The association between periodontitis and erectile dysfunction—how can periodontists help improve men’s health?

What is the evidence for the association between periodontitis and erectile dysfunction?

Several meta-analyses published in the last 10 years have shown that there is indeed a link between periodontitis and erectile dysfunction (Farook et al., 2021; Zhou et al., 2019; Liu et al., 2017; Wang et al., 2016). On average, these analyses found that male patients with periodontitis were two to three times more likely to experience erectile dysfunction.

However, care should be taken when interpreting the results of these meta-analyses: the included studies were very heterogeneous and erectile dysfunction was almost always assessed using self-administered questionnaires (e.g., the International Index of Erectile Function or the Sexual Health Inventory for Men), rather than objective methods such as Doppler ultrasound. Nevertheless, it can be concluded that there is an association between periodontitis and erectile dysfunction.

Given that erectile dysfunction is associated with obesity, diabetes mellitus, and cardiovascular disease—which are all also associated with periodontitis—and the presence of common risk factors, such as age and smoking, how is it possible to be clear that periodontitis alone is associated with erectile dysfunction?

That is a very good, but also very complex, question. Of course, there are many other diseases and conditions associated with erectile dysfunction. For instance, high blood pressure, cardiovascular disease, dyslipidaemia, poorly controlled diabetes, and obesity have been linked to erectile dysfunction. Smoking, chronic heavy alcohol consumption, low socioeconomic status, and older age are also linked to erectile dysfunction.

As these conditions also increase the risk of periodontitis, part of the association between periodontitis and erectile dysfunction could result from these shared risk factors. Studies therefore attempt to exclude, control for, or statistically adjust for such common risk factors where possible in order to better understand the relationship between periodontitis and erectile dysfunction. However, there may also be unknown or not yet fully understood risk factors influencing this relationship.

Are we talking merely about association or is there evidence of a causal relationship?

Recognizing an association between two diseases can also be helpful, even if it is only based on common risk factors and no causality exists. This could enable preventive measures against the second disease to be taken as soon as the first disease occurs. Of course, a causal link between the two diseases—periodontitis and erectile dysfunction in this case—would be even more significant, as we could then directly influence the risk of erectile dysfunction by preventing, diagnosing, and treating periodontitis.

Many of the currently known links between periodontal and systemic diseases are not only related to shared risk factors but also to a causal relationship. This means that periodontitis itself contributes to systemic diseases, and vice versa. There is therefore a bidirectional relationship. However, proving a causal relationship is difficult. Even longitudinal studies are not sufficient evidence, as the occurrence of one disease before the other does not prove that it is responsible for the subsequent disease. A helpful way to establish causality is to conduct an intervention study in which one disease is treated and then examined to see whether this also leads to changes in the second disease.

Regarding the link between periodontitis and erectile dysfunction, there is some evidence—though so far not very much—that periodontitis could directly contribute to erectile dysfunction. This means that there could indeed be a causal relationship. Interestingly, there is also debate as to whether causality could run in both directions. For instance, erectile dysfunction could negatively impact self-confidence, stress levels, and social activities, which could in turn lead to poorer or neglected oral hygiene and thus an increased risk of periodontal diseases.

Is there any evidence that periodontal treatment alone can have a positive effect on erectile dysfunction?

Yes, at least two intervention studies have been performed, in which periodontitis was treated and erectile dysfunction was recorded at the beginning and end of the study (El-Makaky et al., 2020; Eltas et al., 2013). In the study by El-Makaky et al., 140 patients with periodontitis and erectile dysfunction were randomly assigned to either the control group or the test group, both of which had 70 participants. Erectile dysfunction was assessed at the beginning of the study and again after three months of therapy. The study by Eltas et al. involved 120 patients with erectile dysfunction and periodontitis. The treatment and control groups each comprised 60 patients. Erectile dysfunction was assessed at the beginning of the study and one and three months after treatment.

Both studies showed that periodontal therapy led to an improvement in erectile dysfunction, as measured by a questionnaire. As previously mentioned, it would have been preferable to assess erectile dysfunction using Doppler ultrasound. It is also unclear whether the positive effect of periodontal therapy on erectile dysfunction is long-lasting. Nevertheless, it is encouraging that such intervention studies have been conducted. Further research is needed to confirm these results and provide a definitive conclusion regarding causality.