Exploring Alternative Measurements of Cardiorespiratory Fitness in Patients With Mild Ischemic Stroke at Acute Phase

Background: While emerging studies have suggested an association of cardiorespiratory fitness (CRF) with stroke risk and overall health outcomes, little is known regarding the optimum methods of CRF measurement in patients with mild acute ischemic stroke.Objective: The aim of this study was to explore the association between the 6-min walk distance (6MWD) and other measurements related to CRF in patients with mild ischemic stroke at the acute stage.Methods: A total of 30 patients with stroke and 71 healthy subjects matched for age and grip strength (GS) were prospectively recruited. All patients were within 14 days after stroke onset and presented mild motor impairment (with a full score of Fugl-Meyer Motor Assessment). Demographic data of both groups and clinical information of the stroke group were documented, and the CRF comparison between the two groups was conducted. Each participant underwent a one-time assessment of 6MWD and a series of measurements related to CRF, including GS, 10-m walk test (10mWT), five-times sit-to-stand time (FTSST), functional reaching test (FRT), Berg Balance Scale (BBS), and waistline. Pearson's product-moment correlation coefficient test and multiple linear regression were performed to explore the indicators of CRF.Results: Significant moderate correlations (0.3 < r < 0.6) were found between 6MWD and GS of left hand (GS-left) (r = 0.573, p = 0.001), GS of right hand (GS-right) (r = 0.524, p = 0.003), FTSST (r = -0.551, p = 0.002), 10mWT (r = 0.554, p = 0.001), and FRT (r = 0.449, p = 0.021) in the patient group. While 6MWD displayed significant moderate correlations with waistline (r = 0.364, p = 0.002), 10mWT (r = 0.512, p < 0.001), FTSST (r = -0.573, p < 0.001), and FRT (r = 0.550, p < 0.001) in the healthy group. All these dependent variables were entered into a stepwise multiple linear regression analysis to evaluate their values in estimating CRF as measured by 6MWD in each group. Analyses suggested that GS-left (p = 0.002) and FTSST (p = 0.003) were the indicators of CRF in the patient group with stroke and explained 51.4% of the variance of 6MWD (R-2 = 0.514); FTSST (p < 0.001), 10mWT (p < 0.001), and FRT (p = 0.021) were the indicators of CRF in the healthy group and explained 58.9% of variance of 6MWD (R-2 = 0.589).Conclusions: Our data confirmed that CRF is impaired in patients with mild ischemic stroke at the acute phase. Moreover, GS-left may be an optional indicator of CRF in patients with mild acute ischemic stroke, but not in healthy people.