No Adverse Effect of Outdoor Air Pollution on HbA1c in Children and Young Adults With Type 1 Diabetes

Int J Hyg Environ Health. 2016 Jul;219(4-5):349-55. doi: 10.1016/j.ijheh.2016.02.002. Epub 2016 Feb 15.


Background: Evidence is growing that air pollutants deteriorate glucose metabolism and insulin sensitivity by oxidative stress and inflammation. This might affect HbA1c levels and insulin requirements in type 1 diabetes. There are no data available on this association.

Methods: Air pollution values of respirable particulate matter (PM10), nitrogen dioxides (NO2), and accumulated ozone (O3-AOT40) were obtained from the federal environmental agency (Umweltbundesamt II) and assigned to place of residence of 840 participants from a nation-wide population-based type 1 diabetes registry (German Diabetes Center, Düsseldorf, Germany). Information on HbA1c, social status, treatment and co-morbidities was collected by self-administered questionnaires. Complete information was available for 771 patients aged 11-21 years at the time of study.

Results: In linear regression models, no adverse effects of air pollutants (PM10, NO2 or O3-AOT40 on HbA1c level were found, but O3-AOT40 was inversely associated with HbA1c (mmol/mol) in the crude (estimate per IQR: -1.86; 95% CI: (-3.27; -0.44); p=0.01) and the best model adjusting for lifestyle, socioeconomic factors, clinical information, and season (-1.50; (-2.82; -0.17); 0.034). After adding area of residency as random effect to the crude and the best model, the association was no longer significant (-1.64; (-3.84; 0.56); 0.14); (-1.56; (-3.67; 0.55); 0.14). Adjustment for further possible confounders did not affect the estimates seriously. None of the pollutants was associated with insulin dose (IU/kg body weight).

Conclusions: Investigated pollutants had no adverse effect on metabolic control in children and young adults with type 1 diabetes in this cross-sectional study. The weak inverse association of accumulated ozone with HbA1c might be due to confounding by regional characteristics or regional aspects of care.

Keywords: Air pollutants; Child; Glycosylated hemoglobin A; Insulin; Type 1 diabetes mellitus; Young adult.

MeSH terms

  • Adolescent
  • Adult
  • Air Pollutants / analysis
  • Air Pollution / analysis*
  • Child
  • Diabetes Mellitus, Type 1 / blood*
  • Diabetes Mellitus, Type 1 / epidemiology
  • Female
  • Germany / epidemiology
  • Glycated Hemoglobin A / analysis*
  • Humans
  • Male
  • Nitrogen Dioxide / analysis
  • Ozone / analysis
  • Particulate Matter / analysis
  • Young Adult


  • Air Pollutants
  • Glycated Hemoglobin A
  • Particulate Matter
  • hemoglobin A1c protein, human
  • Ozone
  • Nitrogen Dioxide