Table 3. Effect of Glucose, Insulin and Insulin Resistance on Brain 11C-PiB Binding.
The cohort of 53 subjects who had 11C-PiB scans and 2 or more OGTT were divided into 2 groups with near equal numbers of subjects based on mean lifetime fasting or 120 minute post-load glucose, insulin and insulin resistance (HOMA) values. Only 47 had insulin values determined. The mean brain 11C-PiB binding for each group, determined from the final PiB scan for each subject are displayed along with their standard deviation. Differences between the groups were assessed using ANOVA.
| PiB Cohort Grouped by Low or High Fasting Glucose | PiB Cohort Grouped by Low or High Fasting Insulin | PiB Cohort Grouped by Low or High Fasting HOMA | |||||||
|---|---|---|---|---|---|---|---|---|---|
| Low (n=27) | High (n=26) | P-Value | Low (n=24) | High (n=23) | P-Value | Low (n=24) | High (n=23) | P-Value | |
| Fasting Glucose | 93 (3) | 105 (6) | 0.000 | 97.9 (7) | 99 (8) | 0.59 | 97 (8) | 100 (6) | 0.034 |
| Fasting Insulin | 9.3 (3.3) | 9.9 (3.7) | 0.31 | 6.7 (1.1) | 12.2 (2.7) | 0.000 | 7.2 (2.2) | 11.9 (2.8) | 0.000 |
| Fasting HOMA | 2.1 (0.7) | 2.5 (1.0) | 0.04 | 1.6 (0.3) | 2.9 (0.7) | 0.000 | 1.5 (0.23) | 3.0 (0.8) | 0.000 |
| Mean PIB Binding | 1.17 (0.26) | 1.18 (0.27) | 0.96 | 1.21 (0.3) | 1.13 (0.24) | 0.22 | 1.21 (0.30) | 1.14 (0.22) | 0.31 |
| PiB Cohort Grouped By Low or High 120 Minute Glucose | PiB Cohort Grouped by Low or High 120 Minute Insulin | PiB Cohort Grouped by Low or High 120 Minute HOMA | |||||||
|---|---|---|---|---|---|---|---|---|---|
| Low (n=27) | High (n=26) | P-Value | Low (n=24) | High (n=23) | P-Value | Low (n=24) | High (n=23) | P-Value | |
| 120 Min Glucose | 110 (12) | 163 (28) | 0.000 | 121 (24) | 151 (40) | 0.001 | 115 (20) | 156 (37) | 0.000 |
| 120 min Insulin | 37 (12) | 71 (41) | 0.000 | 32 (7) | 75 (36) | 0.000 | 33 (8) | 74 (35) | 0.000 |
| 120 Min HOMA | 9.6 (3.6) | 28.4 (18) | 0.000 | 9.5 (2.8) | 28.5 (18) | 0.000 | 9.4 (2.7) | 29.2 (17) | 0.000 |
| Mean PIB Binding | 1.18 (0.28) | 1.17 (0.24) | 0.66 | 1.19 (0.3) | 1.15 (0.23) | 0.76 | 1.2 (0.3) | 1.14 (0.22) | 0.36 |