Table 5.
Relation of diabetes status categories (normal glucose tolerance [NGT], pre-diabetes, type 2 diabetes [T2D]), and of glycemia ascertained as hemoglobin A1c (HbA1c) with the secondary outcomes of cortical thickness in Alzheimer’s Disease (AD) signature regions, ratio of white matter hyperintensities (WMH) to total cranial volume (TCV) with logarithmic transformation, and total recall of the Selective Reminding Test. Adjusted means and standard deviations (SD) are compared across T2D categories estimated using analysis of covariance. Coefficients (β) and 95% confidence intervals (CI) relating HbA1c and amyloid SUVR were estimated using linear regression models. Model 1 is unadjusted; Model 2 is adjusted for age, sex, and APOE-ε4; Model 3 is adjusted for lipids, body mass index, and differences in medication (lipid, blood pressure, and diabetes).
| Model 1 | Model 2 | Model 3 | |||||
|---|---|---|---|---|---|---|---|
| No. | mean (SD) or β (95% CI) | P value | mean (SD) or β (95% CI) | P value | mean (SD) or β (95% CI) | P value | |
| AD signature region cortical thickness | |||||||
| Type 2 diabetes categories | |||||||
| NGT | 139 | 2.699 (0.009) | 2.695 (0.009) | 2.684 (0.010) | |||
| Pre-diabetes | 100 | 2.683 (0.010) | 0.21 | 2.683 (0.010) | 0.37 | 2.676 (0.010) | 0.53 |
| T2D | 111 | 2.661 (0.010) | 0.0028 | 2.665 (0.009) | 0.018 | 2.689 (0.013) | 0.80 |
| P (global) | 0.012 | 0.061 | 0.73 | ||||
| Hemoglobin A1c (HbA1c) | |||||||
| HbA1c | 350 | −0.21 (−0.31, −0.10) | 0.0001 | −0.17 (−0.28, −0.07) | 0.0009 | −0.08 (−0.21, 0.05) | 0.21 |
| Ln (WMH/TCV) | |||||||
| Type 2 diabetes categories | |||||||
| NGT | 139 | 0.237 (0.102) | 0.276 (0.101) | 0.350 (0.118) | |||
| Pre-diabetes | 100 | 0.319 (0.121) | 0.61 | 0.316 (0.119) | 0.79 | 0.340 (0.131) | 0.95 |
| T2D | 111 | 0.932 (0.115) | <0.0001 | 0.885 (0.114) | <0.0001 | 0.742 (0.166) | 0.098 |
| P (global) | <0.0001 | 0.0001 | 0.20 | ||||
| Hemoglobin A1c (HbA1c) | |||||||
| HbA1c | 350 | 0.19 (0.09, 0.29) | 0.0001 | 0.16 (0.07, 0.26) | 0.0009 | 0.07 (−0.06, 0.19) | 0.30 |
| Selective Reminding Test, Total Recall | |||||||
| Type 2 diabetes categories | |||||||
| NGT | 139 | 40.442 (0.733) | 39.665 (0.680) | 39.579 (0.784) | |||
| Pre-diabetes | 100 | 39.828 (0.865) | 0.59 | 39.893 (0.792) | 0.83 | 39.678 (0.862) | 0.93 |
| T2D | 111 | 36.270 (0.817) | 0.0002 | 37.129 (0.756) | 0.014 | 37.626 (1.077) | 0.21 |
| P (global) | 0.0004 | 0.017 | 0.38 | ||||
| Hemoglobin A1c (HbA1c) | |||||||
| HbA1c | 350 | −0.10 (−0.20, 0.01) | 0.074 | −0.04 (−0.14, 0.06) | 0.41 | 0.05 (−0.07, 0.17) | 0.44 |