GSTM1, GSTT1, and GSTP1 Polymorphisms and Associations Between Air Pollutants and Markers of Insulin Resistance in Elderly Koreans

Environ Health Perspect. 2012 Oct;120(10):1378-84. doi: 10.1289/ehp.1104406. Epub 2012 Jun 25.

Abstract

Background: Previous studies have suggested that diabetes mellitus (DM) is an outcome of exposure to air pollution, and metabolic detoxification genes affect air pollution-related outcomes.

Objectives: We evaluated associations between air pollutants and markers of insulin resistance (IR), an underlying mechanism of type 2 DM, and effect modification by GSTM1, GSTT1, and GSTP1 genotypes among elderly participants in the Korean Elderly Environmental Panel (KEEP) study.

Methods: We recruited 560 people ≥ 60 years of age and obtained blood samples from them up to three times between 2008 and 2010. For air pollution exposure, we used ambient air pollutant [i.e., particulate matter ≤ 10 µm in diameter (PM10), sulfur dioxide (SO2), ozone (O3), and nitrogen dioxide (NO2)] monitoring data. We measured levels of fasting glucose and insulin and derived the homeostatic model assessment (HOMA) index to assess IR. Mixed-effect models were used to estimate associations between air pollutants and IR indices on the same day or lagged up to 10 days prior, and effect modification by GSTM1, GSTT1, and GSTP1 genotypes.

Results: Interquartile range increases in PM10, O3, and NO2 were significantly associated with IR indices, depending on the lag period. Associations were stronger among participants with a history of DM and among those with GSTM1-null, GSTT1-null, and GSTP1 AG or GG genotypes.

Conclusions: Our results suggest that PM10, O3, and NO2 may increase IR in the elderly, and that GSTM1-null, GSTT1-null, and GSTP1 AG or GG genotypes may increase susceptibility to potential effects of ambient air pollutants on IR.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aged, 80 and over
  • Air Pollutants / toxicity*
  • Biomarkers
  • Blood Glucose / analysis*
  • Diabetes Mellitus / chemically induced
  • Diabetes Mellitus / epidemiology*
  • Diabetes Mellitus / genetics
  • Environmental Exposure*
  • Environmental Monitoring
  • Fasting
  • Female
  • Glutathione S-Transferase pi / genetics
  • Glutathione S-Transferase pi / metabolism
  • Glutathione Transferase / genetics*
  • Glutathione Transferase / metabolism
  • Humans
  • Insulin / blood*
  • Insulin Resistance*
  • Male
  • Middle Aged
  • Multiplex Polymerase Chain Reaction
  • Nitrogen Dioxide / toxicity
  • Ozone / toxicity
  • Particulate Matter / toxicity
  • Polymorphism, Genetic*
  • Radioimmunoassay
  • Republic of Korea / epidemiology
  • Sulfur Dioxide / toxicity

Substances

  • Air Pollutants
  • Biomarkers
  • Blood Glucose
  • Insulin
  • Particulate Matter
  • Sulfur Dioxide
  • Ozone
  • glutathione S-transferase T1
  • GSTP1 protein, human
  • Glutathione S-Transferase pi
  • Glutathione Transferase
  • glutathione S-transferase M1
  • Nitrogen Dioxide