Relationship Between Energy Expenditure During Walking and Step Length in Patients With Heart Failure

摘要

Objective: Step length (SL) is an important indicator of physical function in older individuals and patients with heart failure (HF). The aim of this study was to investigate correlations between energy expenditure during walking and SL in patients with HF in different age groups. Subjects and Methods: A total of 44 patients participated in this study. The patients were divided into 2 groups with age younger than 65 years (the nonelderly group) and 65 years or older (the elderly group). Oxygen uptake (o(2)) during walking was measured for 6 minutes at a self-selected speed using the FitMate Pro (COSMED, Rome, Italy). The highest values of o(2) (ho(2)) and O-2 cost during walking were determined. Step length (m), SL/height ratio (%), walking speed, and handgrip strength (HS) were also measured. All patients underwent a symptom-limited, graded exercise test on a cycle ergometer to derive peak o(2). Results and Conclusions: Height was significantly correlated with SL in the nonelderly group (r = 0.56, P = .010) but not in the elderly group. ho(2) was not correlated with SL or SL/height ratio. In the elderly group, O-2 cost was negatively correlated with SL (r =-0.61, P = .027) but not with SL/height ratio. There was a significant correlation between HS and SL only in the elderly group (r = 0.58, P = .001). These results suggest that SL might be a useful index that reflects energy expenditure during walking in elderly patients with HF.