Perteklinis ekrano laikas, susijęs su ankstesniu brendimu


Vaikų išmaniojo telefono švytėjimas

Kuo ilgiau ekspozicija, tuo anksčiau prasideda brendimas.

Tyrimas parodė, kad mėlyna šviesa taip pat gali pakeisti hormonų lygį.

Remiantis žiurkių tyrimo, pristatyto 60-ajame kasmetiniame Europos vaikų endokrinologijos draugijos susitikime, rezultatais, reguliarus mėlynos šviesos poveikis planšetiniuose kompiuteriuose ir išmaniuosiuose telefonuose gali pakeisti hormonų lygį ir padidinti ankstyvo brendimo riziką. Ilgesnis mėlynos šviesos poveikis buvo susijęs su ankstyvu žiurkių patelių brendimu, kurios taip pat turėjo mažesnį melatonino kiekį, didesnį tam tikrų reprodukcinių hormonų kiekį ir fizinius kiaušidžių pokyčius. Mėlyną šviesą skleidžiančių mobiliųjų įrenginių naudojimas jau buvo susijęs su sutrikusiu vaikų miego režimu, tačiau dabartiniai rezultatai rodo, kad gali kilti papildomų pavojų vaikystės vystymuisi ir būsimam vaisingumui.

Mėlyną šviesą skleidžiantys prietaisai, tokie kaip planšetiniai kompiuteriai ir išmanieji telefonai, anksčiau buvo siejami su pablogėjusia vaikų ir suaugusiųjų miego kokybe. Manoma, kad taip atsitinka todėl, kad mėlyna šviesa trukdo vakare padidėti hormono melatonino, kuris paruošia mūsų kūną poilsiui ir miegui, kiekiui. Melatonino kiekis paprastai būna didesnis prieš brendimą nei per visą brendimą, o tai, manoma, turi įtakos brendimo pradžiai. Brendimas yra sudėtingas procesas, susijęs su kelių kūno sistemų ir hormonų koordinavimu.

Pastaraisiais metais keli tyrimai parodė, kad mergaičių ankstyvas brendimas padaugėjo, ypač[{” attribute=””>COVID-19 pandemic. The link between blue light exposure and reduced melatonin levels suggests that increased screen time, such as during the pandemic restrictions, may be playing a role in this reported increase. However, it is very difficult to assess this in children.

In this study, Dr. Aylin Kilinç Uğurlu and colleagues in Ankara, Turkey, used a rat model to investigate the effects of blue light exposure on reproductive hormone levels and the time of puberty onset. Female rats were divided into three groups of six and exposed to either a normal light cycle, 6 hours, or 12 hours of blue light. The first signs of puberty occurred significantly earlier in both groups exposed to blue light, and the longer the duration of exposure, the earlier the onset of puberty. Rats exposed to blue light also had reduced melatonin levels and elevated levels of specific reproductive hormones (oestradiol and luteinizing hormone), as well as physical changes in their ovarian tissue, all consistent with puberty onset. At the 12 hours of exposure, rats also showed some signs of cell damage and inflammation in their ovaries.

Dr. Aylin Kilinç Uğurlu comments, “We have found that blue light exposure, sufficient to alter melatonin levels, is also able to alter reproductive hormone levels and cause earlier puberty onset in our rat model. In addition, the longer the exposure, the earlier the onset.”

Although Dr. Aylin Kilinç Uğurlu, cautions, “As this a rat study, we can’t be sure that these findings would be replicated in children but these data suggest that blue light exposure could be considered as a risk factor for earlier puberty onset.”

It is difficult to mimic blue light exposure equivalent to a child’s tablet use in rats but the time-point of puberty in rats is roughly equivalent to that of humans if adjusted for rats’ lower life expectancy. The hormonal and ovulation changes that occur during pre-puberty and puberty in female rats are also comparable to humans. So, despite the study limitations, these findings support further investigation of the potential health impacts of blue light exposure on hormone levels and puberty onset in children.

The team plans to investigate the cell damage and inflammatory effects detected after longer blue light exposure since this could have long-term impacts on reproductive health and fertility. They will also assess whether the use of blue light minimizing ‘night light’ mobile device features can reduce the effects observed in the rat model.

Dr. Aylin Kilinç Uğurlu adds, “Although not conclusive, we would advise that the use of blue light emitting devices should be minimized in pre-pubertal children, especially in the evening when exposure may have the most hormone-altering effects.”

Reference: “Blue Light Exposure and Exposure Duration Effects on Rats’ Puberty Process” by Aylin Kılınç Uğurlu, Aysun Bideci, Ayşe Mürşide Demirel, Gülnur Take Kaplanoğlu, Duygu Dayanır, Özlem Gülbahar, Tuba Saadet Deveci Bulut, Esra Döğer and M. Orhun Çamurdan, 16 September 2022, 60th Annual European Society for Paediatric Endocrinology Meeting.

Abstract

Introduction: In the last 10 years, blue light (BL) sources such as tablets and phones has increased in every age group. Especially due to the Covid-19 pandemic, screen exposure has also increased in childhood. However, the effects of BL exposure in the puberty process aren’t clear. We aimed to examine the effect of BL exposure and exposure time on puberty.

Methods: Immature eighteen 21-day-old female Sprague Dawley rats were divided into three groups consisting of six rats in each group: Control Group (CG), Experiment Group-1 (EG-1), Experiment Group-2 (EG-2). CG rats were maintained under standard conditions with 12/12-hour light-dark cycles . The rats of EG-1 and EG-2 were exposed to BL (450-470 nm / irradiance level 0.03 uW/cm2) for 6 hours and 12 hours, respectively. Rats were exposed to BL until the first signs of puberty and then they were euthanasiad. Serum FSH, LH, Estrodiol, testosterone, DHEA-S, leptin, melatonin were studied by ELISA method. Ovaries and uterus were dissected for histomorphological examination

Results: The medians of the pubertal entry days of the CG, EG-1, and EG-2 were 38th, 32nd, and 30th  days, respectively. (p: 0.001) A negative correlation was found between the puberty entry day of the groups and the exposure to BL and the duration of exposure. (r:-0.910, p<0.001)

The FSH, testosterone, DHEA-S, leptin levels of all groups were similar. (p> 0.05) However, LH and estradiol levels of EG-1 were higher compared CG. (p:0.027) There was a negative correlation between BL exposure, exposure time and melatonin levels (ro:- 0.537, p: 0.048)  Ovarian tissue was compatible with pubertal period in all groups. As the BL exposure time increased, capillary dilatation and edema in the over tissue increased. Prolonged exposure caused polycystic over like (PCO-like) morphological changes and apoptosis in granulosa cells.

Conclusion: Our study is the first to show the effects of BL exposure on puberty. In our study, we showed that exposure of BL and the duration of exposure lead to early puberty. PCO-like, inflammation and apoptosis were detected in the ovaries with the increase in BL exposure time.

There are studies showing that there is an increase in cases with precocious puberty and acceleration in puberty pace during the closure period compared to the pre-pandemic period. In our study, we experimentally demonstrated the effects of BL exposure on puberty and the relationship between increased exposure time.