Table 1.
Characteristics of the study sample
| Variable | Overall (N=2858) | Women (N=1493) | Men (N=1365) | P-value |
|---|---|---|---|---|
| Age, years | 54±9 | 53±9 | 54±9 | 0.13 |
| Nonwhite race, N (%) | 263 (9.2) | 137 (9.2) | 126 (9.2) | 1.00 |
| Height, in | 66.8±3.7 | 64.3±2.5 | 69.5±2.7 | <0.001 |
| Body mass index, kg/m2 | 28.1±5.3 | 27.1±5.6 | 29.1±4.7 | <0.001 |
| Hypertension medication use, N (%) | 599 (21) | 256 (17) | 343 (25) | 0.001 |
| AV nodal blocking medication use, N(%) | 230 (8.0) | 98 (6.6) | 132 (9.7) | 0.003 |
| Hypertension, N (%) | 1349 (47) | 540 (36) | 809 (59) | <0.001 |
| Prevalent cardiovascular disease, N (%) | 104 (3.6) | 37 (2.5) | 67 (4.9) | 0.85 |
| Diabetes, N (%) | 206 (7.2) | 69 (4.6) | 137 (10.0) | <0.001 |
| Current smoking, N (%) | 164 (5.7) | 84 (5.6) | 80 (5.9) | <0.001 |
| Total Cholesterol, mg/dL | 191±36 | 196±35 | 184±36 | <0.001 |
| HDL Cholesterol, mg/dL | 60±19 | 68±19 | 51±15 | <0.001 |
| Physical activity index | 34±6 | 33±4 | 35±7 | <0.001 |
| SBP at rest, mm Hg | 119±14 | 116±14 | 123±13 | <0.001 |
| SBP during freewheel exercise, mm Hg | 130±17 | 127±18 | 134±16 | <0.001 |
| SBP at 75 watts, mm Hg | 153±21 | 154±22 | 152±19 | 0.06 |
| SBP at peak, mm Hg | 181±25 | 172±23 | 191±23 | <0.001 |
| SBP/workload slope, mm Hg/watts | 0.3±0.1 | 0.4±0.2 | 0.3±0.1 | <0.001 |
| DBP at rest, mm Hg | 79±8 | 78±8 | 82±8 | <0.001 |
| DBP at peak, mm Hg | 84±10 | 82±9 | 87±10 | <0.001 |
| Resting heart rate, beats/min | 71.9±12.0 | 74.0±11.9 | 69.6 ±11.6 | <0.001 |
| Peak heart rate, beats/min | 152.1±18.7 | 152.5± 18.2 | 151.6 ±19.3 | 0.18 |
| Peak O2 pulse, ml/beat | 12.4±3.9 | 9.7±2.1 | 15.3±3.2 | <0.001 |
| Carotid-femoral pulse wave velocity, m/s | 7.9±1.9 | 7.5±1.7 | 8.3±2.0 | <0.001 |
| Forward wave amplitude, mm Hg | 48±12 | 47±12 | 48±12 | 0.02 |
| Characteristic impedance | 207 (70) | 222 (75) | 190 (60) | <0.001 |
| Augmentation index, % | 16.6±11.8 | 20.9±10.9 | 11.9±10.9 | <0.001 |
| Peak respiratory exchange ratio | 1.23±0.09 | 1.21±0.09 | 1.24±0.09 | <0.001 |
| Peak workload, watts | 173±60 | 136±35 | 214±54 | <0.001 |
| Peak VO2, ml/kg/min | 23.4±6.8 | 21.0±5.9 | 26.1±6.8 | <0.001 |
| Percent predicted peak VO2, % | 96 (20) | 98 (21) | 93 (18) | <0.001 |
Values are displayed as mean ± SD for continuous variables and N (%) for categorical variables. Abbreviations: SBP, systolic blood pressure; DBP, diastolic blood pressure; VO2, oxygen uptake. P-value reflects a comparison of men and women using two sample t-tests for continuous variables and chi-square tests for categorical variables.