Table 1 Baseline characteristics of study participants with mild cognitive impairment (MCI) divided according to diagnosis at the end of follow-up: MCI not converted, any dementia, or Alzheimer’s dementia (AD). Number of overall subjects in each category reported in parenthesis. Median and interquartile range (IQR) levels visible infrared imaging Radiometer Suite (VIIRS) data for 9-year average 2014–2022 period of outdoor artificial light at night (LAN) exposure in nW/cm²/sr for the overall population are reported. Number of overall subjects in each category reported in parenthesis

All subjects (n = 53)

19

100

34

100

26

100

26.2 (14.9–33.8)

Sex

 Males (n = 28)

11

57.9

17

50.0

12

46.1

26.2 (14.1–34.1)

 Females (n = 25)

8

42.1

17

50.0

14

53.9

26.4 (16.9–32.8)

Age at first diagnosis

 < 65 years (n = 22)

10

52.6

12

35.3

8

30.8

25.6 (14.5–32.8)

 ≥ 65 years (n = 31)

9

47.4

22

64.7

18

69.2

26.5 (15.7–34.3)

Educational attainment

 < 8 years (n = 18)

9

47.4

9

26.5

7

26.9

31.4 (23.1–36.0)

 8–12 years (n = 15)

3

15.8

12

35.3

10

38.5

26.1 (14.4–33.0)

 ≥ 12 years (n = 20)

7

36.8

13

38.2

9

34.6

24.7 (11.2–31.7)

Smoking habits

 Non-smokers (n = 46)

18

94.7

28

82.4

21

80.8

26.2 (13.6–33.8)

 Smokers (n = 7)

1

5.3

6

17.6

5

19.2

26.2 (25.4–34.4)

COPD

 No (n = 51)

19

100

32

94.1

25

96.2

26.4 (14.5–34.3)

 Yes (n = 2)

0

0.0

2

5.9

1

3.8

25.8 (25.4–26.1)

Diabetes

 No (n = 51)

18

94.7

33

97.1

25

96.2

26.2 (14.9–34.3)

 Yes (n = 2)

1

5.3

1

2.9

1

3.8

23.6 (14.5–32.8)

APOE4 genotype

 Negative (n = 21)

10

52.6

11

32.3

6

23.1

25.5 (13.6–34.4)

 Positive (n = 17)

3

15.8

14

41.2

12

46.1

31.1 (16.9–33.0)

 Missing (n = 15)

6

31.6

9

26.5

8

30.8

25.7 (23.1–32.8)

Follow-up (months)^a

93

58–110

47

36–59

47

36–65

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