A new study published in the Journal of Clinical Periodontology found an interesting fact: there is a close connection between periodontitis and the complications of COVID-19. After examining more than 500 COVID-19 patients, the researchers established that those with gum disease had a higher risk of being admitted to intensive care or put on a ventilator, and even a higher risk of dying.
Why did the researchers suspect a connection?
Although the coronavirus SARS-CoV-2 responsible for COVID-19 produces mild symptoms in most cases and the mortality rate is only 2%, it has been reported that 14% of patients develop serious illness requiring immediate hospital admission and oxygen support. Acute respiratory distress syndrome, sepsis, septic shock and multi-organ failure are some of the serious complications, and these symptoms are characteristic of cytokine storm syndrome, an intensified immune response in which pro-inflammatory cytokine levels shoot up and tissue is severely damaged. It has also been shown that the severity of COVID-19 is higher in older or obese patients and in those with accompanying conditions such as high blood pressure and diabetes.
Periodontitis is one of the most common gum diseases, and about half the adult population worldwide is affected by a mild to moderate form. In severe periodontitis the attachment tissue between the teeth and the supporting tissue is destroyed, which can lead to tooth loss if untreated. Cases of periodontitis are characterised by chronic inflammation that extends into systemic inflammation. As with COVID-19, a marked rise in cytokines such as TNF-alpha, C-reactive protein, ferritin and interleukins is observed in severe periodontitis. Periodontitis is reported to be closely connected with conditions such as diabetes, cardiovascular disease and even premature death. These similarities prompted the researchers to carry out a case-control study and examine how far the two conditions are connected.
How they carried out their study
A case-control study was conducted using the national electronic health records of the state of Qatar from February to July 2020. Patients who suffered COVID-19 complications such as death, admission to intensive care or assisted ventilation were identified as cases, while patients discharged from hospital without any of the main complications were identified as controls. The periodontal status of both groups, including interdental bone loss, was assessed using dental X-rays uploaded to the electronic records. Information on possible risk factors such as diabetes, smoking habits and body mass index was taken into account. Blood parameters relevant to the disease, such as the concentration of D-dimers, C-reactive protein, vitamin D and blood cells, were also taken from the records and evaluated. The connection between COVID-19 and periodontitis was analysed using logistic regression.
The results
- In total 568 patients were analysed, of whom 528 were discharged without complications (controls), while 40 had severe COVID-19 complications (cases).
- As expected, patients with severe complications were older and had more accompanying conditions than those with mild symptoms. About 80% of the patients with complications had periodontitis.
- In the patients who died, concentrations of C-reactive protein, D-dimers and leucocytes were strikingly high, while lymphocytes were considerably lower than in surviving patients.
- The concentration of D-dimers, C-reactive protein and white blood cells was also higher in patients admitted to intensive care and in those who needed ventilation.
- About half the patients examined had periodontitis.
- Periodontitis was associated with a higher risk of developing COVID-19 complications, of death, of admission to intensive care and of assisted ventilation.
- Blood values of HbA1c, C-reactive protein and white blood cells were considerably higher in COVID-19 patients with periodontitis than in those without.
- It also emerged that successfully treating periodontitis led to a marked improvement in serum markers of systemic inflammation and to better general metabolic control.
And they concluded
On the basis of these findings the researchers concluded that patients with COVID-19 are three times more likely to be admitted to intensive care, 4.5 times more likely to need assisted ventilation and nine times more likely to die if they also have gum disease. Although further research is needed to clarify the connection, it is established that gum disease can worsen systemic inflammation and thereby worsen the condition of COVID-19 patients. It is therefore time to give the health of the gums the importance it deserves and to make sure you look after them well.
