Physical activity (PA) and sedentary behavior (SB) are not stable conditions but change over time and among individuals, and both could have deleterious effects on health-related outcomes among older adults. This study aimed to identify the longitudinal trajectories of PA and SB and estimate their association with quality of life, disability, and all-cause mortality in a national sample of older Mexican adults. Data comes from three waves of the WHO Study on global AGEing and adult health (SAGE) in Mexico (2009, 2014, 2017). In total, 3209 older adults ages 50 and above were included. PA and SB were determined by using the Global Physical Activity Questionnaire (GPAQ). Disability was measured using the WHO Disability Assessment Schedule (WHODAS 2.0), quality of life using the WHOQOL (WHO Quality of Life) instrument, and all-cause mortality using a verbal autopsy. We used growth mixture modeling (GMM) to investigate the longitudinal trajectories of PA and SB. Three-level linear mixed effect models were used to estimate the associations of PA and SB with quality of life and disability and the Cox model for the association with all-cause mortality. Three longitudinal trajectories of PA and SB were found: low-PA-decreasers, moderate-PA-decreasers, and high-PA-decreasers for PA; and low-maintainers, steep-decreasers, and steep-increasers for SB. Decreased quality of life, increased disability, and all-cause mortality were all consistently associated with worse PA and SB trajectories. Our results highlight the need for health policies and prevention strategies that promote PA and limit SB in middle-aged adults. Further studies should consider these activities/behaviors as exposures that vary throughout life and work to identify vulnerable groups of older adults for whom physical activation interventions and programs would be most impactful.

中文翻译：

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身体活动和久坐行为轨迹及其与生活质量、残疾和全因死亡率的关系

身体活动 (PA) 和久坐行为 (SB) 不是稳定的条件，而是随着时间和个体之间的变化而变化，两者都可能对老年人的健康相关结果产生有害影响。本研究旨在确定 PA 和 SB 的纵向轨迹，并估计它们与墨西哥老年人全国样本中的生活质量、残疾和全因死亡率的关系。数据来自世卫组织在墨西哥开展的全球老龄化与成人健康研究 (SAGE) 的三轮研究（2009 年、2014 年、2017 年）。共纳入 3209 名 50 岁及以上的老年人。PA 和 SB 是通过使用全球体力活动问卷 (GPAQ) 确定的。使用 WHO 残疾评估表 (WHODAS 2.0) 测量残疾，使用 WHOQOL (WHO Quality of Life) 仪器测量生活质量，和使用口头尸检的全因死亡率。我们使用生长混合模型 (GMM) 来研究 PA 和 SB 的纵向轨迹。三水平线性混合效应模型用于估计 PA 和 SB 与生活质量和残疾的关联，并使用 Cox 模型估计与全因死亡率的关联。发现了 PA 和 SB 的三个纵向轨迹：PA 的低 PA 降低者、中度 PA 降低者和高 PA 降低者；以及 SB 的低维护者、陡降者和陡增者。生活质量下降、残疾增加和全因死亡率都始终与较差的 PA 和 SB 轨迹相关。我们的结果强调了促进 PA 和限制中年成人 SB 的卫生政策和预防策略的必要性。