Background: Previous studies investigating the association between PM2.5 exposure and fasting plasma glucose levels (FPGLs) are mostly limited to short- and mid-term PM2.5 exposure and lack adjustments for key confounders in adult research.
Objectives: Exploring the relationship between seven years long-term PM2.5 exposure and FPGLs in Chinese children and adolescents aged 6-17 years.
Methods: Between September 2013 and December 2013, 16,489 participants aged 6-17 years were recruited using a four-staged, stratified, cluster sampling strategy from 7 provinces, autonomous regions and municipalities of mainland China. A generalized linear mixed model (GLMM) was used to estimate the relationship between annual PM2.5 exposure (2007-2013) and FPGLs stratified by sex and one-year age increments. Sociodemographic characteristics, living with both parents, early-life factors, behaviours, and infection symptoms were gradually adjusted from the crude model to regression model 6, and BMI was adjusted for in model 7.
Results: The annual concentration of PM2.5 was 56.23 (±12.99) μg/m3. The mean FPGLs in the 8551 boys (4.75 mmol/L ± 0.52) was significantly higher than that in the 8194 girls (4.63 mmol/L ± 0.48) (P < 0.0001). In model 6, for every 10 μg/m3 increase in PM2.5 exposure, the FPGLs in boys and girls increased by 0.048 (95% CIs 0.031 to 0.065) mmol/L (P < 0.0001) and 0.054 (95% CIs 0.039 to 0.069) mmol/L (P < 0.0001), respectively. The FPGLs were significantly positively associated with long-term PM2.5 exposure at the ages of 12, 15 and 16 years in both the boys and girls and exhibited age differences in model 7. The prevalence of impaired fasting plasma glucose (IFP) and diabetes decreased by 0.8% when the exposure concentration of PM2.5 was reduced by 10 μg/m3 in model 6, which assessed the negative effects of PM2.5 exposure and revealed that 1,298,920 children and adolescents could have been protected from IFP and diabetes in 2013 in China.
Conclusions: Long-term PM2.5 exposure may be an independent risk factor of elevated FPGLs. The adverse effect of PM2.5 exposure on FPGLs in children and adolescents could appear after 10 years of cumulative exposure. The precise intervention time was revealed as approximately 12 and 11 years in boys and girls, respectively. There are great public health implications associated with early prevention strategies for the eradication of the negative effects of long-term exposure to PM2.5 on FPGLs.
Keywords: Adolescents; Air pollution; Diabetes; Fasting plasma glucose; PM(2.5); Prevention time clues.
Copyright © 2019. Published by Elsevier B.V.