TABLE 3.
CHARACTERISTICS OF THE COHORT AT BASELINE
| Variable | Mobility Disability Present (n = 270) | Mobility Disability Absent (n = 574) |
|---|---|---|
| Age, yr | 82.9 (6.84) | 79.5 (7.09)* |
| Sex, % female | 225 (83.3%) | 403 (70.2%)* |
| Education, yr | 13.9 (2.85) | 14.8 (2.93)* |
| Mini–mental status exam | 27.5 (2.25) | 28.3 (1.91)* |
| FEV1/FVC < 0.7 | 21 (7.8%) | 21 (3.7%)† |
| Pulmonary function (composite) | −0.32 (0.79) | 0.19 (0.90)* |
| FVC, L | 1.7 (0.55) | 2.0 (0.61)* |
| FEV1, L | 1.4 (0.50) | 1.7 (0.55)* |
| PEF, L/min | 216 (89.0) | 282 (112.4)* |
| Respiratory muscle (composite) | −0.31 (0.78) | 0.15 (0.87)* |
| Maximal expiratory pressure, mm H2O | 59 (21.5) | 70 (24.7)* |
| Maximal inspiratory pressure, mm H2O | 33 (18.0) | 44 (20.2)* |
| Leg strength (composite) | −0.21 (0.75) | 0.10 (0.85)* |
| BMI, kg/m2 | 28.1 (6.10) | 27.0 (4.76)† |
| Physical activity, h/wk | 2.7 (3.66) | 3.4 (3.74)* |
| Vascular risk factors, number | 1.2 (0.81) | 1.1 (0.57)NS |
| Smoking | 101 (41.1%) | 236 (37.4%)NS |
| Diabetes | 41 (15.2%) | 66 (11.5%)NS |
| Hypertension | 187 (69.3%) | 326 (56.8%)* |
| Vascular diseases, number | 0.5 (0.75) | 0.3 (0. 79)* |
| Myocardial infarction | 41 (39.8%) | 62 (10.8%)NS |
| Congestive heart failure | 16 (6.8%) | 21 (4.3%)NS |
| Claudication | 36 (13.3%) | 29 (5.1%)* |
| Stroke | 40 (13.9%) | 44 (7.7%)† |
Definition of abbreviations: BMI = body mass index; NS = not significant.
P < 0.001.
P < 0.01.
The cohort was divided on the basis of presence or absence of mobility disability at baseline (gait speed ≤ 0.55 m/s). Mean (SD, range). For the mini–mental state exam (possible range, 0–30), a higher score indicates a higher level of cognition. Pulmonary function refers to composite measure of pulmonary function based on z score of vital capacity, forced expiratory volume, and peak expiratory flow; a higher score indicates a higher level of pulmonary function. Composite measure of respiratory muscle strength was based on z score of maximal expiratory and inspiratory pressures; a higher score indicates a higher level of cognition. Composite measure of leg strength was based on mean z score of strength of hip flexion, knee extension, ankle dorsiflexion, and ankle plantar flexion bilaterally; a higher score indicates higher strength. Physical activity refers to self-reported frequency of participation in five physical activities (h/wk); a higher score indicates more frequent participation. Vascular risk factors refers to number of three risk factors (smoking, diabetes, and hypertension), self-reported. Vascular diseases refers to number of four vascular diseases (of myocardial infarction, congestive heart failure, claudication and stroke), self-reported.