Pituitary gonadal function in diabetic male patients with and without impotence

The effects of type 1 diabetes on the hypothalamic, pituitary and testes axis

Type 1 diabetes is an autoimmune disorder characterized by a lack of insulin production by the beta cells of the pancreas. This lack of insulin causes a variety of systemic effects on whole-body metabolism. Poorly managed type 1 diabetes can lead to cardiovascular disease, diabetic neuropathy, and diabetic retinopathy. Increasingly, even well-managed type 1 diabetic patients show damage to peripheral organs related to complications from the disease. The central role of insulin in energy homeostasis also renders it an important signaling factor in the reproductive tract. type 1 diabetes has now been demonstrated to cause defects in sperm and testes. The aim of this review is to present the known effects of insulin's role in the function of the male reproductive tract. These effects might be mediated through hormonal alterations in the hypothalamic pituitary gonadal axis or through the direct interaction of insulin on the testes and sperm cells. Although fertility complications also occur in type 2 diabetic males, this review will focus on the defects specifically linked with the lack of insulin seen in type 1 diabetes.

In vitro biological-to-immunological ratio of serum gonadotropins throughout male puberty in children with insulin-dependent diabetes mellitus

Information on the impact of prolonged deficient glycemic control in the quality of the gonadotropin signal delivered by the pituitary gland during puberty in children with insulin-dependent diabetes mellitus (IDDM) is scarce. In the present study, we examined the impact of deficient glycemic control on bioactive LH and FSH concentrations and their corresponding biological-to-immunological (B:I) ratio in boys with poorly controlled, but systemically uncomplicated IDDM. Dual control groups comprising patients with well-controlled IDDM and healthy boys of comparable age and body mass index were included for appropriate comparisons within and between each pubertal stage. Patients with poorly controlled and well-controlled IDDM exhibited serum bioactive FSH levels and B:I FSH ratio similar to those showed by the healthy control group. In contrast, in early and mid-pubertal boys with poorly controlled IDDM bioactive LH levels were normal, but its B:I LH relationship was significantly (P < 0.05) decreased. This attenuation in the quality of the LH signal did not affect total serum T concentrations, and apparently, progression of puberty. Long-standing uncontrolled diabetes and the consequent metabolic disturbances and/or complications may aggravate the reproductive axis dysfunction and eventually provoke pubertal arrest.

Diabetic sexual dysfunction

Although the overall incidence of erectile dysfunction in the general population between the ages of 40 and 70 years is 52%, men with diabetes mellitus have impotence at an earlier age and with a significantly higher prevalence, ranging as high as 75%. Numerous advances have been made in understanding the physiologic and biochemical mechanisms controlling penile erection. Improved clinical techniques for the diagnosis and treatment of impotence, including dynamic vascular testing, intracavernosal pharmacotherapy, and microsurgical revascularization, have allowed us to enter a new and exciting era in the quest for a more complete understanding of erectile dysfunction.

Semen characteristics and diabetes mellitus: significance of insulin in male infertility

A study was made of semen quality and serum hormonal profiles (FSH, LH, prolactin, testosterone) of patients with type I diabetes mellitus. Semen parameters and levels of prolactin and testosterone were significantly altered in the diabetic state. The concentration of insulin in serum and seminal plasma and the serum levels of FSH, LH, and testosterone were measured in 80 men classified in the following groups: fertile subjects, infertile normoglycemic subjects, subjects with carbohydrate intolerance, and excretory and secretory azoospermic subjects. In all groups, seminal insulin concentrations were higher than those obtained in serum. The hormone appears to freely cross the blood-testis barrier, there to be concentrated in the semen. The levels of insulin in serum and seminal plasma did not correlate with semen parameters and are not suitable markers of seminal quality. For unknown reasons, the concentrations of insulin in seminal plasma were lower in the subjects suffering from carbohydrate intolerance.