Table 2.
Hemodynamic response
| Baseline | Intervention | P Value | |
|---|---|---|---|
| Heart rate, beats/min | |||
| Hypercapnia | 66 ± 8 | 63 ± 8* | <0.001 |
| Intravenous insulin | 59 ± 8 | 63 ± 10* | <0.001 |
| Intranasal insulin | 63 ± 8 | 64 ± 9 | 0.943 |
| Time control | 68 ± 10 | 66 ± 11 | 0.249 |
| Mean blood pressure, mmHg | |||
| Hypercapnia | 89 ± 9 | 93 ± 8* | <0.001 |
| Intravenous insulin | 84 ± 8 | 89 ± 7* | 0.012 |
| Intranasal insulin | 94 ± 8 | 98 ± 10* | 0.039 |
| Time control | 93 ± 7 | 96 ± 4 | 0.053 |
| Respiratory rate, breaths/min | |||
| Hypercapnia | 13 ± 4 | 12 ± 4 | 0.138 |
| Intravenous insulin | 15 ± 3 | 16 ± 3 | 0.255 |
| Intranasal insulin | 13 ± 4 | 13 ± 5 | 0.918 |
| Time control | 13 ± 4 | 13 ± 4 | 0.619 |
| Femoral artery diameter, cm | |||
| Hypercapnia | — | — | — |
| Intravenous insulin | 0.62 ± 0.08 | 0.62 ± 0.09 | 0.741 |
| Intranasal insulin | 0.56 ± 0.07 | 0.57 ± 0.07 | 0.111 |
| Time control | 0.58 ± 0.08 | 0.58 ± 0.09 | 0.653 |
| Femoral blood flow, mL/min | |||
| Hypercapnia | — | — | — |
| Intravenous insulin | 122 ± 70 | 143 ± 76* | 0.048 |
| Intranasal insulin | 94 ± 23 | 103 ± 40 | 0.809 |
| Time control | 73 ± 28 | 77 ± 31 | 0.268 |
| Femoral vascular conductance, mL/min/100 mmHg | |||
| Hypercapnia | — | — | — |
| Intravenous insulin | 142 ± 76 | 159 ± 75 | 0.080 |
| Intranasal insulin | 101 ± 25 | 106 ± 39 | 0.463 |
| Time control | 80 ± 33 | 80 ± 34 | 0.884 |
| Insulin, µIU/mL | |||
| Hypercapnia | — | — | — |
| Intravenous insulin | 6.0 ± 2.6 | 52.7 ± 12.7* | <0.001 |
| Intranasal insulin | 6.9 ± 4.5 | 4.9 ± 1.8* | 0.030 |
| Time control | — | — | — |
| Glucose, mg/dL | |||
| Hypercapnia | — | — | — |
| Intravenous insulin | 78 ± 7 | 81 ± 11 | 0.381 |
| Intranasal insulin | 76 ± 8 | 74 ± 9 | 0.375 |
| Time control | — | — | — |
| End-tidal carbon dioxide, % | |||
| Hypercapnia | 5.7 ± 0.9 | 6.5 ± 0.6* | <0.001 |
| Intravenous insulin | 6.4 ± 0.8 | 6.2 ± 0.6 | 0.199 |
| Intranasal insulin | 5.6 ± 0.7 | 5.8 ± 0.7 | 0.625 |
| Time control | 5.2 ± 0.6 | 5.5 ± 0.4 | 0.149 |
Data are reported as means ± SD from prior to and during hypercapnia (n = 23), intravenous insulin (n = 13), intranasal insulin (n = 17), and time control (n = 9) unless otherwise specified (intravenous insulin: respiratory rate, n = 12; intravenous insulin: carbon dioxide, n = 3; intranasal insulin: insulin, n = 15).
*
P < 0.05 vs. baseline determined via paired t test or Wilcoxon matched-pairs signed rank test if not normally distributed.