Table 1 Characteristics of participants included in this analysis

n

1638

437

Sex, N (%)

Male

812 (49.6)

0

229 (52.4)

0

Female

826 (50.4)

208 (47.6)

Age at scan (years), mean (SD)

70.7 (0.7)

0

APOE4 carrier, N (%)

Non-carrier

1044 (69.6)

8.5

306 (70.3)

0.5

Carrier

455 (30.4)

129 (29.7)

Amyloid status, N (%)

Negative

348 (81.1)

1.8

Positive

81 (18.9)

Hippocampal volume in ml, mean (SD)

3.1 (0.3)

0.5

Brain volume in ml, mean (SD)

1101.8 (99.3)

0.5

Total intracranial volume in ml, mean (SD)

1435.9 (132.2)

0.5

Age at blood collection (years), mean (SD)

63.2 (1.1)

0

63.3 (1.1)

0

Time between blood collection and imaging visit (years), mean (SD)

7.4 (1.3)

0

Lipid medication use (age 60–64), N (%)

No

1232 (75.2)

0

335 (76.7)

0

Yes

406 (24.8)

102 (23.3)

Body mass index (age 60–64) in kg/m², mean (SD)

27.8 (4.7)

0.1

27.4 (4.0)

0

Childhood cognitive ability (age 15)^a, z-score, mean (SD)

0.2 (0.8)

14.3

0.5 (0.7)

8.2

Childhood socioeconomic position (age 11), N (%)

Unskilled

80 (5.1)

5

18 (4.1)

0.5

Partly skilled

274 (17.6)

64 (14.7)

Manual skilled

462 (29.7)

106 (24.4)

Nonmanual skilled

276 (17.7)

90 (20.7)

Intermediate

346 (22.2)

110 (25.3)

Professional

118 (7.6)

47 (10.8)

Adult socioeconomic position (age 53), N (%)

Unskilled or Partly skilled^b

205 (12.5)

0.4

26 (5.9)

0

Manual skilled

238 (14.6)

40 (9.2)

Nonmanual skilled

380 (23.3)

91 (20.8)

Intermediate

680 (41.7)

225 (51.5)

Professional

129 (7.9)

55 (12.6)

Highest educational attainment (age 26), N (%)

No qualification

446 (28.6)

4.9

65 (15.3)

3

Up to GCSE

446 (28.6)

125 (29.5)

A-level or higher

665 (42.7)

234 (55.2)