The Sleep Chronotype Dilemma and Age Acceleration

Sleep and Age Acceleration

Night Owls, Take Note: Staying up late might not be the best choice for your mental or respiratory well-being, as well as being age accelerative.

A new study from Stanford Medicine reveals that following your natural tendency to stay awake into the early hours can negatively impact mental health.

Researchers analyzed data from nearly 75,000 adults, comparing their preferred sleep patterns—known as chronotypes—with their actual sleep habits. The results showed that regardless of whether someone is naturally a morning person or a night owl, going to bed earlier benefits mental health. Those who stayed up late were more likely to experience mental and behavioral disorders.

Published on May 19 in Psychiatry Research, the study advises turning off the lights by 1 a.m.

"The key takeaway is that aligning with your chronotype isn’t as important as simply avoiding late nights," said Jamie Zeitzer, PhD, professor of psychiatry and behavioral sciences and the study’s senior author. "The bigger mystery is why this happens."

Renske Lok, PhD, a postdoctoral scholar in psychiatry and behavioral health, led the study.

Not So Surprising Findings

The results were unexpected. Previous research by Zeitzer’s team suggested that women with cancer who slept against their chronotype had shorter lifespans.

"There’s plenty of evidence suggesting that living in sync with your chronotype is important," Zeitzer noted. "That’s what we anticipated this study would reinforce."

To explore this further, researchers examined middle-aged and older adults in the UK, gathering self-reported data on sleep preferences. Participants also wore an accelerometer—a high-tech activity tracker—to monitor their sleep for a week.

Mental health conditions were assessed using participants’ health records, which included any disorders listed in the International Classification of Diseases.

Out of 73,880 participants, 19,065 identified as morning types, 6,844 as evening types, and 47,979 fell somewhere in between that were then decided into quartiles. Night owls being true to their chronotype were 20% to 40% more likely to have been diagnosed with a mental health disorder, compared with night owls following an early or intermediate sleep schedule [1].

Evening types who followed an earlier schedule fared better. Morning types who followed a later schedule suffered, but not too much. Morning larks who rose with the sun tended to have the best mental health of all, to no one's surprise.

Promoting Chronic Respiratory Disease (CRD)

Another prospective study revealed a notable correlation between unhealthy sleep patterns (encompassing excessive and insufficient sleep durations, insomnia, evening chronotype, snoring, and heightened daytime sleepiness) and an elevated risk of asthma [2]. Other studies have also confirmed that insufficient or excessive sleep duration is associated with COPD. Such findings indicate a potential role of sleep patterns in hastening the onset of CRDs [3].

While the exact mechanism are not known the molecular mechanisms underlying the influence of sleep patterns on health closely correlate with the acceleration of biological aging, involving factors such as telomere shortening, cellular senescence, metabolic changes, and impaired repair mechanisms.

That is, individuals of the same age exhibit varying rates of aging, a phenomenon aptly depicted through biological age. Phenotypic age (PhenoAge), a method for calculating biological age, derives from chronological age and nine common clinical biochemical biomarkers.[4].

A very recent study revealed that healthy sleep patterns can decelerate phenotypic aging, rendering individuals biologically younger than their chronological age. Healthy sleep patterns included early chronotype, appropriate sleep duration, absence of snoring, absence of insomnia, and no frequent daytime sleepiness. The prospective cohort investigations revealed that accelerated phenotypic aging (PhenoAgeAccel) was associated with an increased risk of asthma, COPD, ILD, and overall CRDs [5].

This study identified that PhenoAgeAccel had a mediating proportion in the range of 2.81 % to 12.48 % in the association between sleep score and various CRDs. The interpretation of this mediating effect typically involves intermediate mechanisms through which unhealthy sleep patterns contribute to CRD, primarily including proinflammatory and immune dysregulation processes. Sleep regulates downstream inflammation and immune responses through the hypothalamic-pituitary-adrenal (HPA) axis and the sympathetic nervous system. When sleep disturbances occur, continuous activation of the HPA axis and the sympathetic nervous system might lead to cortisol resistance and the release of norepinephrine and adrenaline. This downstream process activated genes involved in the inflammatory immune response, such as those encoding IL-1beta, IL-6, and tumor necrosis factor (TNF), while inhibiting genes related to antiviral immune responses, which could induce and exacerbate CRDs [6] .

Limitations vs Risk

It should be noted that the above study centred on using the large UK Biobank population consisted of a predominantly voluntary cohort, primarily comprising individuals of Caucasian, and may not represent the general population adequately. Extrapolating results to the broader population may be theoretically questionable. Also, sleep traits were self-reported and may result in misclassification of sleep patterns due to recall bias. Nevertheless is it worth the risks. Future research should employ more systematic and comprehensive scales for evaluating sleep patterns, especially given the association between sleep score and phenotypic age is often based on cross-sectional data, preventing the confirmation of the temporal sequence between exposure and outcome.

References

1. Renske Lok, Lara Weed, Joseph Winer, Jamie M. Zeitzer, Perils of the nighttime: Impact of behavioral timing and preference on mental health in 73,888 community-dwelling adults, Psychiatry Research,Volume 337, 2024, 115956.

2. B Xiang, M Hu, H Yu, Y Zhang, Q Wang, F. Xue: Highlighting the importance of healthy sleep patterns in the risk of adult asthma under the combined effects of genetic susceptibility: a large-scale prospective cohort study of 455 405 participants BMJ Open Respir Res (2023), p. 10.

3. C Lu, B Liao, J Nie, W Wang, Y. Wang: The association between sleep duration and chronic diseases: a population-based cross-sectional study

   Sleep Med, 73 (2020), pp. 217-222.

4. Z Liu, PL Kuo, S Horvath, E Crimmins, L Ferrucci, M. Levine Correction: A new aging measure captures morbidity and mortality risk across diverse subpopulations from NHANES IV: A cohort study PLoS Med, 16 (2019), Article e1002760.

5. Dongze Chen, Zekang Su, Yali Zhang, Yi Bai, Guiping Hu, Yi Zhou, Zhisheng Liang, Accelerated biological age mediates the associations between sleep patterns and chronic respiratory diseases: Findings from the UK Biobank Cohort, Heart & Lung, Volume 69, 2025, Pages 192-201.

6. MR. Irwin Sleep and inflammation: partners in sickness and in health Nat Rev Immunol, 19 (2019), pp. 702-715.