Normal Sleep Patterns Linked to Higher Rates of Healthy Aging in Chinese Seniors

Due to the increased life expectancy coupled with lower fertility rates, the elderly population (aged 60 years and above) is expected to rise from 12 to 22% of the global population between the years 2015 and 2050. Aging is rising at a fast rate in China.

The share of the population aged 60 years and older is projected to grow from 12.4% in 2010 to 28% in 2040, more than 397 million people. Nevertheless, although life expectancy continues to improve, the average life span of an average Chinese in the year 2019 stood at 77.6 years, the healthy life expectancy stood at 68.4 years, and this presents a disparity of nearly 9 years.

Successful aging, defined as living longer without significant chronic diseases, maintaining good physical and cognitive health, mental well-being, and social participation, is increasingly recognized as a major public health concern.

International research on successful aging indicates that only 15.7% of older adults in China age successfully, a rate much lower than that in developed countries such as Japan (29.2%) and South Korea (25.5%). Thus, successful aging in China is highlighted as an issue which needs to be addressed. It is also significant to identify the modifiable factors for successful aging in creating policies that can enhance it.

A study published in BMC Public Health analyzed the link between sleep duration and the risk of adverse health events, finding that both too little and too much sleep are associated with increased risk.  However, it is still largely unclear if the sleep duration trajectory is associated with health status in older individuals. The objective of this article was to analyze the connection between sleep duration patterns and successful aging.

The China Health and Retirement Longitudinal Study (CHARLS) included 3,306 participants who had no significant chronic illnesses at baseline and who managed to survive out to the age of sixty years and older by the end of the follow-up period. Baseline total sleep duration was measured in 2011, 2013, and 2015, while successful aging was assessed in 2020 and defined as the absence of major chronic diseases, no physical disability, high mental functioning, a healthy emotional state, and active engagement.

Latent class mixed model (LCMM) was employed to determine the trajectories of sleep duration and logistic regression was done to investigate the relationship between those trajectories and successful aging.

Of the 3,306 individuals included, the median age of the study population was 60 years [Interquartile range (IQR): 56-64 years], with 1,630 participants (49.3%) being female. During the 9-year follow-up, 455 individuals (13.8%) met the criteria for successful aging, 2,679 (81.0%) reported having “no major chronic diseases”, 2,515 (76.4%) indicated “no physical dysfunction”, 1,870 (56.6%) reported “high cognitive function”, 1,990 (60.2%) exhibited “good mental health”, and 1,458 (44.1%) demonstrated “active engagement with life”.

Five sleep duration trajectories were identified: normal stable, long stable, decreasing, increasing, and short stable. Compared with the normal stable trajectory, the adjusted ORs (95% CI) for achieving successful aging for participants with long stable, decreasing, increasing, and short stable trajectories were 1.00 (0.77, 1.30), 0.64 (0.40, 1.03), 0.64 (0.45, 0.92), and 0.48 (0.35, 0.66), respectively. The stratified and sensitivity analyses were generally consistent with the main results.

Study analysis revealed that both increasing and short stable total sleep duration trajectories were related to lower odds of successful aging when compared with normal stable total sleep duration trajectories among Chinese older adult individuals. This stresses that both chronic sleep duration deficits and chronic excessive sleep duration trajectories are barriers to successful aging. In addition, it is worth noting that the results have revealed an interesting finding which pertains to the need to pay attention to sleep duration changes over time.

Reference: Tian L, Ding P, Kuang X, Ai W, Shi H. The association between sleep duration trajectories and successful aging: a population-based cohort study. BMC Public Health. 2024;24:3029. DOI: 10.1186/s12889-024-20524-7