Table 3.
Percent difference and 95% confidence interval (CI) for triglycerides and total cholesterol associated with an interquartile range increase in PM10, stratified by demographic factorsin the Third National Health and Nutrition Examination Survey (NHANES III).
| n | triglycerides1 | p for interaction2 | n | total cholesterol1 | p for interaction2 | |
|---|---|---|---|---|---|---|
| Age | ||||||
| 17–49 years | 6,820 | 1.34 (0.03, 2.67) | 0.23 | 6,821 | 1.09 (0.90, 1.29) | 0.36 |
| 50–90 years | 4,119 | 4.25 (2.49, 6.04) | 4,121 | 1.51 (1.03, 1.99) | ||
| U.S. Census Region3 | ||||||
| Northeast | 1,847 | 0.83 (−4.31, 6.26) | 0.81 | 1,847 | 1.28 (−0.73, 3.33) | 0.57 |
| Midwest | 2,027 | 2.01 (−1.59, 5.76) | 2,027 | 0.78 (−0.63, 2.21) | ||
| South | 3,697 | −0.45 (−4.71, 3.99) | 3,698 | 1.32 (−0.37, 3.05) | ||
| West | 3,368 | 1.58 (0.16, 3.02) | 3,370 | 1.63 (1.04, 2.23) | ||
| Sex | ||||||
| Males | 5,102 | 2.67 (1.36, 3.99) | 0.04 | 5,104 | 2.07 (1.87, 2.27) | <0.01 |
| Females | 5,837 | 2.25 (0.73, 3.79) | 5,838 | 0.81 (0.38, 1.25) | ||
| Race-ethnicity | ||||||
| Non-Hispanic white | 4,065 | 2.44 (0.87,4.04) | 0.17 | 4,066 | 1.49 (1.17, 1.80) | <0.01 |
| Non-Hispanic black | 3,175 | −0.35 (−1.29, 0.60) | 3,175 | 1.19 (0.83, 1.55) | ||
| Mexican-American | 3,108 | 0.65 (0.58, 0.71) | 3,110 | 1.04 (1.02, 1.06) |
Abbreviations: PM10 = particulate matter <10µm in aerodynamic diameter.
Generalized linear model regressionwas used to estimate the association between an interquartile range (IQR) of PM10 (11.1 µg/m3) as the independent variable and the percent difference in lipid levels as the dependent variable, adjusting for NHANES III sampling weights, strata, and clusters, as well as age, sex, race (white, black, other, or unknown), body mass index (15–18.4, 18.5–24.9, 25–29.9, 30–34.9, 35–60 kg/m2, or unknown), smoking status (current, former, never, or unknown), U.S. region (Northeast, Midwest, South, or West), and poverty-income ratio.
P-value for interaction derived from F-test for the interaction term between PM10 and each demographic, health, or lifestyle factor.
Stratified and interaction models for census region excluded NHANESIII sampling weights, clusters, and strata to avoid collinearity.