Table 1.
Characteristics of the 126 Participants From the Baltimore Longitudinal Study of Aging Evaluated in This Study
| Characteristic | Age < 65 y, (n = 30) | Age ≥ 65 y, (n = 96) | p Value |
|---|---|---|---|
| Mean (SD) or No. (%) | Mean (SD) or No. (%) | ||
| Female sex | 19 (63.3) | 54 (56.2) | .64 |
| Height, cm | 168.9 (9.9) | 165.7 (8.3) | .12 |
| Weight, kg | 78.5 (17.2) | 73.6 (15.2) | .17 |
| k PCr, s−1 | 0.029 (0.008) | 0.023 (0.006) | .001 |
| %PCr depletion | 26.67 (8.27) | 29.31 (9.33) | .166 |
| Initial PCr | 24.61 (4.88) | 20.81 (4.73) | <.001 |
| Peak VO2, mL/kg/min | 26.6 (5.6) | 20.0 (4.3) | <.001 |
| Usual gait speed (6 m), m/s | 1.3 (0.2) | 1.2 (0.2) | .001 |
| Usual gait speed (150s), m/s | 1.3 (0.1) | 1.2 (0.1) | .002 |
| Rapid gait speed (6 m), m/s | 2.0 (0.3) | 1.7 (0.3) | <.001 |
| Rapid gait speed (400 m), m/s | 1.7 (0.2) | 1.4 (0.2) | <.001 |
Notes: k PCr = phosphocreatine recovery rate; VO2 = oxygen consumption.
p values were derived using t tests for continuous variables and using chi-square tests for binary variables.