QUESTION: For a number of years, I have suffered from erectile dysfunction. I am a 58-year-old diabetic, but am otherwise fit and healthy. Viagra is proving less and less effective, but my GP treats my issue as an inconvenience rather than a problem.

I am due to get married in June and have avoided intimacy due to fear of failure (my partner thinks I want to wait until we are wed). Is there anything that can help me?

A. G., London.

ANSWER: This is a distressing situation, and a common one - more than 50 per cent of diabetic men in your age group have some degree of erectile dysfunction (ED).

This must be eroding the joy and optimism you feel at the prospect of impending marriage, and although your tactic so far has been avoidance, this may be stacking up greater pressure for the future.

The cause of your erectile dysfunction lies with your diabetes.

Long-term diabetics can suffer nerve damage, possibly because of the combined effect of high blood sugar levels damaging both the nerves themselves and the blood vessels that carry oxygen and nutrients to the nerves.

As well as the nerves that control erection being affected, those in the feet are also damaged, which is why diabetics often suffer lack of sensitivity or burning sensations in their feet.

Diabetes can also trigger the arteries to become furred with cholesterol, which can disrupt blood supply to the penis (an erection is maintained by chambers in the organ filling with blood).

This can be diagnosed by a specialist carrying out an ultrasound of the artery in your pelvis. For this you will need a referral to an ED expert, most commonly a urologist with a special interest in the subject.

Your GP has been, it seems, less than involved in your predicament, so there are definitely grounds for seeking this referral.

Once you have been referred, an expert can also carry out further tests to help identify any other factors that could be causing your condition. There has been some research linking diabetes to low testosterone in men, so your levels should be tested.

Your specialist should also discuss the possibility of you visiting a psychologist or therapist who can give advice on how to share the problem with your fiancée. This may be essential for defusing the damaging effects of anxiety (when you’re anxious, the body diverts all blood to the major organs - so even less goes to the groin).

In addition to this, intensive and diligent control of your diabetes is vital to prevent your condition worsening. Indeed, this may be why you have noticed the Viagra becoming less effective.

There are also medications that may help you. One drug - called Cialis, a member of the Viagra family - has been re-formulated especially for men with diabetes, and is taken on a daily basis.

It is a much longer-acting drug than Viagra, and it has been found that drip-feeding a very small but regular daily dose (rather than the usual one-off 10mg or 20mg dose) is very effective for those in your situation, with minimal side-effects.If this does not work, another treatment option - albeit one that is used less often - involves placing a tiny pellet of the drug alprostadil into the urethra (the tube through the penis).

You would be shown how to do this for yourself and it this is mostly very effective.

Finally, if these do not work, there are other non-drug treatments available. These include constrictive bands around the base of the penis, vascular surgery to improve the blood supply, or the implantation of rigid prosthetic devices.

All is not lost - there are reasons to be cheerful. - Daily Mail