Thanks to advertisements for the once-popular tonic Geritol, most people of a certain age know about “tired blood,” a disorder more accurately called anemia, involving a shortage of healthy red blood cells to carry oxygen to body tissues and cleanse them of carbon dioxide.
It is not really the blood of people with anemia that is “tired.” Rather, it is anemic people themselves who commonly experience chronic fatigue. Other symptoms may include weakness, shortness of breath, impaired athletic performance, rapid heartbeat, irritability, apathy, dizziness, pale skin, headache and numb or cold hands and feet. But in many people the symptoms are too mild to be recognized, and the anemia goes undetected for years.
Anemia is the most common blood disorder in the United States. Statistics indicate that 3.4 million Americans are anemic, but experts say that this is a gross underestimate and that anemia has been viewed for far too long as an “innocent bystander,” considered almost normal in certain groups, like menstruating women and the elderly.
But a growing body of research indicates that anemia can seriously compromise the quality of a person’s life, make sick people sicker and even speed deaths, said Dr. Allen Nissenson, a nephrologist and professor of medicine at the University of California, Los Angeles.
It is time to take anemia much more seriously, he added, making sure people have routine blood tests and are treated to restore healthy supplies of red blood cells. The testing is done either by a finger prick or by drawing blood from a vein. The finger test usually measures the hematocrit level, or percentage of red blood cells in plasma. A normal count is 36 percent to 46 percent for women and 46 percent to 56 percent for men.
A more accurate assessment measures the oxygen-carrying hemoglobin in blood, expressed as grams of hemoglobin per deciliter of blood. A normal hemoglobin for women is 12 to 13 grams, and for men, 13 to 14. Hemoglobin has traditionally been measured in blood from a vein, but a finger-prick test is now available.
Inadequate nutrition is the most common cause of anemia, Dr. Nissenson said. Production of hemoglobin, the oxygen-carrying protein on red blood cells, depends upon the mineral nutrient iron, most prominent in meat and poultry (especially organs like liver and kidneys) and egg yolks.
To a lesser degree, it is found in green leafy vegetables, dried fruits, dried beans and peas and enriched and whole grain cereals and bread. Foods rich in vitamin C help the body to absorb iron.
Also important to the production of healthy red cells are B vitamins, folic acid, B12 and B6. B12 occurs only in animal foods, especially meat, fish, eggs and milk. Dark green leafy vegetables are the best source of folic acid; whole grains are the best source of B6.
These nutrients are often in short supply among women who lose iron in menstrual blood, pregnant women, strict vegetarians, overly zealous dieters and poor people. Increasingly, the problem is found among elderly people on restricted diets.
Anemia afflicts virtually everyone with kidney disease because shrinking kidneys are not able to make enough of the hormone erythropoietin, which controls the production of red blood cells in the bone marrow. In addition, many chronic diseases involving inflammation can result in anemia, including congestive heart failure, inflammatory bowel disease, rheumatoid arthritis, AIDS, liver disease and cancer.
There are also hereditary anemias like sickle cell and thalassemia, and hemolytic anemias that involve the destruction of red blood cells faster than they can be replaced. Immune disorders and medicines can also bring it on.
Anemia can also result from chronic blood loss – from an ulcer, polyp or hemorrhoid – that may not be apparent without a stool test. Occasionally, a previously undetected cancer in the digestive tract can be the cause, so if no other responsible factor is identified, a colonoscopy should be done.
Doctors have long been aware of the risk of anemia in infants and in teenage girls and women of childbearing age, but anemia is far more prevalent in people over 65, studies say. One concluded that the incidence of anemia among the elderly was four to six times as great as had been suspected, affecting as many as a quarter of those over 75.
Even among patients with nearly identical medical disorders, those who are anemic tend to die faster. In one study of Medicare patients with congestive heart failure, for example, for every 1 percent decrease in the hematocrit (or percentage of red blood cells in plasma), the mortality rate rose by 1.6 percent.
In a study of nearly 79,000 elderly patients hospitalized with heart attacks, blood transfusions greatly lowered the death rate among those with hematocrits of less than 33 percent upon admission to the hospital.
Likewise with dialysis patients. In a study of 20,000 such patients with chronic kidney failure, those who were more severely anemic had a death rate twice that of patients less anemic. But when anemia in dialysis patients was treated effectively, the death rate after one year was no different from the rate in those who were not initially anemic.
Cancer patients also seem to do better when they are not anemic. Chemotherapy and radiation often cause anemia, which is associated with a reduced ability to control the disease and a lower survival rate.
Perhaps the most common consequence of anemia is an impaired quality of life, especially among older, ostensibly healthy people. In a study published in The American Journal of Medicine, Dr. Brenda W. J. H. Penninx and co-authors followed a group of 1,146 men and women 71 and older for more than four years.
The participants performed three tests at the start and end of the study: standing balance, a timed eight-foot walk and rising from a chair. Those with hemoglobin levels just slightly below normal were one and a half times as likely to experience physical declines as those with normal hemoglobin. Those with greater degrees of anemia experienced greater declines.
“Although no study yet shows that treating anemia in older people reduces the incidence of physical decline, our study certainly suggests that this may be the case,” Dr. Penninx said.
Anemia treatment is mainly determined by the cause: correcting underlying disorders, changing diets, adding nutritional supplements and for many, costly genetically engineered drugs like Procrit, Epogen and Aranesp.
Some forms of anemia, like those from nutritional deficiencies or bleeding, can be corrected by fixing the underlying problem. But anemia from cancer and chronic ailments like kidney disease are far more complex and can require years of specific treatment. Cancer patients, for example, face severe nausea and other side effects from chemotherapy, but they rate the tiredness from anemia as the most bothersome part of living with the disease.
Studies show that fatigued patients with anemia feel more energized after receiving transfusions of donated red blood cells, a procedure that has been around since the 16th century. But the process is laborious, and transfusions carry serious risks like emerging infectious diseases, mismatched blood types or fluid buildup in the lungs.
In recent years, doctors have found that newer anemia drugs like Procrit and Aranesp could produce roughly the same effects as transfusions, but with greater ease and seemingly less risk. The medications, which are also injected but in less time, made a lasting impact on many fatigued patients, who say they regained at least some of their old vigor when little else worked. Prescriptions for the drugs soared.
Yet the top-selling medications are undergoing a serious reappraisal after being linked to higher rates of heart attacks, stroke and early death. Early in 2008, the Food and Drug Administration’s scientific advisory board issued strict new warnings on the drugs, saying that higher than normal doses can lead to heart problems and also promote tumor growth in certain cancers. It was the second such warning that the F.D.A. had issued on the treatments in nearly a year.
“I think people need to be extremely cautious with the use of these drugs,” said Dr. Allen Nissenson of the University of California, Los Angeles. “At a minimum, patients should be satisfied with modest improvements from low doses as a way to minimize the risks.”
Dr. Douglas Rizzo, who directs the Center for International Blood and Marrow Transplant Research at the Medical College of Wisconsin, said it was still unclear whether high doses were at the root of the problem. The drugs stimulate production of erythropoietin, a hormone that helps blood cells ferry oxygen. But the natural energy booster also plays other roles in the body, including healing wounds, and making it a drug target could produce a range of unknown effects, he said.
“There’s a lot of uncertainty,” Dr. Rizzo said. “I think patients will have a difficult choice to make.”
And it’s not always a choice. A study published in The New England Journal of Medicine found that anemia drugs did not completely replace the use of transfusions in critically ill patients, so some people end up requiring both forms of treatment.
The only natural option, Dr. Nissenson said, is to move to higher ground. “It’s not a joke,” he said. Living at high altitude for a period of time stimulates the production of red blood cells to compensate for the lack of oxygen in mountainous areas.
“You don’t need to go to Mount Everest,” Dr. Nissenson said. “If you look at people in Denver, Colorado their average hemoglobin is significantly higher than people at sea level.”