CoastWatcher
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More and more men come to realize that certain topical testosterone applications fail many patients. A recent Boston-based study looked at why hypogonadal men treated with testosterone gels posted such a substantial variability in the serum levels they obtained from this mode of TRT. Specifically, the researchers hoped to determine whether polymorphisms in genes encoding testosterone enzyme could explain the variation.
In all three studies there was substantial variation in testosterone levels. The authors of the study concluded that baseline characteristics (age, height, weight, baseline testosterone, SHBG, hematocrit, and creatinine) "accounted for only a small fraction of the variance."
What has been observed clinically for some time has been confirmed: many men do not respond to testosterone gels. The authors conclude that the role of SHBG and AKR3C1 polymorphisms are implicated in this phenomenon and call for more testing to see if that can be confirmed.
Contributors to the substantial variation in on-treatment testosterone levels in men receiving transdermal testosterone gels in randomized trials Andrology, 5 October 2017
http://onlinelibrary.wiley.com/doi/10.1111/andr.12428/full
- Data from three randomized trials (detailed below) was used retrospectively.
- All men were treated with 1% transdermal testosterone gel.
- Serum levels were tested two to four weeks after multiple dose adjustments.
In all three studies there was substantial variation in testosterone levels. The authors of the study concluded that baseline characteristics (age, height, weight, baseline testosterone, SHBG, hematocrit, and creatinine) "accounted for only a small fraction of the variance."
- In a study assessing testosterone's use on pain perception, 47% of men failed to raise their testosterone above the 400ng/dL level. Six percent of study participants raised their serum levels to the 1000ng/dL mark.
- A study dealing with testosterone's impact on atherosclerosis indicated that 38% of men failed to raise the level above the same marker (400ng/dL). Only eight percent of men in this study achieved a serum level of 1000ng/dL.
- A study of testosterone on mobility and older men indicated that 9% of participants failed to raise testosterone above 400ng/dL. This study produced the largest number of men who raised testosterone above 1000ngdL - 30%.
What has been observed clinically for some time has been confirmed: many men do not respond to testosterone gels. The authors conclude that the role of SHBG and AKR3C1 polymorphisms are implicated in this phenomenon and call for more testing to see if that can be confirmed.
Contributors to the substantial variation in on-treatment testosterone levels in men receiving transdermal testosterone gels in randomized trials Andrology, 5 October 2017
http://onlinelibrary.wiley.com/doi/10.1111/andr.12428/full
