Table 3. Associations between plasma Aβ levels and composite amyloid PET SUVR.

	All cases	Control	SCD	MCI
Aβ42	r = −0.162, p = 0.003−0.08 (−0.09, −0.07)	r = 0.005,p = 0.953	r = −0.189,p = 0.056	r = −0.295, p = 0.002−0.09 (−0.1, −0.06)
Aβ40	r = −0.012, p = 0.828	r = 0.103,p = 0.251	r = 0.014, p = 0.886	r = −0.199, p = 0.035−0.006 (−0.009, −0.004)
Aβ42/Aβ40	r = −0.167, p = 0.002−18 (−27, −10)	r = −0.130,p = 0.148	r = −0.205,p = 0.038−33 (−42, −25)	r = −0.154, p = 0.105

MCI, mild cognitive impairment; SCD, subjective cognitive decline; PET, positron emission tomography; SUVR, standardized uptake value ratio.

Plasma Aβ were measured using Simoa immunoassay. Associations between plasma Aβ and composite [¹⁸F]flutemetamol SUVR were first evaluated with Pearson’s correlation analysis and if significant correlations were found further investigated using RMA adjusting for age and gender. Data are presented as r, p from Pearson’s correlation analysis and slope estimates (95% CI) from RMA; significant results are shown in bold.