Table 11.

Effect Modification by Position‐Specific TLR2 Methylation Level on the Association Between PM_2.5 Exposure and HRV, Adjusted for Cell Types

Position	% Change*, Original Model, N=500*	% Change*, Adjusted for Cell Types, N=498*
HR
1	0.05	0.03
2	0.17	0.26
3	0.53	0.60
4	0.36	0.44
5	0.83*	0.85*
rMSSD
1	−10.07*	−9.64*
2	−5.60*	−6.10*
3	−7.35*	−7.45*
4	−6.55*	−6.48*
5	−8.29*	−7.88*
SDNN
1	−5.34*	−5.01*
2	−0.34	−0.72
3	−3.87*	−3.97*
4	−1.62	−1.56
5	−4.58*	−4.21*
LF
1	−2.45	−1.65
2	1.75	1.39
3	−8.77*	−8.90*
4	−1.22	−1.23
5	−7.09	−6.46
HF
1	−9.72	−8.72
2	−5.31	−6.35
3	−11.01*	−11.31*
4	−7.63	−7.74
5	−14.20*	−13.33*

HF indicates high‐frequency power (0.15 to 0.4 Hz); HR, heart rate; HRV, heart rate variability; LF, low‐frequency power (0.04 to 0.15 Hz); PM_2.5, particulate matter with aerodynamic diameter <2.5 μm; rMSSD, root mean square of successive differences; SDNN, standard deviation of normal‐to‐normal intervals; TLR2, Toll‐like receptor 2.

^*Results were adjusted for age, body mass index, fasting glucose level, hypertension, smoking status, alcohol consumption, physical exercise, household income, medication use (β‐blocker, calcium channel blocker, angiotensin‐converting enzyme inhibitor), room temperature, outdoor apparent temperature, season, weekday, and visit date.

^*Results were adjusted for all covariates in the original model and the percentage of neutrophil and lymphocyte.

^*P≤0.05, statistically significant.

^*The additional percent change in HRV associated with 10 μg/m³ increase in PM_2.5 concentration, compared to participants with one %5mC lower TLR2 methylation level.