Although it has long been known that diabetic patients experience impaired reproductive health, the mechanisms by which this occurs have not yet been elucidated. The impact of the condition can be on the pretesticular, testicular and posttesticular level. Differences in reproductive health disorders in type 1 or type 2 diabetes are due to the specifics of the two conditions, their duration, and the ability for metabolic compensation. Diabetes is associated with a violation of the quantitative and qualitative parameters of seminal fluid. Type 1 diabetes affects the gene expression of some genes that are important for DNA repair in sperm. In addition, the disease is associated with disorders in the mitochondrial metabolism of male germ cells, which lowers their motility. Insulin levels are important in maintaining the integrity of sperm and acrosome membranes. In patients with insulin resistance or insulin deficiency, disturbances in the normal course of spermatogenesis are observed. The development of hypogonadism, which is associated with impaired secretion of gonadotropic hormones and changes in the normal functions of some cells, is common in patients with diabetes. This results in low serum levels of gonadotropins and testosterone. Diabetes affects testicular health as it is associated with an increased accumulation of free radicals and the occurrence of oxidative stress in the seminal fluid. In addition, the disease causes violations in the integrity of DNA in spermatozoa, damages the mitochondrial metabolism in them and numerous processes that take place with the participation of enzymes. Diabetes can cause damage to sperm or lead to obstructed seminal fluid release due to inflammation of the glands involved in these processes. This is associated with a deterioration of the immune response and damage to the qualitative and quantitative parameters of the seminal fluid. The inflammatory process can become chronic and lead to erectile or ejaculatory dysfunction. The leading concern in diabetic patients is observed in the morphology and motility of the spermatozoa in the composition of the seminal fluid. The longer the diabetes was until the moment of trying to conceive, the more significant the changes in the motility of the male germ cells. The mitochondrial membrane and, more specifically, its potential are equally important in the regulation of sperm motility. Diabetes has a direct impact on its functionality, which explains why a reduced motility of male germ cells is observed in these patients. References: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5980990/