Poor sleep health may accelerate brain ageing and this may be driven by higher levels of systemic inflammation.

These findings were made in the research study titled ‘Poor sleep health is associated with older brain age: The role of systemic inflammation’ which was authored by Y. Miao, J. Wang, X. Li, J. Guo, M.M. Ekblom, S. Sindi, Q. Zhang and A. Dove and published in the eBioMedicine journal, part of The Lancet's Discovery Science, last month (September).

The study included 27,500 adults from the United Kingdom Biobank (mean age 54.7 years, 54% female). The presence of five self-reported healthy sleep characteristics (early chronotype, seven-eight hours daily sleep, no insomnia, no snoring, no excessive daytime sleepiness) were summed into a score and used to define three sleep patterns: healthy, intermediate, and poor. Low-grade inflammation was estimated using a score which is a composite index of inflammatory biomarkers. 

After a mean follow-up of 8.9 years, the brain age was estimated using a machine learning model based on 1,079 brain phenotypes and used to calculate the brain age gap (brain age minus chronological age). 

At the baseline, 898/3.3% participants had poor sleep, 15,283/55.6% had intermediate sleep, and 11,319/41.2% had healthy sleep. Compared to healthy sleep, intermediate and poor sleep were associated with a significantly higher brain age gap. 

Poor-quality sleep has also been linked to increased dementia risk.