Wingood Mariana, Jaeger Byron C, Fanning Jason, Callahan Kathryn E
Department of Implementation Science, Wake Forest University School of Medicine, Winston-Salem, North Carolina, United States.
Department of Internal Medicine, Section on Gerontology and Geriatric Medicine, Wake Forest University School of Medicine, Winston Salem, North Carolina, United States.
J Gerontol A Biol Sci Med Sci. 2025 Jul 24;80(8). doi: 10.1093/gerona/glaf125.
Frailty, defined as diminished physiological and functional reserve, is linked to negative health outcomes such as falls, fractures, and disability. Physical activity dose plays a significant role in preventing and reducing physical frailty, but the influence of different PA variables on deficit accumulation (ie, frailty index [FI]) is not fully understood. Thus, we examined the relationship between physical activity variables and FI among older adults.
We utilized Round 11 (2021) data from the National Health and Aging Trends Study, a longitudinal study of Medicare beneficiaries aged 65 and older in the United States. Our participants included 726 community-dwelling older adults who had at least 3 valid days of accelerometer data and all data needed to calculate FI. Demographic variables, health conditions, and physical function were assessed through standardized interviews and objective assessments. We completed regression and Poisson models to estimate FI value and prevalence ratios for frailty.
Participants spent 339 daily minutes performing physical activity. The activity was accumulated over 88 bouts averaging 3.8 minutes. Those with frailty have lower levels of activity, higher levels of non-activity and sleep, higher activity fragmentation, fewer bouts, shorter bouts, and lower intensity over 10 consecutive minutes (ps < .001). After adjusting for all activity metrics, activity fragmentation (B = 1.32) and intensity of the most active 10-minute bout (B= -0.46) remained significantly associated with FI (P ≤ .04).
Low-intensity and fragmented physical activity is linked to frailty. Further research should explore the role of sustained activity and fragmentation in monitoring and guiding interventions for frailty.
虚弱被定义为生理和功能储备的下降，与跌倒、骨折和残疾等不良健康结果相关。体力活动剂量在预防和减少身体虚弱方面起着重要作用，但不同的体力活动变量对缺陷积累（即虚弱指数[FI]）的影响尚未完全了解。因此，我们研究了老年人体力活动变量与FI之间的关系。
我们利用了美国国家健康与老龄化趋势研究第11轮（2021年）的数据，这是一项对65岁及以上医疗保险受益人的纵向研究。我们的参与者包括726名社区居住的老年人，他们至少有3天有效的加速度计数据以及计算FI所需的所有数据。通过标准化访谈和客观评估来评估人口统计学变量、健康状况和身体功能。我们完成了回归模型和泊松模型，以估计FI值和虚弱的患病率比值。
参与者每天花费339分钟进行体力活动。活动累积在88次发作中，平均每次发作3.8分钟。虚弱者的活动水平较低，非活动和睡眠水平较高，活动碎片化程度较高，发作次数较少，每次发作时间较短，且连续10分钟的强度较低（p<0.001）。在对所有活动指标进行调整后，活动碎片化程度（B = 1.32）和最活跃的10分钟发作的强度（B = -0.46）仍与FI显著相关（P≤0.04）。
低强度和碎片化的体力活动与虚弱有关。进一步的研究应探索持续活动和碎片化在监测和指导虚弱干预措施中的作用。
