Male Infertility in Diabetes Mellitus

Abstract

Both diabetes mellitus (DM) and male infertility are widely prevalent, and their prevalence has increasing trends. Diabetes is known to have negative impacts on almost all aspects of male reproductive functions. Such pathophysiology is more widely studied in animal models, and in men with type 2 DM (T2DM), similar reproductive dysfunctions are also described in type 1 DM (T1DM). T1DM and T2DM may have different underlying mechanisms contributing to the changes seen in their sperm parameters. At the pretesticular level, DM causes hypogonadotropic hypogonadism. DM affects many aspects of testicular function. Increased oxidative stress and inflammation, increased reactive oxygen species, lipid peroxidation, advanced glycation end products, disrupted energy metabolism, and nuclear and mitochondrial deoxyribonucleic acid damage alter sperm count and quality. The structure and function of the epididymis, vas deferens, seminal vesicles, and prostate are also affected, changing sperm quality and viability. Genitourinary infections are common in DM and might alter reproductive homeostasis. Erectile and ejaculatory dysfunction frequently affects men with DM. Retrograde ejaculation and anejaculation may lead to infertility. Glucose-lowering drugs may also influence the male reproductive process; insulin, metformin, pioglitazone, sodium-glucose cotransporters, and glucagon-like peptide 1 agonist drugs may have favorable impacts. The pathophysiology of reproductive dysfunction and fertility in men with DM is yet to be completely elucidated. Many factors, including duration of diabetes, glycemic control, and associated comorbidities, may obscure the real impact of DM-related male infertility. The ongoing molecular studies generating new insights are expected to better clarify DM-induced alterations in male reproductive function.