Effects of Metformin on the Cerebral Metabolic Changes in Type 2 Diabetic Patients

Figure 2

VOI-based (Top) group comparisons (middle) and correlation analyses (bottom). Top: (a) the red VOIs overlaid on volume rendering magnetic resonance images represent hypermetabolic clusters obtained from the voxel-wise comparison (MET > noMET, 𝑃<0.005, uncorrected, 𝑘>150 voxels). (b) The blue VOIs overlaid on volume rendering magnetic resonance images represent hypometabolic clusters obtained from the voxel-wise comparison (MET < noMET, 𝑃<0.005, uncorrected, 𝑘>150 voxels). Middle: VOI-based group comparisons between the MET (𝑛=18), wdMET (𝑛=13), and noMET (𝑛=9) groups. Box plots (median, interquartile range, and extreme values) for normalized FDG uptake values in hypermetabolic clusters (c) and in hypometabolic clusters (d) between the 3 groups (𝑃<0.001). Bottom:VOI-based correlation analyses across the MET and wdMET groups. The normalized FDG uptake values in the hypermetabolic clusters (e) and in the hypometabolic clusters (f) of the patients plotted against their metformin withdrawal durations. The solid line is a significant linear regression line (𝑟=−0.417, 𝑃=0.020) and the dotted line is an estimated linear regression line (𝑟=0.280, 𝑃=0.127). FG: fusiform gyrus; MET: patients taking metformin; noMET: patients not taking metformin; PH: parahippocampal gyrus; VMPFC: ventromedial prefrontal cortex; VOI: volume of interest; wdMET: patients withdrawing from metformin for more than 3 days.

(a)

(b)

(c)

(d)

(e)

(f)