Table 3.
Respiratory and Cardiovascular Responses to Hypercapnia.
| Variable | baseline | PETCO2 = 3 mmHg | PETCO2 = 6 mmHg | PETCO2 = 9 mmHg | group p-value (ηp2) | hypercapnia p-value (ηp2) | interaction p-value (ηp2) |
|---|---|---|---|---|---|---|---|
| Respiratory Rate (breaths•min−1) | |||||||
| HA | 14 ± 4 | 12 ± 2 | 12 ± 3 | 12 ± 3 | 0.79(0.003) | 0.13(0.07) | 0.37(0.04) |
| MDD | 12 ± 4 | 12 ± 5 | 12 ± 4 | 12 ± 3 | |||
| Heart Rate (bpm) | |||||||
| HA | 69 ± 6 | 73 ± 7 | 72 ± 7 | 72 ± 9 | 0.67(0.007) | <0.01(0.23) | 0.25(0.05) |
| MDD | 68 ± 12 | 72 ± 13* | 69 ± 12 | 71 ± 13* | |||
| Systolic BP (mmHg) | |||||||
| HA | 124 ± 12 | 122 ± 14 | 126 ± 13 | 127 ± 13 | 0.51(0.02) | <0.01(0.19) | 0.08(0.08) |
| MDD | 120 ± 9 | 122 ± 10 | 122 ± 10 | 123 ± 10 | |||
| Diastolic BP (mmHg) | |||||||
| HA | 70 ± 6 | 68 ± 7 | 72 ± 7 | 73 ± 8* | 0.79(0.003) | <0.01(0.46) | 0.34(0.04) |
| MDD | 70 ± 4 | 70 ± 6 | 71 ± 6 | 73 ± 6* | |||
| MAP (mmHg) | |||||||
| HA | 88 ± 7 | 86 ± 9 | 90 ± 8 | 90 ± 9 | 0.85(0.001) | <0.01(0.37) | 0.17(0.06) |
| MDD | 87 ± 4 | 87 ± 6 | 88 ± 6 | 89 ± 7* | |||
HA, healthy non-depressed adults; MDD, major depressive disorder; BP, blood pressure; MAP, mean arterial pressure; PETCO2, end-tidal carbon dioxide. Values are mean ± SD; effect sizes are reported as partial eta squared (ηp2).
*
p<0.05 vs. baseline.