Table 2.

Summary of Demographics, Biomarkers, and Imaging Outcomes

	N	Frequency (%)	Mean (SD)	Median (IQR)
Ethnicity, frequency (%) White British	317	317 (100)	—	—
Sex, frequency (%) female	317	153 (48)	—	—
Age at baseline (phase 1) scan, y	317	—	70.5 (0.6)	70.5 (70.0 to 71.0)
Scan interval, y	317	—	2.4 (0.2)	2.4 (2.3 to 2.5)
Baseline (phase 1) WMHV, mL	317	—	5.7 (5.9)	3.51 (1.81 to 7.50)
WMHV change rate, mL/y	317	—	1.0 (1.6)	0.22 (0.05 to 0.56)
Hippocampal atrophy rate, mL/y	317	—	0.04 (0.04)	0.04 (0.01 to 0.06)
Baseline (phase 1) Aβ status, frequency (%) positive	311	74 (24)	—	—
Baseline (phase 1) Aβ CL score	311	—	(9.6–22.7)	0.9 (−3.4 to 10.4)
APOE-ε4 status, frequency (%) ε4 carrier	316	95 (30)	—	—
Systolic BP, mm Hg
Age 36, seated	286	—	120 (14)	119 (110 to 130)
Age 43, seated	303	—	123 (14)	123 (114 to 130)
Age 53, seated	310	—	133 (19)	131 (120 to 148)
Age 60–64, seated	317	—	134 (17)	133 (123 to 145)
Age 69, seated	315	—	132 (16)	132 (122 to 143)
Age 70, lying	315	—	137 (17)	136 (126 to 147)
Age 70, standing	315	—	137 (19)	135 (123 to 149)
Diastolic BP, mm Hg
Age 36, seated	286	—	78 (10)	79 (72 to 84)
Age 43, seated	303	—	80 (9)	79 (74 to 85)
Age 53, seated	310	—	83 (12)	82 (76 to 89)
Age 60–64, seated	317	—	76 (10)	76 (70 to 82)
Age 69, seated	315	—	73 (10)	73 (66 to 80)
Age 70, lying	315	—	73 (10)	73 (66 to 80)
Age 70, standing	315	—	80 (11)	80 (72 to 87)
FHS-CVS
Age 36	286	—	2.9 (1.8)	2.7 (1.5 to 3.5)
Age 53	307	—	11.7 (7.1)	10.6 (6.3 to 15.6)
Age 69	312	—	25.3 (13.2)	23.3 (14.5 to 34.3)
Follow-up (phase 2) plasma NfL, pg/mL	312	—	16.7 (7.9)	15 (11.8 to 19.4)

Abbreviations: Aβ = β-amyloid; CL = Centiloid; DBP = diastolic blood pressure; FHS-CVS = Framingham Heart Study Cardiovascular Risk Score; HAR = hippocampal atrophy rate; IQR = interquartile range; NfL = neurofilament light chain; SBP = systolic blood pressure; WMHV = white matter hyperintensity volume.