Traffic-Related Air Pollution and Dementia Incidence in Northern Sweden: A Longitudinal Study

http://dx.doi.org/10.1289/ehp.1408322



Table 1. Distribution of dementia and population characteristics at baseline according to quartiles of NOx exposure [n (%)].
Characteristic NOx Q1
4.8–9 μg/m3
NOx Q2
> 9–17 μg/m3
NOx Q3
> 17–26 μg/m3
NOx Q4
> 26 μg/m3
All
aBody mass index. BMI cut-offs between normal weight and overweight were 23.8 for women and 25.0 for men. bWaist–hip ratio. Cut-offs were at 0.8 for women and 1.0 for men.
All observations 433 476 459 438 1,806
Total dementia 55 (13) 65 (15) 90 (21) 92 (22) 302 (18)
Vascular dementia 23 (5) 22 (5) 31 (7) 35 (8) 111 (6)
Alzheimer’s disease 32 (8) 43 (10) 59 (14) 57 (14) 191 (11)
Sex
Male 205 (47) 205 (43) 189 (41) 174 (40) 773 (43)
Female 228 (53) 271 (57) 270 (59) 264 (60) 1,033 (57)
Age (years)
55 83 (19) 84 (18) 65 (14) 58 (13) 290 (16)
60 65 (15) 94 (20) 72 (16) 55 (13) 286 (16)
65 64 (15) 92 (20) 76 (17) 54 (13) 286 (16)
70 65 (15) 74 (16) 70 (15) 69 (16) 278 (15)
75 71 (16) 65 (14) 76 (17) 62 (14) 274 (15)
80 57 (13) 53 (11) 67 (15) 89 (20) 266 (15)
85 28 (6) 14 (3) 33 (7) 51 (12) 126 (7)
Education
Compulsory 360 (83) 354 (74) 344 (75) 345 (79) 1,403 (78)
High school 31 (7) 46 (10) 34 (7) 22 (5) 133 (7)
University 36 (8) 70 (15) 74 (16) 66 (15) 246 (14)
Missing 6 (1) 6 (1) 7 (1) 5 (1) 24 (1)
Physical activity
Never 91 (21) 90 (19) 105 (23) 126 (29) 412 (23)
Occasionally 57 (13) 61 (13) 57 (12) 44 (10) 219 (12)
A few times per month 38 (9) 46 (10) 39 (9) 53 (12) 176 (10)
Weekly 148 (34) 165 (35) 154 (34) 121 (28) 588 (33)
Daily 92 (21) 106 (22) 95 (21) 84 (19) 377 (21)
Missing 7 (2) 8 (2) 9 (2) 10 (2) 34 (2)
Smoking
Nonsmoker 236 (55) 278 (57) 249 (54) 238 (55) 1,001 (55)
Smoker 60 (14) 50 (11) 59 (13) 56 (13) 225 (12)
Former smoker 137 (32) 148 (31) 151 (33) 144 (33) 580 (32)
Alcohol
Yes 291 (67) 331 (70) 328 (71) 322 (74) 1,272 (70)
No, never 122 (28) 122 (26) 103 (22) 99 (23) 445 (25)
No, quit 19 (4) 21 (4) 28 (6) 17 (4) 85 (5)
Missing 1 (0.2) 2 (0.5) 0 (0) 1 (0.2) 4 (0.2)
BMIa
Overweight 293 (68) 318 (67) 288 (63) 281 (64) 1,180 (65)
Missing 8 (2) 22 (5) 15 (3) 15 (3) 60 (3)
WHRb
> Recommended 157 (36) 178 (37) 177 (39) 185 (42) 697 (39)
Missing 34 (8) 39 (8) 35 (8) 38 (9) 146 (8)
Hypertension 146 (34) 161 (34) 174 (38) 142 (32) 623 (34)
Missing 1 (0.2) 2 (0.4) 1 (0.2) 0 (0) 4 (0.2)
Diabetes 39 (9) 35 (7) 25 (5) 20 (5) 119 (7)
Missing 3 (0.7) 3 (0.7) 2 (0.5) 1 (0.2) 9 (0.5)
Stroke 18 (4) 28 (6) 33 (7) 38 (9) 117 (6)
Missing 2 (0.5) 3 (0.6) 2 (0.4) 1 (0.2) 8 (0.4)
ApoE4 114 (26) 115 (24) 130 (28) 135 (31) 494 (27)
Missing 11 (3) 21 (4) 16 (3) 13 (3) 61 (3)
Deceased 157 (36) 131 (28) 146 (32) 165 (38) 599 (33)