Table 7.
Effect of PM2.5 Exposure on HRV at Different Daily Flavonoid Intake Levels, Normative Aging Study, 2000–2011 (N=513)
| Flavonoid Intake | % Change* | 95% CI | P Value |
|---|---|---|---|
| HR | |||
| Midpoint of Q1 (128 mg/d) | 0.06 | −1.65 to 1.80 | 0.95 |
| Midpoint of Q2 (228 mg/d) | 0.00 | −1.51 to 1.53 | 1.00 |
| Midpoint of Q3 (370 mg/d) | −0.09 | −1.45 to 1.30 | 0.90 |
| Midpoint of Q4 (673 mg/d) | −0.26 | −1.98 to 1.48 | 0.76 |
| P for interaction | 0.76 | ||
| rMSSD | |||
| Midpoint of Q1 (128 mg/d) | −5.32 | −16.91 to 7.88 | 0.41 |
| Midpoint of Q2 (228 mg/d) | −4.94 | −15.25 to 6.62 | 0.39 |
| Midpoint of Q3 (370 mg/d) | −4.41 | −13.82 to 6.03 | 0.39 |
| Midpoint of Q4 (673 mg/d) | −3.25 | −15.28 to 10.49 | 0.63 |
| P for interaction | 0.79 | ||
| SDNN | |||
| Midpoint of Q1 (128 mg/d) | −6.14 | −14.57 to 3.11 | 0.19 |
| Midpoint of Q2 (228 mg/d) | −5.22 | −12.74 to 2.95 | 0.20 |
| Midpoint of Q3 (370 mg/d) | −3.89 | −10.81 to 3.56 | 0.30 |
| Midpoint of Q4 (673 mg/d) | −1.00 | −10.03 to 8.93 | 0.84 |
| P for interaction | 0.37 | ||
| LF | |||
| Midpoint of Q1 (128 mg/d) | −16.48 | −31.35 to 1.61 | 0.07 |
| Midpoint of Q2 (228 mg/d) | −12.55 | −26.37 to 3.87 | 0.13 |
| Midpoint of Q3 (370 mg/d) | −6.65 | −20.07 to 9.03 | 0.39 |
| Midpoint of Q4 (673 mg/d) | 7.31 | −12.16 to 31.11 | 0.49 |
| P for interaction | 0.05 | ||
| HF | |||
| Midpoint of Q1 (128 mg/d) | −10.42 | −28.69 to 12.54 | 0.34 |
| Midpoint of Q2 (228 mg/d) | −7.78 | −24.49 to 12.63 | 0.43 |
| Midpoint of Q3 (370 mg/d) | −3.89 | −19.74 to 15.09 | 0.67 |
| Midpoint of Q4 (673 mg/d) | 4.96 | −16.93 to 32.63 | 0.68 |
| P for interaction | 0.28 |
Results were adjusted for age; body mass index; total caloric intake; total vitamin C intake; total fiber intake; fasting glucose level; hypertension; smoking status; alcohol consumption; physical exercise; household income; the use of calcium channel blocker, β‐blocker, and angiotensin‐converting enzyme inhibitor; room temperature; outdoor apparent temperature; season; weekday; and visit date. 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); PM2.5, particulate matter with aerodynamic diameter <2.5 μm; Q1, Q2, Q3, and Q4 indicate the first, second, third, and fourth quartile; rMSSD, root mean square of successive differences; SDNN, standard deviation of normal‐to‐normal intervals.
The percent change in HRV per 10 μg/m3 increase in PM2.5 concentration.