November 01, 2017
2 min read

Exposure to air pollution in utero linked to accelerated biological aging

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Newborns exposed to greater amounts of air pollution while in utero are more likely to have shorter telomere length, a determining factor for many age-related diseases and mortality, according to a study published in JAMA Pediatrics.

“The ability of particulate matter air pollution to generate reactive oxygen species has led to the hypothesis that telomere attrition is influenced by air pollution exposure,” Dries S. Martens, MSc, from the Centre for Environmental Sciences at Hasselt University, and colleagues wrote. “Because telomere length is highly variable at birth, potential determinants, such as newborn sex, paternal age, maternal prepregnancy body mass index, maternal stress, maternal educational level, maternal smoking during pregnancy and maternal residential proximity to a major road, have recently been explored for explaining this phenomenon.”

To examine the connection between in utero exposure to particulate matter (PM) with telomere length in newborns as represented by cord blood and placental telomere length, the researchers conducted a study involving a prospective birth cohort composed of 730 pairs of mothers and newborns. All pairs were recruited in Flanders, Belgium between February 2010 and December 2014. Infants were full term (at least 37 weeks’ gestation) and had data available on cord blood and placental telomere lengths.

The researchers measured cord blood and placental tissue relative telomere length to determine whether they were significantly related — or inversely related to — exposure to PM with an aerodynamic diameter no greater than 2.5 µm (PM2.5) during midgestation.

Of the 641 newborns included, a significant inverse relationship was observed regarding PM2.5 at midgestation (weeks 12-25 for cord blood and weeks 15-27 for placenta). Blood leukocyte telomeres were 8.8% shorter in infants exposed to a 5-µg/m3 increment of PM2.5 (95% CI, 14.1% to 3.1%) as well as 13.2% shorter placental telomere length (95% CI, -19.3% to 6.7%).

Martens and colleagues controlled all connections observed in the study, including delivery date, gestational age, maternal BMI, maternal and paternal age, sex and ethnicity of the newborn, season of delivery, parity, maternal smoking status, maternal education level, pregnancy complications and ambient temperature.

“Parental telomere length may be a determinant of the initial telomere length of the next generation,” Martens and colleagues wrote. “Because parents exposed to PM2.5 may have shorter telomeres, the association between PM2.5 exposure and newborn telomere length may be mediated by parental telomere lengths.” – by Katherine Bortz


Disclosure: The author reports no relevant financial disclosures.