Individual Responsiveness to Physical Exercise Intervention in Acutely Hospitalized Older Adults

Abstract

We analyzed inter-individual variability in response to exercise among acutely hospitalized oldest-old adults. In this ancillary analysis of a randomized controlled trial, 268 patients (mean age 88 years) were assigned to a control (n = 125, usual care) or intervention group (n = 143, supervised exercise, i.e., walking and rising from a chair [1-3 sessions/day]). Intervention group patients were categorized as responders, non-responders, or adverse responders (improved, no change, or impaired function in activities of daily living [ADL, Katz index] from hospital admission to discharge, respectively). We analyzed the association between responsiveness to exercise and variables assessed at baseline (2 weeks pre-admission), admission, during hospitalization, at discharge, and during a subsequent 3-month follow-up. An impaired ADL function and worse nutritional status at admission were associated to a greater responsiveness, whereas a better ADL function at admission, longer hospitalization and lower comorbidity index were associated with a poorer response (p < 0.05). Adverse responders had worse outcomes at discharge and during the follow-up (e.g., impaired physical performance and greater fall number) (p < 0.05). Although exercise intervention helps to prevent ADL function decline in hospitalized oldest-old people, a number of them-particularly those with a better functional/health status at admission and longer hospitalization-are at higher risk of being adverse responders, which can have negative short/middle-term consequences.

Keywords: activities of daily living; elders; functional ability; hospital-associated disability; training.

Figure 1

Significant (p < 0.05) associations between: (i) demographic and clinical variables at baseline (i.e., two weeks before hospitalization) or upon hospital admission; and (ii) the response of functional ability (i.e., ability to perform activities of daily living [ADLs] independently) to the exercise intervention (i.e., responder [improvement], non-responder [no change] or adverse responder [decrease]). Data are shown as odds ratio (OR) along with 95% confidence interval (CI), and were computed through multivariate logistic regression analyses (fitted for those variables showing a p-value ≤ 0.157 in univariate analyses).

Figure 2

Significant (p < 0.05) association between: (i) the response of functional ability (i.e., ability to perform activities of daily living [ADL] independently) to the exercise intervention (i.e., responder, non-responder or adverse responder to exercise (i.e., responder [improvement], non-responder [no change] or adverse responder [decrease]); and (ii) different outcomes at discharge or during a 3-month follow-up. Data were analysed using linear regression and are expressed as β along with 95% confidence intervals (CI). No significant associations were found for non-responders. Abbreviations: FAC, functional ambulatory category; SPPB, short physical performance battery.