Table 1.
Baseline Characteristics of Study Population
| All Participants (N = 402) | DHA (n = 238) | Placebo (n = 164) | P Value | |
|---|---|---|---|---|
| Age, mean (SD), y | 76 (8.7) | 76 (9.3) | 76 (7.8) | .49 |
| Female sex, No. (%) | 210 (52.2) | 112 (47.1) | 98 (59.8) | .02 |
| Education, mean (SD), ya | 14 (2.8) | 14 (2.9) | 14 (2.7) | .57 |
| APOE ε4 carriers, No. (%) | 232 (57.7) | 137 (57.6) | 95 (57.9) | .83 |
| Body mass indexb | 26 (4) | 26 (4) | 26 (4) | .33 |
| Modified Hachinski ischemia scale, mean (SD)c | 0.77 (0.78) | 0.79 (0.78) | 0.74 (0.78) | .45 |
| Smokers, No. (%) | 94 (23.4) | 58 (24.4) | 36 (21.9) | .63 |
| Blood pressure, mean (SD), mm Hg | ||||
| Systolic | 134 (18) | 134 (19) | 134 (18) | .98 |
| Diastolic | 73 (10) | 73 (10) | 73 (10) | .54 |
| Mini-Mental State Examination, mean (SD)d | 20.7 (3.6) | 20.9 (3.6) | 20.3 (3.7) | .10 |
| Cognitive subscale on Alzheimer’s Disease Assessment Scale, mean (SD)e | 23.85 (9.0) | 23.77 (8.9) | 23.96 (9.2) | .87 |
| Clinical Dementia Rating sum of boxes, mean (SD)f | 5.68 (2.61) | 5.61 (2.62) | 5.77 (2.61) | .73 |
| DHA intake on food frequency questionnaire, mean (SD), mg/d | 89 (53) | 88 (51) | 90 (57) | .95 |
| Plasma DHA, mean (SD) weight, % | 3.16 (1.12) | 3.18 (1.21) | 3.13 (0.96) | .86 |
| Cholinesterase inhibitor use at baseline, No. (%) | 345 (85.8) | 208 (87.4) | 137 (83.5) | .31 |
| Memantine use at baseline, No. (%) | 243 (60.4) | 139 (58.4) | 104 (63.4) | .35 |
Abbreviations: APOE, apolipoprotein E gene; DHA, docosahexaenoic acid.
a
Expressed as total years of formal education and was determined by report of the participant and caregiver.
b
Calculated as weight in kilograms divided by height in meters squared.
c
The range of possible scores is 0 to 12.
d
A 30-point scale of cognitive function in which higher scores indicate less cognitive impairment.
e
A 70-point scale of cognitive function in which higher scores indicate more cognitive impairment.
f
A global measure of dementia severity with a range from 0 to 18, with higher scores indicating greater impairment.