Table 2 Cohort demographics and cognitive outcomes at study entry

Mean age, years (SD)

78.5 (10.3)

81.5 (9.2)

78.1 (7.8)

79.4 (7.7)

< 0.001

0.035

< 0.001

Mean education, years (SD)

14.8 (3.3)

13.7 (2.9)

15.9 (2.7)

14.5 (2.7)

< 0.0001

< 0.001

0.72

Cumulative Illness Rating Scale (SD)

22.5 (4.3)

22.4 (3.9)

21.8 (3.7)

21.6 (3.4)

0.66

0.003

0.002

Presence of an APOE4 allele (%)

39

28

22

25

0.008

0.014

–

Asian

0

6

1

0

–

–

–

Black

6

36

6

28

–

–

–

Native American

1

2

0

0

–

–

–

Caucasian/White

285

443

82

135

–

–

–

Obesity (%)

66

26

65

29

< 0.0001

0.51

0.065

Diabetes (%)

10

11

13

12

1

0.68

0.003

Hypertension (%)

56

65

52

74

< 0.001

0.014

0.082

Thyroid disorder (%)

2

7

2

11

< 0.0001

0.19

0.87

MMSE

24.9 (5.8)

26.0 (5.3)

28.6 (1.4)

28.5 (1.5)

0.008

< 0.001

< 0.001

CDR-SB

1.8 (2.9)

1.4 (3.1)

0.1 (0.27)

0.1 (0.26)

0.11

< 0.001

< 0.001

Logical Memory Delayed Recall

8.3 (4.7)

9.3 (4.9)

11.6 (4.3)

11.5 (4.2)

0.19

< 0.001

0.004

CERAD Delayed Word List

4.9 (2.4)

5.7 (2.5)

6.6 (1.7)

6.8 (2.0)

0.002

< 0.001

< 0.001

Digit Symbol

32.5 (13.6)

37.2 (10.6)

40.1 (8.8)

41.7 (11.4)

0.003

< 0.001

0.073

SDMT

39.9 (11.1)

38.3 (10.3)

47.2 (14.2)

39.7 (12.6)

0.088

0.40

0.62

Trails Making Test B

141.7 (80.8)

133.0 (69.2)

90.5 (30.1)

112.5 (45.6)

0.94

0.006

0.27

Animal Category Fluency

16.9 (5.3)

15.9 (5.2)

20.6 (5.0)

17.7 (4.7)

< 0.0001

< 0.001

0.30