title: Air pollution exposure and abnormal glucose tolerance during pregnancy: the project Viva cohort.
abstract: BACKGROUND
  Exposure to fine particulate matter (PM with diameter ≤ 2.5 μm; PM2.5) has been linked to type 2 diabetes mellitus, but associations with hyperglycemia in pregnancy have not been well studied.
  
  
  METHODS
  We studied Boston, Massachusetts-area pregnant women without known diabetes. We identified impaired glucose tolerance (IGT) and gestational diabetes mellitus (GDM) during pregnancy from clinical glucose tolerance tests at median 28.1 weeks gestation. We used residential addresses to estimate second-trimester PM2.5 and black carbon exposure via a central monitoring site and spatiotemporal models. We estimated residential traffic density and roadway proximity as surrogates for exposure to traffic-related air pollution. We performed multinomial logistic regression analyses adjusted for sociodemographic covariates, and used multiple imputation to account for missing data.
  
  
  RESULTS
  Of 2,093 women, 65 (3%) had IGT and 118 (6%) had GDM. Second-trimester spatiotemporal exposures ranged from 8.5 to 15.9 μg/m3 for PM2.5 and from 0.1 to 1.7 μg/m3 for black carbon. Traffic density was 0-30,860 vehicles/day × length of road (kilometers) within 100 m; 281 (13%) women lived ≤ 200 m from a major road. The prevalence of IGT was elevated in the highest (vs. lowest) quartile of exposure to spatiotemporal PM2.5 [odds ratio (OR) = 2.63; 95% CI: 1.15, 6.01] and traffic density (OR = 2.66; 95% CI: 1.24, 5.71). IGT also was positively associated with other exposure measures, although associations were not statistically significant. No pollutant exposures were positively associated with GDM.
  
  
  CONCLUSIONS
  Greater exposure to PM2.5 and other traffic-related pollutants during pregnancy was associated with IGT but not GDM. Air pollution may contribute to abnormal glycemia in pregnancy.
authors: Division of Endocrinology, Boston Children's Hospital, Boston, Massachusetts, USA.
authors: Abby F
authors: AF
authors: Fleisch
authors: Diane R
authors: DR
authors: Gold
authors: Sheryl L
authors: SL
authors: Rifas-Shiman
authors: Petros
authors: P
authors: Koutrakis
authors: Joel D
authors: JD
authors: Schwartz
authors: Itai
authors: I
authors: Kloog
authors: Steven
authors: S
authors: Melly
authors: Brent A
authors: BA
authors: Coull
authors: Antonella
authors: A
authors: Zanobetti
authors: Matthew W
authors: MW
authors: Gillman
authors: Emily
authors: E
authors: Oken
mesh_terms: D000328:Adult; D000393:Air Pollutants / Q000633:toxicity; D000397:Air Pollution / Q000009:adverse effects*; D016640:Diabetes, Gestational / Q000139:chemically induced; D004784:Environmental Monitoring; D005260:Female; D018149:Glucose Intolerance / Q000139:chemically induced*; D006801:Humans; D052638:Particulate Matter / Q000633:toxicity; D011247:Pregnancy; D001335:Vehicle Emissions / Q000633:toxicity
chemical_list: D000393:Air Pollutants; D052638:Particulate Matter; D001335:Vehicle Emissions