Subcutaneous Testosterone and the Effect of BMI on Serum T in Men with low T

[madman]

In this video, Jesse N. Mills, MD, discusses the important findings from the study, “Subcutaneous Testosterone Enanthate and the Effect of Body Mass Index on Serum Testosterone in Men with Testosterone Deficiency,” presented recently at the 2021 Sexual Medicine Society of North America Fall Scientific Meeting. Mills is an associate clinical professor of urology at the David Geffen School of Medicine, the director of the UCLA Division of Andrology, the director of the Men’s Clinic, and the chief of UCLA Santa Monica Urology, University of California, Los Angeles

Dr. Mills weighs in on the benefits of testosterone enanthate

“There's 3 different levels of dosing…so this does provide you with a mechanism for titration if you're going to be using that in your patients,” says Jesse N. Mills, MD.

www.urologytimes.com

 

[madman]

In this video, Martin M. Miner, MD, discusses the background and findings of the study, “Subcutaneous Testosterone Enanthate and the Effect of Body Mass Index on Serum Testosterone in Men with Testosterone Deficiency,” presented recently at the 2021 Sexual Medicine Society of North America Fall Scientific Meeting. Miner is the founder of the Men’s Health Center at Miriam Hospital and clinical professor of family medicine and urology in the Warren Alpert School of Medicine at Brown University, Providence, Rhode Island.

Dr. Miner on the effect of BMI on dosing in patients with testosterone deficiency

“The initial levels were inversely related to body mass index, so…men who are the largest…or had the largest BMI have the lowest testosterone levels,” says Martin M. Miner, MD.

www.urologytimes.com

 

[madman]

Body mass index is key when selecting dosage of testosterone enanthate

By the end of a 12-week period, total testosterone C-trough, C-avg (0 to 168 hours), and C-max were inversely related to BMI.

www.urologytimes.com

Body mass index (BMI) is an important factor when selecting dosage of subcutaneous testosterone enanthate (TE; Xysoted), investigators report.1

By the end of a 12-week period, total testosterone C-trough, C-avg (0 to 168 hours), and C-max were inversely related to BMI, according to findings presented at the 2021 Sexual Medicine Society of North America Fall Scientific Meeting.

“[This is] an intuitive assumption that never has been found to be the case before,” said co-author Martin M. Miner, MD, in an interview with Urology Times®.

Because there is little knowledge about how BMI affects the pharmacokinetic (PK) profile or dosing of testosterone therapies in men with testosterone deficiency, even though obesity or high BMI (≥30 kg/m2) is typically associated with low levels of testosterone, Miner and co-authors sought to understand the potential relationship.

“My question was: in men with a larger BMI, would they have data to support the use of a larger dose of their weekly testosterone injection? This is part of men receiving testosterone therapy for hypogonadism or low testosterone levels associated with clinical signs and symptoms of testosterone deficiency,” Miner said.

In this post-hoc analysis, a single-arm phase 3 trial of subcutaneous TE was examined to determine PK parameters of weekly subcutaneous TE treatment among men with testosterone deficiency and varying BMIs. The primary endpoint was the percentage of patients who received at least 1 dose of subcutaneous TE and achieved an average serum total testosterone concentration of 300 ng/dL to 1100 ng/dL over 7-day dosing of TE (C-avg [0 to 168 hours]) at week 12.

The PK population consisted of 142 patients, all of whom were patients in the safety population (received 1 or more doses of subcutaneous TE) with at least 1 blood sample drawn after the dose was administered. Of this population, 137 patients finished the study to completion (12 weeks) and were categorized into tertiles based on baseline BMI. Tertile 1 had a BMI ≤29 kg/m2 (n=45). Tertile 2 had a BMI > 29-32 kg/m2 (n=33). Tertile 3 had a BMI > 32 kg/m2 (n=59).

PK parameters included total testosterone trough concentration (C-trough), AUC-(0 to 168 hours), C-avg (0 to 168 hours), and C-max. At weeks 6 and 12, BMI tertiles were used to assess C-trough and C-avg (0 to 168 hours). At week 12, C-trough and C-avg (0 to 168 hours) were calculated according to their treatment doses and an overall dose-normalized linear regression model was utilized.

At baseline, the mean (SD) serum total testosterone levels for patients in tertiles 1-3 were 250.7 (101.3) ng/dL, 235.3 (91.2) ng/dL, and 226.4 (81.1) ng/dL, respectively. Prior to dosing adjustments at week 6, tertiles 2 and 3 mean (SD) C-trough (459.2 [157.0] ng/dL and 453.2 [133.0] ng/dL) were lower than tertile 1 (616.9 [181.6] ng/dL). At week 6, 21.2% of the total variance in C-trough levels could be predicted from BMI (P < .001).

At the completion of this study, results showed that tertiles 2 and 3 had lower serum total testosterone C-trough compared with tertile 1 (494.8 [137.6] ng/dL and 469.0 [146.2] ng/dL, respectively, vs 517.7 (153.5) ng/dL). For tertiles 1-3, the mean (SD) C-avg (0 to 168 hours) values were 585.2 (148.1) ng/dL, 554.2 (104.5) ng/dL, and 528.5 (118.0) ng/dL, respectively. And at week 12, the mean doses were 65.0 (13.48) ng/dL, 78.0 (12.12) ng/dL, and 78.4 (12.68) mg, respectively. So, patients in Tertiles 2 and 3 required higher final doses of subcutaneous TE vs those in tertile 1, demonstrating an inverse relationship related to BMI.

In addition, the regression model found that 9.36% (P < .001) and 16.96% (P < .001) of the total variance in C-trough and C-avg (0 to 168 hours) could be predicted from independent BMI and dose variables at the completion of this study (12 weeks), respectively.

Overall, 98.5% of men with testosterone deficiency who made it to the end of this study (12 weeks) achieved a C-avg (0 to 168 hours) of 300 ng/dL to 1100 ng/dL.

Reflecting on these findings, Miner explained, “The initial levels were inversely related to body mass index, so…men who are the largest…or had the largest BMI have the lowest testosterone levels. And that's what you would expect with obese men, that the greater the amount of obesity, the lower their endogenous levels would be, and that men would require the largest dose adjustment if they had a larger BMI.”

 

[madman]

Effect of Weight on Serum T with Sub-Q TE in Men with TD

Effect of Weight on Serum Testosterone with Subcutaneous Testosterone Enanthate in Men with Testosterone Deficiency (2020) SAT-037 Background: In men, obesity is often associated with low testosterone (T) levels, but the information is limited as to how body weight affects the pharmacokinetic...

www.excelmale.com

 

[Ardoc2]

I'd like to see a study like this done using % body fat rather than BMI which can inaccurately reflect obesity in larger (heavily muscled) individuals.

 

[tareload]

I read Antares did a poster on this:

Antares Pharma Announces Oral Presentation at the 22nd Annual Fall Scientific Meeting of SMSNA

EWING, N.J., Oct. 25, 2021 (GLOBE NEWSWIRE) -- Antares Pharma, Inc. (NASDAQ: ATRS) (the “Company”), a specialty pharmaceutical company, today announced...

www.globenewswire.com

Is SHBG the lurking variable here? The guy on the video invokes clearance volume but where's SHBG in this? Back to @Cataceous point, these guys may be getting same fT but different TT from same injection amount with different SHBG.

The association of obesity with sex hormone-binding globulin is stronger than the association with ageing – implications for the interpretation of total testosterone measurements - PMC

Total testosterone concentrations are influenced by sex hormone-binding globulin (SHBG) concentrations, which are decreased by obesity and increased with ageing. Therefore, we sought to understand and compare the associations of ageing and obesity ...

www.ncbi.nlm.nih.gov

Mechanistically they should dig deeper or maybe it will be in subsequent paper/analysis.