UTHealth School of Public Health in Austin; Department of Epidemiology, Human Genetics, and Environmental Sciences; The Michael and Susan Dell Center for Healthy Living; Austin, TX 78701, USA; The University of Texas at Austin, Dell Medical School; Department of Women's Health; Austin, TX 78712, USA.
Kaiser Permanente Northern California; Division of Research, Oakland, CA 94612, USA.
Prev Med. 2017 Dec;105:287-294. doi: 10.1016/j.ypmed.2017.10.005. Epub 2017 Oct 5.
The purpose of this study was to examine the importance of midlife physical activity on physical functioning in later life. Data are from 1771 Study of Women's Health Across the Nation (SWAN) participants, aged 42-52 (46.4±2.7) years at baseline (1996-97). Latent class growth analysis was used to identify physical activity trajectory groups using reported sports and exercise index data collected at seven time-points from baseline to Visit 13 (2011-13); objective measures of physical functioning performance were collected at Visit 13. The sports and exercise index (henceforth: physical activity) is a measure of moderate to vigorous intensity physical activity during discretionary periods of the day. Multivariable linear regression analyses were used to model each continuous physical performance measure as a function of the physical activity trajectory class. Across midlife, five physical activity trajectory classes emerged, including: lowest (26.2% of participants), increasing (13.4%), decreasing (22.4%), middle (23.9%), and highest (14.1%) physical activity. After full adjustment, women included in the middle and highest physical activity groups demonstrated ≥5% better physical functioning performance than those who maintained low physical activity levels (all comparisons; p<0.05). Statistically significant differences were also noted when physical activity trajectory groups were compared to the increasing physical activity group. Results from the current study support health promotion efforts targeting increased (or maintenance of) habitual physical activity in women during midlife to reduce future risk of functional limitations and disability. These findings have important public health and clinical relevance as future generations continue to transition into older adulthood.
本研究旨在探讨中年期身体活动对晚年身体机能的重要性。数据来自于 1771 项妇女健康全国研究（SWAN）参与者，基线时年龄为 42-52 岁（46.4±2.7）岁（1996-97 年）。使用报告的体育和运动指数数据，采用潜在类别增长分析，根据从基线到第 13 次就诊（2011-13 年）的七个时间点收集的数据，确定身体活动轨迹组；在第 13 次就诊时收集身体机能表现的客观测量结果。体育和运动指数（以下简称：身体活动）是日间自由时间内中等至剧烈强度身体活动的度量。多变量线性回归分析用于将每个连续的身体表现测量值作为身体活动轨迹类别的函数进行建模。在中年期，出现了五种身体活动轨迹组，包括：最低（26.2%的参与者）、增加（13.4%）、减少（22.4%）、中等（23.9%）和最高（14.1%）身体活动。经过充分调整后，处于中等和最高身体活动组的女性的身体机能表现比保持低身体活动水平的女性要好≥5%（所有比较；p<0.05）。当比较身体活动轨迹组与增加身体活动组时，也观察到了统计学上的显著差异。本研究的结果支持在中年期针对女性增加（或维持）习惯性身体活动的健康促进努力，以降低未来功能受限和残疾的风险。随着未来几代人继续进入老年期，这些发现具有重要的公共卫生和临床意义。
