Rush Alzheimer's Disease Center, Department of Neurological Sciences, Rush University Medical Center, Chicago, IL 60612, USA.
Rush Alzheimer's Disease Center, Department of Psychiatry and Behavioral Sciences, Rush University Medical Center, Chicago, IL 60612, USA.
Sensors (Basel). 2023 Apr 21;23(8):4152. doi: 10.3390/s23084152.
This study characterized person-specific rates of change of total daily physical activity (TDPA) and identified correlates of this change. TDPA metrics were extracted from multiday wrist-sensor recordings from 1083 older adults (average age 81 years; 76% female). Thirty-two covariates were collected at baseline. A series of linear mixed-effect models were used to identify covariates independently associated with the level and annual rate of change of TDPA. Though, person-specific rates of change varied during a mean follow-up of 5 years, 1079 of 1083 showed declining TDPA. The average decline was 16%/year, with a 4% increased rate of decline for every 10 years of age older at baseline. Following variable selection using multivariate modeling with forward and then backward elimination, age, sex, education, and 3 of 27 non-demographic covariates including motor abilities, a fractal metric, and IADL disability remained significantly associated with declining TDPA accounting for 21% of its variance (9% non-demographic and 12% demographics covariates). These results show that declining TDPA occurs in many very old adults. Few covariates remained correlated with this decline and the majority of its variance remained unexplained. Further work is needed to elucidate the biology underlying TDPA and to identify other factors that account for its decline.
本研究描述了个体日常总体力活动（TDPA）的变化率，并确定了这种变化的相关因素。TDPA 指标是从 1083 名老年人（平均年龄 81 岁；76%为女性）多天腕部传感器记录中提取出来的。在基线时收集了 32 个协变量。使用一系列线性混合效应模型来确定与 TDPA 水平和年度变化率独立相关的协变量。尽管个体的变化率在平均 5 年的随访期间有所不同，但在 1083 人中，有 1079 人显示 TDPA 下降。平均下降率为 16%/年，基线时每增加 10 岁，下降率增加 4%。经过使用向前和向后逐步消除的多变量建模进行变量选择后，年龄、性别、教育程度以及包括运动能力、分形指标和 IADL 残疾在内的 27 个非人口统计学协变量中的 3 个与 TDPA 下降显著相关，占其变异的 21%（9%为非人口统计学协变量，12%为人口统计学协变量）。这些结果表明，许多非常老的成年人的 TDPA 都在下降。与这种下降相关的协变量很少，其大部分变异仍未得到解释。需要进一步的工作来阐明 TDPA 背后的生物学，并确定其他导致其下降的因素。
