Table 1.
Sample n’s, means and standard deviations by gender and zygosity for resting and standing hemodynamic data.
| Monozygotic Twins | Dizygotic Twins | ||||||
|---|---|---|---|---|---|---|---|
| M(SD) | Male | Female | MZ Total | Male | Female | DZ Total | |
| n(pairs) | 37 | 62 | 99 | 41 | 67 | 108 | |
| Age (yrs) | 45.86 (15.73) | 47.50 (14.46) | 46.90 (14.92) | 47.27 (11.76) | 46.54 (13.21) | 46.83 (12.64) | |
| SBP (mmHg) | |||||||
| Baseline | 134.30 (17.47) | 127.18 (19.11) | 129.80(18.80) | 134.63 (18.20) | 131.97 (19.94)a* | 133.00 (19.29)b* | |
| Orthostasis | 137.64 (19.39) | 128.90 (18.56) | 132.15 (19.30) | 136.04 (18.53) | 133.54 (19.17)a* | 134.51 (18.93) | |
| DBP (mmHg) | |||||||
| Baseline | 80.75 (11.75) | 78.49 (11.51) | 79.32 (11.62) | 82.37 (11.45) | 82.75 (12.40)a** | 82.60 (12.02)b** | |
| Orthostasis | 85.63 (10.51) | 82.80 (11.44) | 83.85 (11.16) | 87.97 (13.11) | 88.04 (13.88)a** | 88.01 (13.55) b** | |
| MAP (mmHg) | |||||||
| Baseline | 107.52 (13.30) | 102.83 (14.04) | 104.56 (13.92) | 108.50 (13.82) | 107.36 (15.00)a** | 107.80 (14.54)b** | |
| Orthostasis | 102.97 (11.75) | 98.17 (12.69) | 99.95 (12.53) | 103.99 (13.80) | 103.20 (14.41)a** | 103.51 (14.15)b** | |
| COest (L/min) | |||||||
| Baseline | 7.75 (2.39) | 7.26 (2.17) | 7.44 (2.26) | 7.91 (2.72) | 7.50 (2.4) | 7.65 (2.53) | |
| Orthostasis | 8.42 (2.94) | 7.41 (2.33) | 7.79 (2.62) | 8.32 (3.45) | 7.52 (2.41) | 7.84 (2.88) | |
| TPRest (mmHg.s/ml) | |||||||
| Baseline | 0.82 (0.23) | 0.83 (0.22) | 0.83 (0.22) | 0.81 (0.20) | 0.86 (0.23) | 0.84 (0.22) | |
| Orthostasis | 0.81 (0.26) | 0.88 (0.42) | 0.85 (0.37) | 0.84 (0.29) | 0.90 (0.30) | 0.88 (0.30) | |
SBP = Systolic Blood Pressure, DBP = Diastolic Blood Pressure, MAP = Mean Arterial Pressure, mmHg = millimeters of Mercury, COest = estimated Cardiac Output, L/min = liters per minute, TPRest = estimated Total Peripheral Resistance, mmHg.s/ml = millimeters of Mercury per second per milliliter,
a
= between-zygosity, within-gender comparison,
b
= between-zygosity comparison,
*
p ≤.05,
**
p ≤.01.