Low–T can affect men of all ages. Even adolescents can suffer from low-T. An aging testis in older males leading to physiologic changes is the main cause of gonadal dysfunction, or primary hypogonadism.
In younger males the cause of low-T is commonly due to congenital or acquired conditions that disrupt the testosterone production in the testes due to HPT axis issues. (Hypothalamic-pituitary-gonadal axis.) which results in declines of LH(Luteinizing Hormone and FSH(Follicle Stimulating Hormone).
This is also called secondary hypogonadism.
Diagnosis & treatment parameters for young males suffering from low testosterone
To diagnose low-T in younger males is challenging due to absence of decreased libido or erectile dysfunction, a telltale symptom of low testosterone, common in older males. Instead, hypogonadism manifests as fatigue and lack of energy, which is the common complaint of younger males suffering from low testosterone.
While an underlying congenital cause should be investigated for younger men suffering from low-T, acquired conditions such as obesity, diabetes, anabolic steroid or drug abuse are all associated with low testosterone levels. Environmental factors like pesticides, past infection or injury to the testis can also cause low testosterone.
A comprehensive medical history is necessary to rule out other causes of hypogonadism like toxins, heavy metal ingestion, damage from smoking etc.
Apart from modifying identifiable risk factors for hypogonadism, external testosterone therapy for younger men presents challenges for those wanting children.
Externally supplementing testosterone disrupts the signaling mechanism of the pituitary gland which reduces spermatogenesis or sperm generation by the leydig cells in the testes.
Topical or injectable administration of testosterone leads to infertility risks due to the feedback mechanism of the HPG axis.
A fasting serum T level between 7 to 11 AM or within 3 hours of waking up is used for diagnosis. Lack of consensus for the exact testosterone level to diagnose low -T exists. But a recent publication of the Endocrine Society with support from CDC has a level <264 ng/dl in non-obese males to diagnose low-T.
250 to 300 ng/dl is the threshold set by the American urological Association and other societies to determine low testosterone regardless of age following many large-scale population studies.
As mentioned previously, symptoms of fatigue and lack of energy may be more specific in the younger adult cohort than sexual symptoms. Following confirmation of low serum T levels and other signs and symptoms of hypogonadism, clinicians should use serum LH and FSH in conjunction with testosterone to differentiate between primary and secondary hypogonadism.
How to deal with infertility from external testosterone supplements?
Infertility problems from external supplementing of testosterone can be countered by treatments which augment the body's own testosterone production or external testosterone that do not affect sperm generation. HCG or Human Chorionic Gonadotropin works on the pituitary gland which does not affect sperm generation. HCG with selective estrogen modulators and aromatase inhibitors are used in combination to up testosterone without affecting spermatogenesis.
It is very important not only to diagnose low-T as the underlying cause of hypogonadism in younger men, but also to make sure treatment does not hamper fertility. Proper counseling for younger males is a must explaining the effects of externally supplementing testosterone on fertility.
Nasal testosterone which is a newer form of testosterone intervention seems to be evolving as a solution to prevent infertility and boost testosterone. This short acting testosterone which is a gel applied in the nose appears to significantly increase median morning testosterone levels without affecting median FSH(Follicle Stimulating Hormone), LH(Luteinizing hormone) and semen level parameters at 6 month follow up, in phase 4 of clinical trials. Apparently this is because of the short half life of intranasal T which maintains the pulsatile release of GnRH compared to other forms of external testosterone therapies that impact HGP axis which causes steep declines in LH and FST to maintain sperm generation.