Table 1.
Baseline Characteristics by Sex in the BLSA Analytic Sample
| Characteristic | Men | Women |
|---|---|---|
| N = 602, No. | 335 | 267 |
| Age, mean (SD), y | 78.6 (6.6) | 77.4 (6.7) |
| Black, % | 17.0 | 31.1 |
| Health status and behaviors | ||
| Current or recent smoker, % | 2.1 | 4.1 |
| Uses a walking aid, % | 3.0 | 3.4 |
| Fair to poor self-rated health, % | 4.2 | 3.4 |
| Very good to excellent self-rated health, % | 66.9 | 65.9 |
| Obese (BMI ≥30kg/m2), % | 23.9 | 23.6 |
| Sedentary (active < 30min/wk), % | 37.6 | 47.9 |
| Physically active at least 150min/wk, % | 40.3 | 27.3 |
| Thyroid hormone status | ||
| Thyroid stimulating hormone, mean (SD), mU/L | 2.76 (1.52) | 2.69 (1.44) |
| Subclinical hypothyroidism (TSH = 4.50–9.99 mU/L), % | 11.3 | 10.1 |
| Free thyroxine, mean (SD), ng/Dl | 1.02 (0.14) | 1.01 (0.13) |
| Mobility and fatigue | ||
| Walking ability index score, mean (SD), points | 7.66 (2.13) | 7.40 (2.40) |
| Usual gait speed, mean (SD), m/s | 1.09 (0.25) | 1.06 (0.24) |
| Rapid gait speed, mean (SD), m/s | 1.66 (0.41) | 1.52 (0.36) |
| 400-m time*, mean (SD), s | 293 (70.9) | 312 (81.7) |
| Fatigability score†, mean (SD), points | 9.14 (2.33) | 9.17 (2.14) |
| Usual energy level past month, mean (SD), points | 7.44 (1.61) | 7.42 (1.61) |
| Frequency a lot of energy past 4 weeks, mean (SD) | 2.60 (1.05) | 2.61 (1.05) |
Notes: BLSA = Baltimore Longitudinal Study of Aging; BMI = body mass index.
*Persons able to complete the full 400-m walk only (281 men and 215 women).
†Subsample administered the fatigability test which was implemented later in the study (290 men and 224 women).