Changes in Body Mass Index (BMI) during adolescence play an important role in the association between air pollution exposure and insulin resistance, according to a new study led by investigators from the Keck School of Medicine of USC.
The study, published in JAMA Network Open, found that children who were exposed to higher levels of traffic-related air pollution—specifically nitrogen oxides—tended to have a higher BMI by age 13, and experienced rapid weight gain from adolescence to young adulthood. This, in turn, was linked to higher levels of insulin resistance in their mid-20s.
“We estimated about 42% of the relationship between early pollution exposure and insulin resistance can be explained by accelerated BMI growth trajectories—which describes how an individual’s BMI changes over time—and further contributes to insulin resistance, a key risk factor for type 2 diabetes,” says Fangqi Guo, Ph.D., MPH, postdoctoral scholar research associate in the Department of Population and Public Health Sciences at Keck School of Medicine, and lead author of the study.
“These findings held, even after accounting for other factors such as smoking, race/ethnicity, socioeconomic status, and parental history of diabetes,” says Guo. “Our discovery is especially important for families and children living in high-traffic urban areas who may already face other socioeconomic or health disparities,” says Guo.
Implications on metabolic health
With the rising incidence of type 2 diabetes and insulin resistance among young adults and children, the study’s findings uncover how the harmful effects of air pollution may contribute to long-term metabolic problems.
In this study, the team of researchers specifically explored nitrogen oxides (NOx) emitted into the air from motor vehicles, categorized as traffic-related air pollution. (TRAP). TRAP exposure has been associated with a higher risk of developing type 2 diabetes, but the underlying mechanism of this association has not been fully understood.
This study found that exposure to TRAP in childhood is associated with higher risk of insulin resistance in young adulthood, and the association may be partially explained by higher BMI and accelerated BMI growth from early adolescence into young adulthood.
The study included data from Meta-Air2, an ongoing substudy of the Southern California’s Children’s Health Study (CHS) and featured 282 participants enrolled in kindergarten or first grade in 2003, who were actively followed up until 2014. The study’s researchers initiated a follow-up study in 2023 where participants, now young adults, provided blood samples for metabolic biomarker testing.
“By identifying weight gain during adolescence as a key pathway between air pollution exposure and insulin resistance, our research underscores the importance of early interventions. These include promoting healthy lifestyle habits and weight management and improving air quality—in a bid to reduce the risk of chronic disease later in life,” says Guo. “Public health efforts that address both environmental exposures and childhood obesity could make a significant impact.”
More information:
Fangqi Guo et al, Childhood Exposure to Air Pollution, Body Mass Index Trajectories, and Insulin Resistance Among Young Adults, JAMA Network Open (2025). DOI: 10.1001/jamanetworkopen.2025.6431
Citation:
Changes in BMI during adolescence may explain link between air pollution exposure and insulin resistance (2025, May 20)
retrieved 20 May 2025
from https://medicalxpress.com/news/2025-05-bmi-adolescence-link-air-pollution.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no
part may be reproduced without the written permission. The content is provided for information purposes only.
Changes in Body Mass Index (BMI) during adolescence play an important role in the association between air pollution exposure and insulin resistance, according to a new study led by investigators from the Keck School of Medicine of USC. The study, published in JAMA Network Open, found that children who were exposed to higher levels of traffic-related air pollution—specifically nitrogen oxides—tended to have a higher BMI by age 13, and experienced rapid weight gain from adolescence to young adulthood. This, in turn, was linked to higher levels of insulin resistance in their mid-20s. “We estimated about 42% of the relationship between early pollution exposure and insulin resistance can be explained by accelerated BMI growth trajectories—which describes how an individual’s BMI changes over time—and further contributes to insulin resistance, a key risk factor for type 2 diabetes,” says Fangqi Guo, Ph.D., MPH, postdoctoral scholar research associate in the Department of Population and Public Health Sciences at Keck School of Medicine, and lead author of the study. “These findings held, even after accounting for other factors such as smoking, race/ethnicity, socioeconomic status, and parental history of diabetes,” says Guo. “Our discovery is especially important for families and children living in high-traffic urban areas who may already face other socioeconomic or health disparities,” says Guo. With the rising incidence of type 2 diabetes and insulin resistance among young adults and children, the study’s findings uncover how the harmful effects of air pollution may contribute to long-term metabolic problems. In this study, the team of researchers specifically explored nitrogen oxides (NOx) emitted into the air from motor vehicles, categorized as traffic-related air pollution. (TRAP). TRAP exposure has been associated with a higher risk of developing type 2 diabetes, but the underlying mechanism of this association has not been fully understood. This study found that exposure to TRAP in childhood is associated with higher risk of insulin resistance in young adulthood, and the association may be partially explained by higher BMI and accelerated BMI growth from early adolescence into young adulthood. The study included data from Meta-Air2, an ongoing substudy of the Southern California’s Children’s Health Study (CHS) and featured 282 participants enrolled in kindergarten or first grade in 2003, who were actively followed up until 2014. The study’s researchers initiated a follow-up study in 2023 where participants, now young adults, provided blood samples for metabolic biomarker testing. “By identifying weight gain during adolescence as a key pathway between air pollution exposure and insulin resistance, our research underscores the importance of early interventions. These include promoting healthy lifestyle habits and weight management and improving air quality—in a bid to reduce the risk of chronic disease later in life,” says Guo. “Public health efforts that address both environmental exposures and childhood obesity could make a significant impact.” More information: Citation: This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no
Implications on metabolic health
Fangqi Guo et al, Childhood Exposure to Air Pollution, Body Mass Index Trajectories, and Insulin Resistance Among Young Adults, JAMA Network Open (2025). DOI: 10.1001/jamanetworkopen.2025.6431
Changes in BMI during adolescence may explain link between air pollution exposure and insulin resistance (2025, May 20)
retrieved 20 May 2025
from https://medicalxpress.com/news/2025-05-bmi-adolescence-link-air-pollution.html
part may be reproduced without the written permission. The content is provided for information purposes only.
