Addition of the Aβ42/40 ratio to the cerebrospinal fluid biomarker profile increases the predictive value for underlying Alzheimer’s disease dementia in mild cognitive impairment

Table 1 Demographic, clinical, genetic and biomarker data of the study population

	Controls (n = 66)	AD-dementia(n = 168)	MCI total(n = 197)	MCI-St(n = 74)	MCI-AD(n = 70)
Gender (M/F)	27/39	56/112	68/127	25/49	26/44
Age (years)	58.8 ± 11.9	68.1 ± 8.8***	67.1 ± 9.4***	65.2 ± 9.3*	71.0 ± 8.0***^,§§
Age onset (years)		64.6 ± 8.7	64.2 ± 9.3	60.5 ± 9.4	68.8 ± 7.7^γ,§§§
Education (years)		5.5 ± 4.0	6.0 ± 3.8	5.7 ± 3.6	5.8 ± 3.9
MMSE	28.4±1.8	17.2 ± 5.9***	25.9 ± 4.0***^,γγγ	26.5 ± 4.9***^,γγγ	25.1 ± 3.3***^,γγγ,§
MoCA		10.5 ± 5.1	17.7 ± 5.6^γγγ	19.9 ± 4.9^γγγ	15.5 ± 5.3^γγ,§§§
ADAS-Cog		26.0 ± 12.3	11.8 ± 6.1^γγγ	9.0 ± 4.3^γγγ	14.7 ± 6.3^{γγγ,§§§}
APOE-ε4 (%)		46%	42%	28%	60%^§§§
Aβ42 (pg/ml)	928 ± 435	455 ± 225***	689 ± 322***^,γγγ	785 ± 309*^,γγγ	476 ± 180***^,§§§
Aβ40 (pg/ml)	10,055 ± 4314	9229 ± 3668	11,097 ± 4635^γγγ	10,916 ± 4379^γγ	10,157 ± 3381
Aβ42/40 ratio	0.100 ± 0.034	0.055 ± 0.029***	0.070 ± 0.039***^,γγγ	0.083 ± 0.046*^,γγγ	0.050 ± 0.020***^,§§§
t-Tau (pg/ml)	196 ± 95	543 ± 363***	374 ± 269***^,γγγ	253 ± 151^γγγ	511 ± 307***^,§§§
p-Tau (pg/ml)	33 ± 15	64 ± 37***	50 ± 28**^,γγγ	38 ± 19^γγγ	62 ± 30***^,§§§
t-Tau/Aβ42	0.22 ± 0.11	1.53 ± 1.36***	0.74 ± 0.73***^,γγγ	0.41 ± 0.39^γγγ	1.18 ± 0.85***^,§§§
Aβ42/p-Tau	32.0 ± 15.3	9.3 ± 8.2***	18.6 ± 14.2***^,γγγ	25.7 ± 16.3^γγγ	9.7 ± 6.6***^,§§§

Data expressed as mean ± standard deviation, except for APOE expressed as percentage of ε4 carriers
MMSE and MoCA, higher scores correspond to better performance; ADAS-Cog, lower scores correspond to better performance. For MMSE and CSF biomarkers, data were adjusted for age
AD Alzheimer’s disease, MCI mild cognitive impairment, MCI-St stable mild cognitive impairment, MCI-AD mild cognitive impairment patients who progress to Alzheimer’s disease, M male, F female, MMSE Mini Mental State Examination, MoCA Montreal Cognitive Assessment, ADAS-Cog Alzheimer Disease Assessment Scale—Cognitive, APOE Apolipoprotein E, Aβ42 42-aminoacid isoform of amyloid beta, Aβ40 40-aminoacid isoform of amyloid beta, t-Tau total Tau protein, p-Tau hyperphosphorylated Tau protein
*p < 0.05 vs controls
**p < 0.01 vs controls
***p < 0.001 vs controls
^γp < 0.05 vs AD-dementia
^γγp < 0.01 vs AD-dementia
^γγγp < 0.001 vs AD-dementia
^§p < 0.05 vs MCI-St
^§§p < 0.01 vs MCI-St
^§§§p < 0.001 vs MCI-St