Patients diagnosed with rheumatoid arthritis (RA) often are affected by functional disability a year or two before the disease is diagnosed, according to new Mayo Clinic research.

The results of the study, to be published in June in Mayo Clinic Proceedings, suggest that daily activities such as eating, dressing, and walking are affected early in the course of the disease, and that most rheumatoid arthritis patients are affected by functional disability issues.

"This is a new finding and a finding that is quite intriguing," says Elena Myasoedova, MD, PhD, a Mayo Clinic rheumatologist and the study's primary author. "It may reflect an accumulation of symptoms between the time of first onset and the time required for providers to actually diagnose patients."

Also notable is that persistent excess in functional disability continued even after diagnosis and treatment, Dr. Myasoedova says, which may be due to a growing burden of mental and physical pain, use of glucocorticoids and antidepressants, increasing expectations for relief from symptoms, and other factors.

The study's implications for additional vigilance by patients and physicians in the early stages of RA are especially relevant since May is National Arthritis Awareness Month. More than 50 million US adults have some form of arthritis. About 1.5 million Americans have been diagnosed with RA, which is an autoimmune disease that most commonly affects the joints but also has an impact on other body systems.

RA significantly affects quality of life and well-being, and is one of the most common chronic conditions associated with functional disability in the United States. The study is the first to quantify the long-term trends in prevalence of functional disability in RA patients, with trends noted for patients' ages and genders, as well as the length of time that disabilities were reported and the duration of the disease after diagnosis. The study also is the first to show that functional disabilities manifest one to two years prior to an RA diagnosis.

"These findings suggest that the burden of functional disability affects most patients with RA, begins early in the disease course, and may precede RA diagnosis," the study authors say.

The retroactive, population-based study accessed information from the Rochester Epidemiology Project database of medical records, and examined questionnaires from 586 patients with RA and 531 people without the disease. The prevalence of functional disability was more than twice as high in those with RA as those without. Patients with RA had a 15% or greater prevalence of functional disability than individuals without RA in most age groups.

Dr. Myasoedova says the study shows the prevalence of functional disability for RA patients and the importance of early treatment. "Alerting your health-care provider to difficulties in daily living can assure that patients receive the help they need," she says.

Symptoms of RA may include joint pain or swelling, though 40% of patients experience symptoms that don't involve the joints, such as fatigue, fever, and loss of appetite. Early RA tends to affect smaller joints first. In most cases, the symptoms occur in the same joints on both sides of the body.

Unlike osteoarthritis, which occurs as cartilage that cushions the joints breaks down over time, RA affects the lining of the joints. This leads to swelling that can cause bone erosion and joint deformity, as well as damage to other parts of the body. In addition to medical treatment, daily physical activity and a healthy lifestyle are among the best ways to relieve symptoms and overcome functional disability, Dr. Myasoedova says.