Table 3.
Exposure to PM and risk of PD in the Nurses’ Health Study, 1990–2008 (N = 111,769) by smoking status, caffeine intake and ibuprofen use
| PY | Cases | RR a | 95% CI | PY | Cases | RR a | 95% CI | p-int | |
|---|---|---|---|---|---|---|---|---|---|
| By smoking status: | Never smokers | Ever smokers | |||||||
| Quartiles of PM 10 | |||||||||
| Q1 | 206697 | 73 | 1.00 | Ref | 278761 | 68 | 1.00 | Ref | |
| Q2 | 209774 | 75 | 1.14 | (0.82, 1.58) | 275654 | 60 | 1.03 | (0.72, 1.47) | |
| Q3 | 213834 | 63 | 0.99 | (0.70, 1.41) | 271618 | 57 | 1.05 | (0.73, 1.52) | |
| Q4 | 213834 | 56 | 0.92 | (0.62, 1.36) | 265933 | 56 | 1.14 | (0.76, 1.71) | 0.31 |
| Continuous* PM 10 | 849835 | 267 | 0.96 | (0.85, 1.09) | 1091965 | 241 | 1.04 | (0.92, 1.18) | 0.42 |
| Quartiles of PM 2.5 | |||||||||
| Q1 | 210817 | 69 | 1.00 | Ref | 274637 | 62 | 1.00 | Ref | |
| Q2 | 204967 | 69 | 1.07 | (0.76, 1.52) | 280601 | 62 | 1.06 | (0.74, 1.54) | |
| Q3 | 214387 | 70 | 1.07 | (0.74, 1.53) | 271003 | 67 | 1.21 | (0.84, 1.76) | |
| Q4 | 219664 | 59 | 1.06 | (0.72, 1.55) | 265724 | 50 | 1.12 | (0.74, 1.69) | 0.58 |
| Continuous* PM 2.5 | 849835 | 267 | 1.01 | (0.90, 1.15) | 1091965 | 241 | 1.05 | (0.92, 1.19) | 0.66 |
| Quartiles of PM 10–2.5 | |||||||||
| Q1 | 212002 | 85 | 1.00 | Ref | 273461 | 64 | 1.00 | Ref | |
| Q2 | 204860 | 60 | 0.79 | (0.57, 1.11) | 280562 | 61 | 1.05 | (0.74, 1.51) | |
| Q3 | 210385 | 58 | 0.77 | (0.54, 1.09) | 274925 | 61 | 1.14 | (0.79, 1.65) | |
| Q4 | 222580 | 64 | 0.82 | (0.54, 1.24) | 263007 | 55 | 1.05 | (0.67, 1.65) | 0.26 |
| Continuous^ PM 10–25 | 849835 | 267 | 0.93 | (0.81, 1.05) | 1091965 | 241 | 1.03 | (0.90, 1.18) | 0.41 |
| By Caffeine intake: | <100 mg/day caffeine | > = 100 mg/day caffeine | |||||||
| Quartiles of PM 10 | |||||||||
| Q1 | 196761 | 69 | 1.00 | Ref | 287683 | 72 | 1.00 | (Ref) | |
| Q2 | 189470 | 69 | 1.20 | (0.85, 1.68) | 295013 | 66 | 0.99 | (0.70, 1.40) | |
| Q3 | 189270 | 73 | 1.35 | (0.95, 1.91) | 295251 | 47 | 0.74 | (0.50, 1.08) | |
| Q4 | 184296 | 57 | 1.20 | (0.81, 1.78) | 300254 | 55 | 0.87 | (0.60, 1.31) | 0.23 |
| Continuous* PM 10 | 759796 | 268 | 1.08 | (0.95, 1.22) | 1178200 | 240 | 0.93 | (0.81, 1.06) | 0.49 |
| Quartiles of PM 2.5 | |||||||||
| Q1 | 194876 | 65 | (Ref) | 289553 | 66 | 1.00 | (Ref) | ||
| Q2 | 189312 | 68 | 1.02 | (0.71, 1.46) | 295169 | 63 | 0.77 | (0.53, 1.10) | |
| Q3 | 194935 | 74 | 1.06 | (0.73, 1.55) | 289578 | 63 | 0.86 | (0.60, 1.24) | |
| Q4 | 180673 | 61 | 0.88 | (0.58, 1.32) | 303900 | 48 | 0.69 | (0.44, 1.09) | 0.22 |
| Continuous* PM 25 | 759796 | 268 | 0.97 | (0.85, 1.10) | 120299 | 240 | 0.91 | (0.79, 1.04) | 0.38 |
| Quartiles of PM 10–2.5 | |||||||||
| Q1 | 196694 | 76 | 1.00 | (Ref) | 287785 | 73 | 1.00 | (Ref) | |
| Q2 | 185789 | 67 | 1.05 | (0.75, 1.47) | 298707 | 54 | 0.77 | (0.53, 1.10) | |
| Q3 | 188793 | 59 | 0.99 | (0.70, 1.43) | 295702 | 60 | 0.86 | (0.60, 1,24) | |
| Q4 | 188513 | 66 | 1.20 | (0.79, 1.80) | 295993 | 53 | 0.69 | (0.44, 1.09) | 0.45 |
| Continuous^ PM 10–25 | 759796 | 268 | 1.04 | (0.92, 1.19) | 1178200 | 240 | 0.91 | (0.79, 1.04) | 0.72 |
| By use of ibuprofen | Never user | Ever user | |||||||
| Quartiles of PM 10 | |||||||||
| Q1 | 378733 | 101 | 1.00 | (Ref) | 105711 | 40 | 1.00 | (Ref) | |
| Q2 | 375957 | 110 | 1.22 | (0.93, 1.61) | 108526 | 25 | 0.76 | (0.45, 1.26) | |
| Q3 | 373161 | 87 | 1.04 | (0.77, 1.40) | 111359 | 33 | 1.03 | (0.63, 1.68) | |
| Q4 | 369737 | 95 | 1.20 | (0.87, 1.65) | 114813 | 17 | 0.62 | (0.33, 1.16) | 0.04 |
| Continuous* PM 10 | 1491149 | 375 | 1.04 | (0.04, 1.15) | 440409 | 115 | 0.91 | (0.75, 1.10) | 0.03 |
| Quartiles of PM 2.5 | |||||||||
| Q1 | 377642 | 101 | 1.00 | (Ref) | 106787 | 30 | 1.00 | (Ref) | |
| Q2 | 376538 | 103 | 1.16 | (0.87, 1.55) | 107943 | 28 | 0.81 | (0.47, 1.37) | |
| Q3 | 375892 | 98 | 1.13 | (0.84, 1.52) | 108622 | 39 | 1.14 | (0.68, 1.91) | |
| Q4 | 367516 | 91 | 1.26 | (0.87, 1.55) | 117056 | 18 | 0.64 | (0.34, 1.20) | 0.43 |
| Continuous* PM 25 | 1491149 | 393 | 1.07 | (0.97, 1.18) | 440409 | 115 | 0.93 | (0.77, 1.12) | 0.38 |
| Quartiles of PM 10–2.5 | |||||||||
| Q1 | 375666 | 107 | 1.00 | Ref | 108813 | 42 | 1.00 | (Ref) | |
| Q2 | 374592 | 90 | 0.92 | (0.70, 1.23) | 109905 | 31 | 0.81 | (0.50, 1.30) | |
| Q3 | 375149 | 98 | 1.02 | (0.77, 1.35) | 109346 | 21 | 0.56 | (0.33, 0.96) | |
| Q4 | 372167 | 98 | 1.01 | (0.76, 1.36) | 112339 | 21 | 0.55 | (0.32, 0.97) | 0.01 |
| Continuous^ PM 10–25 | 1497588 | 393 | 1.01 | (0.92, 1.11) | 440409 | 115 | 0.80 | (0.67, 0.96) | 0.01 |
Abbreviations: PY person years; RR relative risk; 95% CI 95 percent confidence interval.
aadjusted for age, smoking (except in smoking stratified analyses), region (northeast, midwest, west, and south), population density, caffeine intake (<100 mg/day vs. over 100 mg/day, except in caffeine stratified analyses) and ibuprofen use (ever/never user, except in ibuprofen stratified analyses).
^per 10 μg/m3.