Table 3

Main effect of PM2.5 (mg/m3) on acceleration capacity (AC; ms) and deceleration capacity (DC; ms) without adjustment for hourly pre-exposures from the linear mixed effect response-lagged models with 48 participants

Parameter(95% CI)(95% CI)
 No lag1.46 (1.00 to 1.92)−1.00 (−0.53 to −1.46)
 1 h lag†0.73 (0.26 to 1.20)−0.40 (0.08 to −0.87)
 2 h lag†−0.29 (−0.83 to 0.24)0.65 (1.22 to 0.07)
 3 h lag†−0.34 (−0.92 to 0.25)0.52 (1.15 to −0.12)
  • Bold values indicate significant associations (p<0.05). Models are adjusted for age, smoker status, actively smoking, secondhand smoke exposure, time of day and season of ECG reading, and baseline AC or DC.

  • *AC is measured on a negative scale; therefore, a 1 mg/m3 increase in PM2.5 results in a decrease in AC by 1.46 ms (on a negative scale) for the association without any lag.

  • †Lagged models adjust for exposure time points before the lags. For example, a 1 hour lag model also adjusts for PM2.5 measurements in the preceding hour before the exposure time point of interest.