Testosterone Does Not Guarantee Good Health: What a 15-Year Study of Men Revealed

The researchers used data from the Northern Finland Birth Cohort 1966. They measured participants’ testosterone levels at age 31 and divided the men into four groups, ranging from the lowest to the highest levels. At age 46, participants rated their own health and completed a questionnaire assessing 15 aspects of quality of life, including physical functioning, breathing, mood, and sexual activity.

Overall, 63.9% of the men who answered questions about their health rated it as good or excellent, 32.1% described it as average, and 4% rated it as poor or very poor. The researchers found no substantial differences between groups with different testosterone levels. Average quality-of-life scores were high across all four groups.

However, men with the lowest testosterone levels were more likely to have certain metabolic and gastrointestinal conditions. After waist circumference was taken into account, these differences were no longer statistically significant. This suggests that obesity may play an important role in the relationship between hormonal status and health.

Substance use disorders were also less common among men in the lowest-testosterone group. In addition, men in this group had slightly better overall quality-of-life scores after statistical adjustment. However, the difference was small, and comparisons across all four groups revealed no significant differences.

Some findings concerned individual measures. Men with the lowest testosterone levels had higher scores on the depression-related scale of the quality-of-life questionnaire, and this association persisted after accounting for other factors. However, the study cannot establish why this difference occurred. The findings on lung diseases were also considered insufficiently reliable because of the large number of missing responses.