The relationship between long-term exposure to PM and fasting plasma glucose levels in Chinese children and adolescents aged 6-17 years: A national cross-sectional study.

BACKGROUND

Previous studies investigating the association between PM exposure and fasting plasma glucose levels (FPGLs) are mostly limited to short- and mid-term PM exposure and lack adjustments for key confounders in adult research.

OBJECTIVES

Exploring the relationship between seven years long-term PM 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 PM 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 PM was 56.23 (±12.99) μg/m. 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 PM 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 PM 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 PM was reduced by 10 μg/m in model 6, which assessed the negative effects of PM 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 PM exposure may be an independent risk factor of elevated FPGLs. The adverse effect of PM 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 PM on FPGLs.