Common risk factors are found in both hypertension and periodontitis
Approximately one-third of adults in the United States (which amounts to as many as 75 million people) has high blood pressure, according to government statistics. Worldwide, this number is expected to increase to as many as 1.56 billion by the year 2025. This is significant because high blood pressure is thought to dramatically increase the risk of heart attack and stroke.
In addition, periodontal disease prevalence is also high, with milder to more severe forms (gingivitis or periodontitis) affecting up to 90% of the population globally. As many as half of all Americans aged 30 years or older have periodontitis, which is the more advanced form of periodontal disease.
There are shared risk factors for hypertension and periodontitis: namely, smoking, stress, advanced age, and social deprivation; which may increase the likelihood of hypertension and periodontitis being associated. Regardless of the presence of shared risk factors, observational studies maintain there is an association between periodontal disease and cardiovascular disease regardless, therefore it is an important issue when considering dental health.
Possible pathways linking hypertension and periodontitis
Hypertension and periodontitis are two conditions which superficially appear to be unrelated. However, as periodontitis is a chronic infection that causes inflammation over the long term, acknowledging that periodontitis may be a risk factor for hypertension has been of specific interest.
Evidence now exists that reinforces the idea that periodontitis should be recognized as an important risk factor for cardiovascular disease including:
peripheral artery disease, and
coronary heart disease.
In particular, the inflammatory response associated with periodontitis is considered to be an important factor that may impact adversely upon blood pressure regulation.
Increased levels of serum high-sensitivity CRP (hs-CRP), which is an acute-phase reactant (a protein that increases or decreases the body's response to inflammation) have been found in patients with periodontitis. This protein is reported to predict the outcome of cardiovascular disease and has been observed to decrease considerably after periodontal treatment.
Periodontal bacterial infection may also be partly implicated in the development of high blood pressure. Periodontitis is caused by the accumulation of specific bacterias (particularly by gram-negative anaerobic and microaerophilic bacteria) found in subgingival biofilm (plaque below the gums). These periodontal bacteria can invade and destroy gum tissues and then enter the body via the bloodstream, thus causing widespread bacteremia. Unfortunately, the bacteria may directly attack the heart by invading the arterial wall resulting in vascular inflammation and hardening of the arteries (atherosclerosis).
Reactive oxygen species are chemical substances containing oxygen which can be generated from tobacco, pollutants, drugs, and ionizing radiation. Excessive production of these in the body leads to oxidative stress which is an imbalance between free radicals (which can cause cell death) and antioxidant levels; free radicals are often associated with the development of cancer.
There is emerging evidence indicating that periodontitis leads to excessive reactive oxygen species in the periodontal tissue. As this leads to oxidative stress, it is therefore suggested that this plays a part in the disease process of periodontitis.
It is hypothesized that as the condition of periodontitis increases in severity, reactive oxygen species increase in response to periodontal inflammation and consequently they enter the circulatory system and can damage organs in the body. Therefore, the increased circulating oxidative stress caused by periodontitis may have a negative effect on general health, as well as in terms of hypertension.
Periodontal disease may contribute to endothelial dysfunction (malfunctioning of the inner lining of the small arteries), which eventually increases the risk of high blood pressure.
Can treating your gum disease lower blood pressure? The answer appears to be yes!
Research from 2017 asserted that treating gum disease very assertively may help reduce blood pressure in those at high risk for hypertension.
The study involved 107 Chinese women and men, aged 18 and older, who had pre-hypertension (blood pressure at the high end of the normal range) and moderate to severe gum disease. Half of them received the standard treatment consisting of basic oral hygiene instructions and teeth cleaning with plaque removal above the gum line; and half had intensive treatment for gum disease which was the standard treatment alongside cleaning down to the roots of teeth, treatment with antibiotics and tooth removal where necessary.
The results were unexpected as they confirmed for the first time that intensive intervention in terms of periodontal disease can alone reduce blood pressure levels, prevent inflammation and improve endothelial function:
Four weeks following the gum disease treatment, the participants' systolic blood pressure (the top number in a reading) was three points lower in the intensive treatment group although the diastolic blood pressure (the bottom number) remained the same.
12 weeks following treatment, systolic blood pressure was nearly eight points lower and diastolic pressure nearly four points lower in the same group.
24 weeks following treatment, systolic blood pressure was nearly 13 points lower and diastolic blood pressure was almost 10 points lower.
Gum disease may also interfere with attempts to manage high blood pressure
Researchers analyzed medical and dental records of more than 3,600 people diagnosed with hypertension and in comparison with people with good oral health, those with gum disease were less responsive to high blood pressure medications and less likely (by 20 percent) to reach healthy blood pressure targets.
Therefore physicians are advised to pay close attention to their patients' oral health especially when they are being treated for hypertension; and those with signs of periodontal disease are advised to seek dental care.