Type 1 Diabetes Might Affect Male Fertility & Testicular Functions
Infertility affects about 15% of couples worldwide, among which 50% is a malefactor. Environmental and genetic factors have been implicated, but in about one in three infertile patients, a specific cause is still not identified. In a recent study, researchers of Italy have found that type 1 diabetes mellitus (DM1) might impair male fertility and testis functions. The study findings were published in the journal Andrology on December 14, 2021.
Previous studies have demonstrated that DM1 could affect male fertility, gonadal axis, semen parameters, and spermatogenesis due to the effects of hyperglycemia and insulin deficiency. However, the exact impact of DM1 on male fertility remains unclear. Therefore, Dr Alberto Ferlin and his team conducted a systemic review and meta-analysis to evaluate paternity rate, male gonadal axis, and semen parameters in men with DM1.
The researchers performed a systemic review of relevant literature from January 1980 to December 2020. They included a total of 14 prospective and retrospective observational studies with reporting information on fatherhood (rate of children by natural fertility), hormonal and seminal parameters in men with DM1. Among 14 retrieved articles, eight studies evaluating semen parameters were meta-analyzed.
Key findings of the study:
♦ Upon analysis, the researchers noted that the rate of children (four studies) was lower than controls among men affected by DM1, especially in men with a longer duration of disease.
♦ They noted that the data of gonadal hormonal profile in DM1 men (6 studies) were very heterogeneous and, a neutral effect of DM1 or a condition of subclinical hypogonadism could not be concluded.
♦ Upon meta-analysis, they found that the men with DM1 (n = 380), compared to controls (n = 434), have significantly:
- Lower normal sperm morphology [-0.36% (-0.66;-0.06), 6 studies]
- Sperm progressive motility [33.62% (-39.13;-28.11), 2 studies] and
- Lower seminal volume [-0.51 (-1.03;0.02), 8 studies], without difference in total sperm count and concentration.
♦ They noted that the data on scrotal ultrasound and sperm DNA fragmentation were scarce.
♦They further noted that no study evaluated other factors of male infertility such as transrectal ultrasound, semen infections, sperm auto-antibodies, and retrograde ejaculation.
The authors concluded, "This review and meta-analysis shows that DM1 might impair reproductive health at different levels, including functional sperm alterations definitively leading to reduced fertility rate in these patients. Further studies investigating in full details male fertility potential in patients with DM1 compared to healthy controls are necessary."
For further information:
DOI: https://doi.org/10.1111/andr.13140
