An investigation into some aspects of the relationship between diabetes mellitus and male sexual dysfunction.

Abstract

This investigation reports the effects of diabetes mellitus on some aspects of the male reproductive system. When compared to non-diabetic controls, human diabetics indicated a 35% reduction in gross sperm motility, a 13% decrease in progressive sperm motility and a 49% reduction in rapid sperm motility. Sperm viability also decreased by 35% in this group. Semen carnitine and acid phosphatase levels were elevated by 47% and 13% respectively, whilst the circulating testosterone level decreased by 20%. Semen pH and volume, sperm concentration and sperm morphology did not differ significantly between the diabetic and non-diabetic control patients. Circulating LH, FSH and prolactin, as well as seminal zinc, fructose and citric acid levels were found to be similar in the two groups. In a human infertility group, the number of morphologically normal sperm was 46% lower in comparison to the control group. Gross sperm motility decreased by 21%, progressive motility by 11% and sperm viability by 9%. Carnitine concentration in semen was 38% higher and fructose levels 27% lower than that of the control group. There were also significant reductions in circulating testosterone and LH levels (16% and 28% respectively). other parameters investigated, but which were not significantly different from the control, were semen pH and volume, sperm concentration, seminal zinc, acid phosphatase and citric acid concentrations, and circulating FSH and prolactin levels. streptozotocin-induced diabetic rats maintained on insulin for 90 days, were also assessed for testicular function. Extracts from the cauda epididymis indicated a 39% decrease in sperm motility and a 19% reduction in viability. Unlike the human diabetics, a 59% reduction in sperm number per cauda was also noted, together with an 86% rise in morphologically abnormal sperm. Measurements of the accessory organ weights indicated a 44% loss in prostate weight only. The testicular weight and testicular cell size and number did not differ significantly between the two groups. Circulating testosterone levels also remained unchanged. Reduced fecundity in these animals was displayed by the reduction in the number of pups sired. Collectively these results indicate that diabetes adversely affects the male reproductive system. The profile of the human diabetes group was similar to that of a group of infertile males, indicating a severe loss in reproductive potential in these patients. The results obtained from the streptozotocin-induced diabetic rats complimented the investigation on human diabetics. The animal studies further indicated reduced fecundity and a compromised accessory organ function, as suggested by the weight loss of these organs.