TABLE 3.
Summary of scores for cognitive tests and mean (95% CI) values for effects of treatment with EPA and DHA compared with control over the 30-mo period1
| Baseline | 12 mo | 30 mo | Effect of treatment (EPA+DHA − control) | P value for interaction (treatment × time) | |||||
|---|---|---|---|---|---|---|---|---|---|
| Cognitive function test | EPA+DHA (n = 144) | Control (n = 141) | EPA+DHA (n = 138) | Control (n = 130) | EPA+DHA (n = 129) | Control (n = 121) | Mean (95% CI) | P | |
| COWAT 1 | 20.4 ± 5.4 | 19.6 ± 4.7 | 21.2 ± 5.0 | 19.5 ± 5.0 | 20.9 ± 5.2 | 19.2 ± 5.5 | 1.08 (0.25, 1.91) | 0.011 | 0.22 |
| COWAT 2 | 26.2 ± 5.8 | 26.2 ± 5.8 | 26.1 ± 6.2 | 25.7 ± 5.8 | 25.7 ± 5.7 | 24.9 ± 6.2 | 0.50 (−0.43, 1.42) | 0.29 | 0.18 |
| DSST | 58.6 ± 13.5 | 57.2 ± 13.8 | 61.5 ± 13.5 | 57.7 ± 14.9 | 61.4 ± 13.5 | 58.7 ± 15.0 | 1.32 (−0.32, 2.96) | 0.12 | 0.79 |
| TMT A2 | 35.2 ± 13.7 | 35.8 ± 13.5 | 33.0 ± 11.9 | 36.8 ± 11.0 | 34.0 ± 12.6 | 38.1 ± 18.0 | −2.95 (−5.33, −0.57) | 0.015 | 0.08 |
| TMT B2 | 77.5 [60.4–101.2] | 80.2 [60.7–116.2] | 74.0 [60.4–95.9] | 80.1 [64.5–111.3] | 74.5 [60.0–101.9] | 80.2 [62.5–119.1] | −9.44 (−18.60, −0.30) | 0.043 | 0.08 |
| RAVLT1 | 31.2 ± 5.5 | 30.0 ± 5.5 | 32.1 ± 6.1 | 32.1 ± 5.7 | 32.3 ± 5.9 | 31.3 ± 6.7 | −0.44 (−1.41, 0.54) | 0.38 | 0.88 |
| RAVLT2 | 6.5 ± 2.5 | 6.3 ± 2.4 | 7.0 ± 2.2 | 7.2 ± 2.4 | 7.0 ± 2.5 | 7.0 ± 2.4 | −0.15 (−0.53, 0.23) | 0.44 | 0.63 |
| RAVLT3 | 6.0 ± 2.6 | 5.6 ± 2.3 | 6.7 ± 2.6 | 6.6 ± 2.6 | 6.6 ± 2.6 | 6.7 ± 2.7 | −0.19 (−0.58, 0.20) | 0.33 | 0.09 |
| RAVLT4 | 22.7 ± 1.5 | 22.6 ± 1.7 | 23.0 ± 1.5 | 23.0 ± 1.5 | 22.8 ± 1.4 | 22.8 ± 1.6 | −0.18 (−0.44, 0.08) | 0.18 | 0.10 |
Values are mean ± SD except TMT B, for which they are median [IQR]. A linear mixed-effects repeated-measures model was fitted to the data for each cognitive test. Test score was the dependent variable; randomized treatment, sex, and diabetic status were fixed effects; age and baseline score were covariates; subject was a random effect; and assessment time (12 or 30 mo) was a repeated measure. COWAT, Controlled Oral Word Association Test; DSST, Digit-Symbol Substitution Test; RAVLT, Rey Auditory Verbal Learning Test; RAVLT1, immediate recall as a sum of 4 trials; RAVLT2, short delay recall; RAVLT3, delayed recall; RAVLT4, delayed recognition; TMT, Trail Making Test.
A lower score is better. For all other tests, a higher score is better.