Table 4. Effect of Testosterone on Cognitive Function Outcomes Among All Men in the Testosterone Trials.
| No. of Participants | Mean (95% CI) | Difference (95% CI)c,d | P Valued | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Unadjusteda | Change From Baseline Values, Adjustedb | ||||||||
| Baseline | Treatment Period Values | ||||||||
| Month 6 | Month 12 | Month 6 | Month 12 | ||||||
| Primary Outcome | |||||||||
| Delayed paragraph recall (Logical Memory II) | Testosterone | 392 | 15.3 (14.6 to 16.0) |
17.3 (16.5 to 18.0) |
17.6 (16.9 to 18.4) |
0.5 (−0.4 to 1.4) |
0.8 (−0.1 to 1.7) |
0.09 (−0.57 to 0.75) |
.80 |
| Placebo | 393 | 15.7 (15.0 to 16.3) |
17.3 (16.5 to 18.0) |
17.5 (16.8 to 18.3) |
0.4 (−0.5 to 1.3) |
0.7 (−0.2 to 1.6) |
|||
| Secondary Outcome | |||||||||
| Visual memory (Benton Visual Retention Test) | Testosterone | 391 | −7.5 (−7.8 to −7.1) |
−7.3 (−7.8 to −6.9) |
−7.1 (−7.5 to −6.7) |
−0.2 (−0.7 to 0.3) |
−0.0 (−0.5 to 0.5) |
−0.34 (−0.70 to 0.01) |
.06 |
| Placebo | 393 | −7.3 (−7.6 to −6.9) |
−7.1 (−7.5 to −6.7) |
−6.6 (−7.0 to −6.2) |
−0.0 (−0.5 to 0.5) |
0.4 (−0.1 to 0.9) |
|||
| Spatial ability (Card Rotation Test) | Testosterone | 387 | 29.7 (28.2 to 31.2) |
31.8 (130.2 to 33.2) |
32.7 (31.0 to 34.5) |
0.9 (−1.1 to 2.8) |
1.4 (−0.5 to 3.4) |
−0.08 (−1.44 to 1.28) |
.91 |
| Placebo | 388 | 31.4 (29.9 to 32.9) |
33.0 (31.3 to 34.6) |
34.0 (32.3 to 35.8) |
0.8 (−1.1 to 2.7) |
1.6 (−0.3 to 3.6) |
|||
| Executive function (Trail-Making Test B − A), s | Testosterone | 389 | 83.1 (76.8 to 89.4) |
69.2 (63.5 to 74.8) |
70.5 (64.9 to 76.1) |
−4.5 (−12.4 to 3.3) |
−1.8 (−9.7 to 6.1) |
−5.68 (−11.18 to −0.17) |
|
| Placebo | 392 | 73.3 (68.1 to 78.5) |
70.6 (64.7 to 76.5) |
72.9 (66.9 to 79.0) |
0.7 (−7.0 to 8.4) |
4.3 (−3.4 to 12.0) |
|||
| Exploratory Outcomes | |||||||||
| Subjective memory complaints (MAC-Q) | Testosterone | 392 | 23.3 (22.7 to 23.8) |
22.6 (22.0 to 23.1) |
22.9 (22.3 to 23.4) |
−0.8 (−1.5 to −0.2) |
−0.6 (−1.3 to 0.1) |
−0.24 (−0.72 to 0.23) |
.32 |
| Placebo | 393 | 23.5 (23.0 to 24.0) |
23.0 (22.5 to 23.5) |
23.2 (22.7 to 23.8) |
−0.6 (−1.2 to 0.1) |
−0.4 (−1.1 to 0.3) |
|||
| Global cognitive function (3MSE) | Testosterone | 388 | 92.8 (92.2 to 93.4) |
93.7 (93.1 to 94.3) |
−0.5 (−1.2 to 0.2) |
−0.22 (−0.76 to 0.31) |
.41 | ||
| Placebo | 386 | 93.4 (92.9 to 93.9) |
94.0 (93.4 to 94.5) |
−0.3 (−1.0 to 0.4) |
|||||
| Immediate paragraph recall (Logical Memory I) | Testosterone | 392 | 19.5 (18.8 to 20.1) |
20.7 (20.0 to 21.4) |
21.5 (20.7 to 22.2) |
0.1 (−0.9 to 1.0) |
0.7 (−0.2 to 1.7) |
−0.05 (−0.72 to 0.61) |
.87 |
| Placebo | 393 | 19.7 (19.1 to 20.3) |
20.9 (20.2 to 21.6) |
21.3 (20.6 to 21.9) |
0.3 (−0.6 to 1.2) |
0.6 (−0.4 to 1.5) |
|||
Abbreviation: 3MSE, Modified Mini-Mental State Examination; MAC-Q, Memory Assessment Clinics Questionnaire.
Higher scores reflect better cognitive function except for Trail-Making Test B minus A and MAC-Q scores wherein lower scores indicate better cognitive function.
Positive values indicate greater increase or less decrease for participants allocated to testosterone vs placebo. Variables included for adjustment are listed in footnote c.
The difference is the mean difference in the change from baseline to 6 months and 12 months in participants allocated to testosterone vs placebo adjusted for balancing factors: baseline testosterone level (≤200ng/dL), age(≤75), site, participation in main trials, use of antidepressants, and use of phosphodiesterase type 5 inhibitors. Analyses were also adjusted for education level. A positive estimated difference indicates greater increases, smaller decreases, or both for the testosterone group compared with the placebo group.
The estimated difference and P value were determined by a linear mixed-model with a random effect for participants using outcomes at month 6 and month 12.