Table 6.
Percent difference (95% CI) in three arterial stiffness outcomes per 10-μg/m3 increment in 2001 PM exposure under various covariate adjustment schemes, stratified by study site: MESA, 2000–2002.
| YM
|
C1 |
C2 |
||||
|---|---|---|---|---|---|---|
| Outcome/covariates | PM10 | PM2.5 | PM10 | PM2.5 | PM10 | PM2.5 |
| New York (n = 575)
| ||||||
| PM (weather/season only)a | −0.1 (−0.4 to 0.2) | −0.9 (−2.9 to 1.1) | −0.1 (−0.4 to 0.2) | −0.9 (−2.9 to 1.1) | −0.4 (−0.9 to 0.1) | 0.6 (−2.8 to 4.2) |
| Add age, sex, race | 0.0 (−0.3 to 0.2) | −0.4 (−2.3 to 1.5) | 0.0 (−0.3 to 0.2) | −0.4 (−2.3 to 1.5) | −0.2 (−0.7 to 0.3) | 0.9 (−2.5 to 4.5) |
| All covariatesb | 0.0 (−0.3 to 0.3) | −0.3 (−2.2 to 1.6) | 0.0 (−0.3 to 0.3) | −0.3 (−2.2 to 1.6) | −0.2 (−0.7 to 0.3) | 0.8 (−2.6 to 4.3) |
| Chicago (n = 753)
| ||||||
| PM (weather/season only)a | 0.7 (−0.1 to 1.4) | 0.9 (−1.9 to 3.7) | −0.7 (−1.4 to −0.1) | −2.6 (−4.8 to −0.3) | −0.2 (−1.2 to 0.9) | −0.4 (−4.0 to 3.4) |
| AAdd age, sex, race | 0.9 (0.1 to 1.6) | 1.7 (−1.0 to 4.5) | −0.5 (−1.1 to 0.1) | −1.5 (−3.7 to 0.8) | −0.3 (−1.3 to 0.7) | 0.8 (−2.7 to 4.5) |
| All covariatesb | 0.7 (0.0 to 1.5) | 1 (−1.7 to 3.8) | −0.6 (−1.2 to 0.1) | −1.8 (−4.0 to 0.5) | −0.2 (−1.2 to 0.8) | 1 (−2.5 to 4.7) |
| Winston-Salem (n = 720)
| ||||||
| PM (weather/season only)a | −0.1 (−3.0 to 3.0) | −0.2 (−5.1 to 5.0) | 1.1 (−0.7 to 2.9) | 0.6 (−2.4 to 3.8) | 1.3 (−1.5 to 4.1) | −0.8 (−5.4 to 3.9) |
| Add age, sex, race | 0.7 (−2.3 to 3.7) | −2.0 (−6.7 to 3.0) | 1.5 (−0.2 to 3.2) | 0.6 (−2.2 to 3.4) | 0.5 (−2.2 to 3.1) | 0.5 (−3.8 to 5.1) |
| All covariatesb | 0.6 (−2.3 to 3.5) | −0.3 (−5.0 to 4.6) | 1.6 (0.0 to 3.3) | 0.6 (−2.1 to 3.5) | 0.1 (−2.4 to 2.8) | 0.7 (−3.6 to 5.2) |
| St. Paul (n = 705)
| ||||||
| PM (weather/season only)a | −0.8 (−1.8 to 0.2) | 0.6 (−2.8 to 4.2) | −0.2 (−0.9 to 0.6) | 0.2 (−2.4 to 2.9) | −0.5 (−1.7 to 0.7) | 1.2 (−2.9 to 5.5) |
| Add age, sex, race | −0.7 (−1.7 to 0.3) | 1.5 (−1.9 to 5.0) | 0.2 (−0.4 to 0.9) | −1.5 (−3.7 to 0.8) | −0.1 (−1.2 to 1.0) | −1.5 (−5.2 to 2.3) |
| All covariatesb | −0.7 (−1.7 to 0.3) | 1.7 (−1.6 to 5.2) | 0.2 (−0.5 to 0.9) | −1.6 (−3.8 to 0.7) | −0.2 (−1.3 to 0.9) | −1.6 (−5.3 to 2.2) |
| Los Angeles (n = 683)
| ||||||
| PM (weather/season only)a | 1.2 (−0.3 to 2.7) | 0.4 (−0.7 to 1.5) | 0.9 (−0.1 to 1.8) | −0.7 (−1.4 to −0.1) | 1.2 (−0.2 to 2.7) | −0.7 (−1.8 to 0.3) |
| Add age, sex, race | −0.1 (−1.9 to 1.8) | 0.2 (−0.9 to 1.4) | 0.2 (−0.9 to 1.3) | −0.4 (−1.1 to 0.3) | 0.2 (−1.4 to 1.9) | −0.1 (−1.1 to 0.9) |
| All covariatesb | 0.0 (−1.7 to 1.8) | 0.0 (−1.1 to 1.1) | 0.1 (−1.0 to 1.2) | −0.4 (−1.1 to 0.3) | 0.2 (−1.4 to 1.8) | −0.3 (−1.3 to 0.7) |
| Baltimore (n = 560)
| ||||||
| PM (weather/season only)a | 1.1 (−0.4 to 2.7) | 1.8 (−2.2 to 6.0) | −1.3 (−2.3 to −0.3) | −0.5 (−3.0 to 2.0) | −1.2 (−2.7 to 0.3) | 0.6 (−3.1 to 4.5) |
| Add age, sex, race | 0.7 (−1.0 to 2.4) | 1 (−2.9 to 5.0) | −0.8 (−1.8 to 0.2) | 0.2 (−2.1 to 2.7) | 0.2 (−1.3 to 1.7) | 1.5 (−2.0 to 5.2) |
| All covariatesb | 0.7 (−0.9 to 2.4) | 2.3 (−1.6 to 6.4) | −0.6 (−1.6 to 0.4) | 0.6 (−1.9 to 3.0) | 0.5 (−1.0 to 2.0) | 2.3 (−1.3 to 6.1) |
Regression results reported as percent differences (95% CI) in outcome variables [100 × (exponentiated mean difference − 1)]. A positive point estimate for YM indicates greater arterial stiffness with higher exposure; a negative point estimate for C1 and C2 indicates reduced compliance with higher exposure. Yearly average of PM concentrations taken from monitor nearest the MESA participant’s residence in 2001.
Weather and season terms included in all models: apparent temperate spline with 3 degrees of freedom, interacted with site; and indicator variables to represent months with average monthly temperature above 10°C (50°F) during baseline recruitment period (all year for Los Angeles; May–October for Chicago and St. Paul; April–October for remaining three sites).
All covariates for YM are age, sex, race, fasting blood glucose, triglycerides, diabetes, seated MAP, smoking status, pack-years, cigarettes per day, ETS exposure, physical activities, waist:hip ratio, season, and weather. For C1 and C2, in addition, height, weight, and heart rate were included.