Odor-induced brain responses in patients with type 2 diabetes (A) and normal control subjects (B) (with AlphaSim correction, voxel level: P < 0.001, cluster level: P < 0.05, cluster size threshold: 23 voxels). Odor-induced brain responses in patients with type 2 diabetes (A) and normal control subjects (B) (with AlphaSim correction, voxel level: P < 0.001, cluster level: P < 0.05, cluster size threshold: 23 voxels). Independent-sample t test corrected for age, education, sex, BMI, and vascular risk factors indicated significantly decreased brain activations in patients with type 2 diabetes compared with the control group (with AlphaSim correction, voxel level: P < 0.01, cluster level: P < 0.05, cluster size threshold: 71 voxels) (C). Specifically, the average activation (β values) is decreased in the left hippocampus (lHip) and left parahippocampus (lPara) in diabetes (D and E). Independent sample t test. **P < 0.01; ***P < 0.001. L, left; R, right. Zhou Zhang et al. Diabetes 2018;67:994-1006 ©2018 by American Diabetes Association