Physical activity and physical function in older adults: the 45 and up study.

OBJECTIVES

To determine the strength of the relationship between physical activity and physical function in older adults.

DESIGN

Cross-sectional.

SETTING

The 45 and Up Study baseline questionnaire, New South Wales, Australia.

PARTICIPANTS

Ninety-one thousand three hundred seventy-five Australian men and women aged 65 and older from the 45 and Up Study.

MEASUREMENTS

Physical activity engagement (Active Australia Survey), physical function (Medical Outcomes Study Physical Functioning), psychological distress (Kessler-10), and self-reported age, smoking history, education, height, and weight were all measured.

RESULTS

Higher levels of physical activity were associated with better physical function in older adults (correlation coefficient = 0.166, P < .001). Participants engaging in higher levels of physical activity had progressively lower likelihoods of functional limitation (middle tertile: odds ratio (OR) = 0.39, 95% confidence interval (CI) = 0.38-0.41; highest tertile: OR = 0.28, 95% CI = 0.27-0.29). This relationship remained significant, but weakened slightly, when adjusted for age, sex, body mass index, smoking history, psychological distress, and educational attainment (middle tertile: adjusted OR (AOR) = 0.48, 95% CI = 0.46-0.50; highest tertile: AOR = 0.36, 95% CI = 0.34-0.37).

CONCLUSION

There is a significant, positive relationship between physical activity and physical function in older adults, with older adults who are more physically active being less likely to experience functional limitation than their more-sedentary counterparts. Level of engagement in physical activity is an important predictor of physical function in older adults.