Table 1.
Baseline Characteristics of the Study Participants.*
| Characteristic | Testosterone Gel (N = 106) |
Placebo Gel (N = 103) |
P Value† |
|---|---|---|---|
| Enrollment site — no. (%) | 0.72 | ||
| Boston University Medical Center | 26 (25) | 30 (29) | |
| New England Research Institutes | 70 (66) | 65 (63) | |
| Veterans Affairs Boston Healthcare System | 10 (9) | 8 (8) | |
| Age — yr | 74±6 | 74±5 | 0.84 |
| Body-mass index‡ | 29.7±4.1 | 30.0±4.2 | 0.58 |
| Race — no./total no. (%)§ | 0.04 | ||
| Black | 15/105 (14) | 4/102 (4) | |
| White | 87/105 (83) | 93/102 (91) | |
| Asian or Pacific Islander | 1/105 (1) | 1/102 (1) | |
| Other¶ | 2/105 (2) | 4/102 (4) | |
| Hispanic or Latino ethnic group — no./total no. (%)§ | 2/97 (2) | 2/88 (2) | 0.99 |
| Testosterone level‖ | |||
| Total — ng/dl | 250±57 | 236±66 | 0.11 |
| Free — pg/ml | 48±12 | 43±14 | 0.003 |
| Score on the Short Physical Performance Battery** | 7.6±1.5 | 7.7±1.4 | 0.74 |
| Measure of strength | |||
| Leg press | 0.51 | ||
| No. who performed the test | 75 | 69 | |
| Force — newtons | 1947±430 | 1991±365 | |
| Chest press | 0.74 | ||
| No. who performed the test | 66 | 62 | |
| Force — newtons | 424±112 | 418±102 | |
| Dominant-hand grip | 0.46 | ||
| No. who performed the test | 97 | 92 | |
| Force — kg | 27.3±6.7 | 26.6±7.4 | |
| 50-m walking test | |||
| Without a load | 0.64 | ||
| No. who performed the test | 84 | 79 | |
| Speed — m/sec | 1.62±0.40 | 1.60±0.37 | |
| With a load | 0.99 | ||
| No. who performed the test | 54 | 49 | |
| Speed — m/sec | 1.63±0.34 | 1.63±0.36 | |
| Stair-climbing test | |||
| Without a load | 0.59 | ||
| No. who performed the test | 72 | 68 | |
| Power — W | 329±113 | 320±90 | |
| With a load | 0.44 | ||
| No. who performed the test | 69 | 66 | |
| Power — W | 363±135 | 346±115 | |
| Lift-and-lower test†† | 0.77 | ||
| No. who performed the test | 64 | 58 | |
| Score | 24.4±9.2 | 23.9±9.8 |
Plus–minus values are means ±SD.
The P values were calculated with the use of Fisher’s exact test and Student’s t-test.
The body-mass index is the weight in kilograms divided by the square of the height in meters.
Race or ethnic group was determined by self-report.
Included in this category were subjects who described themselves as being of mixed race, who did not report their race, or who described themselves in categories that were not black, white, or Asian–Pacific Islander.
To convert the values for total testosterone to nanomoles per liter, multiply by 0.0347. To convert the values for free testosterone to picomoles per liter, multiply by 3.467. Total and free testosterone levels were measured in a single blood sample that was obtained between 7 a.m. and 11 a.m. The subjects were eligible if they had a total testosterone level between 100 and 350 ng per deciliter or a free testosterone level of less than 50 pg per milliliter.
Scores on the Short Physical Performance Battery range from 0 to 12, with higher scores indicating better performance.
The scores on the lift-and-lower test refer to the number of shelves a subject was able to touch with a weighted basket in 1 minute. Higher scores indicate better performance.