INTRODUCTION:

Problem with penis erection and unsatisfactory sex in diabetics is Erectile Dysfunction (ED). Alternatively ED is problem in keeping erection long enough to have satisfactory sex. This lack of erection may be during sex or masturbation or typically during morning hours on waking up. Most common reason being Diabetes Mellitus (DM) as ED occurs in majority of patients suffering from DM. In a scientific study done in the USA and published across various research journals which are available on google scholar too, patients getting ED was 3 times higher if  having DM too, & it increases as age increases starting earlier in Type 1 DM than Type 2 patients. Besides DM the cause of ED could also be due to diseases of nerves, muscles, hormones or psychological issues. Hence it is believed that better control of DM reduces better control of ED in males, but treating patients of diabetes having ED is difficult with medicines and direct injections into penis as response is poor. Recently trials with gene therapy have also started & if this works, then patients will have advantage of using these medicines themselves without going to a hospital.

EPIDEMIOLOGY:

Smoking, obesity, aging, & DM complications such as neuropathy, vascular diseases, retinopathy and nephropathy are connected with having ED in diabetic patients. In 10 out of 100 cases ED is the main reason why a patient comes to a doctor.

PATHOPHYSIOLOGY: 

Diabetes could affect working of sex & hormonal glands but now role of muscle cells in penis and its muscle rigidity is also attracting attention. Increased BP in diabetics, excessive smoking, weight gain & increased fat levels in blood & certain common medicines such as steroids that increase sugar levels in patient’s impact penis muscle cells. It was also found out that certain chemicals in the blood of diabetics also affects the cells lining the penis & could also affect muscle stiffness.

The penis functions by controlling its blood flow. Increased inflow and relaxation of the smooth muscle cells around them is critical to the process of penis erection. Factors that block the blood flow into the penis will lead to ED. Diabetes is associated both with atherosclerosis in large arteries (which appears more frequently and at an earlier age than in non-diabetics) and with microangiopathy - very small arteries known as capillaries which become thick causing space for blood flow to become narrow. 

In diabetes, some develop postural hypotension and disorders of the gastrointestinal tract, alterations of thermal sensation such as not feeling cold or feeling too hot and abnormalities of sweating such as too much sweating. All this might have a role in the appearance of ED

Studies show that hypogonadism is common in diabetics and that treatment with testosterone - the male sex hormone is useful. However, in a recent scientific report based upon around 1000 consultations for ED indicate that hypogonadism may be present in few men with diabetic ED which is primarily due to a problem with gonads and NOT due to DM 

DIAGNOSIS:

Scientifically designed questions which assesses sexual function, i.e. capacity for erection, desire for sex, ejaculation issues including premature, intercourse satisfaction and overall satisfaction with sexual relationship are useful and will be given in the next part of this article.

DM itself may cause muscular diseases, because increased levels of fats in blood can cause diseases leading to ED. Also many men could have ED due to mental problems such as feeling of guilt or childhood abuse.

It is important to ask about libido-desire for sex accurately, as decreased libido and ED are the earliest signs of problem due to low testosterone (or more prolactin) and may be common amongst the diabetic population. Enquiries should also be made as to whether the problem is confined to sexual encounters with one partner or occurs with others as well.

Sometimes ED is ‘situational’ due to associated psychological issues. Ejaculation may be as commonly affected as erection itself and questions should be asked about whether ejaculation is normal, too early, too late or dry (as frequently occurs following prostate operation), or absent (as occurs in some nerve diseases ). The patient should also be questioned about pain during sex and the presence of deformity or plaques on penis, which are more frequent in diabetics than in the general population.

A thorough physical examination is an important part of the basic assessment for men with ED. Signs of the following should be looked for:

• Thyroid problem;

• Liver failure;

• Anaemia;

• Hypertension;

• Heart failure;

• Kidney failure.

 

Investigations:

Nocturnal penile tumescence (NPT) monitoring is sometimes useful when one has find out that the reason for ED is either due to psychological problem or Diabetic etc ( termed Organic ) In the normal male, 3–5 erections occur nightly and account for up to 40% of sleep time. The use of NPT is based on the thinking that during sleep emotional factors, such as fear and anxiety, are neutralized and subjects suffering from psychological ED have normal NPT; Compare this with patients with organic ED, in whom the underlying cause (vascular, hormonal or neurological) does not change with sleep. The NPT testing device is capable of continuously monitoring penis circumference and rigidity.  Rigidity is expressed as a percentage; 100% is taken as the rigidity of a noncompressible rubber shaft. 

Penile blood flow studies using Doppler ultrasound are the most reliable in identifying ED due to blood vessel disease (vascular). After injection if a good-quality sustained erection is achieved, then a blood vessel disease is ruled out but if a half-tight but continuous erection is achieved, then blood vessel disease is seen in up to 60% of patients. If the response is poor, Doppler ultrasound allows the rapid measurement of blood flow in small blood vessels and confirms the diagnosis.

After this we also need to check the out flow of blood FROM the penis using special instruments

Such as cavernosography

Sadly till date there is no single test that can find out if the case for ED is either nerve related or psychological.

TREATMENT:

The first step for a doctor in treating ED is to tackle the diseases that can be controlled or cured, which means to control diabetes, blood pressure & reduce fat levels in the blood.

Other treatments include injection of Papaverine which was the first medicine used to treat diabetic ED. Phentolamine is also used to some extent but now a days PGE 1 & Trimix injection have a success rate of around 75%.In a scientific study it was found that injection of blood vessel dilating agents (PGE 1 alone or Trimix solution) into penis generally has a 75% success rate, while therapy with the oral PDE5 inhibitors is less effective (50%). Alternate to PDE5 inhibitors have only marginal effects in less than 35% of our diabetic population.

FUTURE DIRECTIONS:

It must be noted that the treatments discussed above are basically aim to obtain a satisfactory erection when needed, i.e. the controlled relaxation of the penis muscle, without curing the actual disease. A reasonable approach is to try to overcome two of the problems frequently associated with erectile dysfunction, namely penis thickening (fibrosis) and neuropathy. To prevent fibrosis of penis Prostaglandins or other adenyl cyclase activators and PDE5 inhibitors injections might be used as anti-fibrotic agents in the penis, possibly in long-term treatments at doses lower than those capable of causing penis muscle relaxation. In rats, it has been shown that it is possible to reverse or prevent diabetic nerve damage by targeted delivery of neurotrophins by constant infusion with mini pumps. In cancer patients having streptozotocin-induced diabetes, direct delivery of insulin-like growth factor I into the sciatic nerve reduced the nerve damage. Other future treatment alternatives include the use of medicines such as nimodipine. 

The ultimate goal of novel medical therapies for ED should be to achieve desired erections without the need to treat immediately prior to the having sex and eventually to achieve longterm correction of the ED. Therefore finding a way to make a substance (known as the chemical NO - more on this in our next article) in the penis which increases its blood supply may lead to a much better effect than that caused by other drugs or injections. A promising approach for raising the levels of this critical chemical in the penis is by gene transfer techniques. This correction of the specific functional defect genetically using virus as delivery agents is known as gene therapy. Evidence so far shows that the transfer of genes into human tissues is feasible, with creation of the desired chemical varying from just a few days to several months and years.  

Compiled from various international research journals available at google scholar by D. Mukherjee having 38 years of pharmaceutical (Cardiac, Diabetic, Neurology, Pain & Inflammation products) experience with a Swiss Multinational Company NOVARTIS   and edited by : Dr Sandeep Ahlawat , MBBS