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But what are telomeres? Telomeres are structures found at the ends of chromosomes, which are made up of DNA and protein sequences. These telomeres act as “plugs” which protect the genetic material of the chromosomes and prevent them from deteriorating. As our cells divide, telomeres naturally shorten, contributing to the aging process. The innovation of this work is to verify the effect of sedentary behaviours on the length of telomeres.

Sedentary behaviours, downtime in front of the television, video games, etc., during childhood can have negative effects on the health and well-being of children. In particular, there are studies that have shown that more time dedicated to sedentary behaviours in childhood influences having less muscular development, less concentration and poorer academic performance, as well as affecting their interaction and socialization skills. In addition, scientific evidence has observed that more time dedicated to sedentary behaviours in childhood can influence having more obesity, cardiovascular problems, type 2 diabetes, and anxiety and depression in adult life. Regarding telomeres, sedentary behaviours could contribute to accelerate their shortening due to their oxidative and inflammatory action on the cells of our body. However, to date no studies have been carried out to see if sedentary behaviours influence telomere length in childhood.

Thanks to the participation of 669 children from the INMA Study who gave a blood sample and answered several questionnaires at 4 years of age and 530 children at 8 years of age, this manuscript has been possible. These blood samples allowed us to determine telomere length at 4 and 8 years and with these measurements we were able to calculate changes between 4-8 years. In addition, at the follow-up visit at child’s age 4, information was collected on the sedentary behaviours reported by the parents. Specifically, screen viewing time (television, videos, etc.), other sedentary activities (puzzles, reading, homework, etc.) and total time (the sum of these two) were calculated. These variables were transformed into three levels of sedentary behaviours (low, medium or high level).

The results obtained showed that children who spent more time viewing screens at age 4 (highest level, between 1.6 and 5.0 hours a day) had a telomere length 3.9% shorter compared to children at the lowest level (between 0 and 1.0 hours per day). In addition, these children exposed to more screen time at age 4 showed a greater acceleration of telomere shortening. This study corroborates the potential negative effect of sedentary behaviours during childhood with respect to cellular longevity and focuses on the importance of promoting an active lifestyle from an early age to promote the health of children.

If you want to know more about telomeres, you can consult the following informative video: https://www.youtube.com/watch?v=IvnMDa-p-nE&t=46s&ab_channel=UniversidadMiguelHern%C3%A1ndezdeElche

Photo source: https://www.freepik.es/foto-gratis/nina-que-sienta-cerca-su-hermano-que-mira-tableta-digital-sofa-casa_3753618.htm#query=ni%C3%B1o%20sof%C3%A1&position=24&from_view=search&track=robertav1_2_sidr

Reference: Prieto-Botella D, Martens DS, Valera-Gran D, Subiza-Pérez M, Tardón A, Lozano M, Casas M, Bustamante M, Jimeno-Romero A, Fernández-Somoano A, Llop S, Vrijheid M, Nawrot TS, Navarrete-Muñoz EM. Sedentary Behaviour and Telomere Length Shortening during Early Childhood: Evidence from the Multicentre Prospective INMA Cohort Study. Int J Environ Res Public Health. 2023 Mar 14;20(6):5134.

Link to the scientific article: https://www.mdpi.com/1660-4601/20/6/5134

Sleep is an essential biological process that serves vital functions, including promotion of neuroplasticity and neural development. Sleep disruption has been related with numerous short- and long-term health consequences. Short-term consequences include increased stress responsivity, cognitive deficits as well as emotional and behavioral problems. Long-term consequences of sleep disruption include hypertension, cardiovascular diseases, and diabetes mellitus type 2. Several studies have linked environmental noise exposure to higher sleep disturbances in adults, but are less conclusive in children. To date, most studies have used parental- or self-reports to characterize sleep, and few studies have included objective measurements to assess sleep quality. Also, previous literature has mostly ignored other noise sources such as railway, aircraft, or industry, which could play a different role in sleep patterns.

The main objective of the study was to determine whether road traffic and multiple noise exposure (i.e. road, railway, aircraft, and industry) could affect sleep in preadolescents, using maternal-reported and wrist-actigraphy data from two birth cohorts in Europe.

A total of 1477 children aged 12 years from the INMA Sabadell (Spain) and the Generation R Study (the Netherlands) were included. Noise levels were modelled at the participants addresses using noise maps created in 2012. Children’s sleep disturbances were reported by mothers through questionnaires for assessing: i) problems with initiating and maintaining sleep, ii) excessive somnolence, and iii) arousal problems (i.e. partial awakening from deep to light sleep, or from sleep to a state of being awake in which the subjects are partially or totally unconscious). Sleep was objectively measured with a wrist accelerometer placed on the non-dominant wrist during 7 days for obtaining the following physiological parameters: total sleep time (i.e., total amount of time asleep during the night, extracting time scored as awake in between), sleep efficiency (i.e., ratio of total sleep time to total time in bed), sleep onset latency (i.e., time a child needs to fall asleep), and wake after sleep onset (i.e., amount of time a child spends awake, starting from the time they fall asleep until the time they become fully awake). Lifestyle and socioeconomic variables were recorded using questionnaires and instruments completed by the parents.

Exposure to road traffic noise was on average 53.2 dB in the Generation R Study and 61.3 dB in the INMA-Sabadell cohort. Results suggest that exposure to noise was related with reduced total sleep time and longer wake after sleep onset in both cohorts. Authors reported no association between noise exposure and maternal-reported sleep disturbances. Results were similar for multiple noise exposure, but most of the association was attributable to road traffic noise as it is the most predominant noise source. Authors say that “although the observed estimates were relatively small, these results might be more meaningful at the population-level due to the high prevalence of exposure to environmental noise”.

Referencia: Pérez-Crespo L, Essers E, Foraster M, Ambrós A, Tiemeier H, Guxens M. Outdoor residential noise exposure and sleep in preadolescents from two European birth cohorts. Environ Res. 2023 Feb 16;225:115502. doi: 10.1016/j.envres.2023.115502. Epub ahead of print

Link al artículo científico: https://doi.org/10.1016/j.envres.2023.115502

Kisspeptins are a set of neuroactive peptides that play an important role in sexual maturation. Thus, their inclusion in epidemiological studies could help to understand how environmental pollutants alter hormone levels and sexual maturation during adolescence, a crucial period for human development.

Objective: To ascertain whether kisspeptin serum protein and DNA methylation levels are associated with exposure to several contaminants (assessed individually and as a mixture) and the reproductive hormone profile in adolescent males.

For this purpose, the levels of a set of environmental pollutants of very different origin, use, and source of exposure were quantified in the urine of adolescents aged 15 to 17 years: Three phenols (bisphenol A [BPA], methyl-paraben [MPB] and benzophenone-3 [BP3]); two heavy metals (arsenic and cadmium) and four pesticide metabolites, three insecticides (2-isopropyl-6-methyl-4-pyrimidinol [IMPy], malathion diacid [MDA] and dimethylcyclopropane carboxylic acid [DCCA]) and one fungicide (ethylene thiourea [ETU]). In addition, the concentration of kiss54 in serum and KISS1 gene methylation in whole blood were determined. Serum levels of the following sex hormones were also quantified: total testosterone (TT), estradiol (E2), sex hormone binding globulin (SHBG), dehydroepiandrosterone (DHEAS), luteinizing hormone (LH), and follicle-stimulating hormone (FSH).

Quantile G-computational was used to evaluate the impact of the mixture of contaminants, by families (phenols; metals; pesticides), and the total mixture (all quantified compounds). Linear regression models were also performed to investigate the association between each of the individual chemical contaminants with the kisspeptin protein and its DNA methylation levels. The association between kisspeptin and reproductive hormones was also assessed. All models were adjusted for variables of interest (adolescent age, waist-to-height ratio, Tanner genital stage; annual household income, the season of sample collection, and urinary creatinine levels).

We observed that exposure to the pesticide mixture and the total chemical mixture was associated with higher protein levels of kiss54 [% change (95%CI)=9.09 (3.29;15.21) and 11.61 (3.96;19.82), respectively] and lower levels of total methylation (∑CpGs). Individual MDA and DCCA concentrations were also associated with higher kisspeptin levels [% change (95% CI) 2.90 (0.32;5.56), and 1.93 (0.45,3. 43), respectively]; IMPy concentrations with lower percent methylation for sum CpGs and for CpG1 [% change (95% CI)= -0.89 (-1.73;-0.01), -1.15 (-1.96;-0.33), respectively]. BP3 and DCCA appeared, in addition, to be associated with lower total methylation (∑CpGs) [-0.53 (-1.04;-0.01) and -0.69 (-1.37;-0.01), respectively]. Adolescents with higher kiss54 concentrations (third tertile), also had higher LH levels [% change (95% CI) = 28.69 (3.75-59.63)], and those with higher CpG1, CpG2, and total CpG methylation percentages (third tertile) had lower FSH and E2 levels.

The negative correlation between serum kiss54 levels and KISS1 DNA methylation percentages places the kiss54 measure in an excellent position in the battery of biomarkers studied so far. This study highlights, on the one hand, the seriousness of the exposure of young people to environmental pollutants with the capacity to influence hormones, the variety of sources of exposure – plastics, cosmetics, and food – and the need to incorporate strategies for evaluating the effect of mixtures of pollutants, knowing that this is the real scenario in which human exposure to environmental pollutants occurs.

Figure. Effects of contaminant mixture on kiss54 (serum and methylation levels in several CpGs) and on reproductive hormones (SHBG, LH).

Reference: Rodriguez-Carrillo A, Remy S, D’Cruz SC, Salamanca-Fernandez E, Gil F, Olmedo P, Mustieles V, Vela-Soria F, Baken K, Olea N, Smagulova F, Fernandez MF, Freire C. Kisspeptin as potential biomarker of environmental chemical mixture effect on reproductive hormone profile: A pilot study in adolescent males. Sci Total Environ. 2023 Apr 10;868:161668. doi: 10.1016/j.scitotenv.2023.161668. Epub 2023 Jan 16. PMID: 36657687.

Link to the scientific article: https://pubmed.ncbi.nlm.nih.gov/36657687/

Andrea Rodríguez-Carrillo (andrearc@ugr.es). Flemish Institute for Technilogical Research (VITO); University of Antwerp (UA). Instituto de Investigación Biosanitaria (Ibs.GRANADA)
Mariana (Marieta) Fernández (marieta@ugr.es). Universidad de Granada, Centro de Investigación Biomédica. Instituto de Investigación Biosanitaria (ibs.GRANADA), CIBERESP
Carmen Freire (cfreire@ugr.es) Instituto de Investigación Biosanitaria (Ibs.GRANADA), CIBERESP

During the conferences have been presented the results of the various studies under the INMA Project and we have had plenary sessions by both national and international speakers of recognized prestige. Dr. Miquel Casas (Hospital de Sant Joan de Déu. Barcelona) delighted us with the talk entitled “Neurodevelopmental Disorders, Academic Performance and Behavioural Problems in Childhood and Adolescence“, Dr. Xavier Basagaña (ISGlobal) enlightened us with the session “Formative pill: The statistical challenges of working with multiple correlated exposures“, and Dr. Kate Northstone (ALSPAC) fascinated us with her talk “The Avon Longitudinal Study of Parents and Children (ALSPAC): Three decades of follow-up“.

The meeting ended with the conference “How is time measured and what are the temporal perspectives of environmental health?” given by Dr. Joan Grimalt, from the Institute for Environmental Assessment and Water Research (IDAEA) – Spanish National Research Council (CSIC).

We have had 136 registered participants, 83 of them participated in person and 53 followed the conference via Streaming.

Congratulations to all for this successful conference!

• Scientific Program: Link NEW!

These conference will follow the following format:

• Plenary sessions and INMA results presentation: in person on February 7 and 8 in Parc de Recerca Biomedica de Barcelona – PRBB, Barcelona (it will be broadcast in Streaming)

Reserve these dates! We will wait for you!

• REGISTRATION:
  Registration is mandatory since we need to have your data to send you the information so that you can attend, follow and connect by streaming to the different sessions.
  Send us an e-mail to: inma@proyectoinma.org with this data (all fields are required!):
  • Subject for the e-mail: REGISTRATION INMA CONFERENCE 2023
  • Name:
  • Surname:
  • E-mail:
  • Relationship with the INMA Project:
    – Do you belong to any cohort of the INMA Project? to which?:
    – Do you collaborate with any cohort of the INMA Project? with which?:
    – Do you have an INMA External Collaboration proposal approved and under development?:
    – Are you external to the INMA Project?:
  • Your participation will be:
    – I will attend the sessions in person on February 7 in Barcelona: (Yes or No)
    – I will attend the sessions in person on February 8 in Barcelona: (Yes or No)
    – I will participate in the lunch (after closure) on February 8 in Barcelona: (Yes or No)
    – I will participate in the Social Activity on February 7: (Yes or No)
    – I will participate in the dinner on February 7 (no funded by the organization): (Yes or No)
    – I will follow the sessions on February 7 and 8 by Streaming: (Yes or No)

Registration will be open until January 10, 2023. EXTENSION: January 20, 2023

Collaborators:

Days: 7 and 8 of February, 2023
Place: Barcelona

Reserve these dates! We will wait for you!

Collaborators:

Although acute stress can be beneficial and adaptive, chronic stress is thought to be detrimental to several health outcomes, including the stress response. Bullying, defined as a type of aggressive behavior that occurs in the school environment, has been identified as one of the main stress sources among children and adolescents. The association between bullying and cortisol levels, a indicator of chronic stress, has been explored in some studies, and findings were inconsistent.

The main objective of the study was to determine whether bullying, along with other school-related factors (i.e., problems with peers, school environment, and academic performance) could predict chronic stress in preadolescents. Authors also considered whether risk-taking behaviors function and sex may modify this association.

At the 11-year-old visit, a total of 659 children from Gipuzkoa and Sabadell were included. Cortisol concentrations were measured in hair strands of 3cm, to reflect the chronic stress of the past 3 months. Bullying experience in the past 2 months were estimated using the validated Olweus Bully Victim Questionnaire. Other environmental and behavioral variables, including school environment, problems with peers, risky decision making and academic achievement, were recorded using questionnaires at the 11-year-old visit.

The results suggest that being involved as a bully or a victim was related to higher cortisol levels and, higher cortisol concentration was associated with more risk-taking behavior. This is the first study showing the association of different roles that children may take in bullying with cortisol concentration. Authors say that the study “allows to gain a deeper understanding of the relationship between school stressors and neurophysiological function”. Besides, they plead for programs of prevention and intervention that “could modify individual physiological responses to stress and reduce the effects of stress on the health”.

Reference: Babarro I, Ibarluzea J, Theodorsson E, Fano E, Lebeña A, Guxens M, Sunyer J, Andiarena A. Hair cortisol as a biomarker of chronic stress in preadolescents: influence of school context and bullying. Child Neuropsychol. 2022 Aug 28:1-18. doi: 10.1080/09297049.2022.2115991. Epub ahead of print. PMID: 36036166.

Link to the scientific article: https://www.tandfonline.com/doi/full/10.1080/09297049.2022.2115991