Evolution of cardiorespiratory fitness after stroke: a 1-year follow-up study. Influence of prestroke patients' characteristics and stroke-related factors

Abstract

Objectives: To examine changes in cardiorespiratory fitness over the first year poststroke and explore the effect of prestroke patients' characteristics and stroke-related factors on this evolution.

Design: Descriptive, longitudinal study with repeated measures of exercise capacity at 3, 6, and 12 months poststroke.

Setting: Rehabilitation center and exercise testing laboratory.

Participants: Consecutive sample of patients with stroke (N=33; mean age ± SD, 59.0±11.3 y).

Interventions: Not applicable.

Main outcome measures: Peak oxygen consumption (VO(2)peak) and oxygen uptake efficiency slope (OUES) were determined during a symptom-limited graded cycle ergometer test at 3, 6, and 12 months poststroke. Age, sex, premorbid physical activity level, clinical history (smoking, diabetes mellitus, chronic pulmonary diseases, cardiovascular diseases, overweight, and hypertension), stroke type and area, side of lesion, and assessments of stroke severity were evaluated at intake.

Results: Mean VO(2)peak ± SD was 18.1±6.6 mL·kg(-1)·min(-1), 19.8±8.0 mL·kg(-1)·min(-1), and 19.7±8.4 mL·kg(-1)·min(-1) at 3, 6, and 12 months poststroke. Values for OUES were 1575.3±638.3, 1710.7±710.3, and 1687.2±777.5, respectively. Mixed models showed no significant difference over time for VO(2)peak (P=.10), nor for the logarithm of OUES (P=.09). Stroke survivors at risk of deconditioning were premorbidly less active at work or in sport activities, diabetic, or initially more severely impaired. Combination of factors revealed that older patients with stroke and diabetes were less likely to improve on VO(2)peak and that older, women, diabetic nonsmokers improved less on log OUES.

Conclusions: Cardiorespiratory fitness was reduced from 3 to 12 months poststroke and on average did not significantly change over time. Further studies should elucidate methods of increasing cardiorespiratory fitness during stay in the rehabilitation center and how community-based aerobic exercise training postrehabilitation can be organized.