Table 2.
Arterial plasma insulin levels (pmol/L) during clamp
| Portal Vein GLP-1 (n = 10) | Jugular Vein GLP-1 (n = 10) | P Value | |
|---|---|---|---|
| Hyperglycemia | 282 ± 33 | 318 ± 29 | ns |
| + GLP-1 1.5 μg·kg−1·h−1 | 300 ± 36 | 378 ± 28 | ns |
| + GLP-1 2.5 μg·kg−1·h−1 | 396 ± 44 | 679 ± 112 | ns |
| + GLP-1 5.0 μg·kg−1·h−1 | 577 ± 71 | 1,178 ± 235* | <0.05 |
| With DPP4 Inhibition (Vildagliptin) | |||
|---|---|---|---|
| Portal Vein GLP-1 (n = 9) | Jugular Vein GLP-1 (n = 12) | P Value | |
| Hyperglycemia | 543 ± 59 | 672 ± 135 | ns |
| + GLP-1 1.5 μg·kg−1·h−1 | 932 ± 168 | 1,569 ± 264 | ns |
| + GLP-1 2.5 μg·kg−1·h−1 | 1,535 ± 366 | 2,310 ± 340 | ns |
| + GLP-1 5.0 μg·kg−1·h−1 | 1,822 ± 300 | 1,788 ± 425 | ns |
Values are mean ± SE. Both the doses (P < 0.0001) of GLP-1 and the infusion site (P = 0.0207) had a significant impact on arterial plasma insulin levels when analyzed by RM two-way ANOVA. Bonferroni post tests demonstrated significantly higher insulin levels during infusion of GLP-1 into the jugular vs. portal vein at a dose of 5 μg·kg−1·h−1. With DPP4 inhibition, the dose (P < 0.0001) of GLP-1 but not infusion site (P = 0.2799) had a significant impact on arterial plasma insulin levels when analyzed by RM two-way ANOVA. All values are mean ± SE. GLP-1, glucagon-like peptide-1; RM, repeated measures; ns, not significant.
*
P < 0.05.