Christopher Faulk, Ph.D.; Brisa N. Sánchez, Ph.D.; Karen E. Peterson, Sc.D.; Dana C. Dolinoy, Ph.D.
University of Michigan
NIEHS Grants T32ES007062, K99ES02222, P20ES018171
NIEHS grantees report that perinatal lead exposure is associated with obesity, even at low levels. The data supports the hypothesis that toxicant exposures in the womb can contribute to higher risk for obesity later in life.
To assess the effects of prenatal and early-life exposure to multiple physiologically relevant levels of lead, groups of female mice were exposed to lead in drinking water for two weeks before mating and then throughout pregnancy and nursing. The mice were exposed to lead concentrations of 2.1 parts per million (ppm), 16 ppm, and 32 ppm, and a control group received no lead exposure. For the exposed groups, maternal blood lead levels tested at weaning were 4.1 (±1.3) micrograms per deciliter (μg/dL), 25.1 (±7.3) μg/dL and 32.1 (±11.4) μg/dL, respectively.
Both females and males with perinatal lead exposure showed increased energy expenditure compared to controls (p<0.0001 for both), and exposed female offspring had higher average activity compared to controls throughout their life. Overall, food consumption increased in exposed males and females (and p<0.0001 and p<0.0008, respectively), with significant linear trends at 6 months in males (p<0.01) and 9 months in females (p=0.01). The researchers also observed significant increases in body weight for males that experienced medium and high exposures (p=0.001 and p=0.006) and significantly increased insulin response in males with medium levels of exposure (p<0.05).
The researchers conclude that perinatal lead exposure at maternal blood lead levels between 4.1 and 32 µg/dL is associated with increases in food consumption in offspring that bring about increased body weight as well as changes in energy expenditure, activity, glucose tolerance, and insulin response.
Citation: Faulk C, Barks A, Sánchez BN, Zhang Z, Anderson OS, Peterson KE, Dolinoy DC. 2014. Perinatal lead (Pb) exposure results in sex-specific effects on food intake, fat, weight, and insulin response across the murine life-course. PLoS One 9(8):e104273.