Children who sleep more may have longer telomeres: evidence from a longitudinal population study in Spain

Cellular senescence and sleep in childhood and adolescence: A scoping review focusing on sleep-disordered breathing

BACKGROUND

Sleep is a fundamental and complex physiological process whose duration decreases and characteristics change with age. Around 50 % of children will experience sleep disturbances at some point in their early life. Sleep disturbances can result in a number of deleterious consequences, including alterations in the levels of cellular senescence (CS) markers. CS is a complex process essential for homeostasis characterized by the irreversible loss of cell proliferation capacity; however, the accumulation of senescent cells can lead to age-related diseases.

OBJECTIVE

In this review, our objective was to gather information about the relationship between sleep duration, sleep-disordered breathing (SDB) and cellular senescence markers, namely: oxidative stress, inflammation, insulin-like growth factor 1 (IGF-1), and growth hormone (GH) in newborns, children, and teenagers.

METHODS

To achieve this, we searched six databases: MEDLINE, Scopus, LILACS, Web of Science, Embase, and SciELO, and identified 20 articles that met our inclusion criteria.

RESULTS

Our results show that better sleep quality and duration and, both the surgical and non-surgical treatment of sleep disorders are associated with a reduction in oxidative stress, inflammation, and telomeric attrition levels. Furthermore, our results also show that surgical treatment for SDB significantly reduced the levels of cellular senescence markers. Further studies need to be conducted in this area, particularly longitudinal studies, for a greater understanding of the mechanisms involved in the relationship between sleep and senescence.

CONCLUSION

Better sleep quality and duration were associated with less oxidative stress, inflammation, and telomeric attrition and a higher level of IGF-1 in children and teenagers.

Association between telomere length and neuropsychological function at 4-5 years in children from the INMA project: a cross-sectional study

Shortened telomere length (TL) has been associated with lower cognitive performance, different neurological diseases in adults, and certain neurodevelopmental disorders in children. However, the evidence about the association between TL and neuropsychological developmental outcomes in children from the general population is scarce. Therefore, this study aimed to explore the association between TL and neuropsychological function in children 4-5 years of age. We included 686 children from the INMA Project, a population-based birth cohort in Spain. Leucocyte TL was determined by quantitative PCR method, and neuropsychological outcomes were measured using the McCarthy Scales of Children's Abilities (MCSA). Multiple linear regression models were used to estimate associations adjusted for potential confounding variables. Main findings showed that a longer TL was associated with a higher mean working memory score (β = 4.55; 95% CI = 0.39, 8.71). In addition, longer TL was associated with a higher mean global quantitative score (β = 3.85; 95% CI = -0.19, 7.89), although the association was marginally significant. To our knowledge, this is the first study that shows a positive association between TL and better neuropsychological outcomes in children. Although further research is required to confirm these results, this study supports the hypothesis that TL is essential in protecting and maintaining a child's health, including cognitive functions such as working memory.

The association of sleep duration and leukocyte telomere length in middle-aged and young-old adults: A cross-sectional study of UK Biobank

BACKGROUND

The relationships between sleep duration and aging-associated diseases are intricate. Leukocyte telomere length (LTL) is a biomarker of aging, while the association of sleep duration and LTL is unclear.

METHODS

The 310,091 study participants from UK Biobank were enrolled in this cross-sectional study. Restricted cubic splines (RCS) analysis was firstly performed to assess the nonlinear relationship between sleep duration and LTL. Sleep duration was then categorized into three groups: <7 h (short sleep duration), 7-8 h (reference group), and >8 h (long sleep duration) and multiple linear regression was applied to analyze the association of short sleep and long sleep duration with LTL. We further performed subgroup analyses stratified by sex, age, chronotype and snoring.

RESULTS

RCS showed an inverted J-shaped relationship between sleep duration and LTL. Compared with the reference group, the inverse association of long sleep duration and LTL was statistically significant in fully-adjusted model (P = 0.001). Subgroup analyses showed that this association was more apparent in people over 50 years (51-60 y: P = 0.002; >60 y: P = 0.005), in men (P = 0.022), and in people preferred evening chronotype (P = 0.001).

CONCLUSION

Compared with participants sleeping 7-8 h, those sleep longer than 8 h had shorter LTL in middle-aged and young-old adults. The negative association between long sleep duration and LTL was more apparent in older people, in men, and in people preferred evening chronotype.

Sleep matters: Neurodegeneration spectrum heterogeneity, combustion and friction ultrafine particles, industrial nanoparticle pollution, and sleep disorders-Denial is not an option

Sustained exposures to ubiquitous outdoor/indoor fine particulate matter (PM_2.5), including combustion and friction ultrafine PM (UFPM) and industrial nanoparticles (NPs) starting in utero, are linked to early pediatric and young adulthood aberrant neural protein accumulation, including hyperphosphorylated tau (p-tau), beta-amyloid (Aβ_{1 - 42}), α-synuclein (α syn) and TAR DNA-binding protein 43 (TDP-43), hallmarks of Alzheimer's (AD), Parkinson's disease (PD), frontotemporal lobar degeneration (FTLD), and amyotrophic lateral sclerosis (ALS). UFPM from anthropogenic and natural sources and NPs enter the brain through the nasal/olfactory pathway, lung, gastrointestinal (GI) tract, skin, and placental barriers. On a global scale, the most important sources of outdoor UFPM are motor traffic emissions. This study focuses on the neuropathology heterogeneity and overlap of AD, PD, FTLD, and ALS in older adults, their similarities with the neuropathology of young, highly exposed urbanites, and their strong link with sleep disorders. Critical information includes how this UFPM and NPs cross all biological barriers, interact with brain soluble proteins and key organelles, and result in the oxidative, endoplasmic reticulum, and mitochondrial stress, neuroinflammation, DNA damage, protein aggregation and misfolding, and faulty complex protein quality control. The brain toxicity of UFPM and NPs makes them powerful candidates for early development and progression of fatal common neurodegenerative diseases, all having sleep disturbances. A detailed residential history, proximity to high-traffic roads, occupational histories, exposures to high-emission sources (i.e., factories, burning pits, forest fires, and airports), indoor PM sources (tobacco, wood burning in winter, cooking fumes, and microplastics in house dust), and consumption of industrial NPs, along with neurocognitive and neuropsychiatric histories, are critical. Environmental pollution is a ubiquitous, early, and cumulative risk factor for neurodegeneration and sleep disorders. Prevention of deadly neurological diseases associated with air pollution should be a public health priority.

Telomere dysfunction in some pediatric congenital and growth-related diseases

Telomere wear and dysfunction may lead to aging-related diseases. Moreover, increasing evidence show that the occurrence, development, and prognosis of some pediatric diseases are also related to telomere dysfunction. In this review, we systematically analyzed the relationship between telomere biology and some pediatric congenital and growth-related diseases and proposed new theoretical basis and therapeutic targets for the treatment of these diseases.