Sleep Patterns Linked to Healthy Aging Outcomes

A recent study published in the journal BMC Public Health investigated how varied sleep duration patterns link to’successful aging’ among older persons in China. The study stressed the importance of sleep duration and consistency in achieving good aging outcomes. Their findings show that increasing and short sleep patterns are associated with a poorer likelihood of effective aging, underlining the importance of monitoring sleep alterations among older and middle-aged persons.

Background

The global population of adults over 60 is anticipated to increase from 12% in 2015 to 22% by 2050. China, in particular, has a fast aging population, which is expected to reach 397 million and account for 28% of the total population by 2040. Its average life expectancy is 77.6 years, greatly exceeding the healthy life expectancy of 68.4 years.

Successful aging is characterized as living longer while retaining cognitive and physical health, social participation, and mental well-being while avoiding serious diseases. Less than 16% of senior persons in China attain this, while South Korea and Japan have much higher percentages. To promote successful aging in the Chinese population, it is necessary to identify modifiable risk factors.

Both excessive and insufficient sleep have been related to negative outcomes such as depression, cognitive deterioration, and death. Prior research has yielded mixed results on the relationship between successful aging and sleep duration, with one study in China finding associations between short sleep and lower odds of successful aging and another in the United States suggesting that long sleep may reduce the likelihood of aging healthfully.

Previous research did not account for long-term changes in sleep duration over time, instead concentrating on sleep duration recorded at a single point. Persistent short sleep is linked to an increased risk of mortality, dementia, heart disease, and type 2 diabetes, but the association between sleep patterns throughout time and effective aging has not been investigated.

Sleep Patterns – About the Study

In this study, researchers looked at how varied sleep duration patterns connected to successful aging in older and middle-aged Chinese adults, and how tracking these patterns could help influence public health efforts.

The study used data from longitudinal surveys performed between 2011 and 2020, which were supposed to be typical of persons over 45 in China. The final analysis comprised 3,306 people who were disease-free at baseline and older than 60 in 2020.

Participants’ total sleep duration was determined by combining nighttime sleep and daytime naps based on self-reported sleep patterns. Sleep patterns from 2011, 2013, and 2015 were investigated to determine the trend of sleep habits.

Researchers defined successful aging using five criteria: the absence of chronic diseases such as heart disease, cancer, and diabetes; independent physical functioning for daily activities; cognitive functioning; minimal depression symptoms; and social well-being through participation in community events or games.

The study used a latent class mixed model to categorize individuals’ sleep length trajectories into diverse patterns, as well as logistic regression models to assess the probability of successful aging for various sleep trajectory groups. The study controlled for body mass index (BMI) and lifestyle characteristics such as physical activity, drinking and smoking, income, education, housing, marital status, gender, and age.

Findings

The median age of the 3,306 participants was 60, and nearly half were women. Over nine years, 81% had no severe chronic conditions, but only 13.8% matched the criterion for healthy aging.

Researchers identified five distinct sleep patterns: short stable, growing, decreasing, long stable, and normal stable. The group with typical, steady sleep patterns had the highest successful aging rates (18.1%). Normal stable and long stable sleep patterns were more beneficial for effective aging, whereas short stable, increasing, and declining sleep patterns were associated with a reduced likelihood of success. Notably, the declining sleep trajectory was not statistically significant, most likely due to sample size.

Sleeping for less than seven hours was also found to impair the probability of effective aging, as were people with substantial sleep duration variability. These results were consistent across many groups, such as weight classes, smoking and alcohol consumption, gender, and age.

Conclusions

Researchers discovered that a constant, normal, and stable sleep pattern is the best path for optimal aging. Chronic lack of sleep may elevate stress hormones (such as cortisol) and inflammation, increasing the risk of age-related disorders. Long-term sleep disturbances may be associated with mental and cognitive impairments, sarcopenia (muscle loss), and disturbed metabolism. Gradual increases in sleep length may suggest health difficulties such as sleep apnea or depression, both of which hinder effective aging.

Importantly, these findings support the notion that sleep consistency is just as important as duration for beneficial aging effects. They argue that persistent sleep deficits or gradual increases in sleep duration are barriers to effective aging, emphasizing the significance of dynamic sleep monitoring as a preventive approach.

For more information: Hongying Shi, et al. The association between sleep duration trajectories and successful aging: a population-based cohort study, BMC Public Health, https://doi.org/10.1186/s12889-024-20524-7