Categories
CDE Diabetes

Study Guide: Sexual Dysfunction and Hypogonadism in Men with Diabetes (Chapter 33)

1. Overview & Epidemiology

Sexual dysfunction is a common but often overlooked complication in men with diabetes. It significantly impacts quality of life and can serve as a “canary in the coal mine” for cardiovascular health.

  • Erectile Dysfunction (ED): Affects approximately 34% to 45% of adult men with diabetes.
    • Prevalence: Increases with age and duration of diabetes. Up to 50% of men have ED within 6 years of diagnosis.
    • CVD Link: ED may be an early clinical indication of cardiovascular disease (CVD). It is an independent marker for future cardiovascular events.
  • Hypogonadism (Low Testosterone):
    • Type 2 Diabetes: Highly prevalent (up to 40% of men).
    • Type 1 Diabetes: Prevalence is similar to the general population (not elevated).
    • Risk: Hypogonadism in men with diabetes is associated with higher cardiovascular mortality.

2. Screening Protocols

Because these issues are common and treatable, proactive screening is required.

  • Who to Screen for ED: All adult men with diabetes should be regularly screened.
  • How to Screen: A sexual function history is the primary tool. Validated questionnaires (like the IIEF or SHIM) can also be used.
  • When to Screen for Hypogonadism:
    • Screen men who are symptomatic (e.g., low libido, ED not responding to treatment, fatigue, muscle weakness).
    • Routine biochemical screening in asymptomatic men is not indicated.

3. Diagnosis of Hypogonadism (Testosterone Deficiency Syndrome)

Diagnosis requires careful timing due to natural hormonal fluctuations.

  • Test Timing: Measure Total Testosterone in the morning (between 7 am and 11 am or within 3 hours of waking).
  • Confirmation: If levels are low or borderline, repeat the test to confirm.
  • Bioavailable Testosterone: If Total Testosterone is borderline low-normal but symptoms are strong, measuring bioavailable testosterone is helpful (especially since SHBG is often low in insulin-resistant states, artificially lowering Total T).

4. Management of Erectile Dysfunction

A. First-Line Therapy: PDE5 Inhibitors

  • Agents: Sildenafil, Tadalafil, Vardenafil.
  • Efficacy: They are the mainstay of therapy and should be offered first-line.
  • Dosing: Can be “on-demand” or “daily” (scheduled).
  • Contraindications:
    • Nitrates: Absolute contraindication (risk of severe hypotension).
    • Unstable angina or untreated cardiac ischemia.

B. Second-Line & Adjunctive Therapies

  • Vacuum Constriction Devices: Useful for men who fail or cannot use PDE5 inhibitors.
  • Intracavernosal Injections: Prostaglandin E1 alone or in combination.
  • Referral: Men who do not respond to PDE5 inhibitors should be referred to a specialist.

5. Management of Hypogonadism

  • Weight Loss: In men with Type 2 diabetes and obesity, significant weight loss can increase testosterone levels, sometimes restoring eugonadism without medication.
  • Testosterone Replacement Therapy (TRT):
    • Considered for men who are symptomatic and biochemically hypogonadal.
    • Controversy: Evidence is conflicting regarding CV safety. Some studies suggest benefit, others potential risk. It is prudent to discuss this uncertainty with the patient.
    • Prostate Health: Monitor for prostate cancer before and during therapy (PSA, DRE).

6. Diabetes Canada 2018 Clinical Practice Guidelines Recommendations

Key takeaways from the “Recommendations” section (Page S231).

  1. Screening for ED: All adult men with diabetes should be regularly screened for ED with a sexual function history [Grade D, Consensus].
  2. First-Line ED Treatment: A PDE5 inhibitor should be offered as first-line therapy (on-demand or daily) [Grade A / Grade B].
  3. Investigating Non-Responders: Men with diabetes and ED who do not respond to PDE5 inhibitors should be investigated for hypogonadism (measure morning Total Testosterone) [Grade D, Level 4].
  4. Referral: Consider referral to a specialist for men who do not respond to or cannot take PDE5 inhibitors [Grade D, Consensus].
  5. Fertility: Men with ejaculatory dysfunction interested in fertility should be referred to a specialist [Grade D, Consensus].

 

Reference:

Bebb R, Millar A, Brock G. Sexual Dysfunction and Hypogonadism in Men With Diabetes. Canadian Journal of Diabetes. 2018;42:S228-S233. doi:10.1016/j.jcjd.2017.10.035