I wrote this review article of a meta-analysis as part of a private contest, since I have not published anything here in a long time I thought to publish it here too.
Why testosterone replacement therapy is good for your health
If you have been training for a while, you have surely heard of testosterone replacement therapy (TRT) and its effects, for some people it is a panacea and for others it is a way to destroy our health.
I am going to explain scientifically why it is not only beneficial to health but also increases the life expectancy of the person who undergoes TRT for life.
I will argue this based on the meta-analysis of people subjected to the use of testosterone replacement therapies with suboptimal levels of testosterone and its effects on body composition and health.
Corona & Co.'s original meta-analysis was published in the Journal of Endocrine Investigation, in which an extensive search was carried out in MEDLINE, Embase and Cochrane including the following words: testosterone and body composition, all observational studies that compared the effect of TS on body weight and body composition and other metabolic parameters.
The meta-analysis gathers 824 articles that speak of a total of 4513 patients whose average age is 51.7 years, all these patients underwent TRT and their data was measured as time passed.
From the meta-analysis we can extract the following data:
Weight loss and waist reduction after 24 months was −3.50 [−5.21; -1.80] kg and -6.23 [-7.94; −4.76] cm, respectively, thus a significant reduction in body fat (risk factor) and an increase in lean mass can be seen.
In other trials such as those by Zitzmann (2014) it produced a great effect on waist reduction, for example here the tolerability and effectiveness of injectable testosterone undecanoate for the treatment of male hypogonadism was studied in a worldwide sample of 1,438 men; With a basal waist circumference of 99.5 +/- 15.25cm, we are talking about a ~ 20% reduction.
Studies that were based on people with diabetes could see a reduction in fasting blood glucose and a considerable improvement in insulin sensitivity as detected by the HOMA-IR index.
Now we are going to talk about the most striking data, cholesterol and blood pressure are two of the greatest risk factors for the mortality rate, today it is believed that the use of testosterone considerably worsens the lipid profile and raises blood pressure material.
In the meta-analysis, it can be appreciated that providing exogenous testosterone (even in supraphysiological doses) caused considerable improvements in blood lipids and blood pressure, especially an increase in good cholesterol levels and a reduction in bad cholesterol levels.
Zitzmann and colleagues also saw significant improvements in mood and ability to concentrate in hypogonadic subjects.
Conclusion:
As you can see, the use of testosterone replacement therapy offers many benefits in terms of both health and body composition.

If you want to check the Bibliography:

[1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1484557/
[2] https://www.ncbi.nlm.nih.gov/pubmed/17098591
[3] https://www.ncbi.nlm.nih.gov/pubmed/11701431
[4] https://www.ncbi.nlm.nih.gov/pubmed/27241317
[5] https://www.researchgate.net/publication/273062611_Anabolic_Steroid_Use
[6] https://heinonline.org/HOL/LandingPage?handle=hein.journals/syrlr63&div=...
[7] https://www.ncbi.nlm.nih.gov/pubmed/19209124
[8] https://www.ncbi.nlm.nih.gov/pubmed/24636400
[9] https://www.ncbi.nlm.nih.gov/pubmed/22812645
[10] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5833963/