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The problems of erectile dysfunction in diabetic men

Nollie Biggins
RGN ONC
Clinical Nurse Specialist/Continence Advisor
Doncaster and Bassetlaw Foundation Hospital
Trainer and ­assessor for Nurse Education in Erectile Dysfunction
RCN-accredited distance-learning course
E:nollie.biggins@dbh.nhs.uk

Diabetes mellitus is strongly associated with ED. Diabetes UK (formerly the British Diabetic Association) has estimated that as many as 30% of all diabetic men suffer with some form of ED.(2) In men over 60 years of age, this prevalence may be at least 55%.(2) And in a study of male diabetic patients aged 18-75 in primary care, the prevalence of ED was 53%, of whom 39% suffered from ED all the time.(3)

Causes
The cause of ED in men with diabetes is usually multifactorial, although alterations in vascular and neurological systems are most commonly responsible.(4) There is often a psychogenic component caused by fear, guilt, anger and anxiety as the ability to obtain an erection is important and integral to a man's perception of wellbeing and to his attitude to life in general.(3) The loss of this ability can result in feelings of worthlessness and can result in the breakdown of relationships. In a survey carried out by the Impotence Association, 21% of patient relationships had broken down as a result of ED, while a further 8% of partners thought about breaking off the relationship due to their partner's erection problems.(5)
Perceived heightened public awareness towards men's health and sexual health coupled with an increasing number of more convenient treatments options gave us an expectation that more men would seek professional advice. It appears, however, that patients are still reluctant to request help, perhaps due to embarrassment and/or ignorance. Even with regular attendance at clinics, only a third of men with diabetes discuss their erection problems with healthcare professionals. This may be because fewer than half of these men associate their ED with diabetes or because 1 in 5 blame their medication.(3) Sadly, many healthcare professionals are still reluctant to ask the question.
Routine questioning about sexual function should be as much a part of the diabetes assessment as asking about symptoms affecting the patient's feet and eyes. If the patient is given "permission" to talk about problems there is a strong likelihood that he will want to discuss a sexual problem further and consider treatment options.
Treatment for ED has traditionally been the province of secondary care professionals. This situation arose, at least in part, because available treatments were considered too time-consuming or invasive to provide in general practice. With the advent of newer therapies, this is beginning to change. Prior knowledge of the patient and the dynamics of their relationship, combined with the administrative infrastructure to monitor treatment for ED over a prolonged period, makes primary care the ideal place to deliver high-quality local care to individuals and couples affected by ED.

Treatment options

Psychosexual therapy

Psychosexual and couple therapy is indicated if disturbances in the relationship and other psychogenic factors are felt to be the primary cause of the ED.  However, the patient and partner may often be reluctant to consider this because of a desire for a "quick fix". There are advantages to psychosexual therapy, as the treatment is noninvasive and can lead to significant and sustained improvement in sexual satisfaction and functioning. It can improve the couple's communication and satisfaction with the general relationship and can address the partner's problems.(6) On the negative side, NHS counselling services may be difficult to access, therapy is time-consuming and there are variable reports of success.

Medical treatments

Oral medications
Normal penile erection depends on the relaxation of the smooth muscle of the corpora cavernosa. In response to sexual stimuli, cavernous nerves and endothelial cells release nitric oxide, which stimulates the formation of cyclic guanosine monophosphate (cGMP) by guanylate cyclase.(7)
Oral treatments such as sildenafil, vardenafil and tadalafil are selective inhibitors of phosphodiesterase type 5 (PDE5), the enzyme that is responsible for the breakdown of cGMP.(7)
Efficacy of all the PDE5 inhibitors is evident through good response rates. Improved erections have been reported by 83% of nondiabetic men, 59% of those with type 1 diabetes and 63% of those with type 2 diabetes.(8) Side-effects are usually mild and transient - the most commonly reported are headache, flushing and dyspepsia. Less frequently reported side-effects include nasal congestion and changes in colour vision. These are often dose-related and completely reversible when the drug is discontinued.(8) Oral treatments offer a simple-to-use, noninvasive option and have been viewed as an important breakthrough in the management of ED. Although the way each of the drugs works is similar, pharmacological differences between these compounds may result in patient preferences for one over the other and may influence treatment decisions.(9) However, an absolute contraindication to the use of a PDE5 is the concurrent use of nitrates because of the possibility that the combination may potentiate vasodilatation and hypertension.(10) For those patients who fail with an oral therapy or are excluded, other options are available.

Intracavernosal injection therapy
Intracavernosal injection therapy involves injecting agents (prostaglandin E1) directly into the penis to relax smooth muscle in the corpora cavernosa. As the smooth muscle relaxes, blood flow increases into the penis, producing an erection. Although initial injections must be given under medical supervision, patients can self-administer after one or more training sessions.
It has advantages in that it is effective in about 80% of patients, is rapidly effective (the patient can expect an erection in 5-20 minutes), has few contraindications and does not require the patient to be sexually stimulated. It is, however, invasive, manual dexterity and eyesight need to be good, and there can be local side-effects, such as penile pain, bleeding, bruising, fibrosis and priapism (an erection that does not go down for more than 6 hours), and there is a high dropout rate.(11)

Transurethral drug application
Transurethral drug application uses a noninjectable delivery system that administers a narrow pellet of prostaglandin E1 directly into the male urethra. The drug dissolves quickly on insertion and is absorbed by the blood vessel interconnections between the corpora spongiosum and the copra cavernosa. As with injections, an erection is normally achieved in 5-10 minutes and lasts for between 30 and 60 minutes. It has the advantage of no needle involvement and is acceptable to most patients. Because the prostaglandin E1 is not administered directly to the corpora cavernosa, there is conflicting evidence as to the efficacy.(12) Side-effects include penile/testicular pain, dizziness, and some partners complain of vaginal irritation.(13) It requires dexterity, and the man must remain standing after the pellet has been inserted to increase penile blood flow, which can compromise spontaneity.

Vacuum devices
Vacuum devices have been in use for the treatment of ED for many years but have become available on prescription only recently. The concept is relatively simple: a cylinder is placed over the flaccid penis, creating an airtight seal and generating suction via a hand- or battery-operated pump to effect an erection. When a this is obtained, a constriction ring is slipped off the cylinder onto the base of the penis to maintain the rigidity. The ring can stay in situ for 30 minutes. They are the safest, most reliable option, with satisfactory erections noted in more than 92% of diabetic men.(14) They can be used as an exerciser and as an adjunctive to other therapies. Although efficacy is excellent, some manual dexterity is required. It is a machine, so can be perceived by some patients as too mechanical.
Complications are reported to be minimal, the commonest being: lack of satisfactory ejaculate (due to the ring), the penis feeling cool (because the blood is being artificially drawn in) and pivoting /hinging (as the pump can engorge only the external penis and not the erectile tissue inside the body).(15) Vacuum devices seem to be similar in efficacy and have a lower dropout rate among users compared with intracavernosal injections.(16)

Surgical prosthesis
There are several types of penile prosthetic implants available, which can be divided into semirigid rods or inflatable penile prostheses. Insertion of a penile implant requires the removal of the erectile tissue. There is a higher incidence of morbidity and complications than with other therapy options, and the risk of infection is higher in the diabetic population.(17) Therefore, prosthetic implants are considered as a last resort. For those patients who finally undergo this form of treatment, there is good patient-partner satisfaction,(17) and it provides a one-off solution and the spontaneity that can be lacking from other treatment options.

Conclusion
Be aware that most men are not comfortable discussing their sexual needs and activities and often suffer in silence, but consider asking the question during routine diabetic checks. If you are not comfortable with that, at least be aware of what can be done to help, the options available and the likely outcomes of those options.

References

  1. NIH Consensus Conference. Impotence. Development Panel on Impotence. JAMA 1993:279:83-90.
  2. Pickup J, William G. Textbook of diabetes. 2nd ed. Oxford: Blackwell Science; 1997. Chapter 59 (59.1-59.12).
  3. Hackett G. Impotence - the most neglected complication of diabetes. Diabetes Res 1995;28:75.
  4. Alexander W. Identifying men with erectile failure. Prescriber Supplement. 1998:4-5.
  5. Impotence Association surveys, conducted by Taylor Nelson AGB Healthcare. 1997.
  6. McCulloch DK, Hosking DJ, Tobert A. A pragmatic approach to sexual dysfunction in diabetic men: psychosexual counselling. Diabet Med 1986;3:485-9.
  7. Rosen RC, Kostis JB. Overview of phosphodiesterase 5 ­inhibition in erectile dysfunction. Am J Cardiol 2003;92:9M-18M.
  8. Dey J, Shepherd M. Evaluation and treatment of erectile dysfunction in men with diabetes mellitus. Mayo Clin Proc 2002;77:276-8.
  9. Stroberg P, Murphy A, Costigan T. Switching patients with erectile dysfunction from sildenafil citrate to tadalafil; results of a European multicenter, open-label study of patient preference. Clin Ther 2003;25:272437.
  10. Cheitlin MD, Hutter AM Jr, Brindis RG, et al. Use of ­sildenafil in patients with cardiovascular disease. Circulation 1999;99:168-87.
  11. Wagner G, Saenz de Tejada I. Fortnightly review: update on male erectile dysfunction. BMJ 1998;316:678-82.
  12. Fulgham PF, et al. Disappointing results with transurethral alprostadil in men with erectile dysfunction in a urology practice setting. J Urol 1998;160:2041-6.
  13. Padma-Nathan H, et al. Treatment of men with erectile dysfunction with transurethral alprostadil. N Engl J Med1997;336:1-7.
  14. Price DE, Cooksey G, et al. The management of impotence in diabetic men by vacuum tumescence therapy. Diabet Med 1991;8:964-7.
  15. Bodansky HJ. Treatment of male erectile dysfunction using the active vacuum assist device. Diabet Med 1994;11:410-2.
  16. Turner LA, Althof SE, Levine SB, Bodner DR, Kursh ED, Resnick MI. Twelve month comparison of two treatments for erectile dysfunction; self-injection versus external vacuum devices. Urology 1992;39:139-44.
  17. Mulcahy JJ. Overview of penile implants. In: Mulcahy JJ, editor. Diagnosis and management of male sexual dysfunction. New York: Igaku-shoin; 1997. p. 218-30.