Group differences of regional GM volumes in left hemisphere and their relationship with Multi-Scale GV.

<p>‘*’ indicates significant differences between the type 2 DM group (white) and controls (grey) in GM volumes (One-Way ANOVA); regional GM volumes in left hemisphere were correlated with Multi-Scale GV for diabetics and/or controls, blue indicates positive correlation, red indicates negative correlation with each GVC, G' = gyrus, ‘#’ indicates we found similar relationship between Multi-Scale GV and GM volumes in the right hemisphere (<i>r²</i> = 0.26–074, <i>P</i><0.05). The bar graphs are presented as mean ± SEM.</p

The brain regions associated with Multi-Scale GV.

<p>Higher glycemic variability of GVC_1–3 (period 0.5–2 hours) were associated with lower gray matter (GM) volume (red color; both hemispheres in the cingulate gyrus, hippocampal gyrus, middle and inferior temporal gyrus, insular cortex, the left superior parietal gyrus and right fusiform gyrus), greater GM volume (blue color; the bilateral supramarginal gyrus, left angular gyrus and left middle orbitofrontal gyrus), and greater cerebrospinal fluid (CSF) in the right lingual gyrus (green color).</p

Day and night Multi-Scale Glycemic Variability in older adults with and without type 2 DM As compared to controls, the type 2 DM group had greater variability during the day in GVC_2–5, and night GVC_3–5.

<p>At night, glycemic variability declined in type 2 DM in GVC_2–4 and in controls in GVC₃. ‘*’ (<i>P</i> = 0.002) and ‘‡’ (<i>P</i><0.0001) indicate significant differences between diabetics/day and controls/day; ‘∥∥’ (<i>P</i><0.0001) indicates significant differences between diabetics/night and controls/night; ‘†’ (<i>P</i> = 0.003) and ‘§’ (<i>P</i><0.0001) indicates significant differences between diabetics/day and diabetics/night; ‘¶’ (<i>P</i> = 0.028) indicates significant difference between control/day and control/night. All the <i>P</i> values were obtained by ANOVA. Results are presented as mean ± SEM.</p

Relationships between the fourth glycemic variability cycle (GVC₄) and conventional measures of glycemic control.

<p>The degree of glycemic variability within GVC₄ was highly correlated with SD (A) and MAGE (B), but the areas under the curves of GVC₄ and GVC₅ were greater than SD and MAGE (C). The degree of glycemic variability within GVC₄ was highly correlated several markers of glucose control including HbA1c (D). As with GVC₄ (the cycle linked with meal intake), the example in this figure, similar relationships were observed for all other GVC cycles. The <i>r²</i> and <i>P</i> values represent the least square model fit.</p

Examples of least squares models indicating negative relationships between Multi-Scale GV and regional GM volumes as well as cognitive performance.

<p>(A) relationship between GVC₂ and GM volume in the left insular cortex; (B) relationship between GVC₁ and GM volume in the right fusiform gyrus; (C) relationship between GVC₂ and GM volume in the left cingulate gyrus; (D) relationship between GVC₂ and overall cognitive performance (composite T score) (diabetics: triangles; controls: circles). We presented <i>r²</i> for the entire model adjusted for age and sex and group, and <i>P</i> values for the specific effect of Multi-scale GV.</p

Characteristics of the study cohort.

<p>Data are presented as mean ± standard deviation (SD). P values were obtained by One-Way ANOVA to compare group means and using Wilcoxon Test for not normally distributed variables. The variables analyzed using Wilcoxon Test are Age, Sex, Race, Education, Hypertension, Microalbumin (urine), Cholesterol-to-HDL ratio, Triglycerides, Total number of Hypoglycemic Events, Average duration of Hypoglycemic Events, and Hematocrit, and other variables were analyzed using One-Way ANOVA. MMSE: Mini-Mental State Examination.</p