Degenerative Diseases - Arthritis

The word "arthritis" comes from Greek words that literally translate as "joint inflammation." The name applies to more than 100 related diseases known as rheumatic diseases. A joint is any point where two bones meet. When a joint becomes inflamed, swelling, redness, pain, and loss of motion occur. Arthritis can be physically disabling.

Normally, inflammation is the body's response to an injury or a disease. It causes pain, redness, swelling, and warmth in the inflamed body part. Once the injury is healed or the disease is cured, the inflammation stops. In arthritis, however, the inflammation does not subside. Instead, it becomes part of the problem, damaging healthy tissues. This generates more inflammation and more damage, and the painful cycle continues. The damage can change the shape of bones and other tissues of the joints, making movement difficult and painful.

Types of Arthritis

More than one hundred types of arthritis have been identified, but four major types affect large numbers of Americans:

• Osteoarthritis—The most common type of arthritis, osteoarthritis generally affects people as they grow older. Sometimes called degenerative arthritis, it causes the breakdown of bones and cartilage (connective tissue attached to bones) and usually causes pain and stiffness in the fingers, knees, feet, hips, and back. Osteoarthritis affects more than twenty million Americans, usually after age forty-five.
• Fibromyalgia—Fibromyalgia affects the muscles and connective tissues and causes widespread pain, fatigue, sleep problems, and stiffness. Fibromyalgia also causes "tender points" that are more sensitive to pain than other areas of the body. According to the National Fibromyalgia Association, about 3–6 percent of Americans, mostly women, have this condition.
• Rheumatoid arthritis—Rheumatoid arthritis is caused by a flaw in the body's immune system that results in inflammation and swelling in joint linings, followed by damage to bone and cartilage in the hands, wrists, feet, knees, ankles, shoulders, or elbows. In the United States about 2.1 million people, mostly women, have this form of arthritis.
• Gout—Gout is an inflammation of a joint caused by an accumulation of a natural substance, uric acid, in the joint, usually the big toe, knee, or wrist. The uric acid forms crystals in the affected joint, causing severe pain and swelling. According to the Arthritis Foundation, gout affects more men than women and occurs in about two million Americans.

Other Inflammatory and Autoimmune Disorders

Another less common, but potentially life-threatening, form of rheumatic disease is systemic lupus erythematosus (known as SLE or lupus), an inflammatory autoimmune disease (the immune system mistakenly attacks the body's own tissues) that attacks skin, joints, blood, and kidneys. SLE occurs more frequently among women than men, and three times as many African-American women are diagnosed with SLE than white women. Generally diagnosed in people age fifteen to forty-five years, the symptoms of SLE include the following:

• Painful or swollen joints, muscle pain, and fatigue
• Fever, weight loss, hair loss, and skin rashes
• Cold, pale, or blue fingers, also known as Raynaud's phenomenon
• Swollen legs or glands
• Nephritis (inflammation of the kidneys)
• Pleuritis (inflammation of the lungs) that may produce chest pain or increase the risk of developing pneumonia
• Myocarditis, endocarditis, or pericarditis (inflammation of the heart valves and the membrane around the heart, respectively) and vasculitis (inflammation of blood vessels)

As with other inflammatory and autoimmune disorders, each patient experiences the disease differently. SLE symptoms ranging from mild to severe flare up and subside throughout the course of illness. Some patients with SLE also experience headaches, vision disturbances, strokes, or behavior changes as a result of the effects of the disease on the central nervous system.

No cure exists for SLE, and treatment aims to relieve symptoms and reduce the potential for organ damage and complications. Most patients receive corticosteroid hormones, such as prednisone and dexamethasone, which rapidly reduce inflammation. Patients with SLE also are treated with nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen (Motrin, Advil), naproxen (Naprosyn, Aleve), and indomethacin (Indocin), along with other drugs to combat pain, swelling, and fever. Drugs originally used to treat malaria (antimalarials, such as Plaquenil) also are used to treat the fatigue, joint pain, rashes, and pleuritis resulting from SLE.

Many chronic degenerative diseases, especially autoimmune diseases, are thought to occur when a genetically susceptible individual encounters an environmental trigger. For example, some researchers believe that viruses may be the environmental triggers for diseases such as lupus and scleroderma, an illness in which skin and internal organs thicken and harden.

Prevalence of Arthritis

Arthritis is a very common problem. The Arthritis Foundation reports that in 2002 more than seventy million Americans (one in three adults) were affected by arthritis and more than seven million arthritis sufferers were disabled by the disease. In 1985, half that many (thirty-five million) Americans had some form of arthritis. Its prevalence continues to grow.

Arthritis is the leading cause of disability among Americans older than age 15 years. Rheumatic and musculoskeletal disorders are the most frequently reported causes of impairment in the adult population, the leading causes of limitation of mobility, and the second leading causes of activity restriction. In 1999 nearly three-quarters of the 7.2 million people who attributed their disability to arthritis or rheumatism were women. (See Table 5.1.) Lost wages, medical bills, and other costs to the U.S. economy resulting from the effects of arthritis amount to more than $125 billion annually.

About half of all people older than age sixty-five will experience some form of arthritis in their lifetimes. Although some think of it as only an older person's disease, nearly three of five arthritis sufferers are younger than age sixty-five, and 29 percent of people between the ages of forty-five and sixty-four have arthritis. It also can affect children. According to the Arthritis Foundation, a not-for-profit research and advocacy organization, an estimated 300,000 children and teenagers suffer from arthritis. Of these, approximately 71,000 have rheumatoid arthritis, a potentially crippling disease that eventually destroys the joints.

In all age groups, women have a slightly higher likelihood of developing arthritis, and as they age, women have an increasingly higher prevalence of arthritis than men do. (The Arthritis Foundation notes that in 2003, the number of women with arthritis was forty-one million compared to 28.9 million men.) Between the ages of sixty-five and seventy-four, women have a 20 percent greater likelihood of developing arthritis than men, and women age seventy-five and older are 40 percent more likely to develop the disease.

By 2020 the population age sixty-five and older will reach an estimated 54.6 million. (See Figure 5.1.) Because of the expected increase in the proportion of persons age sixty-five and older in the population, the number of arthritis sufferers also is expected to grow.

Developments in Arthritis Research

As researchers learn more about inflammation and the body's immune system, they come closer to finding new drugs designed to relieve the pain of arthritis and to block the degenerative process of these diseases. Researchers are investigating ways to improve treatment by using the body's own biologic response modifiers (products that modify immune responses). They expect that these substances can be used to control the destructive processes of autoimmune diseases (in which the immune system attacks one's own cells) without weakening the whole immune system. One thing researchers know for sure is that the sooner arthritis is treated, the better.

Medications used to help relieve the symptoms of joint pain, stiffness, and swelling include nonsteroidal anti-inflammatory drugs (NSAIDs), aspirin, analgesics, and corticosteroids. These drugs may be used in combination. Among recent advances are more effective pain-relief drugs with fewer adverse side effects than those already on the market. One of the problems with NSAIDs, the most widely used class of drugs for osteoarthritis, is the potential to irritate the stomach and cause ulcers.

TABLE 5.1
Number and percentage of civilian noninstitutionalized persons age 18 and older with disabilities reporting selected conditions as the main cause of the disability, by sex, 1999
[Numbers in thousands]

	All persons		Men		Women
Main condition1	No.	(%)	No.	(%)	No.	(%)
Arthritis or rheumatism	7,207	17.5	1,955	11.0	5,235	22.4
Back or spine problem	6,780	16.5	2,903	16.3	3,877	16.6
Heart trouble/hardening of the arteries	3,209	7.8	1,666	9.4	1,543	6.6
Lung or respiratory problem	1,931	4.7	883	5.0	1,048	4.5
Deafness or hearing problem	1,794	4.4	1,183	6.7	611	2.6
Limb/extremity stiffness	1,747	4.2	842	4.7	905	3.9
Mental or emotional problem	1,541	3.7	733	4.1	808	3.5
Diabetes	1,399	3.4	610	3.4	789	3.4
Blindness or vision problem	1,361	3.3	629	3.5	732	3.1
Stroke	1,160	2.8	592	3.3	567	2.4
Broken bone/fracture	885	2.1	373	2.1	512	2.2
Mental retardation	827	2.0	507	2.9	320	1.4
Cancer	792	1.9	303	1.7	489	2.1
High blood pressure	692	1.7	255	1.4	437	1.9
Head or spinal cord injury	452	1.1	280	1.6	172	0.7
Learning disability	408	1.0	257	1.4	150	0.6
Alzheimer's disease/senility/dementia	354	0.9	110	0.6	244	1.0
Kidney problems	348	0.8	172	1.0	177	0.8
Paralysis	310	0.8	175	1.0	135	0.6
Missing limbs	299	0.7	211	1.2	—
Stomach/digestive problems	279	0.7	112	0.6	167	0.7
Epilepsy	217	0.5	117	0.7	—	—
Alcohol or drug problem	210	0.5	155	0.9	—	—
Hernia or rupture	210	0.5	—	—	130	0.6
AIDS or AIDS-related condition	132	0.3	—	—	—	—
Cerebral palsy	141	0.3	—	—	—	—
Tumor/cyst/growth	116	0.3	—	—	—	—
Speech disorder	101	0.2	—	—	—	—
Thyroid problems	77	0.2	—	—	—	—
Other	6,188	15.0	2,375	13.4	3,813	16.3
Total	41,168	100.0	17,767	100.0	23,401	100.0
1Persons who reported difficulty with functional limitations (except vision, hearing, or speech), activities of daily living, instrumental activities of daily living, the inability to do housework or the inability to work at a job or business identified the "main" cause and up to two other causes of the disability from a list of 30 conditions.
2Estimates are based on fewer than 30 unweighted cases and may not be reliable.
SOURCE: "Table 2. Number and Percentage of Civilian Noninstitutionalized Persons Aged <18 Years with Disabilities Reporting Selected Conditions as the Main Cause of the Disability, by Sex—Survey of Income and Program Participation, United States, 1999," in Morbidity and Mortality Weekly Report (MMWR), vol. 50, no. 7, February 23, 2001 [Online] http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5007a3.htm [accessed March 15, 2004]

Disease-modifying antirheumatic drugs (DMARDs) help reduce joint inflammation. They are generally effective, but they take time to show results (sometimes three or four months) so they must be started as early as possible to help prevent joint deformities and disability later in life. Doctors often prescribe an additional medication, such as a corticosteroid or an NSAID, to help control pain and inflammation while the DMARD starts to work.

DMARDs include low doses of methotrexate, leflunomide, penicillamine, sulfasalazine, Auranofin (oral gold), gold sodium thiomalate (injectable gold), minocycline, azathioprine, hydroxychloroquine sulfate (and other anti-malarials), cyclosporine, and biologic agents. DMARDs are used most often for rheumatoid arthritis, but some DMARDs also can be used for juvenile rheumatoid arthritis, ankylosing spondylitis, psoriatic arthritis and lupus.

Alternative therapies also are available. For instance, patients with moderate to severe rheumatoid arthritis who have not responded well to DMARDs may try Prosorba therapy. This involves drawing blood from the arm, separating plasma from red blood cells, and treating plasma through a Prosorba column (a cylinder the size of a soup can that holds a sandlike substance coated with protein A, a molecule that binds antibodies.) Treated plasma then is rejoined with red blood cells and returned to the body through the other arm. Treatments are given in twelve weekly sessions that last about 2.5 hours each. It may take as long as sixteen weeks to feel the benefits of the therapy.

Some scientists are studying how joints respond to different types of stresses. This may help in developing more effective exercises or new self-help devices. Researchers have found that regular exercise, weight control, and other self-care measures considerably reduce the incidence and effects of the disease.