Interactive and Additive Influences of Gender, BMI and Apolipoprotein 4 on Cognition in Children Chronically Exposed to High Concentrations of PM2.5 and Ozone. APOE 4 Females Are at Highest Risk in Mexico City

Environ Res. 2016 Oct;150:411-422. doi: 10.1016/j.envres.2016.06.026. Epub 2016 Jul 2.

Abstract

Children's air pollution exposures are associated with systemic and brain inflammation and the early hallmarks of Alzheimer's disease (AD). The Apolipoprotein E (APOE) 4 allele is the most prevalent genetic risk for AD, with higher risk for women. We assessed whether gender, BMI, APOE and metabolic variables in healthy children with high exposures to ozone and fine particulate matter (PM2.5) influence cognition. The Wechsler Intelligence Scale for Children (WISC-R) was administered to 105 Mexico City children (12.32±5.4 years, 69 APOE 3/3 and 36 APOE 3/4). APOE 4v 3 children showed decrements on attention and short-term memory subscales, and below-average scores in Verbal, Performance and Full Scale IQ. APOE 4 females had higher BMI and females with normal BMI between 75-94% percentiles had the highest deficits in Total IQ, Performance IQ, Digit Span, Picture Arrangement, Block Design and Object Assembly. Fasting glucose was significantly higher in APOE 4 children p=0.006, while Gender was the main variable accounting for the difference in insulin, HOMA-IR and leptin (p<.05). Gender, BMI and APOE influence children's cognitive responses to air pollution and glucose is likely a key player. APOE 4 heterozygous females with >75% to <94% BMI percentiles are at the highest risk of severe cognitive deficits (1.5-2SD from average IQ). Young female results highlight the urgent need for gender-targeted health programmes to improve cognitive responses. Multidisciplinary intervention strategies could provide paths for prevention or amelioration of female air pollution targeted cognitive deficits and possible long-term AD progression.

Keywords: Air pollution; Alzheimer; Apoe; Children; Cognition deficits; Females; Fine particulate matter; Gender; IQ; Mexico city; Neuroprevention; Ozone; WISC(R).

MeSH terms

  • Adolescent
  • Air Pollutants / analysis*
  • Apolipoprotein E4 / genetics*
  • Blood Glucose / analysis
  • Body Mass Index
  • Child
  • Cities
  • Cognition*
  • Environmental Exposure / adverse effects
  • Environmental Exposure / analysis
  • Female
  • Humans
  • Male
  • Mexico
  • Ozone / analysis*
  • Particulate Matter / analysis*
  • Wechsler Scales

Substances

  • Air Pollutants
  • Apolipoprotein E4
  • Blood Glucose
  • Particulate Matter
  • Ozone