The Effect of Physical Performance and Physical Activity on Quality of Life in Old People: The Korean Longitudinal Study on Health and Aging

Abstract

Background: To investigate the physical function of elderly people in Korea using quantitative and objective tools and to assess the impact of declined physical function on their quality of life. Methods: The Korean Longitudinal Study on Health and Aging was designed as a population-based prospective cohort study on the health and aging of the elderly people in Korea aged 65 years and older. Within one city's central metro- politan area, 1,000 subjects including a simple random sample and an oldest-old subpopulation participated in a base- line study for one year. We evaluated the isokinetic peak torque of the knee extensors and flexors, grip force, and Short Physical Performance Battery (SPPB) and surveyed their daily physical activities and quality of life using the 36-Item Short Form Health Survey (SF-36). Results: Overall, 676 subjects completed the evaluations of physical function and activity. The isokinetic torque of the knee extensors and flexors declined with age in both men and women. The women in the old-old (75-84 years) group showed lower SPPB and physical activity than women in the young-old (65-74 years) group, but these measures were main- tained till age 85 in the men. SPPB and physical activity were significantly associated with the physical component scale (PCS) of the SF-36 in both men and women, while isokinetic torque was associated with PCS in women only. Conclusion: Physical performance and activity declined differently in Korean elderly men and women. Both these meas- ures showed to be the main factors associated with quality of life.