TABLE 5.

Conversion from HC to MCI/DAT and from MCI to DAT at 20-Month Follow-up

Characteristic	HC Nonconverter to MCI/DAT	HC Converter to MCI/DAT	MCI Nonconverter to DAT	MCI Converter to DAT	DAT
Participants, No.	100	6	34	31	35
Age at baseline, yr	72.9±7.4	75.2±8.4	72.8±8.9	74.1±8.2	71.7±8.9
Gender, M/F	48/52	1/5a	22/12	14/17	19/16
Years of education	13.2±3.6	13.0±3.3	12.3±4.7	12.1±3.9	11.9±3.4
MMSE at baseline	29.3±0.9	28.2±1.2	27.5±2.2	25.5±3.2a	22.5±3.7a
CDR at baseline	0.05±0.14	0.33±0.26a	0.44±0.21	0.50±0.13	0.93±0.35a
CDR-SOB at baseline	0.14±0.42	0.40±0.22	1.20±1.0	1.89±1.1a	4.53±2.2a
%ApoE ε4	31%	67%	38%	90%b	71%b
Episodic memory score	−0.11±0.8	−1.28±0.4a	−1.63±1.0	−2.90±0.8a	−3.31±0.6a
Nonmemory score	−0.01±0.7	−0.01±0.4	−0.91±0.9	−1.28±1.4	−2.33±1.5a
PiB SUVR	1.4±0.4	2.0±0.6a	1.7±0.6	2.3±0.4	2.3±0.4a
% high PIB	28%	83%b	44%	97%b	97%b
PiB SUVR increase	0.01±0.06 (0.7%)	0.05±0.04a (2.5%)	0.02±0.06 (1.2%)	0.05±0.12 (2.2%)	0.13±0.1a (5.7%)

^aSignificantly different from nonconverters (p < 0.05).

^bSignificantly different from nonconverters (Fisher exact test p < 0.01).

HC = healthy control; MCI = mild cognitive impairment; DAT = dementia of the Alzheimer type; MMSE = Mini Mental State Examination; CDR = Clinical Dementia Rating; SOB = sum of boxes; ApoE = apolipoprotein E; PiB = [¹¹C]Pittsburgh compound B; SUVR = standardized uptake value ratio.