Summary of main findings
With a clinical improvement of 6.74 points on the erectile function domain of the IIEF, the intervention group showed a significant improvement (P = 0.004) in erectile function compared with the control group after 3 months. The control group showed no significant increase in erectile function following lifestyle changes (P = 0.658), but a highly significant increase following intervention at 6 months (P<0.001). At 6 months, there was clinical improvement of 9.88 points on the erectile function domain of the IIEF for the intervention group and 10.94 points for men initially assigned to the control group. There was, however, no further significant improvement with the pelvic floor exercises in either the intervention group (P = 0.108) or control group (P = 0.646). There was good correlation between the IIEF and the PIIEF. The ED-EQoL correlated poorly with the erectile function domain of the IIEF.
Manometric measurements and digital anal measurements showed that both groups improved significantly (P<0.001) after intervention. Further improvement after engaging in pelvic floor exercises was not significant.
After 3 months of intervention and 3 months of pelvic floor exercises, 40.0% of all participants had attained normal function, 34.5% had improved, and 25.5% failed to improve.
Strengths and limitations of this study
This was the first randomised controlled trial to use a validated outcome to measure the effectiveness of pelvic floor muscle exercises enhanced by manometric biofeedback. The anal pressure biofeedback displayed on a computer screen motivated the subjects to attain a pelvic floor muscle exercise contraction of maximum strength. The men worked hard to improve on previous readings. Results are in line with other non-randomised or uncontrolled trials using similar treatment modalities.7.9,10,17 Previously, pelvic floor exercises may not have been routinely given for erectile dysfunction following these non-randomised or uncontrolled trials due to their methodological limitations.
It was a limitation of the IIEF that it did not provide any specific information about the partner relationship or the non-erectile components of sexual response.14 It would be useful to have a tool that explored cultural, social, ethnic, and religious perspectives. Another perceived limitation was the use of the non-validated PIIEF; however, the inclusion of the PIIEF did involve partners in the research process and provided reinforcement to the accuracy of the IIEF responses by the subjects. A validated partner's questionnaire in this study may have indicated the different sexual and non-sexual needs of the partners, which could have been relayed to the men.
The study was limited by the small number of subjects. Further trials could be multicentred and thereby involve a larger sample size with an opportunity to investigate a more heterogeneous sample.
Comparison with existing literature
The blind assessment indicated that 40.0% of participants regained normal erectile function. These results were comparable to previous studies using pelvic floor muscle exercises which reported that 26–46% of men had regained normal function following a similar exercise regime.7,9,10,17
The number of participants who withdrew from the trial was a concern, although a high drop-out rate has been reported previously in this type of study18 and may reflect the embarrassment and unease suffered by this cohort of men or possibly the commitment involved in performing daily exercises. However, some of the men who withdrew from the study did so because they had achieved normal erectile function.
All participants who received the allocated intervention reported completion of their pelvic floor home exercise regime. All men were able to achieve a penile retraction and scrotal lift during training with pelvic floor muscle exercises, although, initially, this response was often difficult and slow. As muscle strength improved, this response was initiated at a faster rate. Examination of individual cases revealed the return of self-reported nocturnal erections following 1–4 weeks of pelvic floor muscle exercises and prior to regaining erectile function. Weak evidence showed that orgasmic and ejaculatory function also improved with pelvic floor muscle exercises. This improvement was not surprising as the bulbocavernosus muscle, which is strengthened by pelvic floor muscle exercises, pumps the ejaculate.19
The erectile function domain of the IIEF showed poor correlation with the ED-EQoL in both groups. These results were similar to the findings of MacDonagh et al,16 and demonstrated a clear reason for the clinical usefulness of the ED-EQoL to monitor men's feelings about their erectile difficulties. The quality of life of some men who experienced severe erectile function was unaffected by their lack of erectile function while others with less severe symptoms reported that their quality of life was severely negatively affected.
This was the first time that anal manometric measurements have been used as an outcome measure for pelvic floor muscle strength in men with erectile dysfunction. These measures have previously been shown to have good within-day and day-to-day intrarater reliability.20 Six participants who had low anal pressure measurements after intervention failed to achieve normal function, suggesting that weak pelvic floor muscles are a risk factor for erectile dysfunction.
In this trial the median age of the participants was 59.2 years and much higher than the subjects in all the other trials.7-9,17,21 The duration and severity of erectile dysfunction were not predictors of the results of therapy in this trial.
It was expected that the control group would show some improvement by reducing alcohol levels, quitting smoking, increasing fitness levels, losing weight, and avoiding saddle pressure. This did not seem to be the case. Although the majority of participants reduced alcohol levels, lost some weight, and performed daily exercises such as hill walking and running up and down stairs, no participant ceased smoking, and two participants remained addicted to alcohol. It may be that 3 months of lifestyle changes was too short a time to effect a reversal of symptoms.
Comparison with sildenafil. The results of this trial were compared with a large grade II trial using oral sildenafil for 329 participants with similar mixed aetiology.15 Both trials used the erectile function domain of the IIEF as the main outcome measure. In the sildenafil trial at 12 weeks, participants receiving up to 100 mg sildenafil based on efficacy and tolerance improved by 10 points to attain a score of 21 points (Figure 3). In our trial, participants in the intervention group improved at 3 months by eight points from the overall baseline score to attain a score of 17 points. An increase in six points was considered a clinical improvement as this indicated that the men moved up a category in each of the erectile function scores, for example, from ‘almost never’ to ‘a few times’, or from ‘sometimes’ to ‘most times’.
Figure 3 Comparison of pelvic floor muscle exercises in our trial and sildenafil15 at 3 months using the erectile function domain of the International Index of Erectile Function.
Implications for future research or clinical practice
Evidence has shown that pelvic floor muscle exercises are significantly effective for some men with erectile dysfunction. To obtain a benefit, pelvic floor muscle exercises should be properly taught and practised for at least 3 months. A maintenance programme may then be implemented for life.
Not all men with erectile dysfunction may be suitable for pelvic floor muscle training. Those men with severe arteriogenic and neurological causes may well not benefit. The results of this trial may have been more impressive if men with severe low back pain, addiction to alcohol, cardiovascular disease, diabetes mellitus, Peyronie's disease, and bilateral orchidectomies had been excluded in the first instance.
Pelvic floor muscle exercises could be considered as a first-line approach for men seeking resolution of erectile dysfunction without pharmacological and surgical interventions. Also, men receiving other forms of therapy for erectile dysfunction could be advised to practise pelvic floor muscle exercises in addition to the therapy prescribed. Although pelvic floor muscle exercises are more labour intensive than using a pharmacological agent, men could be given a choice of treatment. Some men may prefer a more natural approach. Figure 4 details a suggested management pathway for men with erectile dysfunction.
Figure 4 Suggested algorithm for treatment of erectile dysfunction.
