Table 2 Age-adjusted cognitive z scores (95% CI) by baseline glucose level

Cognitive testNormal glucose, n = 6,463Impaired fasting glucose, n = 297Diabetes, n = 267p For trend
* A negative z score means it is below the standardized mean; a positive z score means it is above the standardized mean. A negative value for the z scores implies worse cognitive function than the overall average at baseline, and worse cognitive change than average for the 4-year change data.
Trails A
    Baseline0.02 (−0.00, 0.04)−0.21 (−0.32, −0.10)−0.25 (−0.38, −0.134)<0.001
    4-Year change*0.00 (−0.03, 0.03)0.01 (−0.14, 0.15)−0.09 (−0.23, 0.06)0.296
Trails B
    Baseline0.01 (−0.01, 0.03)−0.06 (−0.18, 0.06)−0.17 (−0.29, −0.05)0.003
    4-Year change*0.01 (−0.01, 0.04)−0.02 (−0.17, 0.13)−0.30 (−0.45, −0.16)<0.001
Word List Fluency
    Baseline0.01 (−0.01, 0.03)−0.07 (−0.18, 0.05)−0.19 (−0.31, −0.07)<0.001
    4-Year change*0.00 (−0.03, 0.03)0.15 (0.01, 0.28)−0.18 (−0.33, −0.04)0.179
Word List Memory
    Baseline0.01 (−0.02, 0.04)−0.04 (0.20, 0.12)−0.22 (−0.36, −0.07)0.003
    4-Year change*0.01 (−0.03, 0.04)−0.03 (−0.24, 0.18)−0.16 (−0.34, 0.02)0.071
Word List Recall
    Baseline0.01 (−0.02, 0.04)−0.03 (−0.19, 0.13)−0.24 (−0.38, −0.09)0.001
    4-Year change*0.00 (−0.03, 0.04)0.03 (−0.18, 0.24)−0.10 (−0.27, 0.08)0.363
Composite Z-score
    Baseline0.40 (0.30, 0.49)0.14 (−0.36, 0.64)−0.78 (−1.23, −0.33)<0.001
    4-Year change*−0.05 (−0.16, 0.05)0.11 (−0.53, 0.75)−1.00 (−1.50, −0.50)0.001