Table 2.

Participant Characteristics at Baseline by Follow-up Diagnosis

Variable	Remained Normal (N = 237)	Progressed to MCI/Dementia (N = 66)
Age in years, mean (SD)	55.7 (9.4)	63.0 (10.8)**
Follow-up years, mean (SD)	12.1 (4.1)	12.0 (4.4)
Gender, females (%)	62.0%	51.5%
Ethnicity, Caucasians (%)	98.7%	93.9%
APOE ε4 carriers (%)	32.5%	36.4%
MMSE, mean score (SD)	29.6 (0.7)	29.3 (1.0)*
Education, mean years (SD)	17.2 (2.3)	16.6 (2.5)
NART, mean (SD)	121.1 (7.0)	116.7 (8.8)**
WAIS-R vocabulary, mean (SD)	14.6 (2.1)	13.1 (2.5)**
CR Composite, mean (SD)	0.1 (0.8)	−0.3 (0.9)**
Paired Associates Immediate (SD)	20.9 (2.8)	19.1 (3.0)**
Logical Memory Delayed (SD)	13.1 (3.8)	11.0 (3.7)**
Boston Naming, % Correct (SD)	96.7 (4.8)	94.1 (6.2)**
Digit Symbol Substitution (SD)	54.8 (12.0)	46.1 (7.8)**
Cognitive Composite, mean (SD)	0.1 (0.6)	−0.5 (0.5)**
Biomarker Composite, mean (SD)	−0.1 (0.4) (N=136)	0.3 (0.7)** (N=34)

Abbreviations: NART = National Adult Reading Test; WAIS-R = Wechsler Adult Intelligence Scale - Revised. Significant differences between the group who remained normal and the group who progressed are indicated by asterisks:

^*p < 0.05;

^**p < 0.005.