Stroke, physical activity, exercise and metabolism

Abstract

Stroke is the main cause of disability worldwide. With over 110,000 first strokes occurring in the UK every year, the individual and societal burden of stroke will continue to increase. Consequently, there is a pressing need to develop therapies to both reduce the burden of stroke and the risk of stroke recurrence. Hyperglycaemia, dyslipidaemia, hypertension, reduced cardiorespiratory fitness and obesity are metabolic irregularities closely linked to stroke risk and represent possible therapeutic targets. In healthy individuals, a physically active lifestyle and structured exercise have been found to improve metabolic control. Research reporting the impact of physical activity and exercise on metabolic control, stroke risk and wellbeing is lacking in the study of stroke. This thesis aims to define and explore physical activity, exercise and metabolic control following stroke with a view to improving clinical care. A cross-sectional longitudinal study (n=31) demonstrates physical activity levels are low immediately following stroke and do not return to levels comparable to healthy individuals after six months, despite individuals having only mild impairment. A randomised controlled trial (n=40) of a community based exercise intervention post stroke investigated the impact of exercise primarily on metabolic risk factors. Significant improvements occurred in cardiorespiratory fitness (p<0.01); high density lipoprotein cholesterol (p<0.01); and diastolic blood pressure (p<0.04). The intervention also resulted in improvements in cognition, overall stroke recovery and mood, with the most marked changes occurring in walking endurance, walking speed and balance. This thesis delivers two clear messages: physical activity is reduced following stroke and does not fully recover after time; and the reversal of low levels of physical activity with a community based exercise therapy programme provides significant benefit to individuals after stroke. This information suggests that clinicians should consider both the importance of physical activity and the therapeutic potential of structured exercise therapy post stroke.