Table 2. Differences in Standardized Cognitive Scores Associated With Quintiles of Gluten Intake Among 13 494 Womena.
Model | Differences by quintiles of gluten intake, mean (95% CI) | |||||
---|---|---|---|---|---|---|
1, lowest | 2 | 3 | 4 | 5, highest | P value for trendb | |
Psychomotor speed and attentionc | ||||||
Standardized score, mean (SD) | −0.03 (1.03) | 0.01 (1.00) | 0.02 (0.96) | −0.002 (1.02) | 0.02 (0.99) | NA |
Age-adjusted | 0 [Reference] | 0.01 (−0.04 to 0.07) | 0.02 (−0.03 to 0.07) | −0.02 (−0.07 to 0.04) | −0.005 (−0.06 to 0.05) | .55 |
Multivariable-adjustedd | 0 [Reference] | 0.01 (−0.04 to 0.06) | 0.01(−0.04 to 0.06) | −0.02 (−0.08 to 0.03) | −0.02 (−0.07 to 0.03) | .22 |
Multivariable-adjusted, with additional adjustment for refined grainsd | 0 [Reference] | 0.01 (−0.04 to 0.07) | 0.02 (−0.03 to 0.07) | −0.02 (−0.07 to 0.04) | −0.01 (−0.06 to 0.05) | .51 |
Multivariable-adjusted, with additional adjustment for whole grainsd | 0 [Reference] | 0.01 (−0.04 to 0.07) | 0.02 (−0.03 to 0.07) | −0.01 (−0.07 to 0.04) | −0.002 (−0.06 to 0.06) | .66 |
Learning and working memoryc | ||||||
Standardized score, mean (SD) | −0.04 (0.98) | 0.0001 (0.96) | 0.07 (0.98) | 0.05 (0.98) | 0.05 (0.96) | NA |
Age-adjusted | 0 [Reference] | 0.03 (−0.03 to 0.08) | 0.09 (0.04 to 0.14) | 0.06 (0.01 to 0.11) | 0.05 (−0.004 to 0.10) | .04 |
Multivariable-adjustedd | 0 [Reference] | 0.01 (−0.04 to 0.06) | 0.07 (0.02 to 0.13) | 0.04 (−0.01 to 0.09) | 0.02 (−0.03 to 0.07) | .30 |
Multivariable-adjusted, with additional adjustment for refined grainsd | 0 [Reference] | 0.01 (−0.04 to 0.06) | 0.07 (0.02 to 0.12) | 0.04 (−0.02 to 0.09) | 0.02 (−0.04 to 0.07) | .49 |
Multivariable-adjusted, with additional adjustment for whole grainsd | 0 [Reference] | 0.01 (−0.04 to 0.07) | 0.07 (0.02 to 0.13) | 0.04 (−0.01 to 0.09) | 0.02 (−0.03 to 0.08) | .33 |
Global cognitionc | ||||||
Standardized score, mean (SD) | −0.05 (1.02) | −0.001 (0.98) | 0.05 (0.97) | 0.02 (1.02) | 0.03 (0.97) | NA |
Age-adjusted | 0 [Reference] | 0.02 (−0.03 to 0.08) | 0.06 (0.01 to 0.11) | 0.02 (−0.03 to 0.07) | 0.02 (−0.03 to 0.07) | .50 |
Multivariable-adjustedd | 0 [Reference] | 0.01 (−0.04 to 0.07) | 0.05 (−0.004 to 0.10) | 0.01 (−0.05 to 0.06) | −0.002 (−0.05 to 0.05) | .78 |
Multivariable-adjusted, with additional adjustment for refined grainsd | 0 [Reference] | 0.02 (−0.04 to 0.07) | 0.05 (−0.002 to 0.10) | 0.01 (−0.05 to 0.06) | −0.003 (−0.05 to 0.06) | .95 |
Multivariable-adjusted, with additional adjustment for whole grainsd | 0 [Reference] | 0.02 (−0.04 to 0.07) | 0.05 (0.001 to 0.11) | 0.01 (−0.04 to 0.07) | 0.01 (−0.05 to 0.07) | .82 |
Abbreviation: NA, not applicable.
Energy-adjusted gluten intake was cumulatively averaged from 1991 to the last questionnaire cycle preceding the cognitive assessment. To infer age-equivalent differences in standardized cognitive scores, parameter estimates for age in the same multivariable-adjusted models for gluten intake were −0.04 (95% CI, −0.04 to −0.03), −0.03 (95% CI, −0.04 to −0.03), and −0.04 (95% CI, −0.05 to −0.04) for psychomotor speed and attention score, learning and working memory score, and global cognition score, respectively.
P value for trend was calculated using the median value for each gluten intake quintile as a continuous variable.
Standardized scores for psychomotor speed and attention, learning and working memory, and global cognition were calculated by standardizing the mean standardized scores of the following Cogstate battery tasks: Detection and Identification, One Card Learning and One Back, and all 4 tasks, respectively. Higher scores indicate better performance, with 1 unit increase representing 1 SD higher than the mean.
Adjusted for age, race, body mass index, husband’s educational attainment, family income, history of diabetes, history of hypertension, history of hypercholesterolemia, history of myocardial infarction, current depression status, smoking, aspirin or nonsteroid anti-inflammatory drug use, multivitamin use, physical activity, menopausal status and hormone use, total energy intake, alcohol intake, and Alternative Healthy Eating Index score, excluding alcohol and whole grains.