Research finds connection between risk factors for periodontitis and general health

Periodontitis is a disease that affects the supporting tissues of the teeth and is associated with other types of diseases. A study conducted at the faculty of dentistry shows that patients with severe periodontitis also have a higher prevalence of cardiovascular disease, diabetes, and COPD.

The study is published in the journal BMC Oral Health with related previous research published in Journal of Clinical Periodontology.

Ida Haukåen Stødle is a specialist in periodontology and has just completed her doctorate at the faculty.

She shares the following:

The overall purpose of my thesis was to investigate the prevalence of periodontitis and to examine whether we could identify conditions that may be associated with periodontitis. Since periodontitis affects many people, these associations may also be relevant for many, and therefore we have a responsibility to address these potential associations with our patients, says Ida.

Oral health is important for overall health. Maybe we should not consider oral health as something separate but consider health in general. To highlight oral health on its own entails an artificial focus. Interaction between different diseases indicates that we must consider general health as part of periodontal treatment. We should inform patients and encourage them to speak to their general practitioner if they have severe periodontitis and other health challenges, Ida continues.

Periodontitis is an inflammatory condition that can lead to tooth loss and is caused by bacteria that naturally occur in the oral flora. The disease can develop if there is an overgrowth of these bacteria, but not for everyone. The susceptibility varies among individuals.

A new classification of periodontitis

Part of the task was to look at the prevalence of periodontitis in the surveyed population. In 2018, a new globally accepted classification of periodontal diseases was published, which forms the basis for the initial investigations, says Stødle.

We reported the overall prevalence and further prevalence of different severity levels of periodontitis. Once we had identified the participants with periodontitis, we further examined them for any other concurrent diseases, such as cardiovascular disease and diabetes.

We know that several conditions are associated with periodontitis. We selected some to see how they were expressed using the new classification. The findings largely corresponded to previous observations. We also found that those with severe periodontitis, those with significant periodontal bone loss, also have a higher prevalence of other diseases compared to those with little or no periodontitis.

We also included rheumatic conditions in this research but found no association with periodontitis for individuals with rheumatism. This was somewhat surprising because we already know about this association, and since rheumatoid arthritis is also an inflammatory condition, one would expect these diseases to occur together, Ida explains.

There may be several reasons why we did not observe any association. How we included rheumatic conditions in the material, whether we have thoroughly differentiated between healthy and sick individuals, and whether the dataset is large enough, for example. We did not attempt to distinguish between the various forms of rheumatoid arthritis. These factors contribute to the findings in our studies.

Uncertain findings for celiac disease and associations with periodontitis

We also looked at celiac disease. It was a separate study; it was exciting because there is little research on these two diseases. We had no expectations that there would be any difference in periodontal bone loss in individuals with and without celiac disease.

Nevertheless, we found that those with celiac disease have less frequent bone loss as if celiac disease protected against periodontitis. We do not know what lies behind this observation or how the relationship can be explained, and due to this uncertainty, it is hard to draw any conclusions. It would be exciting if further research could be done on this, says Ida.

Extensive and comprehensive material

The studies are based on a vast material, in which almost 5,000 adults from Nord-Trøndelag have participated. The transferability is good for small towns and rural areas. The population from larger cities, where the demography may differ, is not included. Therefore, the findings cannot necessarily represent all population groups in Norway. Population studies (the HUNT studies) have been conducted in this population in Nord-Trøndelag several times, precisely because it is particularly suitable due to stability.

The public dental service (DOT) in Trøndelag, in collaboration with the Oral Health Competence Center, TkMidt carried out the clinical oral and dental health examinations used in the doctoral work. The dentists and dental hygienists who collected this large amount of data did extensive work.

There were periodontal examinations, but also caries examinations and examinations of mucous membranes, in addition to X-rays of all the nearly 5000 participants. The X-rays consisted of a panoramic X-ray image and four smaller images from each participant.

X-rays and further work were analyzed in collaboration with my supervisors, Odd Carsten Koldsland and Anders Verket. The results of the X-ray analysis were compared with data from the clinical examinations. Statistical calculations also made up a significant part of the analyses. Several employees from TkMidt contributed to this. The work has resulted in three articles, Ida explains.

Self-reported disease

The method is partly based on self-reported illness and not exclusively on medical examinations. Self-reported data is weaker than if we had confirmed medical diagnoses and it must be considered when interpreting findings. Blood samples have been obtained from all participants, including blood sugar measurements.

This strengthens the material, and studies have shown that when the disease is well-defined, such as diabetes, there is a good correlation between self-reported illness and an actual diagnosis. Self-reporting is a limitation in our data, but not to such an extensive extent that we do not believe the results.

Medical personnel also obtained many other variables, such as weight, height, and blood pressure. We had a vast amount of data on inflammatory mediators or cells. We did not use it because some choices had to be made. But the data from HUNT are extensive and good and are well-suited for a hypothesis-generating study like this, says Ida.

Preventing periodontitis and diseases associated with periodontitis

We know that the treatment of periodontitis reduces inflammation and can improve blood sugar control in some cases for diabetics. These are connections we need to keep a high focus on. We need to communicate information so patients and health care professionals can benefit from this knowledge—for treatment and to prevent disease.

Risk factors are often the same for several diseases and conditions, including periodontitis, such as smoking. By reducing smoking, the risk for multiple conditions is also reduced. We can discuss this with patients and refer them further if needed.

We should specifically pay attention to the part of the population that goes to the dentist but may not easily seek other health care services. Collaboration across health care professions and having good information flow should be central in preventing periodontitis and diseases associated with periodontitis, concludes Ida.