Sleep Patterns Linked to Accelerated Phenotypic Aging

Biological, phenotypic aging has been linked to sleep factors such as sleep duration and sleep chronotype (individual preferences and inclinations for timing of activity and sleep), according to a study recently published in Sleep Health: Journal of the National Sleep Foundation.

It is well known that aging is a major risk factor for many chronic diseases, and the rapidly aging population represents a burden on the health system. However, aging at the biological level, an indicator for individual susceptibility to disease and mortality, is heterogenous, making it important to identify factors that reflect and contribute to individual states of biologic aging, the authors noted.

Pillow in the Clouds for Sweet Dreams | image credit: Ziyan Yang - stock.adobe.com

“Sleep is a critical health-related behavior and is considered an important marker of overall health status,” Tao et al wrote. They go on to cite multiple studies that linked sleep patterns and characteristics to increased risks of mortality, age-related conditions, reduced length of leukocyte telomeres, and phenotypic aging itself.

Amongst the available literature, data on the relationship between phenotypic age acceleration (PhenoAgeAccel) and sleep traits are still lacking. To expand on this knowledge, researchers gathered data between 2017 and March of 2020 from the National Health and Nutrition Examination Survey (NHANES) to analyze any associations between social jet lag, sleep duration, sleep disturbance, and chronotype with PhenoAgeAccel in US adults.

Sleep disorders and behavior were discerned from personal interviews, a questionnaire, participant self-reports on sleep duration on weekday/workday, and sleep duration on workfree days (SDF). The American Academy of Sleep Medicine and Sleep Research Society considers optimal sleep as 7 to 8 hours of sleep and short sleep duration as less than 7 hours, but it has not come to a consensus on long sleep duration. For this reason, the researchers split their sleep categories into ≤ 4 hours, > 4 to 5 hours, > 5 to 6 hours, > 6 to < 7 hours, 7-8 hours (optimal sleep), > 8 to 9 hours, and > 9 hours.

Assessments of PhenoAgeAccel were conducted through an analysis of 9 blood biomarkers. Negative or positive values were a sign that an individual’s perceived biologic age was younger or older than their chronological age.

A total of 6534 participants were included in this study. The mean chronological was 48.65 years whereas phenotypic age was 45.33 years. The majority of participants were non-Hispanic White (65.9%), followed by Hispanic (15.3%). Approximately half (51.0%) were women.

Across the group, there was a mean PhenoAgeAccel of –1.12 years. Less than 7 hours of sleep on workdays, workfree days, and throughout the entire week was recorded in an estimated 24%, 13%, and 23% of participants, respectively. Just under 27% achieved over 8 hours of sleep on workdays; this number jumped to 46% on workfree days. Around 31% of individuals reported disturbances in their sleep.

Those who slept and average of 7 or more hours throughout the week were found to drink 1 or fewer cups of coffee or tea per day, be physically active, never smoke, have less social jetlag time, have lower body mass index (BMI), and less PhenoAgeAccel.

On workdays, longer sleep duration (> 9 hours) and extremely short duration (≤ 4 hours) were associated with faster rates of PhenoAgeAccel when compared with optimal (7-8 hours) sleep (long sleep: β = 1.19; 95% CI, 0.34-2.04; extremely short sleep: β = 1.59; 95% CI, 0.02-3.17). In a similar trend, individuals with sleep duration on workfree days of ≤ 4 hours and > 9 hours had higher PhenoAgeAccel when compared with those with optimal sleep (≤ 4: β = 1.94; 95% CI, 0.04-3.84; > 9: β = 0.69; 95% CI, 0.01-1.37).

The authors also evaluated sleep chronotypes. There was a significant association between quicker PhenoAgeAccel, evening (indicating a preference for staying up late and sleeping in), and slightly evening chronotypes compared with morning (preference of sleeping and waking early) chronotypes (slightly evening: β = 0.64; 95% CI, 0.22-1.06; evening: β = 1.48; 95% CI, 0.75-2.22; chronotype and PhenoAgeAccel association: P = .003). There were no significant associations found between PhenoAgeAccel and sleep disturbances or social jetlag.

“Chronotype is an important aspect of the circadian rhythm and maintaining sleep-wake homeostasis in an individual,” the authors wrote, adding, “Numerous studies have suggested that normal aging is accompanied by dampened circadian rhythms and changes in sleep patterns such as a phase tendency of going to sleep and waking up earlier.”

The authors concluded by highlighting how their findings regarding chronotype and phenotypic aging present a “new avenue” for sleep research to explore the connection between individual health, age-related disease, and sleep behaviors.

Research

Tao MH, Drake CL, Lin CH. Association of sleep duration, chronotype, social jetlag, and sleep disturbance with phenotypic age acceleration: A cross-sectional analysis. Sleep Health. 2024 Jan 17:S2352-7218(23)00298-X. doi: 10.1016/j.sleh.2023.11.015