How fast can you run a mile?

Your answer may predict your risk of a heart attack or stroke in the next decade or so, according to two new studies.

UT Southwestern Medical Center researchers say that how fast a middle-age person can run a mile can help predict the risk of dying of heart attack or stroke decades later for men and could be an early indicator of cardiovascular disease for women.

The researchers analyzed the heart disease risk of 45 to 65 year-old men based on fitness levels and other traditional risk factors such as age, blood pressure, cholesterol and smoking habits.

They found that fitness levels among middleaged men show marked differences in risk for cardiovascular disease.

For instance, a 55-year-old man runs a mile in 15 minutes has a 30 percent lifetime risk of developing heart disease. In contrast, a 55-year-old who runs a mile in eight minutes has a lifetime risk of less than 10 percent.

“Heart disease tends to cluster at older ages, but if you want to prevent it, our research suggests that the prescription for prevention needs to occur earlier – when a person is in his 40s and 50s,” said Dr. Jarett Berry, assistant professor of internal medicine and a corresponding author on both studies.

According to the results, a high fitness level can lower the risk of heart disease even when other risk factors are present.

Heart disease is the number one cause of death in industrialized nations.  It is especially lethal for women, whose risk for heart disease is hard to assess and rises dramatically as they age.

The fitness test, researchers said, were particularly helpful in identifying women at risk for heart disease over the long term.

The studies mark the first time fitness levels have been used to attempt to predict risk for heart disease.

They were published in the Journal of the American College of Cardiology and Circulation.

More than 200,000 people are treated for cardiac arrest in the United States each year, and the number may be on the rise, according a study conducted by University of Pennsylvania researchers.

Though cardiac arrest has long been known to be a chief cause of in-hospital deaths, no prior report was able to calculate its true incidence and to study trends in mortality and resuscitation care.

In the report, the researchers suggested that many of the cardiac arrest deaths may have been prevented through better monitoring of patients, quicker response time to administer CPR and defibrillation, and improved adherence to best practices in resuscitation guidelines.

Nevertheless, patients who suffer in-hospital cardiac arrests are twice as likely to survive than the people who have heart attacks in public settings – a 21 percent survival rate versus a less than 10 percent survival rate essentially, the researchers said.

“Our study proves that cardiac arrest represents a tremendous problem for hospitals in the United States,” said lead researcher Raina Merchant, MD, MS, an assistant professor of Emergency Medicine. “Until now, we could only guess about how many patients were suffering these events. These numbers finally provide us with a roadmap for improving allocation of resources to care for these critically ill patients and improve survival.”

The study was published in the journal Critical Care Medicine.

An analysis of heart disease and stroke statistics collected from 192 countries by the World Health Organization shows that the relative burden of the two diseases is closely linked to national income.

University of California researchers found that developing countries tend to suffer more death and disability by stroke than heart disease.  Meanwhile, the United States and other countries with higher national incomes tend to experience the opposite.

This finding may help health officials design tailored interventions to best fit the needs of developing countries, the researchers say.

“In general, heart disease is still the number one cause of death worldwide, but there is quite a lot of variation across the globe,” said Anthony  Kim, MD, MAS, assistant professor of neurology at UCSF .

For instance, there was a wide variation in the mortality rate for stroke highlighted by the new research.  Rates ranged from a worldwide low of 25 deaths per 100,000 in the island nation of Seychelles to a high of 249 deaths per 100,000 in Kyrgyzstan – a rate nearly 10 times greater.

In the United States, there are approximately 45 deaths per 100,000 people due to stroke.

Heart disease and stroke are similar in that they are both are caused by reduced or restricted blood flow to vital organs and share many of the same common risk factors, such as hypertension, diabetes, high cholesterol, obesity, physical inactivity and smoking.

However, because they affect very different tissues – the heart and the brain – they diverge in terms of symptoms, approaches to critical care, follow-up treatment and the duration and cost of recovery.

“There was a striking association with national income,” Kim said.

In the United States, for instance, heart disease is the number one killer and stroke the number four, according to the Centers for Disease Control and Prevention. This also holds true for the Middle East, most of North America, Australia and much of Western Europe.

The opposite is true in many developing countries. Stroke  is more prevalent in China, many parts of Africa, Asia and South America.

Overall, nearly 40 percent of all nations have a greater burden of stroke compared to heart disease.

“This is significant,” said Kim, “because knowing that the burden of stroke is higher in some countries focuses attention on developing a better understanding of the reasons for this pattern of disease and may help public health officials to prioritize resources appropriately.”

The study was published in the journal Circulation.

Exposure to high levels of pollution can temporarily increase the risk of having a heart attack for up to six hours afterward, according to a new study.

After the six hour time-frame, a person’s risk of a heart attack returns to normal.

For the study, British researchers reviewed more than 79,000 heart attack cases in conjunction with exposure, by the hour, to pollution levels using a national air quality database.

The results did indicate that there was a limited time-span in which heart attacks increased after excess exposure to traffic-related pollution or carbon monoxide, but the researchers added there may be a caveat to the findings.

Due to the transient nature of the phenomenon, the researchers speculated that the heart attacks may have happened anyway, but the pollution exposure could have brought them forward by a few hours.

This is an effect of pollution called short-term displacement or “harvesting,” the researchers said.

Prior studies have proven that high pollution levels are linked with premature death from heart disease, but the link between pollution and sudden heart attack is less clear.

The study was published in the British Medical Journal.

Government and medical intervention policies that promote health eating could cut the death rate for cardiovascular disease by half, according to new data.

British researchers found that intervention policies aimed at reducing unhealthy eating habits can have a significant effect on cardiovascular disease rates in a population.

Cardiovascular disease is the number one killer in the United States. It is responsible for approximately one out of every four deaths.

Poor diet is one of the major causes of cardiovascular disease, though prior research has shown that small improvements can make a positive and rapid impact.

The study in question pointed to six foods that could slash the cardiovascular disease rate, including fruits, vegetables, whole grains, nuts, vegetable oils and seafood. Meanwhile, cutting out excess starch, animal fat, salt and trans fats could also decrease the risk of heart disease.

The researchers also pointed out specific population-wide programs that were effective and inexpensive in decreasing heart disease rates. These included pricing policies that subsidized healthier foods and taxed less healthy ones, improved transportation and marketing of healthier foods, strict guidelines of food marketing to children and increased support of local markets that provide healthy foods.

Whilst drug and hospital based prevention are successful for high-risk individuals with cardiovascular diseases, these methods are relatively costly and not sustainable in many countries.

The study was published in the British Medical Journal.

Colorado researchers have found that high levels of a specific hormone can predict which kidney patients will develop heart problems, require dialysis or die prematurely.

“This discovery allows us to predict at-risk patients before they require dialysis,” said lead researcher Michel Chonchol, MD. “That’s critical because approximately 23 percent of patients on dialysis die in the first year.”

Chonchol and his colleagues at the University of Colorado studied the blood plasma of patients with advanced kidney disease and found that levels of a hormone called fibroblast growth factor-23, or FGF-23, increased as kidney function deteriorated.

The hormone in question is responsible for regulating phosphorous levels in the body. As the kidneys fail, they are rendered incapable of excreting phosphorous which causes FGF-23 levels to rise.

The higher the level of the hormone in the body, the greater the chance the patient will die, though researchers are uncertain exactly how the hormone affects the body.

By the time the patient is down to 30 or 40 percent kidney function, the levels of FGF-23 can predict who will die, have a heart attack or require dialysis, the researchers said. Nearly 50 percent of deaths in kidney patients are due to cardiovascular problems like heart attacks.

Until now, doctors relied on measuring phosphorous to assess a patient’s condition.
“Prior to a patient going on dialysis the phosphorous levels shoot up,” Chonchol said.

However, the researchers found that FGF-23 levels actually increase long before phosphorous levels jump. Being able to identify problematic conditions earlier will allow doctors to intervene with drugs that can lower phosphorous and in turn lower the levels of the hormone.

“This has provided us a critical marker to look for,” Chonchol said, “A marker that could save lives.”

Kidney disease affects 20 million Americans and is a growing problem due to obesity and diabetes.

“The best ways to prevent kidney disease is through blood pressure control, diet, exercise and maintaining a healthy body weight,” Chonchol said.

The study was published in the Journal of the American Society of Nephrology.