Table 1.
Summary statistics of subject characteristics
| Characteristic | All (N = 559) | Control (n = 308) | Cases (n = 251) | P-value |
|---|---|---|---|---|
| Mean age, years (SD) | 78.1 (7.4) | 76.5 (6.7) | 80.2 (7.7) | <.001 |
| Male, n (%) | 216 (38) | 125 (39) | 91 (36) | .22 |
| Mean MMSE (SD) | 24.4 (6.8) | 28.8 (1.2) | 18.0 (6.5) | <.001 |
| Presence of E4 allele, n (%) | 240 (42) | 71 (25) | 169 (69) | <.001 |
| Mean systolic blood pressure, mm Hg (SD) | 139 (18) | 144 (18) | 134 (18) | <.001 |
| Education—left school at 14 years, n (%) | 274 (48) | 138 (45) | 136 (58) | <.01 |
| Never smoked, n (%) | 321 (59) | 191 (62) | 130 (54) | .12 |
| Diabetes mellitus, n (%) | 59 (10) | 37 (12) | 22 (9) | .17 |
| Hypertension, n (%) | 221 (391) | 131 (43) | 90 (38) | .14 |
| Cardiovascular disease, n (%) | 129 (23) | 76 (25) | 53 (22) | .27 |
| Cerebrovascular disease, n (%) | 70 (12) | 38 (12) | 32 (13) | .42 |
| Hypercholesterolemia, n (%) | 216 (38) | 124 (41) | 92 (39) | .37 |
| Aspirin/clopidogrel, n (%)∗ | 229 (40) | 116 (39) | 113 (48) | .02 |
Abbreviations: SD, standard deviation; MMSE, Mini–Mental State Examination.
∗
Medications taken with a frequency >5%.