Osteoarthritis, common among older adults, is strongly linked to late-life disability, but the process by which this happens has not been well studied.
A recent study published in the April 2006 issue of Arthritis Care & Research examined the impact of osteoarthritis in the lower extremities and found that women with this condition have a greater risk of developing decreased mobility, a risk which is further increased by being overweight.
Led by Shari M. Ling of Intramural Research Program, National Institute on Aging/NIH together with investigators in the Center on Aging and Health at the Johns Hopkins Medical Institutions in Baltimore, MD, researchers used data obtained from participants in the Women's Health and Aging Study II (WHAS II) to determine whether patients with osteoarthritis in their lower extremities were more prone to developing mobility limitations than women who did not have the disease. They also looked at whether limitations in mobility tended to develop before difficulty in activities of daily living. Their analysis included 199 women with lower extremity osteoarthritis who had no difficulty with mobility tasks at the beginning of the study and 140 women without osteoarthritis in the knee or hip, all of whom were between 70 and 79 years old. Patients were evaluated as to their osteoarthritis status, the presence of pain, knee strength, knee torque, and their level of mobility 18, 36 and 72 months following the initial evaluation.
The results showed that even though more women with osteoarthritis reported using arthritis medications, a greater proportion reported having pain most days and greater pain severity while walking and climbing stairs compared to women with no OA. In addition, 26% of the women with osteoarthritis were obese compared to 11% of the women without the disease, and an additional 40% were overweight. The two groups were similar, however, with regard to knee strength and torque. Overall, women with osteoarthritis were about 2.5 times more likely to develop difficulty in both lower extremity mobility and activities of daily living than those who did not have osteoarthritis. Greater knee strength reduced the risk of developing difficulty performing daily activities whether or not the woman had osteoarthritis, and greater knee torque had the same effect, although it did not reduce the risk for lower extremity difficulty.