Sexual dysfunction is common in patients with diabetes, and over half of diabetic men have erectile dysfunction (ED).2,3 This is defined as failure to obtain and maintain an erection sufficient for sexual activity, or decreased erectile turgidity on 75% of sexual occasions, and lasting for at least six months.4
ED is three times more common and occurs 10-15 years earlier in men with diabetes than in those without.5 Full management guidelines and a shorter ED practical guide are available on the British Society for Sexual Medicine website.6,7
Importantly, 5% of men with ED have undiagnosed diabetes8 – anecdotally, many patients with ED will have an abnormally raised fasting blood glucose. ED is therefore a ‘sentinel marker for future cardiovascular events, occurring three to five years before an event’.7 A consultation about ED provides a golden opportunity to proactively educate, empower and enthuse the patient and his partner to fine-tune lifestyle changes and to optimise management of existing or potential comorbidities – it should not just focus on the erection. Factors involved with ED in diabetics are listed in box 1. Although ED in diabetic men is associated with alterations in the vascular and neurological system, they may also have a psychogenic component caused by fear, guilt, anger, stress, anxiety or fatigue. An example of this could be the young 32-year-old diabetic who is under pressure to get his partner pregnant.
Local factors affecting the penis can be associated with diabetes and certainly can cause sexual problems for both the patient and his partner. Peyronie’s disease has a prevalence of 20.3% in diabetics compared with 3.2% in general population studies9,10 and similarly, balanitis is 16% and 5.8% respectively.11 In addition, almost a third of men presenting with phimosis to a urology clinic have diabetes.12 Penile fibrosis can occur if the corpora cavernosa is starved of oxygenated blood, which happens if early morning erections cease. The penis shortens and has less girth, becoming shrivelled and rubbery.13 Again, if a patient presents with any of the above symptoms, they should be opportunistically assessed for diabetes.
NICE has offered advice for adults with type 2 diabetes about ED in its guideline NG28:1
- Offer men with type 2 diabetes the opportunity to discuss ED as part of their annual review.
- Assess, educate and support men with type 2 diabetes who have problematic ED, addressing contributory factors such as cardiovascular disease as well as treatment options.
- Consider a phosphodiesterase 5 inhibitor (PDE5i) to treat problematic ED in men with type 2 diabetes, initially choosing the drug with the lowest acquisition cost and taking into account any contraindications.
- Following discussion, refer men with type 2 diabetes to a service offering other medical, surgical or psychological management of ED if treatment (including PDE5i, as appropriate) has been unsuccessful.
Treatments for ED
Modifying risk factors (see box 2) is the long-term foundation for any treatment programme, but various combinations of therapy can be used depending on the patient. PDE5is have been available since 1998 and are effective, safe and well tolerated. Now that many are off-patent they are cheap and can be used either on demand or daily at a low dose. Other therapies include intracavernous injections, topical and intraurethral alprostadil, vacuum erection devices, penile implants, shockwave therapy and testosterone therapy.6,7
Around 16% of men with type 2 diabetes have low testosterone levels and an additional 24% have borderline low levels.14 The diagnosis of symptomatic testosterone deficiency is made by reduced serum concentrations of total testosterone or free testosterone, together with characteristic signs and symptoms, of which the three most common are ED, low sexual desire and loss of early morning erections. Others that commonly occur in diabetes patients are listed in box 3 (below).
Advice on managing patients with potential testosterone deficiency is available on the British Society for Sexual Medicine website, either as a full guideline or a shorter practical guide.15,16
Nurses should actively screen for testosterone deficiency – see box 4.
Blood tests should include prostate specific antigen (PSA), haematocrit and other tests, depending on a holistic assessment. Serum testosterone should be measured as a fasting sample between 7am and 11am on at least two occasions. If it is low (≤8nmo/l) or borderline (8-12nmol/l), measure prolactin (to exclude pituitary microadenoma) and follicle stimulating hormone (FSH), luteinising hormone (LH) and sex hormone binding globulin (SHBG), in order to calculate free testosterone.
It is within the remit of GP surgeries to diagnose and manage testosterone deficiency, except in prostate cancer, male breast cancer, fertility issues, patients with a haematocrit >54%, or other endocrinopathies.
Testosterone therapy options include gels, long-acting (three months) or short-acting (two to three weeks) injections and tablets. I am not enthusiastic about using the latter two preparations because of the risk of supraphysiological levels of testosterone, and varying levels of absorption with the tablets.
The development of sexual difficulties in diabetic men is attributable to vascular, neuronal, metabolic and hormonal changes in the lining of blood vessels (endothelial dysfunction), and smooth muscle dysfunction.17 Although the physical effects of diabetes are well established, it should be remembered that psychological and social aspects can also play a part in sexual dysfunction.
Maintaining sexual health can be challenging for those with diabetes (for example, there is a higher prevalence of fungal and bacterial infections). In addition, some prescribed medications can cause sexual issues, such as antidepressants, antihypertensives and statins. It would be wrong to advise such medications be stopped, but it might be possible to alter and adjust them. The chronic nature of diabetes (and its complications) can lead to relationship problems, including arousal difficulties and sexual inhibition. Men with diabetes may need more physical stimulation, which may not be appreciated by the partner, who might feel unloved and less attractive. This can then lead to poor self-esteem, anxiety and depression for all concerned.18
In general, men can be a stubborn patient group. However, if they can be educated and encouraged, and undergo regular evaluations of their sexual and general health, they can be empowered to make changes for the better. This may involve frequent input from more than one healthcare professional.2
Dr David Edwards is a GPSI in sexual dysfunction in Oxfordshire. He is a past president of the British Society for Sexual Medicine, chair of the Primary Care Testosterone Advisory Group and vice chair of trustees of the College of Sexual and Relationship Therapists