Does Viagra Increase Sperm Quality in Male Infertility?
With the industrialization process of humanity, infertility has become a threat to men's health all over the world. There are many causes of male infertility, most of which are unknown. Phosphodiesterase-5 inhibitors (PDE5is) are first-line drugs to treat erectile dysfunction (ED). PDE5 competitively binds to the catalytic site of PDE5, preventing the degradation of nitric oxide (NO)-derived cyclic guanosine monophosphate (cGMP). It increases penile blood flow during sexual stimulation and thus enhances penile erection.
When we look at the studies examining the effects of PDE5i in the treatment of male infertility.
PDE5is is increasingly used to improve sperm quality and achieve fertility goal in patients with male infertility.. The study involving 1,211 men showed that with PDE5is, sperm concentration, flat progressive motility, morphology of normal forms, and progressive motile sperm were significantly improved. However, semen volume and sperm count results are conflicting.. The results of this study show that PDE5is can improve male sperm quality in clinical practice.
How does PDE5i improve sperm quality?
PDE5is inhibits PDE5 in the corpus cavernosum and raises the intracellular cGMP level, increases the NO content with vasodilatory effect, thereby promoting the relaxation of smooth muscles and causing penile erection. The role of NO has been confirmed after studies that may play an important role in changes in chromatin concentration, sperm morphology and eventual release of sperm from the seminiferous epithelium.
NO may be associated with spermatogenesis, steroid production and apoptotic cell death. Thus, the NO-mediated mechanism in prostate and testicular parenchyma enhanced by PDE5i may be the basis for improved sperm quality..
Some researchers believe that the positive effect of PDE5i on ejaculatory concentration may be due to its effect on certain smooth muscle pathways in the seminal system.
Different PDE5s increase human testosterone by acting directly on the testis.It can lead to the epididymal sperm maturation process and subsequent improvement in spermatozoal potential to achieve optimal sperm motility in oligoasthenospermics.
Men Sildenafil and Vardenafil can increase serum insulin-like 3-peptide level leading to increased secretory function of Leydig cells, resulting in better secretion by Sertoli cells. In addition, vardenafil may have a positive effect on sperm motility by acting directly on sperm mitochondria or calcium channels to increase intracellular cGMP.
Studies have investigated the spermatogenesis of psychological stress caused by infertility. and has also shown that it can affect erectile function. PDE5is can improve erectile function and reduce this psychological stress, which has a positive effect on sperm parameters.
A previous study has shown that different PDE5s, such as sildenafil or vardenafil, can increase prostate secretory function.
Because the substances secreted by the prostate gland play an important role in maintaining sperm motility..
Avanafil was found to increase the percentage of total motile sperm and the percentage of progressive motile sperm, but did not affect sperm DNA integrity; this has been proven to be associated with an increase in prostate secretory function.
Studies have shown that tadalafil improves erectile function and increased sexual activity can result in increased testosterone levels. The effect of androgens on sperm quality is clear.
Further RCTs are needed in the future to analyze the impact of these factors on the efficacy of PDE5is in male infertility patients, along with age and classification of comorbidities.
The main goal of male infertility treatment is to help the sperm and egg fertilize, reach the final pregnancy and even give birth. Currently, there are no studies (laboratory/clinical trial results or any other data) showing that it improves some indicators of male sperm, thus improving fertilization, pregnancy or fertility after PDE5i treatments.
Although men treated with PDE5is show an improvement in sperm quality, more research is needed before this treatment can be accepted worldwide.
