Marina Dimitraki, MD, MSc, M.H.A., PhD, EFOG-EBCOG, Gynecologist in Assisted Reproduction, European Fellow of Reproductive Medicine ESHRE/EBCOG, Scientific Head of Embryolab Fertility Clinic
Diabetes mellitus (DM) (Τype 1,2) is a chronic disease. According to the International Diabetes Federation (IDF) report released in November 2021, the number of adult people suffering from diabetes mellitus (DM) has risen from 108 million in 1980 to 537 million in 2021. Type1 diabetes causes decrease in insulin level and degrades essential proteins of the body. Type 2 Diabetes Mellitus is the most common form of the diabetes mellitus and it was formerly known as non-insulin-dependent diabetes mellitus or adult-onset diabetes.
Throughout various physiological mechanisms type 1 and type 2 diabetes mellitus affect male and female infertility and nowadays a huge number of people suffer from infertility throughout the world due to diabetes and irregular life-style. About 90% of diabetics experience upheaval in sexual function, including a decrease in libido, impotence and infertility. Most of the Type 2 diabetes patients are postmenopausal or postandropausal , but with changing dietary and lifestyle patterns, the prevalence of obesity is increasing, thus raising the incidence of Type 2 diabetes during the reproductive years.
It seems that DM induces subtle molecular changes that are essential for sperm quality and function. Spermatozoa are known to secret their own insulin, they are however sensitive to hormonal fluctuations. Therefore, deficiency of insulin or insensitivity to insulin in DM alters the endocrine pathway, resulting in impaired male reproductive function. Studies revealed a significant decrease in volume, motility and morphology in the semen of diabetic men. Effect of DM on male reproductive function can be explained through the impact of OS, caused by the inequality between reactive oxygen species (ROS) production and antioxidant defence mechanisms. Oxidative stress can lead to sperm DNA damage and mitochondrial DNA fragmentation. Additionally, decreased number and altered morphology of Sertoli cells, decreased number of Leydig cells , alteration of epididymis morphology and density, decreased LH, FSH and testosterone serum levels, were observed in males suffering from DM. Moreover, diabetic neuropathy is one of the most prevalent complications of DM. It has been reported to affect about 50% of patients with Type I and Type II DM. Diabetic neuropathy can result in reduced sexual response, erectile dysfunction and retrograde ejaculation.
Concerning the females, both T1DM and T2DM are significantly associated with female reproductive dysfunction. This includes an increased risk for delayed menarche, menstrual disorders, hormonal disturbances, polycystic ovarian syndrome, decreased ovarian reserve, sexual dysfunction, and early menopause, all of which adversely affect fertility. Potential pathophysiological mechanisms include hypothalamic, pituitary, ovarian dysfunction (general dysfunction of the hypothalamic–pituitary–ovarian axis ) and/or metabolic factors. The presence of diabetic microvascular or cardiovascular complications was associated with particularly low fertility. Additionally, a bidirectional association is present between gestational diabetes mellitus and infertility. Moreover, gestational diabetes mellitus can increase the risk of fetal death and congenital malformation.
Poor glycemic control and the presence of diabetic complications are associated with lower fertility both in males and females. Preconception care should be incorporated in routine diabetes care, starting at puberty. It seems that stricter metabolic control can increase fertility.
It seems that when diabetes is well controlled the risk of fertility issues is lower and stricter metabolic control can increase fertility. Generally, the treatments available to those suffering from diabetes, or diabetes-related infertility, focus on managing the blood sugar levels. This includes lifestyle modifications, dietary changes, regular physical activity and monitoring blood glucose levels. For type 1 diabetes, insulin therapy is the cornerstone of management, while for type 2 diabetes, oral medications and/or insulin injections may be prescribed. For individuals with obesity-related diabetes, achieving and maintaining a healthy body weight can significantly improve fertility . Weight loss through a balanced diet and exercise can enhance hormonal balance and increase the chances of conception. Moreover, antioxidants can help reduce oxidative damage caused by diabetes to reproductive cells, while also boosting sperm quality in men and the health of eggs in women.
In conclusion it is obvious that it is essential preconception care to be incorporated in routine diabetes care, starting as earlier as possible, even during puberty, in case of type 1 diabetes.
