Table 3.
Association between Neuroimaging Biomarkers and B-SIT Score in Cognitively Normal Individuals - the Mayo Clinic Study of Aging.
| Continuous B-SIT | ||
|---|---|---|
|
| ||
| Imaging Biomarkers | slope (95%CI)a | p |
| Basic model | ||
| Abnormal 11C-PiB PETb | −.41 (−.91, .08) | .10 |
| Abnormal 18F-FDG PETc | −.12 (−.67, .42) | .66 |
| Abnormal AD Sig. CTd | −.43 (−.76, −.09) | .01 |
| Abnormal HVae | −.72 (−1.15, −.28) | <.01 |
| Basic model adjusted also for APOE ε4 carrier status | ||
| Abnormal 11C-PiB PET | −.36 (−.87, .15) | .16 |
| Abnormal 18F-FDG PET | −.09 (−.64, .46) | .75 |
| Abnormal AD Sig. CT | −.42 (−.76, −.08) | .01 |
| Abnormal HVa | −.71 (−1.15, −.28) | <.01 |
| Basic model adjusted also for the Boston Naming Testf | ||
| Abnormal 11C-PiB PET | −.38 (−.87, .11) | .13 |
| Abnormal 18F-FDG PET | −.15 (−.70, .40) | .60 |
| Abnormal AD Sig. CT | −.37 (−.71, −.02) | .04 |
| Abnormal HVa | −.71 (−1.14, −.27) | <.01 |
| Basic model adjusted also for UPDRS | ||
| Abnormal 11C-PiB PET | −.42 (−.91, .07) | .09 |
| Abnormal 18F-FDG PET | −.09 (−.64, .45) | .74 |
| Abnormal AD Sig. CT | −.40 (−.74, −.06) | .02 |
| Abnormal HVa | −.70 (−1.14, −.26) | <.01 |
| Basic model adjusted also for history of head traumag | ||
| Abnormal 11C-PiB PET | −.37 (−.93, .19) | .20 |
| Abnormal 18F-FDG PET | −.02 (−.64, .60) | .95 |
| Abnormal AD Sig. CT | −.39 (−.75, −.03) | .03 |
| Abnormal HVa | −.67 (−1.13, −.22) | <.01 |
Slopes (95%CI) retained from multivariable linear regression models. Separate models were run for each neuroimaging biomarker, represented by one row in the table, having continuous B-SIT as the dependent (outcome) variable. Basic model is adjusted for age (at B-SIT testing), education, sex.
Abnormal 11C-PiB PET (elevated amyloid) was defined as standardized uptake value ratio (SUVR)>1.40.
Abnormal 18F-FDG PET (hypometabolism) was defined as SUVR<1.32.
Abnormal (reduced) AD Sig. CT was defined as <2.74 mm.
Abnormal (reduced) hippocampal volume was defined as <−2.40 cm3 (adjusted for total intracranial volume).
Kaplan EGH, Weintraub S. The Boston Naming Test, 2nd ed. Boston, MA: Lea & Fabiger, 1978.
History of head trauma: “Have you ever experienced any head injuries that led you to see a doctor, stay in the hospital, lose your memory, or become unconscious”.
B-SIT = Brief Smell Identification Test; CI = confidence interval. 11C-PiB PET = Pittsburgh compound B positron emission tomography; 18F-FDG = 18fluorodeoxyglucose; AD Sig. CT = Alzheimer’s Disease signature cortical thickness; HVa = hippocampal volume adjusted for total intracranial volume; UPDRS = Unified Parkinson’s Disease Rating Scale.