How does diabetes affect male fertility?

Effects of Diabetes on Male Fertility

Diabetes significantly impairs male fertility through multiple mechanisms including hormonal imbalances, increased oxidative stress, and direct damage to sperm quality and reproductive function. 1

Hormonal Effects

• Low testosterone levels: Men with diabetes have significantly lower testosterone levels compared to age-matched men without diabetes 1

  • Obesity is a major confounder in this relationship
  • Morning total testosterone levels should be measured in men with diabetes who show symptoms of hypogonadism
  • Symptoms include decreased sexual desire, erectile dysfunction, and reduced sexual activity

• Hypogonadism: Diabetes can lead to hypogonadism through:

  • Disruption of the hypothalamic-pituitary-gonadal axis
  • Reduced sex hormone-binding globulin (SHBG) levels
  • Impaired testicular function

Effects on Sperm Parameters

Diabetes negatively affects multiple sperm parameters:

• Reduced semen volume: Studies show significantly lower ejaculate volume in men with diabetes 2
• Decreased sperm motility: Both total and progressive motility are significantly impaired 2
• Altered sperm morphology: Higher rates of abnormal sperm morphology 2
• Impaired sperm metabolism: Diabetes disrupts glucose transport and metabolism in sperm cells 3
• Increased DNA fragmentation: Higher rates of sperm DNA damage, affecting fertility potential 4

Pathophysiological Mechanisms

1. Oxidative stress:

   • Diabetes increases reactive oxygen species (ROS) in sperm 4
   • ROS damage sperm membrane integrity and DNA

2. Mitochondrial dysfunction:

   • Disrupted transmembrane mitochondrial potential 4
   • Activated caspase-3 signaling leading to apoptosis

3. Vascular and neurological damage:

   • Diabetic neuropathy affects ejaculatory function 1
   • Vascular damage impairs erectile function 5

4. Metabolic disruption:

   • Altered glucose metabolism in sperm cells 3
   • Impaired energy production affecting sperm motility

Type 1 vs. Type 2 Diabetes

• Type 1 diabetes: Associated with reduced progressive motility, abnormal morphology, and decreased semen volume 2
• Type 2 diabetes: Generally shows more pronounced effects on sperm quality and apoptosis markers 4

Screening and Management

Screening Recommendations

• Men with diabetes who have symptoms of hypogonadism should be screened with morning serum testosterone levels 1
• For borderline testosterone levels, additional testing (luteinizing hormone and follicle-stimulating hormone) may be needed to distinguish between primary and secondary hypogonadism 1

Management Approaches

1. Glycemic control:

   • Near-normal glycemic control may help prevent or delay reproductive complications 1
   • Early implementation is critical, especially in type 1 diabetes

2. Weight management:

   • Weight loss strategies should be recommended for obese diabetic men 1
   • Obesity compounds the negative effects of diabetes on reproductive function

3. Testosterone replacement:

   • May benefit men with symptomatic hypogonadism 1
   • Can improve sexual function, well-being, muscle mass, and bone density
   • Should be carefully considered due to potential cardiovascular effects

4. Fertility preservation:

   • Men with diabetes planning for future fertility should be counseled about potential reproductive impacts 1
   • Sperm banking may be considered in some cases

Special Considerations

• Erectile dysfunction: Common in diabetic men and warrants evaluation 1
• Ejaculatory dysfunction: More prevalent in diabetic men due to autonomic neuropathy 1
• Anti-sperm antibodies: Higher prevalence in men with type 1 diabetes 2

Understanding these mechanisms is crucial for proper counseling and management of reproductive health in men with diabetes. Early intervention and comprehensive management of diabetes may help mitigate some of these reproductive effects.