Table 2.
Relationship between TRAP-NOx and late-life incident cognitive outcomes.
| Outcome | TRAP-NOx Exposure Category | All SALSA (n=1564) |
Urban Only (n=1359) |
||||
|---|---|---|---|---|---|---|---|
| Cognitive Outcome |
HR (95% CI) |
Cognitive Outcome |
HR (95% CI) |
||||
| No (%) | Yes (%) | No (%) | Yes (%) | ||||
| Time to incident dementia | NOx T3 (yes/no) | ||||||
| ≤ 2.68 ppb | 971 (66.3) | 63 (63.0) | 1.00 (ref) | 790 (62.1) | 49 (57.0) | 1.00 (ref) | |
| 100/86 (urban only) events | >2.68 ppb | 493 (33.7) | 37 (37.0) | 1.55 (1.04, 2.33) | 483 (37.9) | 37 (43.0) | 1.65 (1.10, 2.48) |
| per IQR | 1.20 (0.98, 1.47) | 1.25 (1.03, 1.52) | |||||
| Time to incident CIND† | NOx T3 (yes/no) | ||||||
| ≤ 2.68 ppb | 936 (66.4) | 44 (65.7) | 1.00 (ref) | 764 (62.2) | 35 (60.3) | 1.00 (ref) | |
| 67/58 (urban only) events | >2.68 ppb | 474 (33.6) | 23 (34.3) | 1.21 (0.76, 1.92) | 464 (37.7) | 23 (39.7) | 1.26 (0.79, 2.03) |
| per IQR | 1.21 (1.00, 1.46) | 1.24 (1.02, 1.50) | |||||
| Time to incident dementia/CIND | NOx T3 (yes/no) | ||||||
| ≤ 2.68 ppb | 936 (66.4) | 98 (64.6) | 1.00 (ref) | 764 (62.2) | 75 (57.3) | 1.00 (ref) | |
| 154/131 (urban only) events | >2.68 ppb | 474 (33.6) | 56 (36.4) | 1.45 (1.07, 1.96) | 464 (37.8) | 56 (42.8) | 1.55 (1.15, 2.09) |
| per IQR | 1.21 (1.05, 1.40) | 1.25 (1.09, 1.44) | |||||
Abbreviations: CIND=Cognitive Impairment, non-dementia; T3=tertile 3 (TRAP NOx dichotomized at >T3); IQR=interquartile range (2.31 ppb)
Based on Cox proportional hazards regression with census-tract clustered standard errors.
Models control for baseline 3MSE score, baseline age, sex, years of education, primary language spoken, occupation for most of life (manual, non-manual, or other), NSES, cigarette smoking, a county indicator, and a rural/urban residential neighborhood indicator (excluded for urban only analysis).
†
Excludes those who were diagnosed with dementia (but not CIND) from the control group