Biologic and epigenetic impact of commuting to work by car or using public transportation: A case–control study

Abstract Background and aims Commuting by public transportation (PT) entails more physical activity and energy expenditure than by cars, but its biologic consequences are unknown. Methods In 2009–2010, we randomly sampled New York adults, usually commuting either by car (n = 79) or PT (n = 101). Measures comprised diet and physical activity questionnaires, weight and height, white blood cell (WBC) count, C reactive protein, (CRP) gene-specific methylation ( IL-6 ), and global genomic DNA methylation (LINE-1 methylation). Results Compared to the 101 PT commuters, the 79 car drivers were about 9 years older, 2 kg/m2 heavier, more often non-Hispanic whites, and ate more fruits and more meats. The 2005 guidelines for physical activity were met by more car drivers than PT users (78.5% vs. 65.0%). There were no differences in median levels of CRP (car vs. PT: 0.6 vs. 0.5 mg/dl), mean levels of WBC (car vs. PT: 6.7 vs. 6.5 cells/mm3 ), LINE-1 methylation (car vs. PT: 78.0% vs. 78.3%), and promoter methylation of IL-6 (car vs. PT: 56.1% vs. 58.0%). Conclusions PT users were younger and lighter than car drivers, but their commute mode did not translate into a lower inflammatory response or a higher DNA methylation, maybe because, overall, car drivers were more physically active.