Cohort Study with 27 Years of Follow Up Shows Oral Infections in Children Is Associated with Sub-clinical Atherosclerosis

A study led by Dr. Pirkko Pussinen demonstrated that clinical signs of oral infection during childhood were associated with subclinical atherosclerosis in adulthood. The paper published in JAMA Network Open suggests that childhood oral infection may be a modifiable risk factor for adult cardiovascular disease.

Periodontal disease and dental caries, both oral infections, are some of the most common infection-induced inflammatory conditions worldwide. If left untreated, they may progress to severe infections and ultimately cause tooth loss. Early life exposure to cardiovascular risk factors including high blood pressure, increased body mass index and smoking has been associated with the development of atherosclerosis in adulthood. However, the role of childhood oral infections in increasing cardiovascular risk is not understood.

The Cardiovascular Risk in Young Finns Study is an ongoing prospective cohort study that followed patients from childhood into adulthood. A total of 755 patients in this study underwent a baseline evaluation (including a dental examination) in 1980 at the age of 6, 9 or 12 and a follow up at in adulthood at the age of 27, 30 or 33 years. The dental examination included an assessment of current or previously treated dental infections or caries and the presence of periodontal disease (gingival bleeding on probing and periodontal probing pocket depth). The cardiovascular risk factors assessed included family history, systolic and diastolic blood pressure, and a lipid and diabetic profile. The authors wanted to see if there was an association between the number of signs of oral disease and the cumulative risk of cardiovascular disease. Carotid artery intima-media thickness (IMT) was also measured in these patients. An increased IMT was defined as being in the upper third tertile.

Out of the 755 patients who were included in the study, 82% had signs of periodontal disease and 86.9% had caries. Compared to children without periodontal disease, children with periodontal disease were older (8.26 vs 7.56), had a higher BMI (16.9 vs 16.5) and higher diastolic blood pressure (68.4 vs 65.5). Children with caries, when compared to children without caries, were also older (8.26 vs 6.45), had a higher BMI (16.9 vs 15.7), had higher systolic blood pressure (111 vs 106), and higher diastolic blood pressure (68.1 vs 65.6). When the number of signs of infections was counted, the authors found that 33 children (4.5%) had no signs of infection, 41 children (5.6%) had 1 sign, 127 (17.4%) had 2 signs, 278 (38.3%) had 3 signs, and 248 (34.1%) had 4 signs of infection. The mean number of cardiovascular risk factors during adulthood increased with the increasing number of signs of oral disease (4.9 risk factors for children with no signs of oral disease vs 6.1 risk factors for children with 4 signs of oral disease). Carotid artery intima-media thickness was lower in patients with no signs of oral disease as compared to those with oral disease. While the presence of any sign of oral disease was associated with an increase in IMT (RR 1.87, 95% CI 1.25-2.79), the presence of 4 signs of oral disease was associated with an even higher rate of increased IMT (RR 1.95, 95% CI 1.28-3.00).

In this 27 year follow up study, the authors found that poor oral hygiene was associated with an increased risk of developing subclinical atherosclerotic changes in the carotid artery. Even after adjusting for other risk factors, the association between oral infections and MIT remained significant. The authors offer a potential explanation for this association. Oral infections could contribute to an increased risk of atherosclerosis by inciting the host’s systemic inflammatory response. However, the authors also specify that the association may not necessarily be causal either. Oral infections could be an indicator of poor oral hygiene. Poor oral hygiene could also be accompanied by other generally unhealthy behavior. When commenting on the results of the study, Dr. Pussinen wrote, “An association between childhood oral infections with CVD risk factors, particularly high blood pressure and BMI, was also evident. However, the oral infections remained an independent risk factor of IMT after adjustment for a lifetime cumulative exposure to risk factors, including 31 separate measurements.” When discussing the implications of the study, Dr. Pussinen said, “The results show for the first time, to our knowledge, that childhood oral infections may be a modifiable risk factor for adult cardiovascular disease.”