Table 1.

Demographic features in Subjective Cognitive Decline (SCD), Mild Cognitive Impairment (MCI), and Alzheimer’s disease (AD) groups (110 patients)

	SCD	MCI	AD
	N° 34	N° 53	N° 23
Age at baseline in years	66.30 (± 8.09) *	72.78 (± 8.02) *	70.72 (± 6.08)
Age at onset in years	55.55 (± 7.52) ° ç	64.75 (± 9.10) °	66.79 (± 5.97) ç
Family history of AD	74.19%	60.00%	64.70%
Sex (M–F)	10–24	24–29	9–14
Years of education	12.47 (± 3.46) ^	11.31 (± 4.38)	9.10 (± 3.97) ^
MMSE	28.39 (± 1.52) ψ	27.51 (± 2.07) ϖ	17.81 (± 7.45) ψ ϖ
APOE ɛ4 +	18.18% & §	46.15% &	60.86% §
Plasma NfL (pg/ml)	13.19 (± 4.88) η ϒ	22.32 (± 11.49) η	24.54 (± 7.01) ϒ
A +	37.50% [9/24] ϕ	62.22% [28/45] μ	100% [22/22] ϕ μ

Values are reported as mean and standard deviation or frequencies or percentages for continuous variables and categorical variables, respectively. Statistically significantly different values between the groups are reported as underlined character. M: males; F: females; MMSE: Mini-Mental State Examination. The sample size for A + status is reported into brackets

^*p = 0.001; °p < 0.001; ^çp < 0.001; ^p = 0.010; ^λ; ^ψp < 0.001; ^ϖp < 0.001; ^&χ² 6.91, p = 0.009; ^§χ² 10.75, p = 0.001; ^ηp < 0.001; ^ϒp < 0.001; ^ϕ χ² 20.40, p < 0.001; ^μ χ² 11.13, p = 0.001