Testosterone has been top of mind in medicine over the last decade. And for good reason: It is now clear that testosterone in men is essential for normal growth, maturation, health, and well-being. In the brain, “vitamin T” influences sex drive, assertiveness, mood, energy, thinking and verbal memory. It increases muscle strength and maintains normal bone density, reduces belly fat, and keeps blood counts and clotting normal. Testosterone strengthens the immune system and is important for normal erections and sperm production. I tend to think of testosterone as oil in your car: it helps everything work better, and things will wear out faster if it’s low. Actually, it’s about as close to an “elixir” as any single circulating molecule in our bodies.
But we know even more about testosterone. Unlike oil in your car that stays around until it’s changed (except for in vintage cars that typically leak oil!), testosterone levels vary widely over time, from days to years. Stress of any kind – emotional, physical, financial – can lower testosterone levels dramatically and daily. Testosterone levels also fall in a predictable way with age. Medical illnesses such as diabetes, obesity, and thyroid issues as well as medications such as narcotics and antiandrogens can wreak havoc on testosterone balance. Notably too, recreational drugs including alcohol, pot, tobacco, and amphetamines are classic vitamin T suppressants. And now there’s a new kid on the block that can significantly lower testosterone levels: Male infertility surgeries.
A Hormone Machine
Testicular sperm retrieval (TESE) procedures are a recent development in medicine. First performed in 1992, they are often the only way a sterile man with no ejaculated sperm can have biological children. And given that about 1% of all men worldwide are sterile, these procedures have since become quite popular around the globe. Undoubtedly, it is fantastic workhorse technology that I have embraced with vigor as a male fertility specialist. But the testes do two things for men: make sperm and produce testosterone. In fact, 90% of a man’s testosterone comes from the testicles. So, TESE procedures performed without foreknowledge of sperm presence in the testicle (i.e. blind) can find sperm, which is good, but they can also lower testosterone levels, which is bad. We think that TESE-related low T levels are due to a combination of removing bulk testis tissue for sperm and also from collateral damage (i.e., scarring) to the remaining testis. Indeed, TESE procedures can be a two-edged sword for male reproductive health.
As I was concerned about how big an impact blind TESE procedures were having on men’s health, I studied this in my patients. How commonly do these procedures lower testosterone levels? And by how much? For this research, I took my population of sterile men (n=91) who had had microdissection TESE procedures elsewhere that failed to find sperm. They reportedto me for an alternative sperm-finding procedure that I developed called testicular FNA (Sperm) Mapping that has been shown to “rescue” them and find sperm. Micro-TESE is considered the biggest and most invasive sperm retrieval surgery of them all, the “big daddy” of TESE procedures. Before doing any mapping procedures, I reevaluated their testosterone balance an average of 2 years after their micro-TESE procedure and compared it to their testosterone levels before the micro-TESE procedure. Lo and behold, testosterone levels decreased an average of 16% after micro-TESE. This is equivalent to the decrease in testosterone output that occurs with 10-12 years of normal aging. In addition, fully 1/3 of men (36%) who started out with “normal” (>300ng/dL) levels before the procedure, were found to be low (hypogonadal; < 300ng/dl) afterwards. This convinced me of the fact that TESE procedures can commonly, quickly, and dramatically lower testosterone levels for life, and to the point of prematurely requiring testosterone replacement in young men.
This is sobering news but important to realize and understand. For this reason, I now try to perform the least invasive procedures (TESA) possible on patients. I am also comforted in knowing that there are “kinder” alternatives to blind micro-TESE procedures that do not significantly impact testosterone levels, such as sperm FNA Mapping. In the words of James Barrie: “Always be a little kinder than necessary.”