Abstract: Type 1 diabetes is an autoimmune disease characterized by a lack of insulin production in the beta cells of pancreas, which causes a variety of systemic disorders of the whole-body metabolism. It has been demonstrated that patients with type 1 diabetes have functional defects in the hypothalamic-pituitary-testes axis due to the lack of insulin. Insulin plays an important role in the reproductive system. The lack of insulin could result in the impaired spermatogenesis and clinical subfertility. Those patients with type 1 diabetes showed the insufficient sexual maturation and infertility related to the lack of leptin and its receptor. The lowered level of testosterone in those patients may also cause sexual dysfunction, loss of libido and erectile dysfunction. Besides the lowered levels of hormones, the sperm quality in those patients can be affected by type 1 diabetes and other factors. The effects of type 1 diabetes on male reproduction, especially hypothalamic-pituitary-testes axis, were hereby reviewed.

Key words: Diabetes mellitus, type 1, Reproduction, Testis, Insulin, Spermatozoa