Table 3. Effect of genetically predicted testosterone (nmol/L) on cognitive function among men (50+ years), Guangzhou Biobank Cohort Study, recruitment 2003–2008 and follow up till Dec 31, 2012.
| Outcome | Mean(SD) | n | Model | Beta-coefficienta | 95% CI | P value |
|---|---|---|---|---|---|---|
| Delayed 10-word | 5.5 | 4160 | 1 | −0.02 | −0.06–0.02 | 0.23 |
| 10-word recall | (1.9) | 4160 | 2 | −0.03 | −0.07–0.01 | 0.17 |
| 4129 | 3 | −0.02 | −0.06–0.02 | 0.27 | ||
| 4123 | 4 | −0.02 | −0.06–0.02 | 0.30 | ||
| 4093 | 5 | −0.02 | −0.06–0.02 | 0.30 | ||
| 3470 | 6 | −0.02 | −0.06–0.02 | 0.30 | ||
| MMSE | 27.5 | 4122 | 1 | 0.06 | −0.002–0.12 | 0.06 |
| (2.7) | 4122 | 2 | 0.05 | −0.007–0.11 | 0.08 | |
| 4083 | 3 | 0.06 | 0.0003–0.12 | 0.05 | ||
| 4078 | 4 | 0.06 | −0.0004–0.12 | 0.05 | ||
| 4048 | 5 | 0.06 | −0.001–0.12 | 0.06 | ||
| 3443 | 6 | 0.06 | −0.01–0.13 | 0.10 |
Abbreviations: SD, standard deviation; CI, confidence interval.
Model 1 showed the association of genetically predicted testosterone with cognitive function without any covariates;
Model 2 adjusted for age;
Model 3 additionally adjusted for education, smoking, and use of alcohol;
Model 4 additionally adjusted for body mass index (BMI);
Model 5 additionally adjusted for Framingham score.
Model 6 replicated the analysis in Model 1 excluding men in another cognition project.
aBeta coefficient refers to the average change in cognitive function (the delayed 10-word recall score and MMSE score) with each unit (nmol/L) increase in genetically predicted testosterone.