In a recent large scale study, TSH levels were significantly associated with periodontitis – independent of various risk factors for periodontitis. The relationship between periodontitis and systemic conditions that cause inflammation has frequently been studied. This particular study was not actually conducted in patients with hypothyroidism but instead in patients with no history of thyroid disease. Instead, the study examined thyroid stimulating hormone (TSH) levels in 5,468 individuals and related that to levels of periodontitis.
Periodontitis
It is estimated that 7.8% of the global population suffers from periodontitis. The condition involves chronic infection by subgingival microorganisms. A number of chronic conditions have been studied for possible association with the development of periodontitis including cardiovascular diseases, metabolic syndromes, obesity, rheumatoid arthritis, and more. Studies have shown that the inflammatory reactions associated with periodontal disease can impact systemic health. However there has not been extensive research on the association between thyroid hormone levels and periodontal disease. Oral health can have severe consequences for the integrity of teeth but it can also have consequences for the health of the entire body.
In general periodontitis can be determined based on the level of gum inflammation and how far the gums have retreated. If it is caught early on it can often be reversed with regular deep cleanings at a dental office while maintaining good oral health. The deep cleanings use instrumentation to remove plaque and calculus below the gum line. Medications can sometimes be prescribed as well that are either taken orally or applied directly to the gums. In its more advanced stages periodontal disease can lead to tooth loss as the supporting structures of the teeth are compromised. At any stage, periodontitis can affect an individual’s overall health not just their teeth.
Autoimmune Hypothyroidism (Hashimoto’s)
Hypothyroidism is a condition where the body has insufficient circulating levels of thyroid hormone. The condition called Hashimoto’s thyroiditis is an autoimmune condition where the body’s immune system attacks the thyroid glands. It is not known exactly why this condition develops but there is significant research on the risk factors and associated conditions. Other health conditions have been associated with the development of autoimmune hypothyroidism including periodontal disease.
Study Results
In this study, the participants were categorized into one of three groups based on TSH levels. These were the groups:
Group I: < 1.76 mIU/L TSH
Group II: 1.76–2.83 mIU/L TSH
Group III: > 2.83 mIU/L TSH
Of the 5,468 participants, 1423 had periodontitis (26% of the participants). The highest incidence of periodontitis was found in Group I, which had the lowest TSH levels. In this group, 26.5% of participants had periodontitis. In Group II, 23.1% had periodontitis while in Group III the percentage was 20.9%. When the researchers broke the numbers into groups based on whether the participant was male or female, they found that there were some differences. In males, TSH levels were more significantly linked to incidence of periodontitis. However for females the association was not as significant.
Periodontitis is known to cause a sustained autoimmune response. Patients with autoimmune conditions like rheumatoid arthritis have been found to more frequently have thyroid dysfunction and thyroid autoantibodies. Underlying the process of inflammation is oxidative stress. The process of inflammation associated with periodontal disease results in oxidative stress that extends beyond the mouth, affecting overall health.
We discussed in a recent blog the large-scale study associating vitamin D deficiency and the incidence of autoimmune hypothyroidism. Studies have also shown that patients with periodontitis have low levels of vitamin D. The researchers in the periodontal disease study suggested that it is possible there is a connection between low vitamin D, periodontal disease, and thyroid dysfunction. Unfortunately in their study they did not have information on vitamin D levels which would have been useful to correlate to both diseases. Further research will need to be done to examine this connection.
Next Steps
This study opens up the possibility to perform more research into the link between periodontal disease and thyroid dysfunction. Can early detection and treatment of periodontal disease help prevent thyroid dysfunction? Can maintaining healthy vitamin D levels prevent both periodontal disease and autoimmune thyroiditis? If it is possible to prevent cases of these chronic conditions with simple vitamin supplementation, this could be a great benefit for many patients throughout the world.
Articles
Implication of thyroid function in periodontitis: a nationwide population-based study – Scientific Reports
Vitamin D and Periodontitis: A Systematic Review and Meta-Analysis – Nutrients