Table 4.
Adjusted Percent Change in Heart Rate Variability Indices Per Interquartile-Range Increase in Prior 1-Hour, 4-Hour, and 12-Hour Moving Average Exposure to Ambient Pollutants in Single-Pollutant, Mixed-Effects Modelsa, Beijing, China, 2007–2008
| Heart Rate Variability Index | PM2.5 |
Black Carbon |
Nitrogen Dioxide |
Sulfur Dioxide |
Carbon Monoxide |
Ozone |
||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Effect | 95% CI | Effect | 95% CI | Effect | 95% CI | Effect | 95% CI | Effect | 95% CI | Effect | 95% CI | |
| SDNN | ||||||||||||
| 1-hour | −3.5 | −5.6, −1.4 | −3.3 | −5.7, −0.8 | −1.9 | −3.4, −0.3 | 0.5 | −0.6, 1.6 | −0.3 | −2.5, 2.0 | −1.1 | −3.1, 0.8 |
| 4-hour | −4.2 | −6.4, −1.9 | −4.2 | −6.6, −1.8 | −3.9 | −5.7, −2.2 | 0.6 | −0.4, 1.5 | −2.7 | −5.3, 0.4 | −0.5 | −2.5, 1.5 |
| 12-hour | −4.7 | −7.6, −1.7 | −4.2 | −7.5, −0.8 | −3.6 | −5.5, −1.6 | −0.8 | −2.5, 0.9 | −2.2 | −6.2, 2.1 | 0.8 | −1.8, 3.5 |
| r-MSSD | ||||||||||||
| 1-hour | −4.2 | −7.5, −0.8 | −4.2 | −8.4, 0.1 | 1.4 | −1.1, 3.9 | 1.4 | 0.0, 2.8 | −2.5 | −5.6, 0.5 | −2.6 | −5.6, 0.5 |
| 4-hour | −5.5 | −9.4, −1.5 | −4.1 | −8.4, 0.4 | −2.2 | −5.7, 1.5 | 1.0 | −0.5, 2.5 | −4.0 | −7.5, −0.4 | −4.0 | −7.5, −0.4 |
| 12-hour | −10.7 | −15.5, −5.7 | −5.5 | −11.8, 1.3 | −2.2 | −6.1, 2.0 | 2.6 | −1.1, 6.5 | −3.0 | −7.6, 1.9 | −3.0 | −7.6, 1.9 |
| Low frequency | ||||||||||||
| 1-hour | −8.8 | −14.0, −3.4 | −9.1 | −15.0, −2.7 | −5.4 | −9.3, −1.4 | 1.1 | −1.7, 4.0 | 0.2 | −4.8, 5.5 | 0.2 | −4.8, 5.5 |
| 4-hour | −9.9 | −15.4, −4.1 | −10.5 | −16.3, −4.4 | −8.9 | −13.2, −4.3 | 0.7 | −1.8, 3.2 | −2.4 | −7.4, 2.9 | −2.4 | −7.4, 2.9 |
| 12-hour | −14.2 | −21.0, −6.8 | −9.3 | −17.6, −0.2 | −7.9 | −12.8, −2.8 | −4.8 | −9.1, −0.3 | −6.6 | −12.8, 0.0 | −6.6 | −12.8, 0.0 |
| High frequency | ||||||||||||
| 1-hour | −9.3 | −15.2, −2.9 | −12.1 | −19.1, −4.6 | −3.5 | −8.2, 1.4 | 2.5 | −0.5, 5.7 | −2.3 | −8.1, 3.9 | −2.3 | −8.1, 3.9 |
| 4-hour | −8.4 | −15.2, −1.0 | −9.8 | −17.0, −2.1 | −5.1 | −11.0, 1.3 | 3.4 | 0.3, 6.5 | −6.0 | −12.1, 0.5 | −6.0 | −12.1, 0.5 |
| 12-hour | −16.3 | −24.3, −7.5 | −4.0 | −15.1, 8.6 | −3.7 | −10.4, 3.5 | 4.1 | −2.2, 10.9 | −8.7 | −16.4, -0.2 | −8.7 | −16.4, −0.2 |
Abbreviations: CI, confidence interval; PM2.5, particulate matter with an aerodynamic diameter less than 2.5 µm; r-MSSD, square root of the mean squared difference between adjacent normal-to-normal intervals; SDNN, standard deviation of the normal-to-normal intervals.
a Results were adjusted for age, body mass index, gender, time of day, day of the week, visit, temperature, and relative humidity.