Objective: Long-term exposure to traffic-related air pollution has been linked to increased risk of obesity and diabetes and may be associated with higher serum levels of the adipokine leptin, but this hypothesis has not been previously evaluated in humans.
Methods: In a cohort of older adults, we estimated the association between serum leptin concentrations and two markers of long-term exposure to traffic pollution, adjusting for participant characteristics, temporal trends, socioeconomic factors, and medical history.
Results: An interquartile range increase (0.11 μg/m) in annual mean residential black carbon was associated with 12% (95% confidence interval: 3%, 22%) higher leptin levels. Leptin levels were not associated with residential distance to major roadway.
Conclusions: If confirmed, these findings support the emerging evidence suggesting that certain sources of traffic pollution may be associated with adverse cardiometabolic effects.