Linear regression was used to estimate the difference and associated 95% confidence intervals. Because Akt inhibitor CRP levels did not follow a normal distribution, it was log-transformed in linear regression models. Last, we created case–PT pairs of participants matched on age (± 5 years) and gender and compared their differences in WBC, CRP, LINE-1 methylation and IL-6 methylation using paired-T tests. All statistical analyses were performed using SAS (version 9.1; SAS institute, Cary, NC). There were 79 car drivers and 101 PT users. Car drivers were older, had higher BMI, and included a greater proportion of males and non-Hispanic whites than

PT commuters (Table 1). Car drivers ate more fruits and more meats than PT users (p = 0.02 and 0.04 respectively, Table 2). We identified two dietary patterns in the study population: the prudent dietary pattern was characterized by high intakes of vegetables and fruits; and the western dietary pattern was characterized by high intakes of meats, grains and dairy products. Overall the two groups did not differ in the adherence to the two dietary patterns, either for the prudent or for the western diet (Table 3). Car drivers reported a higher level of light job activities and a lower level of sedentary activities than PT commuters (p = 0.007 and 0.004 respectively). Overall, car drivers had higher adherence to 2005 DGA for physical activity

than PT commuters (78.5% vs. 65.0%). However, after adjusting for age, gender, race/ethnicity and BMI, the difference in adherence to the 2005 DGA for physical activity became statistically insignificant HIF inhibitor review (difference: − 14.2%, 95%CI: − 29.0, 0.5) (Table 4). In Table 5, there were no differences in median level of CRP (car vs. PT: 0.6 vs. 0.5 mg/dl, difference in log-CRP: 0.2, 95%CI: − 0.2, 0.5) and mean level of WBC (car vs. PT: 6.7 vs. 6.5 cells/mm3, difference: − 0.4, 95%CI: − 0.9, 0.2). In Table 6, there were no differences in mean levels of LINE-1 methylation (car: 78.0%;

PT: 78.3%, difference: 0.2, 95%CI: − 0.5, 1.0), and IL-6 promoter methylation (car: 56.1%; PT: 58.0%, difference: 1.7, 95%CI: − 2.4, 5.8). Missing values in Table 6 are due to low DNA yield following extraction from the buffy or low quality also calls on pyrosequencing LINE-1 methylation or IL-6 promoter methylation. A total of 58 1-to-1, age-gender matched pairs comprising one PT commuter and one car commuter were formed. No statistically significant differences were found for WBC (difference = 0.07 cells/mm3, 95%CI: − 0.64, 0.77), CRP (difference = 0.03 mg/dl, 95%CI: − 0.67, 0.74), LINE-1 methylation (difference = − 0.07%, 95%CI: − 0.91, 0.77) and IL-6 methylation (difference = − 3.81%, 95%CI: − 10.15, 2.52) between pairs. There remained, however, an age difference of about 1 year (difference = 0.98 year, 95% CI: 0.58, 1.39) within pairs.