follow our blog in 2018.

Erica Roth 

Look on the Bright Side—It May Improve Your Health

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If you tend to see the proverbial glass as half empty instead of half full, you may want to rethink your position. Looking on the bright side and expecting good things to happen may have a positive effect on your physical health. An optimistic outlook on life may reduce your cardiovascular disease risk, lower blood pressure and improve overall health and longevity. It can also reduce sensitivity to pain and may help people manage chronic pain more easily.

You may be skeptical or cautiously optimistic about this. How can simple optimism lead to good health? The answer is still not entirely clear, but scientists are slowly uncovering the biological details. They’ve learned that the body’s response to stress may be an important factor.

When the body is stressed, it sends biological messengers called stress hormones into the bloodstream to tell different organs to respond in various ways. One of the major stress hormones is cortisol. When cortisol is high, the body responds by making unhealthy amounts of certain substances (such as cholesterol) that can harm the heart. These substances may damage and cause inflammation in the blood vessels. Inflammation may also lead to more damage in the circulatory system. This unfavorable chain of events may increase the risk of heart disease.

People who look on the bright side may be more likely to have markers of good health—including lower stress hormone levels—even when they face stressful situations. One study found rats with pessimistic behavior traits had more inflammation than their optimistic counterparts. Lower cortisol and inflammation levels may be due to decreased activity of the fight-or-flight nervous response, although more research is needed.

Motivation may also play a role in boosting the health of optimists. People who think positively may be more motivated and tend to make more of an effort in social interactions than those who are pessimistic. This can lead to healthier social connections and an increase in beneficial behaviors such as exercising regularly and following a healthy diet. The motivational aspects of optimism (or pessimism) may also affect a person’s behavioral response to stress.

December 21 is “Look on the bright side” day. Try a visualization exercise to boost your optimism. It may have a positive effect on your overall health.

Audrey Vasauskas

Exploring Causes and New Treatments for Sickle Cell Disease

genemarker

Shaina Willen, MD, of Vanderbilt University Medical Center, presents her poster at the Physiological and Pathophysiological Consequences of Sickle Cell Disease conference.

Sickle cell disease (SCD) is a lifelong disorder of the red blood cells. It’s caused by a mutation in a single gene and affects about 100,000 people in the U.S. Normal red blood cells are round, a shape that helps the cells carry oxygen around the body. But red blood cells in people with SCD can become abnormally shaped like a crescent (sickle), which can cause blood cells to get stuck in blood vessels and interfere with blood flow, leading to severe pain.

Scientists and medical doctors who specialize in SCD gathered last month in Washington, D.C., for the American Physiological Society conference “Physiological and Pathophysiological Consequences of Sickle Cell Disease.” They discussed new research into the causes of the disease and new therapies that can treat and even prevent SCD-related pain episodes. Read on to learn more about their findings.

Certain patients with SCD may have a higher risk than others of developing complications—such as increased pain, stroke, eye problems and kidney disease—but finding out which patients have a higher risk is challenging. New research from Vanderbilt University Medical Center has uncovered a genetic marker that may be able to identify which patients are more likely to have these complications.

Emotional stress is known to trigger or worsen physical symptoms of disease, including some types of pain. A group of researchers from California found that stress and the anticipation of pain causes blood vessels to become narrower (vasoconstriction). In people with SCD, vasoconstriction can be dangerous because abnormally shaped (sickled) cells may be more likely to get stuck in the blood vessels and block blood flow.

A healthy digestive system is typically filled with various types of bacteria that aid in digestion. However, researchers from Howard University found that people with SCD are more likely to have higher levels of one specific bacterium, Veillonella. Veillonella link together to form a film in the digestive tract, which can attract red blood cells. When red blood cells stick to the film, it can block blood flow to the rest of the body, which causes increased pain. This discovery may help scientists find a way to rebalance gut bacteria levels and reduce symptoms.

These studies are just a few examples of the high-caliber SCD research being done. Read more highlights from this year’s conference:

Alzheimer’s drugs may improve red blood cell function and quality of life

Scientists explore ways to create red blood cells outside the body and prevent sickling

Erica Roth 

Research and Education Help Babies Born Too Early

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A typical pregnancy lasts 40 weeks, but about 10 percent of babies in the U.S. are born preterm (before 37 weeks’ gestation) or premature. Less time in the womb means the infants’ organs are immature and not yet ready to function on their own. Generally, the earlier a preterm birth happens, the more likely it is that complications will occur. Most premature infants, or preemies, spend some time in the hospital in a special nursery called the neonatal intensive care unit, or NICU.

Preterm birth has occurred throughout history, but the issue did not catch the public’s attention until the death of President Kennedy’s son in 1963. Baby Kennedy was only 37 weeks’ gestation and died of respiratory distress. This increased focus on prematurity led to more funding to research ways to treat premature infants. Advances in medical treatment have dramatically increased the survival of preemies since the 1960s. By the 1980s, babies as young as 21 weeks’ gestation were surviving to adulthood.

Prematurity affects every organ system. Complications can be treated more successfully now than in the past. Some common issues include:

  • Digestive problems: When the cells lining the digestive tract are immature, babies may develop necrotizing enterocolitis (NEC). NEC is inflammation or infection of the intestine that can cause intestinal tissue to die. Doctors recommend breast milk for premature infants because babies who drink breast milk exclusively have a lower risk of NEC.
  • Breathing problems: Immature lungs do not produce a substance called surfactant, which helps the air sacs in the lungs stay open. Without surfactant, preemies may struggle to breathe and go into respiratory distress. Doctors first gave surfactant to premature infants in 1980. Death rates from respiratory distress in premature babies have dropped from over 90 percent in the 1950s to less than 5 percent today.
  • Vision problems: When a premature infant is born, their eyes are still developing. Blood vessels in the retina—the light-sensitive tissue in the back of the eye—can grow too much and pull it away from the rest of the eye. The detachment can lead to a type of vision impairment called retinopathy of prematurity (ROP). Doctors discovered that decreasing the concentration of supplemental oxygen given to preemies could actually help decrease the chances of developing ROP.

While treatment for premature infants continues to improve, the cause of preterm birth is still unknown. Doctors have identified some risk factors, including:

  • age—women over 35 have a higher risk;
  • alcohol or drug use;
  • intrauterine infection;
  • being pregnant with multiples;
  • spacing pregnancies very close together;
  • having a previous preterm birth; and
  • stress.

Both physicians and patients hope that more research and education will lead to fewer preterm births and improve health outcomes for preemies. November is Prematurity Awareness Month. Read more about ongoing research efforts on the March of Dimes website.

Rebekah Morrow 3Rebekah Morrow, PhD, is an assistant professor of immunology and microbiology at the Alabama College of Osteopathic Medicine.