Energy cost and cardiorespiratory adaptation in the "get-up-and- go" test in frail elderly women with postural abnormalities and in controls

Abstract

Background. This study investigated the hypothesis that postural abnormalities might increase energy expenditure during a clinical functional test in frail elderly persons. Methods. Two groups of hospitalized women (aged 73 to 100 years) were recruited. Women who showed postural and gait abnormalities as described in the psychomotor disadaptation syndrome (PDS) were compared with control participants. The authors measured energy expenditure during the timed "up and go" test. For each participant, oxygen uptake, carbon dioxide output, expiratory minute ventilation, breathing frequency, heart rate, and alveolar ventilation were recorded 10 minutes before, during, and 10 minutes after exercise. The arterial pressure of carbon dioxide was estimated from expired gases. Results. The mean oxygen uptake values were significantly higher in women with PDS than in the control group during exercise and recovery periods (4.89 ± 1.68 vs 3.75 ± 1.25 ml · kg-1 · min-1 and 4.69 ± 1.45 vs 3.76 ± 0.97 ml · kg-1. min-1, respectively [p < .05]). Expiratory minute ventilation was always higher in women with PDS than in controls regardless of the period of the test (p < .05), and alveolar ventilation was higher in women with PDS only during the exercise period (p < .05). The estimated arterial pressure of carbon dioxide did not change significantly between the different phases of the test but was always lower (p < .05) in women with PDS compared with the control group. Conclusions. The significant increase in oxygen uptake during the exercise and recovery periods in women with PDS compared with controls suggests that postural abnormalities that characterize PDS may be associated with an increase in energy expenditure. In clinical practice, the low capacity to tolerate even moderate exercise must be considered when specific rehabilitation programs are offered to women with PDS. Copyright 2005 by The Gerontological Society of America.