The Association of Medication-Use and Frailty-Related Factors with Gait Performance in Older Patients

The increased fall risk associated with the use of psychotropic drugs might be caused by underlying problems in postural control that are induced by sedative side-effects of these drugs. The current literature on the effects of psychotropics on postural control only examined acute single-drug effects, and included relatively healthy young elderly. Consequently, it is unclear what the impact of the long-term use of these drugs is on gait in frail older persons with polypharmacy. Therefore, it was aimed in the present study to explore the association between the use of psychotropics, multiple other medications, frailty-related parameters and gait performance in older patients. Eighty older persons (79±5.6 years) were recruited. Comorbid diseases, frailty-related parameters, and medication-use were registered. Trunk accelerations during a 3-minute-walking-task were recorded, whereof walking speed, mean stride times, coefficient of variation (CV) of stride times, and step consistency were determined. Multivariate Partial Least Squares (PLS) regression analysis was used to examine the association between population characteristics and medication-use, versus gait parameters. A PLS-model existing of four latent variables was built, explaining 45% of the variance in four gait parameters. Frailty-related factors, being female, and laxative-use were most strongly associated with lower walking speed, higher mean stride times, higher CV of stride times, and less consistent steps. In conclusion, frailty-related parameters were stronger associated with impaired gait performance than the use of psychotropic drugs. Possibly, at a certain frailty-level, the effect of the deterioration in physical functioning in frailty is so large, that the instability-provoking side-effects of psychotropic drugs have less impact on gait.

精神药物使用相关的跌倒风险升高，可能由这类药物的镇静副作用诱发的姿势控制潜在异常所导致。现有关于精神药物对姿势控制影响的研究，仅考察了单次给药的急性效应，且研究对象多为相对健康的年轻老年群体。因此，目前尚不明确长期使用这类药物，对存在多重用药状况的衰弱老年人群的步态会产生何种影响。鉴于此，本研究旨在探讨老年患者的精神药物使用情况、其他多种药物使用情况、衰弱相关参数与步态表现之间的关联。本研究共招募了80名老年受试者（年龄79±5.6岁），记录了受试者的共病情况、衰弱相关参数以及用药信息。同时记录了受试者在3分钟行走任务中的躯干加速度，并据此计算得到行走速度、平均步时、步时变异系数（coefficient of variation, CV）以及步幅一致性四项步态参数。采用多元偏最小二乘（Multivariate Partial Least Squares, PLS）回归分析，探究人群特征、用药情况与步态参数之间的关联。本研究构建了包含4个潜变量的PLS模型，该模型可解释四项步态参数45%的变异量。研究发现，衰弱相关因素、女性性别以及泻药使用，与更低的行走速度、更长的平均步时、更高的步时变异系数以及更差的步幅一致性显著相关。综上，相较于精神药物的使用，衰弱相关参数与步态功能受损的关联更为显著。推测当达到某一衰弱程度时，衰弱本身引发的躯体功能衰退效应已足够显著，使得精神药物诱发的不稳定副作用对步态的影响被大幅削弱。