步行如何影响老年女性衰弱状态:步数还是步行强度?

How Does Walking Influence Frailty in Older Women:Step Count or Step Intensity?

目的探究步数、步行强度以及有氧步数与老年女性衰弱间的剂量-效应关系。方法采用ActiGraph三轴加速度计测量1099名60~70岁老年女性每日步数、步行强度(峰值1 min步数和峰值30 min步数)及有氧步数(以≥60步/min的步频连续行走≥10 min的步数)。根据衰弱表型评估老年女性衰弱状态,使用Logistic回归和限制性立方样条曲线分析步数、步行强度及有氧步数与衰弱的关联。结果控制混杂因素后,步行强度与老年女性衰弱前期显著相关,有氧步数与衰弱存在非线性关系。随着有氧步数的增加,衰弱患病率逐渐下降,当有氧步数达到4000步时,下降幅度趋于平缓。结论有氧步数而非总步数与衰弱间存在剂量-效应关系,每日有氧步数达到约4000步时,可能对老年女性衰弱的改善效果最佳。

Objective To investigate the dose-response relationships between step count,step intensity and aerobic steps and frailty in older women.Methods Daily steps,step intensity(Peak 1-and 30-minute stepping cadences)and aerobic steps(continuous steps of≥10 minutes at a pace of≥60 steps per minute)were measured using the ActiGraph triaxial accelerometer among 1099 older women aged 60-70 years.The frailty of the older women was assessed according to the frailty phenotype.Logistic regression and restricted cubic spline curve were used to analyse the associations between step counts,step intensity and aerobic steps and frailty.Results After adjusting for other confounders,there was a significant association between step intensity and prefrailty,and a non-linear association between aerobic steps and frailty.As the number of aerobic steps increased,the prevalence of frailty gradually decreased,and when the number of aerobic steps reached 4000,the decrease levelled off.Conclusion There is a dose-response relationship between aerobic steps,but not total step counts,and frailty,and frailty may be best improved when aerobic steps reach about 4000 steps per day.