In Part II of the book, we learned there are many different kinds of risk factors for silent heart disease and coronary heart disease in general. Medical science has divided the risk factors into two broad categories: genetic, also known as “nature,” and environmental, also known as “nurture.” Essentially, you’re born with the nature risk factors, inherited as they are from your parents. The nurture risk factors are acquired after you’re born and are to a large degree the results of your circumstances and behavioral and lifestyle choices.
Let’s quickly review each of these risk factors.
Genetic
•Family history: When it comes to a genetic predisposition for silent heart disease, your family history is a complex factor in determining your overall risk. However, your first-degree relatives—your parents and siblings—are the most important in determining your own risk factors. If they had heart disease before the age of fifty-five, chances are you will too. If there is an upside to bad genes, it is that the genetic effect tends to become diluted later in life. So while you cannot escape your genes, it is possible to stay ahead of them with appropriate lifestyle changes and treatments.
•Age and gender: Older men have the highest risk of silent heart disease. Men are ten times more likely than women to develop a heart attack prior to the age of forty-five and seven times more likely to do so between ages fifty-five and sixty-four. However, the playing field levels out with age, with sixty-five- to seventy-four-year-old men only twice as likely as women to be felled by heart disease. Bottom line: Heart disease remains the number one killer of men and women in the United States.
•High LDL cholesterol: There is a significant correlation between the level of LDL cholesterol and the risk of developing coronary heart disease. Since 1984, it has been clear among medical experts that lowering elevated levels of cholesterol in the blood will reduce the risk of heart disease. This fatty, yellowish substance has been identified as the leading cause of arteriosclerotic plaque buildup in the coronary arteries.
•High blood pressure: While the incidence of heart disease has declined over the past half century (despite its remaining the number one killer of adult men and women in the United States), new research shows that heart disease once again is spiking in the United States because of increased rates of high blood pressure. Genetic risk factors, including family history, age, race, and gender, all figure into abnormally high blood pressure. As with cholesterol, high blood pressure can also be caused by environmental factors, including poor diet and lack of exercise.
•Diabetes and kidney disease: Diabetes puts patients at huge risk for heart disease. Heart attacks and other cardiovascular complications cause the deaths of nearly three out of every four people with diabetes, compared with just one in four people in the general population. Kidney disease is also an inherited risk factor, and the two conditions can be interrelated. Heart disease is the most common cause of death among people who have kidney disease. People with diabetes and kidney disease may also be more at risk for silent heart disease and silent heart attacks—the ones that mostly go unnoticed—because both diseases can cause damage to the peripheral nervous system. As a result, researchers believe that persons with diabetes and kidney disease often simply can’t feel when they have a heart attack.
Environment and Behavior
•Diet: While heart disease has remained the number one cause of death in America, over the last half century the percentage of U.S. citizens succumbing to the disease has gone down. A large part of the reason is that Americans eat a much more “heart-healthy” diet and are much more conscious of the need to lower their cholesterol levels than was the case just a generation ago. Still, we eat too much saturated fat, sugar, and salt, which all contribute to heart disease. Over the decades, as diet fads have come and gone, one type of diet has stood the test of time: the Mediterranean diet, characterized by the consumption of lots of fresh fruits and vegetables, the avoidance of red meat, and an emphasis on fresh seafood and olive oil as the primary sources of fat.
•Sedentary lifestyle: Research gathered on the benefits of exercise since the fitness craze took off in the 1970s clearly shows that keeping the body in motion by exercising regularly can help to lower cholesterol, still the primary cause of silent heart disease. It’s more beneficial to move throughout the day—every hour or so—than it is to exercise strenuously at the beginning or end of each day or just on weekends. Men over fifty years old (the group most at risk for silent heart disease) who engage in vigorous leisure-time exercise—even just a brisk walk thirty minutes a day—reportedly have 50 percent fewer heart attacks than their sedentary peers. Exercise can also be an important component in a weight-reduction program (although not the primary one, which is diet).
•Obesity: While Americans have a new awareness about the benefits of eating a diet that promotes heart health, that positive trend is diminished by the extraordinary rise in obesity in the United States and increasingly worldwide. Today, 40 percent of Americans are clinically obese, or significantly overweight. Perhaps even more alarming, one in six children are now considered obese, and new research conducted over generations clearly indicates that obese children are more likely to become obese adults. The connection between heart disease and obesity is multifaceted, because obesity increases your likelihood of developing many other risk factors for heart disease, including high blood pressure and diabetes. What remains clear is the strong correlation between obesity and heart disease. Adults between ages forty and fifty-nine who are overweight or obese have a 21 to 85 percent higher risk of developing cardiovascular disease as compared with their normal-weight peers.
•Substance abuse: Substance abuse has become a nationwide health crisis in just one generation, causing the deaths of seventy thousand Americans in 2018—more than HIV/AIDS at its peak and more than gun violence or car accidents in 2018. Today, on average 130 Americans die of an opioid overdose every day. Just as we seemed to be getting a handle on one aspect of the opioid crisis—overdose deaths from prescription narcotic painkillers had begun to decline—another opioid drug was becoming popular. The illicit and recreational use of a cheap, synthetic version of fentanyl—a drug ten times more powerful than morphine, originally designed for use in surgical procedures—has increased 45 percent since 2017. Forgotten somewhat in the focus on the opioid epidemic is that America’s favorite legal drug, alcohol, continues to kill more people than all other drugs combined—more than eighty thousand in 2018. And while progress has been made in reducing the rates of smoking, more than 42 million Americans (or one in five) continue to smoke, accounting for 480,000 smoking-related deaths in the United States in 2018. The connection between substance abuse and heart disease is multifaceted, with nicotine, drugs, and alcohol damaging the heart muscle and blood vessels directly as well as contributing to the bad effects of other risk factors, including poor diet, lack of exercise, and impaired sleep.
•Anxiety, stress, and impaired sleep: Recent epidemiological studies have shown that people who face many stressors—from those who survive natural disasters to those who work long hours—are more likely to develop atherosclerosis, the accumulation of fatty plaques inside the coronary arteries. In addition to fats and cholesterols, the plaques contain monocytes and neutrophils, immune cells that cause inflammation in the walls of blood vessels. Chronic stress may cause some people to drink too much alcohol, smoke more, or binge eat, all of which can increase blood pressure and damage artery walls. Impaired sleep conditions, including insomnia and sleep apnea (thought to affect as much as 40 percent of the adult population), often have the same bad health effects and share many of the same symptoms as stress and anxiety.
In summary, your overall propensity for silent heart disease and coronary heart disease involves a unique combination of factors that you inherited from your parents and choices you’ve made as an adult. There’s much you can do to lower your risk factors, particularly when it comes to lifestyle choices. In the next section, Part III, we’ll look at the array of medications and diagnostic techniques that can help you and your physician maximize your heart health.